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Effects of protraction mechanics on the midface
Abstract
Forty patients with Class III maxillary deficiencies were each treated with a bonded maxillary palatal expansion appliance followed by protraction. Nineteen of the 40 patients were retained with a Frankel III appliance. This group was compared with 24 Class I patients treated solely with bonded expansion appliance mechanotherapy. To determine at which level protraction mechanics affects the maxilla, the Walker's analysis and other cephalometric measurements were used. The protraction group showed significant increases (p <.05) in the following measurements: ANB angle, Wits, A perpendicular to nasion and in sella to A point. Anterior molar movement, without changes in posterior nasal spine or upper incisor to SN, was evident (p <.05). Favorable change in the facial profile was noted. There were no changes in the angles between sella-nasion and its relationship with the Frankfurt, occlusal, palatal, and mandibular planes. Walker's analysis showed no change in the position of orbitale. The control group did not demonstrate any significant changes in the position of the maxillary complex as a result of expansion mechanics. The retention group maintained the position of the maxilla postprotraction. Facial contour was maintained and other profile related variables improved.
... Young patients with maxillary hypoplasia are usually treated with a facemask. A heavy force is applied on the maxilla to stimulate its growth in a forward and downward direction and to redirect mandibular growth (3)(4)(5)(6)(7). However, facemask therapy results in a posterior rotation of the mandible and increased vertical dimension of the force. ...
... Before introducing TADs, orthodontists have tried growth modifications by applying orthopedic forces to the teeth (3)(4)(5). Therefore, dentoalveolar compensations rather than alterations of the facial growth were mainly responsible for improvement of malocclusion (3,9). To avoid dental compensations, titanium miniplates can be used to apply the orthopedic forces. ...
... Heyman et al. also reported that maxillary protraction with intermaxillary elastics applied to miniplates resulted in minimal dentoalveolar compensations (14). The elastic forces used in this method were lower than facemask therapy forces (3)(4)(5). This moderate continuous traction may be more favorable than heavy intermittent forces. ...
Introduction:
Treatment of cleft lip and palate patients requires a multidisciplinary plan. These patients usually have a hypoplastic maxilla due to the prior surgical scars. Orthognathic surgery to advance the maxilla in these patients is not very efficient; therefore, orthopedic interventions during an appropriate age seems to be essential.
Case report:
In this article, two cleft lip and palate patients have been treated with Class III elastics anchored to the maxillary posterior and mandibular anterior miniplates in order to induce maxillary advancement.
Conclusion:
Both cases showed a significant improvement in their profiles with minimal dentoalveolar compensations. A counterclockwise rotation of the mandible occurred.
... Várias são as possibilidades de tratamento para a Classe III. Todavia, a maioria dos autores são unânimes em considerar a protração maxilar associada ou não à expansão palatina rápida como a melhor terapia para os pacientes em fase de crescimento 1,2,12,21,24,32,40,41,43 . ...
... O vetor de força de 30º em relação ao Plano Oclusal foi o utilizado pelo maior número de estudos 15,19,22,23,25,27,28,29,[31][32][33][34][35] . ...
... O tratamento da Classe III com protração maxilar tem sido bastante relatado na literatura 1,2,12,21,24,30,32,40,41,43 , porém a maioria dos trabalhos não identifica claramente a magnitude, a direção da força e o tempo de utilização do aparelho para obter-se a correção adequada desse problema. Nessa revisão sistemática, uma cuidadosa pesquisa da literatura foi realizada para encontrar estudos primários nos quais esses fatores fossem abordados. ...
INTRODUCTION: For the treatment of Class III during growth, maxillary protraction therapy is the most reported in the literature. During the treatment is required special attention to the mechanics used to fix the problem. AIM: To synthesize informations about the magnitude, direction and time of daily application of forces, through a systematic review. METHODS: Studies were identified from an electronic search on Medline database - Entrez PubMed (178 articles) and Bireme (550 articles), from January 1983 until December 2008. After rigorous process of inclusion and exclusion 56 primary studies were selected and subjected to a second selection process, remaining 39 articles. It was calculated the average and standard deviation, and the minimum and maximum values for magnitude, direction and usage hours of the maxillary protraction forces. RESULTS AND CONCLUSION: The mean magnitude, direction and duration of the forces of maxillary protraction were, respectively: 447.8 grams, 27.5 degrees of inclination in relation to the occlusal plane and 15.2 hours per day.
... The facemask is a device commonly used to treat early class III malocclusion caused by maxillary deficiency and mandibular prognathism, and which is generally used in combination with expansion therapy. There is a great deal of controversy in literature regarding the effectiveness of protraction facemask treatment as studies report results anywhere from considerable changes to lack of any maxillary improvement (Wisth, 1984; Mermigos et al., 1990; Baik, 1995; Ngan et al., 1997; Williams et al., 1997; Baccetti et al., 1998; da Silva Filho et al., 1998; Gallagher et al., 1998; Kapust et al., 1998; Kiliçoglu and Kirliç, 1998; Pangrazio-Kulbersh et al., 1998; Sung and Baik, 1998; Turley, 2002). This controversy may be due to the fact that the process of placing the orthopaedic facemask on patients has, in part, been done empirically (Grandori et al., 1992), without the use of literature containing the clinical parameters for facemask placement for maxillary protraction. ...
... They analysed the variations in direction and the location of force imposition on upward and outward maxillary rotation, but no study analysed force magnitude and duration. The 10 remaining studies simply mentioned these elements as a part of methodology, but it was not their objective (Ngan et al., 1996; Merwin et al., 1997; Baccetti et al., 1998; Ngan et al., 1998; Pangrazio-Kulbersh et al., 1998; Saadia and Torres, 2000; Suda et al., 2000; Keles et al., 2002; Kajiyama et al., 2004; Vaughn et al., 2005; Tortop et al., 2007).Table 1 describes the characteristics of the articles that were included. Two poor-quality controlled clinical trials (Keles et al., 2002; Vaughn et al., 2005) were found, as well as 12 moderate-to-high quality cohort studies (Tanne and Sakuda, 1991; Grandori et al., 1992; Ngan et al., 1996; Merwin et al., 1997; Baccetti et al., 1998; Ngan et al., 1998; Pangrazio-Kulbersh et al., 1998; Alcan et al., 2000; Saadia and Torres, 2000; Suda et al., 2000; Kajiyama et al., 2004; Tortop et al., 2007).Table 1 shows the results of each study on the main clinical findings regarding maxillary position, dentoalveolar angulation, and mandibular rotation. ...
... The 10 remaining studies simply mentioned these elements as a part of methodology, but it was not their objective (Ngan et al., 1996; Merwin et al., 1997; Baccetti et al., 1998; Ngan et al., 1998; Pangrazio-Kulbersh et al., 1998; Saadia and Torres, 2000; Suda et al., 2000; Keles et al., 2002; Kajiyama et al., 2004; Vaughn et al., 2005; Tortop et al., 2007).Table 1 describes the characteristics of the articles that were included. Two poor-quality controlled clinical trials (Keles et al., 2002; Vaughn et al., 2005) were found, as well as 12 moderate-to-high quality cohort studies (Tanne and Sakuda, 1991; Grandori et al., 1992; Ngan et al., 1996; Merwin et al., 1997; Baccetti et al., 1998; Ngan et al., 1998; Pangrazio-Kulbersh et al., 1998; Alcan et al., 2000; Saadia and Torres, 2000; Suda et al., 2000; Kajiyama et al., 2004; Tortop et al., 2007).Table 1 shows the results of each study on the main clinical findings regarding maxillary position, dentoalveolar angulation, and mandibular rotation. The interobserver agreement for the assessment of methodological quality of the articles was 1.0, which indicates that both researchers had a near perfect agreement. ...
BACKGROUND
The facemask is used to treat early class III malocclusion, in combination with expansion therapy. There is a great deal of controversy in literature regarding the effectiveness of protraction facemask treatment as studies report results anywhere from considerable changes to lack of any maxillary improvement. This controversy may be due to the fact that the process of placing the orthopaedic facemask on patients has, in part, been done empirically, without the use of literature containing the clinical parameters for facemask placement for maxillary protraction.
OBJECTIVE
To determine the optimal magnitude, duration, and direction that should be used in maxillary protraction facemask therapy.
SEARCH METHODS
A systematic search was carried out in the following databases: Medline, Google Scholar, Embase, Cochrane, Lilacs, Scielo, with no restriction placed on the year of publication, in English and Spanish, using MeSH terms and free-text terms.
SELECTION CRITERIA
Clinical trials, systematic reviews, meta-analysis, cohort studies, case-control studies, and cross-sectional studies were included, whereas literature reviews, case reports, case series, symposiums, compendiums, pilot studies, and expert opinions were excluded.
DATA COLLECTION AND ANALYSIS
Data selection and extraction were blinded and performed independently, and the methodology was evaluated using various scales.
RESULTS
A total of 223 articles were found. After eliminating repeated articles and those that did not meet the selection criteria, 14 remained for analysis. Regarding magnitude, there were values ranging from 180 to 800g per side; there were force vector direction values between 20 and 30 degrees below the occlusal plane or parallel to the occlusal plane; and a duration ranging from 10 to 24 hours of use per day.
CONCLUSIONS
There is no scientific evidence that would allow for the definition of adequate parameters for force magnitude, direction, and duration for maxillary protraction facemask treatment in class III patients.
... Mitarb. [33] beobachteten, dass sich der A-Punkt während der Retentionsphase mit einer Fränkel-III-Apparatur um 2,6 mm nach vorne bewegte. Das nächtliche Tragen einer Gesichtsmaske und eines Fränkel-III-Gerätes verbessert die Stabilität [28,33,46]. ...
... [33] beobachteten, dass sich der A-Punkt während der Retentionsphase mit einer Fränkel-III-Apparatur um 2,6 mm nach vorne bewegte. Das nächtliche Tragen einer Gesichtsmaske und eines Fränkel-III-Gerätes verbessert die Stabilität [28,33,46]. McNamara [28] und Turley [46] schlugen vor, die Gesichtsmaske noch zeit-weise tragen zu lassen, sobald eine sagittale Frontzahnstufe von 4-5 mm erreicht sei. ...
... In diesem Zusammenhang ist interessant, dass unsere S-A-Punkt-Messwerte nach Abschluss der Protraktion denselben Wachstumszuwachs von 2,6 mm erkennen ließen, den Pangrazio-Kulbersh u. Mitarb.[33] in ihrer Arbeit beobachten konnten. In der Protraktionsgruppe verringerte sich die sagittale Frontzahnstufe zwischen T 2 und T 3 signifikant (p £ 0,01) aufgrund des kontinuierlichen Wachstums des Unterkiefers nach anterior. ...
Zusammenfassung
Ziele: Ziel der vorliegenden Studie war der Vergleich
der Auswirkungen einer Therapie mit Gesichtsmaske
mit einer unbehandelten Klasse-IIIKontrollgruppe
und mit den Ergebnissen einer
chirurgischen Vorverlagerung des Oberkiefers
mittels einer Le-Fort-I-Osteotomie.
Material: Die Protraktions- und die Chirurgiegruppe
bestanden aus jeweils 17 Patienten mit
einem Durchschnittsalter von 8 Jahren, 7 Monaten
bzw. 19 Jahren und 6Monaten. Jede der
Untersuchungsgruppen wurde mit einer entsprechenden
Kontrollgruppe aus unbehandelten
Klasse-III-Patienten verglichen. Zu den Untersuchungszeitpunkten
T1 (vor Beginn der Behandlung),
T2 (nach Abschluss der aktiven Protraktion
bzw. zwei Wochen nach dem chirurgischen
Eingriff) und T3 (7 Jahre, 6Monate nach Abschluss
der Protraktion bzw. 1 Jahr und 5Monate
nach der chirurgischen Korrektur) wurden jeweils
Fernröntgenseitenaufnahmen angefertigt
und ausgewertet. Für die beschreibenden kephalometrischen
Messwerte wurden Mittelwerte
und Standardabweichungen berechnet. Zur Untersuchung
von Unterschieden zwischen den
Gruppen im Lauf der Zeit wurde eine ANOVA
durchgeführt. Mithilfe von Tukeys Studentized
Range Test wurde versucht, die Ursachen für die
Veränderungen herauszufiltern. Die Unterschiede
zwischen der Protraktions- und der Chirurgiegruppe
und den entsprechenden Kontrollgruppen
wurden mit einem paarweisen t-Test untersucht.
Ergebnisse: Im Vergleich zur Kontrollgruppe war
nach Abschluss der Protraktionstherapie ein fortgesetzt
positives Wachstum des Oberkiefers zu
beobachten. Bei der Chirurgiegruppe kam es
nach der Le-Fort-I-Osteotomie nicht zur Rezidivbildung.
Schlussfolgerung: Die auffälligsten Beobachtungen
in unserer Studie betreffen die generelle
Ähnlichkeit zwischen Protraktions- und Chirurgiegruppe zum
Untersuchungszeitpunkt T3 und die allgemeine Langzeitstabilität
der Ergebnisse beider Therapieverfahren. Selbst wenn
ein Klasse-III-Wachstumsmuster genetisch bedingt sein sollte,
scheinen die Ergebnisse einer frühzeitigen Therapie langzeitstabil
zu sein, wie an den klinischen Fallberichten abzulesen ist.
... Várias são as possibilidades de tratamento para a Classe III. Todavia, a maioria dos autores são unânimes em considerar a protração maxilar associada ou não à expansão palatina rápida como a melhor terapia para os pacientes em fase de crescimento 1,2,12,21,24,32,40,41,43 . ...
... O vetor de força de 30º em relação ao Plano Oclusal foi o utilizado pelo maior número de estudos 15,19,22,23,25,27,28,29,[31][32][33][34][35] . ...
... O tratamento da Classe III com protração maxilar tem sido bastante relatado na literatura 1,2,12,21,24,30,32,40,41,43 , porém a maioria dos trabalhos não identifica claramente a magnitude, a direção da força e o tempo de utilização do aparelho para obter-se a correção adequada desse problema. Nessa revisão sistemática, uma cuidadosa pesquisa da literatura foi realizada para encontrar estudos primários nos quais esses fatores fossem abordados. ...
INTRODUCTION: For the treatment of Class III during growth, maxillary protraction therapy is the most reported in the literature. During the treatment is required special attention to the mechanics used to fix the problem. AIM: To synthesize informations about the magnitude, direction and time of daily application of forces, through a systematic review. METHODS: Studies were identified from an electronic search on Medline database - Entrez PubMed (178 articles) and Bireme (550 articles), from January 1983 until December 2008. After rigorous process of inclusion and exclusion 56 primary studies were selected and subjected to a second selection process, remaining 39 articles. It was calculated the average and standard deviation, and the minimum and maximum values for magnitude, direction and usage hours of the maxillary protraction forces. RESULTS AND CONCLUSION: The mean magnitude, direction and duration of the forces of maxillary protraction were, respectively: 447.8 grams, 27.5 degrees of inclination in relation to the occlusal plane and 15.2 hours per day.
... The short-and long-term effects of conventional facemask therapy are well documented in earlier reports. [1][2][3][4][5][6][7][8][9][10][11] A combination of the advancement of the maxilla, clockwise rotation of the mandible, and mesial displacement of the maxillary dentition has been reported to contribute to the improvement of Class III malocclusion after treatment. [2][3][4] In long-term observation, the treated group exhibited relatively successful outcomes. ...
... Comparison of Dentoskeletal Changes at T3-T2 Between the Miniplate/FM Group and the RME/FM Group a facemask for retention might have inhibited the counterclockwise rotation of the mandible during pubertal growth as a chin cup effect,6 and minimized the relapse tendency of the Class III intermaxillary relationship. ...
Objectives
To investigate long-term outcomes of dentoskeletal changes induced by facemask therapy using skeletal anchorage in Class III patients and compare them to those of conventional tooth-borne anchorage.
Materials and Methods
This retrospective study included 20 patients who received facemask (FM) therapy with miniplates as anchorage for maxillary protraction (Miniplate/FM group, 10.6 ± 1.1 years old [mean ± SD]) and 23 patients who were treated with facemask with rapid maxillary expander (RME/FM group, 10.0 ± 1.5 years old [mean ± SD]). Dentoskeletal changes were evaluated using lateral cephalograms at pretreatment (T1), after facemask therapy (T2), and at the post-pubertal stage (T3). Cephalometric changes were compared between groups and clinical success rates at T3 were evaluated.
Results
SNA and A to N perpendicular to FH increased significantly more in the Miniplate/FM group than in the RME/FM group when comparing short-term effects of facemask therapy (T1–T2). ANB, Wits appraisal, Angle of convexity, mandibular plane angle, and overjet decreased significantly more in the RME/FM group than in the Miniplate/FM group after facemask therapy (T2–T3). A more favorable intermaxillary relationship was observed in the Miniplate/FM group than in the RME/FM group in long-term observations (T1–T3). Clinical success rate at T3 was 95% in the Miniplate/FM group and 85% in the RME/FM group.
Conclusions
Facemask therapy with skeletal anchorage showed a greater advancement of the maxilla and more favorable stability for correction of Class III malocclusion in the long-term than conventional facemask therapy with tooth-borne anchorage.
... Class III malocclusion has conventionally been treated with protraction facemask or reverse pull headgear to achieve the correction into positive overjet [1][2][3][4][5]. But the disadvantage of this technique is that it is dependent on patient compliance. ...
... Such methods for the correction of class III malocclusion, whether the conventional rapid palatal expansion/MARPE and facemask, class III intermaxillary elastics from skeletal anchorage, or MARPE and protraction facemask are indicated in patients with class III malocclusion with retrusive and deficient maxilla [2,3]. The patients in the pre-pubertal period before their growth spurt respond positively to the intervention. ...
Skeletal anchorage has shown good results for the correction of class III malocclusion in patients with retrognathic maxilla. The protraction force applied on the maxillary bone with the use of mini implants or mini plates leads to higher skeletal effects and decreases the negative side effects on dentition. Protraction of maxilla is usually preceded by rapid palatal expansion procedure. Conventional rapid palatal expansion and mini implant assisted rapid palatal expansion can open the maxillary mid-palatal suture and the circummaxillary sutures. With mini implant assisted rapid palatal expansion, higher orthopedic expansion is achieved and this also helps in achieving higher maxillary protraction. This article describes the effects of conventional and mini implant assisted rapid palatal expansion and mini implant supported maxillary protraction.
... Over the course of several decades, patients with class III malocclusion due to deficiency of the middle third of the face, at the stage of growth, have been treated by means of maxillary protraction with a facemask presenting satisfactory results [1][2][3][4][5][6][7][8][9][10][11][12], when the patient cooperates with the use of the extra oral appliance [13,14]. During the last few years, with the justification that it depends less on the patient, and that it eliminates the undesirable results, for example, mandibular rotation and dental effects, some authors have replaced maxillary expansion and the facemask with orthodontic miniplates for skeletal anchorage associated with intermaxillary elastics, and have obtained significant results in maxillary protraction for treatment of class III patients [14][15][16][17][18]. ...
... Table 4 and Fig. 3a, b show a similar pattern between the two techniques, indicating that there were no significant differences between groups FM and MI, in any of the cephalometric measurements in the two time intervals evaluated. In group FM, due to having a tooth-supported anchorage system by means of the expander, dental and skeletal effects, previously known results in the literature [2][3][4][5][6][7], evidently occurred, such as mesialization of the maxillary incisors and posterior movement of the mandibular incisors, increase in the mandibular plane and in the inferior height of the face, with rotation in the clockwise direction and increase in the facial pattern. In spite of not having been statistically significant in the two groups, it was possible to verify the increase in the SN.GoGn values in group FM, while in group MI, there was a mean reduction in these measurements (Tables 2 and 3), which showed different responses between the two techniques. ...
Background:
The use of skeletal anchorage devices for maxillary protraction in patients with class III malocclusion due to deficiency in the middle third of the face has been shown to be a promising approach to treatment of these patients. The aim of this study was to evaluate the treatment of class III patients with maxillary retrusion, using orthodontic mini-implants (MI) associated with intermaxillary elastics in comparison with the rapid maxillary expansion and facemask protocol (RME/FM).
Methods:
In this prospective non-randomized clinical trial, the sample of 24 participants between 7 and 12 years of age (median age of 10.0 years and interquartile range = 3.0 years), at the stage prior to the pre-pubertal growth spurt, was divided in two groups. In group facemask (FM) (n = 12), the individuals received orthopedic treatment with RME/FM. In group MI (n = 12), two mini-implants were inserted in the region close to the maxillary first molar roots, and the other two in the region of the mandibular canines. Initial and final lateral teleradiographs were taken for cephalometric evaluation of all the cases. Statistical analysis included the Mann-Whitney, Wilcoxon, and Fisher's exact tests. The level of significance was 5% (α = 0.05).
Results:
Improvement was verified in the facial profile and occlusion of the participants, showing advancement of the maxilla in the two groups, with significant differences (P ≤ 0.05) between T0 and T1 in the following measurements: SNA, ANB, Wits, Co-A, Co-Gn, NAP, A-Npog, overjet, and molar relationship. There was no statistically significant intergroup difference (P > 0.05) in the cephalometric measurements evaluated, but the time of treatment was significant, and was faster for group MI.
Conclusions:
The protocol with mini-implants may be an option for the correction of Class III due to maxillary deficiency.
... Dentre as modalidades de tratamento precoce do Padrão III, a tração reversa da maxila (TRM) constitui a abordagem mais popular e estudada na literatura ortodôntica, produzindo os melhores resultados no menor intervalo de tempo, principalmente em indivíduos que se encontram no final da dentição decídua ou início da dentição mista. Dentre as alterações ocorridas durante o tratamento, pode-se evidenciar o deslocamento maxilar em direção anterior, giro do plano mandibular no sentido horário, deslocamento anterior da arcada dentária superior, inclinação lingual dos incisivos inferiores, aumento da altura facial anteroinferior e aumento da convexidade facial 1,6,10,16,18,19,23 . Relatos recentemente publicados envolvem o uso de variados expansores maxilares, podendo estar associados a outros dispositivos intra-ou intermaxilares que visem potencializar os efeitos esqueléticos da tração reversa da maxila 3,12,14,22 . ...
... A mecanoterapia empregada nesse estudo mostrou-se superior para promover o avanço esquelético da maxila, quando comparado com a maioria dos estudos presentes na literatura 6,17,19,21,23,29 ; entretanto, apresentou-se similar ou inferior quando comparado a outros 12,13,15,22 . O mesmo ocorreu com a relação maxilomandibular, na qual se observou que a mecanoterapia aplicada no presente trabalho apresentou-se efetiva para o tratamento do Padrão III, porém similar a alguns trabalhos que empregavam máscara facial isoladamente 10,11,15,22 . ...
OBJECTIVE: The early diagnosis and treatment of skeletal Class III (Pattern III) is still a much debated topic in orthodontic literature. Maxillary protraction associated with rapid maxillary expansion is the most popular and widely researched approach, producing the best results in the shortest period of time. This study aimed to evaluate the gradual changes that occur in the dentofacial complex in children with Pattern III growth treated with maxillary protraction associated with intermaxillary mechanics. METHODS: The sample consisted of 10 patients with Pattern III, whose mean age was 8 years and 2 months at the beginning of treatment, consecutively treated with a modified Haas expander, modified lingual arch, intermaxillary elastics and Petit facemask for maxillary protraction during a 9-month period. Four lateral cephalograms were taken of each patient, one at the beginning of treatment and the other three at regular 3-month intervals (T1, T2, T3 and T4). Cephalometric measurements at each of the four times were compared using ANOVA variance for repeated measures and supplemented by Tukey's multiple comparisons test. RESULTS: It was observed that the most significant skeletal changes occurred in the first 3 months of treatment. After that period the changes remained constant until the end of treatment. There were few dental compensations and the vertical changes which occurred showed reduced clinical significance. CONCLUSIONS: The therapy used in this study accomplished not only the correction of overjet but also improvements in the sagittal relationship of the basal bones and in soft tissue esthetics.
... The maxillary splints may be removable [2] [4] incorporating hooks in the canine-premolar region, cemented [6] [7], or bonded [1] [8], but the later causes hygiene problems and should be avoided. An extra oral force of approximately 400 -600 gm per side is applied by daily change of elastics that directed 30˚ downward to pull the maxilla in a downward and forward direction, to compensate for the vertical maxillary deficiency that accompanies most cases with maxillary deficiency [7]. ...
... The start with palatal expansion then maxillary protraction is recommended [7]. Frankel appliance is used after maxillary protraction as a retainer, to remain the facial contour and improves the profile related variables [8]. ...
... As the treatment was undertaken in the early mixed dentition the correction achieved were predominantly skeletal and also due to the clockwise rotation of maxilla along with downward and forward movement of point A. This can be perceived as a reason for [6] retroclination of upper incisors in relation to NA line significance. This was in accordance with the previous studies which showed proclination of upper incisors [14] maxillary protraction using propulsions [1,7] Thus the TTBA has the following advantages Promotes patient compliance, because it is more esthetic and comfortable than extra oral appliances. The TTBA is small enough to be stored in a removable appliance case. ...
Background and Objectives: Skeletal class III is a growth related discrepancy which continues and becomes more severe until active growth is completed. Approximately three percent of Indian population exhibits class III malocclusion. This can be due to a mid face deficiency, a large mandible or their combination. Various treatment modalities are available for correction of class III malocclusion in growing children, one of which is the Tandem Traction Bow Appliance (TTBA). This study was planned and designed to evaluate the dental and skeletal effects of TTBA used for the correction of skeletal Class III malocclusion with maxillary deficiency.
Materials and Methods: An in-vivo study designed to study the effects of TTBA on class III malocclusion with maxillary deficiency. The study was carried out on ten patients (age 6-12 years). Pre and post lateral cephalograms were traced and analyzed. Paired t test was used to compare values.
Result: The significant changes seen in the dental and skeletal parameters were upper and lower incisor retraction, Increase in ANB angulations and forward and downward movement of the maxillary arch.
Conclusion: TTBA is effective in early treatment of Skeletal Class III malocclusion. Being intraoral, patient compliance is improved, thus making TTBA easier to use, both for the clinician as well as for the patient.
... Numerous studies reported the maxillary growth response to various types of maxillary protraction therapy using 2-dimensional lateral cephalometric measurements, and similar skeletal changes were observed in the horizontal advancement of the A-point and the counterclockwise rotation of the occlusal plane despite differences between these treatment protocols [12][13][14][15][16] . However, in the zygomatic and infraorbital regions, contradictory results appeared due to the limitations of cephalometric 2-dimensional evaluation [23][24][25] . With the introduction of 3D image analysis, Heymann et al. 19 and Yatabe et al. 20 reported forward displacement of the zygomatic and infraorbital region in Class III patients and CLP patients, respectively, who underwent bone-anchored maxillary protraction with intermaxillary elastics to miniplates. ...
Trans-sutural distraction osteogenesis (TSDO) promotes midface growth in growing cleft lip and palate (CLP) patients with midfacial hypoplasia. The superficial skeletal changes after therapy revealed rotation advancement of the midfacial skeleton associated with differential displacement in each segment, but reports rarely focus on the changes of internal structures, including circummaxillary sutures, the maxillary tuberosity and the maxillary sinus, which may play a crucial role during this process. This study evaluated the computed tomographic (CT) images of 26 growing CLP patients who received bone-borne TSDO therapy. The results revealed that the most prominent new bone formation occurred in the pterygomaxillary suture and pushed the P-point forward. The maxillary first molar exhibited significantly greater advancement compared with the P-point due to the growth of the maxillary tuberosity. The contribution ratio values of the advancement of the maxillary tuberosity and P-point to the maxillary first molar were 26% and 74%, respectively, in UCLP and 25% and 75%, respectively, in BCLP. Furthermore, the maxillary sinus volume was also significantly increased. In conclusion, midface growth with bone-borne TSDO therapy depends on both secondary displacement promoted by sutural bone formation mainly in the pterygomaxillary suture and primary displacement by growth of the maxillary tuberosity and maxillary sinus volume.
... Some of the other studies that have shown the forward and downward movement of the maxilla during rapid expansion of the palate are studies byHaas in 1961 (21),Davis and Kronman (22), Wertz (23), Sarver and Johnston(24) andBasciftci and Karaman (25). In addition, the results of the present study in relation to the positive effects of facemask on the position of the maxilla are consistent with those of other studies on the effects of facemasks(10,(28)(29)(30)(31)(32)(33)(34)(35). ...
... The Class I patients were treated with a Hyrax expander and space supervision protocol, 20 the Class II patients were treated with a Twin Block appliance, and the Class III patients were treated with a bonded palatal expander followed by a protraction facemask for phase I treatment. 21,22 Edge- wise appliance therapy was instituted during the second phase of treatment. Preliminary orthodontic treatment was not provided prior to functional appli- ances. ...
Objective:
To evaluate the outcome of early treatment in Class I, II, and III malocclusions based on the reduction of weighted Peer Assessment Rating (PAR) scores.
Materials and methods:
Two hundred thirty subjects (female = 105; male = 125) selected from 400 cases were divided into three groups based on their malocclusions (Class I, II, and III). The PAR index was evaluated prior to early treatment (T0), at the end of phase I (T1), and after completion of phase II therapy (T2). The reliability of overall PAR scores was assessed by Bland-Altman plot and intraclass correlation coefficient. The starting age, total weighted PAR scores and their changes after phase I and II treatments, treatment time, and the percentage of correction in the three different malocclusions were assessed by repeated-measures analysis of variance with post hoc analysis. The level of significance was set at P < .05.
Results:
More than 30% reduction of the weighted PAR scores and less than 10 points of the remaining weighted PAR scores were observed in all malocclusion groups at T1. The Class III group had the highest percentage of correction during phase I treatment.
Conclusions:
Early treatment effectively reduced the complexity of Class I, II, and III malocclusions and accounted for 57%, 64%, and 76% of the total correction, respectively, after phase I treatment, as indicated by an overall reduction in weighted PAR scores. The Class III group responded most favorably to early treatment followed by the Class II group.
... Previous studies have shown that skeletal age is more reliable than chronological age in determining the growth period; therefore, in this study, the patients in the two groups were matched according to their skeletal ages. 28,29 The mean treatment period was 1.08 ± 0.35 years and the mean observation period was 0.82 ± 0.28 years. Skeletal Class III malocclusions should be treated at an early stage, and as early as possible in the growth period; therefore, in the present study, the duration of observation was statistically shorter than the duration of treatment (p < 0.05). ...
Objective
To evaluate the effects of facemask therapy, which was anchored from the zygomatic buttresses of the maxilla by using two miniplates, in skeletal Class III patients with maxillary deficiency.
Methods
Eighteen skeletal Class III patients (10 girls and 8 boys; mean age, 11.4 ± 1.28 years) with maxillary deficiency were treated using miniplate-anchored facemasks, and their outcomes were compared with those of a Class III control group (9 girls and 9 boys; mean age, 10.6 ± 1.12 years). Two I-shaped miniplates were placed on the right and left zygomatic buttresses of the maxilla, and a facemask was applied with a 400 g force per side. Intragroup comparisons were made using the Wilcoxon test, and intergroup comparisons were made using the Mann-Whitney U-test (p < 0.05).
Results
In the treatment group, the maxilla moved 3.3 mm forward, the mandible showed posterior rotation by 1.5°, and the lower incisors were retroclined after treatment. These results were significantly different from those in the control group (p < 0.05). No significant anterior rotation of the palatal plane was observed after treatment. Moreover, changes in the sagittal positions of the maxillary incisors and molars were similar between the treatment and control groups.
Conclusions
Skeletally anchored facemask therapy is an effective method for correcting Class III malocclusions, which also minimizes the undesired dental side effects of conventional methods in the maxilla.
... ANB also improved in some studies to around three degrees, often secondary to a downwards and backwards mandibular rotation. On average, there was a 6 mm improvement in overjet (Ngan et al., 1992(Ngan et al., , 1996Chong et al., 1996;Gallagher et al., 1998;Pangrazio-Kulbersh et al., 1998;Kajiyama et al., 2000;Cozza et al., 2004). The weight of evidence, although there is some equivocal data (Merwin et al., 1997;Yuksel, 2001), is towards treating children under 10 years old, since immature circummaxillary sutures may favour treatment success (Baccetti et al., 1998(Baccetti et al., , 2000Kapust et al., 1998;Franchi et al., 2004;Kajiyama et al., 2004). ...
Objective:
To evaluate whether patients who had received early class III protraction facemask treatment were less likely to need orthognathic surgery compared with untreated controls. This paper is a 6-year follow-up of a previous clinical trial.
Design:
Multi-centre 2-arm parallel randomized controlled trial.
Setting:
Eight United Kingdom hospital orthodontic departments.
Participants:
Seventy three 7- to 9-year-old children.
Method:
Patients were randomly allocated, stratified for gender, into an early class III protraction facemask group (PFG) (n = 35) and a control/no treatment group (CG) (n = 38). The primary outcome, need for orthognathic surgery was assessed by panel consensus. Secondary outcomes were changed in skeletal pattern, overjet, Peer Assessment Rating (PAR), self-esteem and the oral aesthetic impact of malocclusion. The data were compared between baseline (DC1) and 6-year follow-up (DC4). A per-protocol analysis was carried out with n = 32 in the CG and n = 33 in the PFG.
Results:
Thirty six percent of the PFG needed orthognathic surgery, compared with 66% of the CG (P = 0.027). The odds of needing surgery was 3.5 times more likely when protraction facemask treatment was not used (odds ratio = 3.34 95% CI 1.21-9.24). The PFG exhibited a clockwise rotation and the CG an anti-clockwise rotation in the maxilla (regression coefficient 8.24 (SE 0.75); 95% CI 6.73-9.75; P < 0.001) and the mandible (regression coefficient 6.72 (SE 0.73); 95% CI 5.27-8.18; P < 0.001). Sixty eight per cent of the PFG maintained a positive overjet at 6-year follow-up. There were no statistically significant differences between the PFG and CG for skeletal/occlusal improvement, self-esteem or oral aesthetic impact.
Conclusions:
Early class III protraction facemask treatment reduces the need for orthognathic surgery. However, this effect cannot be explained by the maintenance of skeletal cephalometric change.
... In this study, patients' upper mo lars moved forward. This result was similar to findings reported in literature (42)(43)(44). All included patients were in mid or late mixed -dentition, either labiolingual appliance or the banded rapid maxillary expansion appliance acted as intraoral appliance for maxillary protraction. ...
The Clin ical effectiveness of sequential treat ment of skeletal class III malocclusion among patients with maxillary ret rognathism at Jilin Un iversity Sto matological Hospital, China. Tanz Dent J 2014, 18(2): 37-48 Running ti tle: Effectiveness of sequential treat ment of skeletal class III Abstract Aim: To assess the dentofacial changes induced by the sequential treat ment in the skeletal class III malocclusion with maxillary ret rognathism. Study design: Controlled clin ical trial assessing the effectiveness of sequential treatment of skeletal class III malocclusion. Materials and Methods: The treated group consisted of 30 patients in pre or during pubertal growth with anterior crossbite, maxillary cro wding and class III mo lar relationship treated with maxillary protraction therapy; Pendulum appliances to dis talize molars followed by fixed appliances. The treated group was compared with a control group of 10 untreated Class III subjects. Cephalo metric analysis and Paired sample t test and Independent sample t test were used to evaluate the changes and treatment effects. The significance level was set at p ≤ 0.05. Results: After the sequential treatment, the maxilla moved forward, the mandible rotated clockwise leading to improved maxillo mandibular sagittal relationship. The upper incisors moved forward, the anteroposterior relat ionship improved, and the class III concave profile turned to straight. The cephalometric variab les; SNA, MP/SN and U1/SN showed significant changes at p ≤ 0.001, p≤ 0.01 and p≤ 0.01 respectively. Conclusion: The sequential treatment approach is effective for skeletal class III malocclusion with maxillary retrognathism for low and average mandible angle young patients.
... The results are as follows: for the first issue, a summary of the meta-analysis suggests that a maxillary protraction appliance is effective for correcting anterior crossbite with a retruded maxilla. The changes in SNA and ANB in the FM group with regard to anterior movement of the maxilla indicate similarity with findings reported in the previous literature [67][68][69][70]. The anterior forward rotation of the maxilla was significant in the FM group (P < 0.00001), whereas no significant change was observed in the control group. ...
We conducted a comprehensive meta-analysis of 12 studies to examine whether maxillary protraction face mask associated with rapid maxillary expansion (FM/RME) could be an effective treatment for Class III malocclusion and to evaluate the effect of timing on treatment response. Patients with a maxillary deficiency who were treated with FM with or without RME were compared with those who had an untreated Class III malocclusion. In both treatment groups, forward displacement of the maxilla and skeletal changes were found to be statistically significant. In addition, posterior rotation of the mandible and increased facial height were more evident in the FM group compared with the control group. However, no significant differences were observed between the early treatment groups and late treatment groups. The results indicated that both FM/RME and FM therapy produced favorable skeletal changes for correcting anterior crossbite, and the curative time was not affected by the presence of deciduous teeth, early mixed dentition or late mixed dentition in the patient.
... Whereas extraoral traction with a facemask applies anteriorly directed forces to the maxilla to mechanically disrupt the sutures and to stimulate maxillary forward growth, reaction forces tend to push the chin posteriorly. [1][2][3][4] These reaction forces result in clockwise rotation of the mandible and increased vertical dimensions 2,3,5 and are also observed in chincup therapy. 6,7 Little is known about eventual modifications in the temporomandibular joint with facemask therapy. ...
OBJECTIVES: To evaluate 3-D changes in the mandible and glenoid fossa of Class III patients treated with bone-anchored maxillary protraction.
MATERIALS & METHODS: 20 consecutive skeletal Class III patients between the ages of 9 and13 (mean age 11.10 +/- 1.1years) were treated using Class III intermaxillary elastics and bilateral miniplates (2 in the infra-zygomatic crests of the maxilla and 2 in the anterior mandible). The patients had CBCTs taken before initial loading (T1), and one year out (T2). 3-D models were generated from the CBCTs, registered on the anterior cranial base and analyzed using color-maps.
RESULTS: miniplates assisted orthopedic traction produced sagittal skeletal changes. Posterior displacement of the mandible at T2 was observed for all subjects (mean 2.9mm (SD+/-0.86) for posterior ramus, 2.0mm (SD +/- 0.79) for the condyles and 0.56mm (SD +/-1.55) for the chin). Remodeling of the glenoid fossa at the anterior eminence (0.89mm +/- 1.38) apposition and resorption at the posterior wall (0.72mm +/- 0.45) was observed in most patients.
CONCLUSION: This new treatment approach induces a favorable control of mandibular growth for patients with components of mandibular prognathism. Futures studies with long-term follow-up and comparisons to facemask/chincup therapies are needed to better understand the treatment effects.
Supported by NIH D005215
... In this study, the significant increase in SNA and horizontal movement of point A showed that maxillary growth was achieved with both treatment alternatives. These findings are in accordance with FM studies, 11,[14][15][16][17] a DPA study, 5 and a DPA-FM study 6 that demonstrated forward and downward movement of the maxilla. Cozza et al. 18 reported that the craniofacial complex response to active orthopedic treatment of Class III malocclusion with an FM combined bite block appliance consisted of significant changes in maxillary growth and position. ...
Objective:
To compare the treatment effects of double-plate appliance/facemask (DPA-FM) combined therapy and facemask (FM) therapy in treating Class III malocclusions.
Materials and methods:
The material consisted of lateral cephalometric radiographs of 45 children with skeletal and dental Class III malocclusion. The first treatment group comprised 15 patients (mean age = 11 years) treated with FM. The second treatment group comprised 15 patients (mean age = 10 years 9 months) treated with DPA-FM. The third group comprised 15 patients (mean age = 10 years 5 months) used as controls. The paired t-test was used to evaluate the treatment effects and changes during the treatment and observation period in each group. Differences between the groups were determined by variance analysis and the Duncan test.
Results:
With the DPA-FM and FM appliances, the SNA and ANB angles increased significantly. These changes were statistically different compared with the control group. Lower facial height showed a greater increase in both treatment groups than in the control group. Molar relation showed a greater increase in the DPA-FM group than in the FM group. The increase in U6/ANS-PNS angle in the FM group was significantly different from the DPA-FM and control groups. The L1/NB angle and Pg-T increased significantly only in the FM group, but no significant difference was found between the treatment groups.
Conclusions:
In the treatment of Class III malocclusion, both appliances were effective. The significant sagittal changes in the lower incisors and pogonion in the FM group compared with the nonsignificant changes in the DPA-FM group might be due to the restriction effect of acrylic blocks in the DPA-FM group.
... On the contrast, it is postulated as well that this entails the circumaxillary structures such as pterygpoid plates to displace the maxilla forward 8,9 (Fig. 2C). These two assumptions explain why some of the clinical studies on Hyrax-typed expanders reported an anterior displacement of maxilla 1,7,30 , while some others reported no significant displacement 22,24 or even a posterior displacement of maxilla 5,23 . The posterior displacement of maxilla compromises the maxillary protraction in Class III patients. ...
... Class III skeletal pattern is one of the most difficult malocclusions to diagnose and treat in orthodontics and is characterized by mandibular prognathism, maxillary retrognathism, retrusive mandibular dentition, protrusive maxillary dentition, and a combination of these components (Sanborn, 1955;Nanda, 1980;Guyer et al., 1986;Pangrazio-Kulbersh et al., 1998;Kilic et al., 2010b). It has been reported that two-thirds of skeletal class III malocclusions are due to either maxillary retrognathism or a combination of maxillary retrognathism and mandibular prognathism (Sanborn, 1955;Nanda, 1980;Guyer et al., 1986). ...
This prospective study investigated the skeletal, dental, and soft-tissue effects of a mini maxillary protractor appliance in class III subjects with maxillary retrusion and mandibular protrusion and compared these changes with those of untreated, well matched control sample with normal occlusions.
Twenty patients with class III malocclusion (mean age 11.1±0.8 years) and 20 subjects with normal occlusion (mean age 10.9±0.4 years) were included to this study. The class III subjects were treated with the mini maxillary protractor appliance, and the others were used as control subjects. Paired t-test and Student’s t-test were used to determine the within- and between-group differences, respectively.
In the study group, the maxilla moved forward (SNA, 2.0 degrees and A–Y, 2.4mm) (P < 0.001) with a slight rotation of palatal and occlusal planes (SN–PP, −0.8 degree and SN–OP, −0.7 degree) (P > 0.05). The mandible displaced backwards and downwards (SNB, −1.1 degrees; SND, −0.9 degree; B–Y, −0.9mm and Pog–Y, −0.3mm; P < 0.001). These movements in the maxilla and mandible caused a significant improvement in intermaxillary sagittal relationship (ANB, 3.0 degrees; Convexity, 6.3 degrees; Wits, 4.6mm; P < 0.001). The maxillary incisors moved forward (2.2 degrees) while the mandibular ones backward (−1.9 degrees). The improvement in overjet was 5.0mm, and 66.1 per cent of this change (3.3mm) was skeletal (A–Y; 2.4mm and B–Y; −0.9mm), and the remaining (1.7mm) dentoalveolar (U1–NA; 0.9mm and L1-NB; −0.8mm). The change in Ls–E measurement was more in the study group (2.1mm), and the difference between the groups was statistically significant (P < 0.001).
... This vast range of variables increases the difficulty to analyse the data successfully and a number of different approaches have been used to overcome this problem. Certain studies used a smaller group with similar starting measurements (Pangrazio-Kulbersch et al., 1998), whilst others only measured incremental growth changes (Franchi et al., 1998). Delaire used cranio-facial architectural analyses and superimposition to overcome the wide variance. ...
The purpose of this study was to compare the effects of facemask therapy in a slightly later age group than average (11.5 years for females, 11.8 years for males), with lighter forces than average (100-200g per side), to a Class III untreated control group and a normal control group. The treatment group consisted of 32 protraction headgear cases (15 males, 17 females). The Class III control group consisted of mixed longitudinal data from 50 untreated subjects (32 males, 18 females). The treatment group was also compared to subjects from the Bhatia and Leighton growth study. Linear and angular cephalometric measurements were taken before and after treatment. The facemask group showed significant dento-alveolar changes but no significant skeletal changes. Therefore facemask therapy in this age group and with light forces can be expected to help correct a Class III relationship with only dento-alveolar changes. INTRODUCTION The use of the protraction face-mask was first described more than 100 years ago by Potpeschnigg (1875). Delaire et al. (1976) revived the interest in this technique and later Petit (1983) modified the basic concepts of Delaire by increasing the amount of force generated by this appliance. There has been very little research in the UK when comparing the effects of protraction headgear to normal growth. Numerous studies have been done in Japan and to a certain extent in America. It is difficult to assess and compare the data from these studies to the UK population, as there are too many variables. Ideally, the effects of treatment with orthopaedic appliances should be compared with samples in the same skeletal category. For this study it has been possible to find a good sample size from the Greater London (UK) area and compare them to an untreated Class III growth study (Kangesu, 2000), and Bhatia and Leighton's growth study (1993). In this study the measurements are taken from longitudinal data and primarily linear measurements and ratios are analysed. These linear measurements would be a true indicator of any changes in normal skeletal growth during the protraction phase of therapy. It is known that the original design of the protraction headgear was to optimise the growth of the maxilla and to restrain the growth of the mandible. There are other documented changes that this type of therapy can introduce and dento-alveolar changes would be the most noticeable. Therefore, certain dental measurements have been included. The use of protraction headgear in the UK seems to be on the decrease but this form of therapy still stays popular in other orthodontic centres throughout the world. This study is to ascertain the outcome of protraction headgear that was used quite extensively at Kingston Hospital (Orton, 1992) during the 80's and early 90's. A number of questions need to be answered regarding the use of protraction headgear and hopefully this study can reveal the affects on skeletal growth with the use of the face-mask. It was intended to compare the treatment changes with normal growth and this would be done with linear and angular measurements. Longitudinal cephalometric radiographs of patients who had undergone orthodontic appliance therapy together with protraction facemasks were analysed with the following objectives in mind: Does this mode of therapy really improve skeletal relationship? 1. Which clinical parameters are influenced the most? 2. Is the effect clinically significant and are treatment objectives obtained? 3.
... Whereas extraoral traction with a facemask applies anteriorly directed forces to the maxilla to mechanically disrupt the sutures and to stimulate maxillary forward growth, reaction forces tend to push the chin posteriorly. [1][2][3][4] These reaction forces result in clockwise rotation of the mandible and increased vertical dimensions 2,3,5 and are also observed in chincup therapy. 6,7 Little is known about eventual modifications in the temporomandibular joint with facemask therapy. ...
Conventional treatment for young Class III patients involves extraoral devices designed to either protract the maxilla or restrain mandibular growth. The use of skeletal anchorage offers a promising alternative to obtain orthopedic results with fewer dental compensations. Our aim was to evaluate 3-dimensional changes in the mandibles and the glenoid fossae of Class III patients treated with bone-anchored maxillary protraction.
Twenty-five consecutive skeletal Class III patients between the ages of 9 and 13 years (mean age, 11.10 ± 1.1 year) were treated with Class III intermaxillary elastics and bilateral miniplates (2 in the infrazygomatic crests of the maxilla and 2 in the anterior mandible). The patients had cone-beam computed tomography images taken before initial loading and at the end of active treatment. Three-dimensional models were generated from these images, registered on the anterior cranial base, and analyzed by using color maps.
Posterior displacement of the mandible at the end of treatment was observed in all subjects (posterior ramus: mean, 2.74 ± 1.36 mm; condyles: mean, 2.07 ± 1.16 mm; chin: mean, -0.13 ± 2.89 mm). Remodeling of the glenoid fossa at the anterior eminence (mean, 1.38 ± 1.03 mm) and bone resorption at the posterior wall (mean, -1.34 ± 0.6 mm) were observed in most patients.
This new treatment approach offers a promising alternative to restrain mandibular growth for Class III patients with a component of mandibular prognathism or to compensate for maxillary deficiency in patients with hypoplasia of the midface. Future studies with long-term follow-up and comparisons with facemask and chincup therapies are needed to better understand the treatment effects.
... This, as well as dental changes, resulted in an average 6 mm improvement in positive overjet. [15][16][17][18][19][20][21][22][23] In addition, younger children under 10 years old, are reported to respond more favourably as, theoretically, the circummaxillary sutures are more amenable to orthopaedic protraction. 5,[24][25][26][27] However, this is not always clear cut, as other authors have not detected improved treatment outcomes in younger patients. ...
To investigate the effectiveness of early class III protraction facemask treatment in children under 10 years of age.
Multicentre, randomized controlled trial.
Eight UK hospital orthodontic units.
Seventy-three patients were randomly allocated, stratified for gender, into an early class III protraction facemask group (PFG) (n = 35) and a control/no treatment group (CG) (n = 38).
Dentofacial changes from lateral cephalograms and occlusal changes using the peer assessment rating (PAR). Self-esteem was assessed using the Piers-Harris children's self-concept scale, and the psychosocial impact of malocclusion with an oral aesthetic subjective impact scores (OASIS) questionnaire. Temporomandibular joint (TMJ) signs and symptoms were also recorded. The time points for data collection were at registration (DC1) and 15 months later (DC2).
The following mean skeletal and occlusal changes occurred from the class III starting point: SNA, PFG moved forwards 1.4 degrees (CG forward 0.3 degrees; P = 0.018); SNB, PFG moved backwards -0.7 degrees (CG forward 0.8 degrees; P<0.001); ANB, PFG class III base improved +2.1 degrees (CG worsened by -0.5 degrees; P<0.001). This contributed to an overall difference in ANB between PFG and CG of 2.6 degrees in favour of early protraction facemask treatment. The overjet improved +4.4 mm in the PFG and marginally changed +0.3 mm in the CG (P<0.001). A 32.2% improvement in PAR was shown in the PFG and the CG worsened by 8.6%. There was no increased self-esteem (Piers-Harris score) for treated children compared with controls (P = 0.22). However, there was a reduced impact of malocclusion (OASIS score) for the PFG compared with the CG (P = 0.003), suggesting treatment resulted in slightly less concern about the tooth appearance. TMJ signs and symptoms were very low at DC1 and DC2 and none were reported during active facemask treatment.
Early class III orthopaedic treatment, with protraction facemask, in patients under 10 years of age, is skeletally and dentally effective in the short term and does not result in TMJ dysfunction. Seventy per cent of patients had successful treatment, defined as achieving a positive overjet. However, early treatment does not seem to confer a clinically significant psychosocial benefit.
... [25][26][27][28][29] Our treatment protocol of combined maxillary expansion, facemask therapy and Class III mechanics straightened the skeletal and soft tissue facial profiles of our young subjects with only a few, small dentoalveolar changes, but it was no more successful than some of the appliance combinations others have used. 2,3,7,8,10,12,13,27,[29][30][31][32][33] It has been reported that combined facemask therapy and Class III mechanics are no more effective in treating skeletal Class III malocclusions than facemask therapy alone. 1,2,29,33 In the first three months of treatment the upper incisors tipped palatally and then tipped labially over the next six months. ...
To determine the dentofacial changes in children with skeletal Class III malocclusions treated with maxillary expansion, external maxillary protraction and intermaxillary traction.
Fifteen Class III patients in either the deciduous or the mixed dentition (Mean age: 7.6 years; SD: 1.9 years) were used. The children were treated with a modified Haas expander, a modified lingual arch, intermaxillary elastics and facemask for nine months. Lateral cephalometric radiographs were taken at the beginning of treatment (T1) and at 3-month intervals (T2, T3, T4).
Most significant sagittal skeletal modifications occurred in the first three months of treatment. During the first three months of treatment the upper and lower incisors tipped lingually and the face height increased. Towards the end of treatment the upper incisors proclined and the upper lip became more protrusive.
The therapy corrected the horizontal skeletal and arch discrepancies and improved the positions of the lips.
Class III malocclusions are one of the most difficult malocclusions to be treated. Anyhow, early Class III treatment can be done successfully when proper diagnosis and proper treatment plan are carefully carried out. The treatments are done following the concept of treating at the right place, at the right time with the right appliances. The purposes of early treatment can be causative treatment for dentoalveolar Class III malocclusion. In skeletal Class III malocclusions, growth modification can be done with awareness of limitation in severe cases where orthognathic surgeries are required in later stage.There have been controversies in early treatment of Class III malocclusions, especially whether growth can be modified and if the results will remain stable. There are natural growth and induced growth which cannot be measured separately. The author believes that the treatment outcomes are most crucial for the decision-making of whether to treat early or not. If the treatment outcomes can reduce severity of malocclusions and are satisfactory to both patients and orthodontists, then the interception is worth doing.The author recommends the use of Class III activator of Thomas Rakosi which has shown good treatment outcomes and long-term stability of skeletal changes, for growth modification in skeletal Class III cases and concluded that Class III activator may be a viable mode for initial stage of Class III treatment in conjunction with fixed or removable therapy.KeywordsClass III malocclusionsEarly treatmentGrowth modificationDifferential diagnosisClass III activator
Purpose
The purpose of this study was to biomechanically evaluate maxillary protraction using an orthodontic anchor screw. We conducted three-dimensional finite element analysis to determine the initial displacement and stress distribution during maxillary protraction by comparing a conventional method involving fixation on teeth with maxillary protraction using an orthodontic anchor screw.
Materials and methods
We used X-ray computed tomography data obtained from Hellman Dental Age IIIA dry human skulls to create a skeletal anchorage model and a dental anchorage model as finite element models. In each model, a load of 6 N was applied in the anteroinferior direction at 0°, 10°, 20°, 30°, and 40° to the occlusal plane by means of a traction hook and the initial displacement and stress distribution were analysed.
Results
For the anterior nasal spine (ANS) sagittal displacement was greater in the skeletal anchorage model than in the dental anchorage model. In the central incisors and first molars, greater sagittal displacement was observed in the dental anchorage model compared with the skeletal anchorage model. In both models, vertical displacement was 20°, indicating maximum suppression of rotation in the maxilla. The zygomaticomaxillary and zygomaticofrontal sutures demonstrated high stress at 0° and 10° in the dental anchorage model, and at 20°, 30°, and 40° in the skeletal anchorage model.
Conclusions
These results indicate that tooth and bone–borne maxillary protraction using an orthodontic anchor screw inserted in the palatal region may be of value for the early mixed dentition period in patients with maxillary deficiency.
Uma alternativa já consolidada ao tratamento ortopédico convencional com disjunção palatina e máscara facial para pacientes em crescimento com Classe III esquelética por deficiência maxilar é a utilização de ancoragem esquelética para protração da maxila. Seu uso elimina os efeitos dentários adversos da terapia convencional, como extrusão e mesialização de molares superiores, projeção de incisivos superiores e retroinclinação de incisivos inferiores. Além disso elimina a necessidade de uso de um dispositivo extra-oral, o que contribui para a motivação dos pacientes. As miniplacas são a forma de ancoragem esquelética mais usada para esse tipo de terapia, entretanto a necessidade de um passo cirúrgico para instalação e outro para remoção das placas representa um ponto desvantajoso para essa técnica, e dessa forma o uso de mini implantes foi proposto com a finalidade de promover protração maxilar eliminando o passo cirúrgico. Este trabalho se propõe a descrever a técnica de prostração maxilar apoiada em mini implantes ortodônticos, ilustrada através de um caso clínico de um paciente tratado com esta terapia, mostrando os resultados faciais e oclusais positivos alcançados.
Class III malocclusions are one of the most difficult malocclusions to be treated. Early Class III treatment can be done successfully when proper diagnosis, proper treatment plan are carefully carried out. The treatments are done following the concept of treating at the right place, at the right time with the right appliances. The purposes of early treatment can be causative treatment for dentoalveolar Class III malocclusion. In skeletal Class III malocclusions, growth modification can be done with awareness of limitation in severe cases where orthognathic surgeries are required in later stage.There have been controversies in early treatment of Class III malocclusions; especially, whether growth can be modified and if the results will remain stable. There are natural growth and induced growth which cannot be measured separately. The author believes that the treatment outcomes are most crucial for the decision making of whether to treat early or not. If the treatment outcomes can reduce severity of malocclusions and are satisfactory to both patients and orthodontists, then the interception is worth doing.
In this chapter, we introduced three new orthodontic and orthopedic techniques and one surgical distraction osteogenesis for the management of maxillary deformities in growing unilateral and bilateral cleft patients. These techniques are the effective maxillary orthopedic protraction for correcting a hypoplastic maxilla and minimizing alveolar cleft, premaxillary orthopedic intrusion for correcting a downward displaced premaxilla, premaxillary orthopedic medial repositioning for correcting a lateral displaced premaxilla, and interdental distraction osteogenesis for approximating a wide alveolar cleft. These techniques utilize principles of distraction osteogenesis. The orthopedic approaches could be a form of sutural expansion or protraction osteogenesis, and their treatment effects are mostly orthopedic and partly orthodontic. The interdental distraction is a form of callus distraction osteogenesis. The clinical and radiographic evaluations have revealed their successful applications for solving maxillary deformities in growing cleft patients.
We evaluated 3-dimensional changes in the temporomandibular joints of children with skeletal Class III malocclusion and maxillary deficiency after facemask therapy for maxillary protraction. Eighteen children with anterior crossbite and a Class III molar relationship underwent facemask therapy for maxillary protraction, after which they exhibited positive overjet and a Class II molar relationship. Three-dimensional cone-beam computed tomography images of the patients were obtained before (T1) and after (T2) facemask protraction, and the 3-dimensional coordinates of the anatomical landmarks in T1 and T2 images were compared. After facemask therapy, the mandibular condyles of the patients were displaced outside, upward, and backward. Additionally, the anterior and posterior walls of the glenoid fossa had negative values for anteroposterior change. Three-dimensional analysis of the temporomandibular joint showed that facemask therapy resulted in bone apposition (to the anterior wall) and bone resorption (of the posterior wall) in the glenoid fossa. This bone remodeling resulted in upward and backward displacement of the condyle.
(J Oral Sci 58, 501-508, 2016)
Introduction:
Cleft lip and palate patients usually have deficient maxilla due to postsurgical scars. The aim this study was to compare the effectiveness of miniplates-anchored face-mask therapy versus intermaxillary elastics to miniplates for maxillary traction in cleft lip and palate patients.
Methods:
This clinical trial included 11 prepubertal patients with cleft lip and palate. Initially, a w-arch expander was cemented and activated 3 mm per month to overcorrect the crossbite. Then, the patients were divided into 2 groups: mini-plate-anchored face-mask (n = 5): 2 miniplates were placed in the maxilla and the patients were instructed to wear a face-mask for 12 to 14 hours/per day. Intermaxillary elastics to miniplates (n = 6): 2 miniplates were inserted in the maxilla; 1 on each side and 2 miniplates were placed in the anterior mandible on both sides. Intermaxillary elastics with a force of 250 g per side were attached to the hooks. Cephalometric parameters before treatment (T1) and after achieving positive overjet (T2) were compared between the 2 groups. Fisher exact, paired, and independent t tests were used for statistical comparison.
Results:
At T1 or T2 there was not a significant difference between the 2 groups in the skeletal, dental, and soft tissue variables.
Conclusion:
According to results of our preliminary study, intermaxillary elastics to miniplates might have a promising effect as an alternative for face mask therapy in maxillary protraction of cleft lip and palate patients.
The maxillary deformities in growing cleft patients could be a hypoplastic maxilla, downward and/or laterally displaced premaxilla in bilateral clefts, wide alveolar cleft and fistula, or combinations of the above deformities. It is a challenge for both orthodontist and surgeon to treat a hypoplastic maxilla with wide alveolar cleft in a growing unilateral or bilateral cleft patient or a downward or laterally displaced premaxilla with wide alveolar cleft and fistula in a growing bilateral cleft patient. © 2013 Springer-Verlag Berlin Heidelberg. All rights are reserved.
Class III therapy using a face mask is a common approach for treatment of a deficient maxilla and reverse overbite. Usually, maxillary protraction is combined with transverse palatal expansion using intraoral appliances. The purpose of this study was to systematically review the effectiveness of face mask therapy in combination with concepts of palatal expansion and compression.
A systematic review and meta-analysis were performed to identify studies that address class III treatment using a face mask. The search was carried out using common electronic databases as well as hand search. Both screening and study eligibility analysis were performed with consideration of PRISMA and Cochrane Guidelines for systematic reviews. Several terms describing class III face mask treatment were searched. Particular attention was paid to new strategies of enhancing maxillary protraction.
The initial search identified 2048 studies. After a thorough selection process, a total of 22 articles met the inclusion criteria. After assessment of the individual quality scoring of each article, eight studies were provided for meta-analysis of the cephalometric parameters. The statistical analysis of treatment changes advocates a positive influence on sagittal maxillary development, which is not primarily influenced by transverse expansion. Dental side effects are more distinct when no expansion was carried out. For the concept of alternating activation/deactivation of the expansion appliance (alt-RAMEC), two articles of high methodological scoring were identified. They indicate an enhancement of face mask treatment.
The findings are consistent with results of previous literature studies regarding the efficiency of class III face mask treatment. A further need for more randomized controlled studies was identified especially with regard to the new concept of alternating maxillary expansion and compression, which showed a positive influence on the maxillary protraction based on two studies.
Class III therapy using extraoral face mask anchorage is effective for maxillary protraction. The recently discussed new protocols potentially improve this treatment.
We aims to evaluate the therapeutic effect of maxillary protraction on maxillary maldevelopment using Coben analysis to illustrate the advantages of Coben analysis in identifying pathogenic mechanisms and in designing treatment plans for Class III malocclusions.
A total of 120 patients were diagnosed to have skeletal Class I maloc- clusions with maxillary maldevelopment. These patients were selected as the subjects of the present research. Maxillary protraction was exerted to promote maxilla growth. Cephalometric analysis was conducted by using Coben analysis and angle analyses of Beijing Medical University to collect data before and after maxillary protraction.
According to Coben analysis measurements, the height of facies cranii increased after maxillary protraction. The depth of lower face decreased, whereas that of mid-face increased and the Ptm-A value increased significantly in the mid-face (P < 0.001). In the angle ana- lysis of Beijing Medical University, SNA, ANB, U1/NA, U1/SN, MP/SN, and Y-axis angles increased significantly (P < 0.001), whereas SNB, U1/L1 (P < 0.001), and L1/MP (P < 0.05) decreased.
Maxillary protraction has a significant effect on growing skeletal Class III malocclusions withthe chief mechanism of Ptm-A value just diagnosed as minor by Coben analysis. Coben analysis is visual and clear in identifying pathogenic mechanisms of Class III malocclusions.
Objective: To evaluate, by means of shape correspondence quantification, the 3D anatomic regional changes in the mandible and condyles of Class III patients treated with bone-anchored intermaxillary traction
Method: 25 consecutive skeletal Class III patients between the ages of 9 and13 (mean age 11.10 +/- 1.1years) were treated using Class III intermaxillary elastics and bilateral miniplates (2 in the infra-zygomatic crests of the maxilla and 2 in the anterior mandible). The patients had CBCTs taken before initial loading (T1), and one year out (T2). 3-D models were generated from the CBCTs, and registered on the anterior cranial base. Treatment outcomes were analyzed and measured using SPHARM-PDM for quantitication of corresponding surface pointts.
Result: Corresponding color-coded difference maps displayed the surface distances and vectors between T1 and T2. Bone-Anchored traction produced sagittal and vertical skeletal changes in the mandible. The posterior ramus was displaced distally by 3.6mm (SD+/-1.4) while the chin was restrained 0.5mm (SD+/- 3.92). The lower border of the mandible at menton was displaced inferiorly by 2.5mm (SD +/-1.4) while the lower border by gonion move downward by 3.6mm (SD+/-1.4) suggesting a closure of the mandibular plane angle. The condyles were displaced distally and superiorly by 2.5mm (SD+/- 1.5mm) and 0.8mm (SD +/-2.4) respectively. Vector SPHARM-PDM analysis showed a downward and backward displacement around gonion producing a closure of the gonial angle.
Conclusion: This new treatment approach induces a favorable control of mandibular growth for patients with components of mandibular prognathism.
The aim of this study is to evaluate whether there is any remodeling of bone at infraorbital rim following maxillary distraction osteogenesis (DO) at Le Fort-I level.
Twelve adult subjects in the age range of 17-21 years with complete unilateral cleft lip and palate underwent advancement of the maxilla by DO. The effect of maxillary DO on the infraorbital rim remodeling was evaluated from lateral cephalograms recorded prior to the DO (T0), at the end of DO (T1), and at least 2-years after the DO (T2) by Walker's analysis. The ANOVA and two-tailed t test were used and probability value (P value) 0.05 was considered as statistically significant level.
There was anterior movement of maxilla by 9.22 ± 3.27 mm and 7.67 ± 3.99 mm at the end of immediate (T1) and long-term (T2) follow-up of maxillary DO, respectively. The Walker's analysis showed 1.49 ± 1.22 mm and 2.31 ± 1.81 mm anterior movement of the infraorbital margin (Orbitale point) at the end of T1 and T2, respectively (P < 0.01). This apposition of bone at the infraorbital rim region further improved the facial profile of these patients.
The advancement of maxilla by distraction osteogenesis at Le Fort-I level induced significant bone apposition at infraorbital rim.
Patients with mild midface hypoplasia who would otherwise may be candidates for osteotomy at Le Fort-II or Le Fort-III level may benefit from maxillary distraction at Le Fort-I level.
Although some early orthodontic procedures have come under scrutiny in recent years, the need for early identification and treatment of the skeletal Class Ill malocclusion has become even more universally accepted. Most Class Ill patients display a retruded maxilla with a normal to deep overbite and are ideally suited for treatment with maxillary expansion and protraction. In addition to maxillary advancement, facemask therapy rotates the maxilla in a counterclockwise direction, and the mandible in a clockwise direction, which results in an increase in lower face height and a profile that is more convex. Early intervention is associated with better patient compliance and possibly a better orthopedic response; however, treatment in the mixed or permanent dentition can produce favorable results. Overcorrection is recommended because treated patients grow similarly to untreated Class Ill patients after treatment. Treatment in the short term (2-3 years) shows good stability with a minority of patients requiring later facemask therapy.
An update is provided on the different types of early treatment for class III malocclusions of maxillary origin. There is an increasing tendency to prescribe maxillary orthopedic treatment with skeletal anchorage, with the purpose of enhancing the skeletal and reducing the dentoalveolar effects--offering a management option for children with important deformations that otherwise would have to wait until adult age to receive surgical treatment.
A literature review has been made of maxillary bone orthopedic traction appliances in growing children with class III malocclusions. A Medline (PubMed) search was made using the following MeSH terms: Cephalometric, Child, Malocclusion class III/therapy, Extraoral traction appliances, Palatal expansion, Bone plates, Skeletal anchorage, Orthodontic anchorage.
Many articles show that the greatest maxillary advances are obtained at very early ages, though with a greater tendency towards relapse. However skeletal anchorage has been seen to afford a lesser relapse rate and greater dentofacial orthopedic efficiency due to its low dentoalveolar impact. In any case, further randomized clinical studies are needed to firmly establish the quantifiable differences in terms of maxillary advance, optimum traction age, optimum traction appliance and potential side effects. At present, the incorporation of surgically inserted bone anchorage appliances (miniplates and miniscrews) offers a purely orthopedic approach to treatment, with minimization of the undesirable side effects of traditional dentofacial orthopedic compensation based on dentoalveolar anchorage. Nevertheless, further studies are needed to consolidate the supporting scientific evidence in this field.
The aim of this study was to explore the biomechanical effects on the craniomaxillary complex of bone anchorage and dental anchorage during maxillary protraction.
We established 2 finite element models. One simulated maxillary protraction with dental anchorage in the maxillary first molars and the other with bone anchorage in the infrazygomatic buttresses of the maxilla. The magnitude of the applied forces was 500 g per side, and the force directions were 0°, 10°, 20°, and 30° forward and downward relative to the occlusal plane.
The finite element model of the craniomaxillary complex could displace in an almost translatory manner when the force direction was about 20° in the bone anchorage model and about 30° in the dental anchorage model. The nodes representing the sutures at the back of the maxilla showed greater stress in the bone anchorage model than in the dental anchorage model in the same force direction. It is the opposite at the front of the maxilla.
We should determine the direction of applied force according to the anchorage location and skeletal characteristics of patients before maxillary protraction. The dramatic effects of maxillary protraction with bone anchorage can be based on the advantages of bone anchorage, not on the changes in the region of the applied force.
The purpose of this randomized trial study was to compare the effects of facemask and Tongue appliance in treatment of Class III malocclusion with maxillary deficiency in growing patients.
45 patients (22 males, 23 females) with maxillary deficiency were selected and randomly assigned to 2 groups. 22 patients (10 boys, 12 girls) with the mean age of 9.3 years±1.2 years were treated with facemask. 23 patients (12 boys, 11 girls) with the mean age of 10.1 years±0.7 years were treated by Tongue appliance. Lateral cephalograms obtained at the beginning and end of the study were analyzed.
Paired t-tests and Wilcoxon test showed that SNA and ANB significantly increased in both groups. Mann-Whitney test showed that there were no statistically significant differences between the two groups except for Jarabak ratio and Upper 1 to SN. U1 to SN increased by 11.1±6.9° in fixed facemask group and 2.5±6.1° in Tongue appliance group (P<0.001). Both treatment modalities were successful in moving the maxilla forward. However, the upper incisors had more labial inclination in the facemask group.
a b s t r a c t Introduction: The early treatment of Class III malocclusion with a protraction facemask can produce forward movement of the maxilla but is generally associated with posterior rotation of the mandible and dentoalveolar compensations. This article shows the dental and skeletal effects of intermaxillary elastics applied to temporary anchorage devices in the treatment of maxillary deficient Class III patients. Materials and methods: A total of 6 patients with skeletal Class III malocclusion were treated with intermaxillary elastics only. This traction was applied between modified miniplates placed in the maxilla and a modified lower acrylic resin plate bonded on mandibular tooth surfaces. To evaluate the ortho-dontic changes, lateral cephalograms were taken at the start of the treatment (T1), at the end of the orthopaedic treatment (T2) and at the follow-up (T3). Results: All patients showed orthopaedic correction of the skeletal Class III relationship with reduction of facial concavity. No dentoalveolar compensations or changes in mandibular position were observed. Conclusion: The treatment of maxillary deficiency with orthopaedic forces from skeletal anchorage directed to the hooks of a modified lower acrylic resin plate bonded on the mandibular tooth surfaces, seems to be a promising technique. Ó 2012 European Association for Cranio-Maxillo-Facial Surgery.
Objective:
To investigate the effectiveness of early class III protraction facemask treatment in children under 10 years of age at 3-year follow-up.
Design:
Multicentre randomized controlled trial.
Subjects and methods:
Seventy-three patients were randomly allocated, stratified for gender, into early class III protraction facemask group (PFG) (n = 35) and a control/no treatment group (CG) (n = 38).
Outcomes:
Dentofacial changes were assessed from lateral cephalograms and occlusal changes using the peer assessment rating (PAR). Self-esteem was assessed using the Piers-Harris children's self-concept scale, and the psychosocial impact of malocclusion with oral aesthetic subjective impact score (OASIS) questionnaire. Temporomandibular joint (TMJ) signs and symptoms were also recorded. The time points for data collection were at registration (DC1), 15 months later (DC2) and 3 years post-registration (DC3).
Results:
The following mean skeletal and occlusal changes occurred from the class III starting point to DC3 (3-year follow-up): SNA, PFG moved forwards +2·3° (CG forward +1·6°; P = 0·14); SNB, PFG moved forwards +0·8° (CG forward +1·5°, P = 0·26); ANB, PFG class III base improved +1·5° (CG stayed about the same at +0·1°; P = 0·001). This contributed to an overall difference in ANB between PFG and CG of +1·4° in favour of early protraction facemask treatment. The overjet was still improved by +3·6 mm in the PFG and changed a small amount +1·1 mm in the CG (P = 0·001). A 21% improvement in PAR was shown in the PFG and the CG worsened by 8·4% (P = 0·02). There was no increase in self-esteem (Piers-Harris score) for PFG compared with the CG (P = 0·56) and no statistically significant difference in the impact of malocclusion (OASIS) between groups in terms of the changes from DC1 to DC3 (P = 0·18). TMJ signs and symptoms were very low at DC1 and DC3.
Conclusions:
The favourable effect of early class III protraction facemask treatment undertaken in patients under 10 years of age, is maintained at 3-year follow-up in terms of ANB, overjet and % PAR improvement. The direct protraction treatment effect at SNA is still favourable although not statistically significantly better than the CG. Seventy per cent of patients in PFG had maintained a positive overjet which we have defined as ongoing treatment success. Early protraction facemask treatment does not seem to influence self-esteem or reduce the patient's personal impact of their malocclusion at 3-year follow-up.
At the age of mixed dentition, a downward or laterally displaced premaxilla with a wide alveolar cleft in patients with bilateral cleft lip and palate remains a dilemma both for orthodontists and surgeons. These premaxillary deformities not only make the alveolar bone grafting difficult but also aesthetically and functionally unacceptable. The purpose of the present article is to introduce three new orthodontic and orthopaedic techniques for solving these premaxillary deformities and facilitating alveolar bone graft through a non-surgical approach. These techniques are the premaxillary orthopaedic intrusion for correcting a downward displaced premaxilla, the premaxillary orthopaedic repositioning for correcting a laterally displaced premaxilla, and maxillary orthopaedic protraction by alternate rapid maxillary expansions and constrictions for minimizing a wide alveolar cleft. They were evaluated clinically and cephalometrically for their treatment effects. The results revealed that the premaxillary and cleft deformities were corrected in a short period of time and therefore the alveolar bone grafting could be carried out without difficulty in all of the patients who received the treatment. The treatment effects were mostly orthopaedic and partly orthodontic. No growth disturbance on the maxilla was observed throughout the treatment. These new orthodontic and orthopaedic techniques are very effective for solving the difficult-to-treat premaxillary deformities and facilitating the alveolar bone grafting in the patients with bilateral cleft.
Long-term follow-up studies have revealed that the shields of the function regulation are capable of influencing the circumoral soft tissue capsule in size and shape. As a result, the disturbed or restricted displacement of teeth and jaw bones could be corrected. The dramatic changes in dentoskeletal development thus achieved demonstrate the morphogenetic impact of the circumoral capsule. In clinical application, the function regulator offers the opportunity to realize Roux's concept of functional orthopedics in the treatment of orofacial dysmorphology, as has long been practiced in the medical field of orthopedics. Zusammenfassung Langzeitbeobachtungen haben den Nachweis erbracht, dass die Schilde des Funktionsreglers die zirkumorale Weichteilkapsel in Gre und Form zu beeinflussen vermgen. Auf diese Weise konnte die gestrte bzw. behinderte Verlagerung von Zhnen und Kieferknochen korrigiert werden. Die dramatischen Vernderungen im dentoskelettalen Bereich, die damit erreicht werden, zeigen die morphogenetische Bedeutung der zirkumoralen Weichteilkapsel. In klinischer Nutzanwendung bietet der Funktionsregler die Mglichkeit, das Roux'sche Konzept der funktionellen Orthopdie bei der Behandlung der Fehlentwicklungen von Gebiss und Gesichtsskelett zu realisieren, wie es seit langem in der medizinischen Disziplin der Orthopdie praktiziert wird.
This article reports on a retrospective study of 25 children (mean age, 4 years 2 months) exhibiting Class III malocclusions and anterior cross-bites who were treated with a face mask and a maxillary intraoral appliance. Cephalometric radiographs were taken for all treated patients at three intervals: before treatment (TO), after treatment (T1), and at posttreatment follow-up (T2). A control group consisted of 10 untreated Class III children (mean age, 3 years 11 months). Cephalometric radiographs were taken periodically for observation in this group. Paired t tests and independent t tests were performed to determine the significance of skeletal and dental changes related to treatment. Early therapy produced significant skeletal and dentoalveolar changes. The maxilla moved further forward in the treated group. Mandibular growth was similar in both treated and untreated groups. There was an improvement in the maxillomandibular relationship in the treated group. This was because of the proclination of the maxillary incisors and the retroclination of the mandibular incisors. Self-correction of the original anterior cross-bite in the untreated group occurred. Long-term follow-up revealed a decrease in overjet mainly caused by the proclination of the mandibular incisors. However, positive overjet was maintained throughout the study period. Despite some relapse, the treated group showed a net positive improvement in occlusion.
Bone-anchored maxillary protraction has been shown to be an effective treatment modality for the correction of Class III malocclusions. The purpose of this study was to evaluate 3-dimensional changes in the maxilla, the surrounding hard and soft tissues, and the circummaxillary sutures after bone-anchored maxillary protraction treatment.
Twenty-five consecutive skeletal Class III patients between the ages of 9 and 13 years (mean, 11.10 ± 1.1 years) were treated with Class III intermaxillary elastics and bilateral miniplates (2 in the infrazygomatic crests of the maxilla and 2 in the anterior mandible). Cone-beam computed tomographs were taken before initial loading and 1 year out. Three-dimensional models were generated from the tomographs, registered on the anterior cranial base, superimposed, and analyzed by using color maps.
The maxilla showed a mean forward displacement of 3.7 mm, and the zygomas and the maxillary incisors came forward 3.7 and 4.3 mm, respectively.
This treatment approach produced significant orthopedic changes in the maxilla and the zygomas in growing Class III patients.
To describe the orthodontic, periodontal and prosthetic management of a case with a 3 mm root fracture below the crest of the alveolar bone.
The root was extruded and periodontal surgery carried out to improve aesthetics and dental function.
A multidisciplinary approach to the management of dental root fractures is necessary for successful treatment.
Ozone water can be used to eliminate micro-organisms from the water systems in dental offices.
To determine if ozone water diminishes the bond strength of orthodontic adhesives.
One hundred and twenty bovine mandibular incisors were randomly divided into four equal groups. The teeth were cleaned with pumice and washed either with tap water (Groups 1 and 3) or with ozone water Groups (2 and 4) before bonding stainless steel orthodontics brackets to the teeth with either a composite resin (Groups 1 and 2; Transbond XT, 3M Unitek, Monrovia, CA, USA) or a resin-modified glass ionomer cement (Groups 3 and 4; Fuji Ortho LC, GC America Corporation, Tokyo, Japan). The manufacturers' recommendations for bonding were followed. All samples were subjected to thermal cycling and the shear bond strengths were determined with a universal testing machine. The Adhesive Remnant Index (ARI) was used to score the amount of resin remaining on the teeth after debonding the brackets.
There were no statistical differences in the shear bond strengths of the brackets debonded from enamel washed with either ozone water or tap water or between the groups bonded with the two adhesive resins (p = 0.595). The ARIs in Groups 2 and 3 were significantly different from the ARIs in Groups 3 and 4 (p = 0.030).
Ozone water did not alter the bond strength of brackets bonded with composite resins, but it did alter the sites of resin fracture when Fuji Ortho LC was used.
A review of the current literature regarding the interaction of morphologic and functional occlusal factors relative to TMD indicates that there is a relatively low association of occlusal factors in characterizing TMD. Skeletal anterior open bite, overjets greater than 6 to 7 mm, retruded cuspal position/intercuspal position slides greater than 4 mm, unilateral lingual crossbite, and five or more missing posterior teeth are the five occlusal features that have been associated with specific diagnostic groups of TMD conditions. The first three factors often are associated with TMJ arthropathies and may be the result of osseous or ligamentous changes within the temporomandibular articulation. With regard to the relationship of orthodontic treatment to TMD, the current literature indicates that orthodontic treatment performed during adolescence generally does not increase or decrease the odds of developing TMD later in life. There is no elevated risk of TMD associated with any particular type of orthodontic mechanics or with extraction protocols. Although a stable occlusion is a reasonable orthodontic treatment goal, not achieving a specific gnathologically ideal occlusion does not result in TMD signs and symptoms. Thus, according to the existing literature, the relationship of TMD to occlusion and orthodontic treatment is minor. Signs and symptoms of TMD occur in healthy individuals and increase with age, particularly during adolescence; thus, TM disorders that originate during various types of dental treatment may not be related to the treatment but may be a naturally occurring phenomenon.
A cephalometric study of the relation of the malar eminence to the A point has been made. It is proposed that the orbital-NA distance is of clinical importance in patients with SNA of less than 79 degrees in whom a Le Fort I osteotomy procedure is contemplated. The measurement of the angle SNO is a significant guide to the malar-maxillary relationship and will assist in complete cephalometric evaluation of these patients.
The "Wits" appraisal of jaw disharmony is a simple method whereby the severity or degree of anteroposterior jaw dysplasia may be measured on a lateral cephalometic head film. The method entails drawing perpendiculars from points A and B on the maxilla and mandible, respectively, onto the occlusal plane. The points of contact of the perpendiculars onto the occlusal plane are labeled AO and BO, respectively. In a sample of twenty-one male and twenty-five female adults selected on the basis of excellence of occlusion, it was found, on the average, that in females points AO and BO coincided and in males point BO was located 1 mm. ahead of point AO. In skeltal Class II jaw dysplasias, point BO would be positioned well behind point AO (positive reading), whereas in Class III skeltal jaw disharmonies, the "Wits" reading would be negative, that is, with point BO ahead of point AO. The advantages of the "Wits" appraisal over that of the conventional ANB angle reading are illustrated and discussed.
Each maxilla is joined to the frontal bone by a veritable fronto-maxillary sutural joint which, in the young subject, permits sliding movements. During growth, the maxilla orients itself in relation to the mechanical effects of the various structures which surround it. The location, below the frontal sinus, of this joint endows it with special properties of resistance and change in position of orientation. These anatomico-functional peculiarities explain certain results obtained by classical heavy antero-posterior of postero-anterior extra-oral forces.
The purpose of this review is to highlight consensus in past research on the role of intercuspal occlusal factors in the pathophysiology of temporomandibular disorders. The occlusal intercuspal relationships considered are skeletal anterior open bite, overbite, overjet, symmetry of contacts in the retruded contact position (RCP), crossbite, and posterior occlusal support. Skeletal anterior open bite, reduced overbite, and increased overjet are associated with osteoarthritic TMJ patients, but lack specificity for defining patient populations per se. There is no evidence that overbite or overjet plays a role in the pathophysiology of nonarthritic disorders. A combination of unilateral RCP with an absence of a clinically apparent RCP-ICP (intercuspal position) slide may encourage TMJ disc displacement, but unilateral RCP per se was not associated with TMJ diagnoses. Crossbite does not seem to provoke TMJ symptoms or disease. Lost molar support may be associated with osteoarthrosis presence and severity, but studies have not yet been distinguished for age effects. Where appropriate, implications for clinical practice are drawn.
The etiology, diagnosis and treatment of temporomandibular joint (TMJ) pain and dysfunction is a controversial subject. There are varying opinions regarding the contribution of occlusion (malocclusion) to the development of mandibular dysfunction and further, the contribution of occlusal alterations (orthodontic and restorative) to the development of pain and dysfunction. Epidemiologic investigations suggest there is a high incidence of subjective and objective symptoms in the pediatric population. Observations on incisal relationships, condyle position and joint sounds, and comparisons to controls seem to suggest that these factors are not the cause of pain or dysfunction. The purpose of this review is: (1) to bring the clinician's attention existing published information reporting the presence of symptoms in children, (2) to evaluate selected information in young adults, (3) to question anecdotal information on the etiology of TMJ problems. It is not in the purview of this paper to determine the overall etiology of TMJ dysfunction.
Two-hundred-and-thirty-eight subjects in three different age-groups (7, 11, and 15 years) were followed over a period of 4–5 years in respect of morphological malocclusions, and signs and symptoms of functional disturbances. About half of the 7-year-olds had at least one of the morphological malocclusions registered while the corresponding figure was 38 per cent at the age of 20.
Some subjects had received corrective orthodontic treatment. When compared with subjects without such treatment, there were no differences in prevalences of occlusal interferences, nor in signs or symptoms of craniomandibular disorders (CMD). The associations between CMD and different morphological malocclusions were low. Nevertheless, some malocclusions were found to be more important than others. In a long-term perspective cross-bite, both uni-and bilateral, anterior open bite, post-, and prenormal occlusion had some association with the development of CMD.
Fifty temporomandibular joints (TMJs) in 30 asymptomatic volunteers were imaged with a 1.5-T magnetic resonance (MR) imaging system to determine (a) the normal range of meniscus position, (b) the best definition of a normal TMJ and criteria to distinguish it from a TMJ with significant internal derangements, (c) the significance of certain findings such as joint effusion and disk distortion, and (d) the optimum mouth position(s) to be used for imaging. A method was devised to quantify meniscus displacement in terms of the number of degrees from a 12 o'clock or vertical position (relative to the condyle). The distribution of meniscus positions defined two groups in this asymptomatic study group. A strong correlation between abnormal joints and a history of orthodontics led to the exclusion of subjects with a history of orthodontics, and those with mouth trauma were also excluded, leaving a better "normal control" group. The junction of the posterior band of the meniscus and the bilaminar zone should fall within 10 degrees of vertical to be within the 95th percentile of normal.
The effect of orthodontic treatment on the functional status of the masticatory system was analysed in 706 children from three Danish communities. Three-hundred-and-eighty-eight (48 per cent) of the children were treated orthodontically and the 295 (37 per cent) of the total population had terminated the treatment and were included in the analysis. Fifty-seven cases (7.1%) of the total population were discontinued before the orthodontic treatment was considered finished by the orthodontist. Discontinuation did not, however, seem to influence the functional status. Increasing the orthodontic treatment frequency from 38 to 51 per cent did not decrease the functional problems of a young population. On the contrary, the community with the lowest treatment frequency (38 per cent) demonstrated fewer functional problems among the orthodontically treated subjects than did the two communities with higher treatment frequencies, indicating paradoxically that it may be a functional risk to treat the last 13 per cent with minor discrepancies. Tenderness on palpation of the musculature and the TMJ capsule were generally more prevalent among orthodontically treated subjects. Children who had their treatments performed by either orthodontist or paedodontist alone demonstrated more muscular problems than children who had been treated by a team of orthodontists and paedodontists. Related to the severity of the malocclusion these findings stress the importance of more consideration to establish a functionally satisfactory occlusion after orthodontic treatment. Functional status was not related to the type of orthodontic treatment, including extraction therapy, use of either fixed or removable appliances.
The purpose of this study was: (1) to analyse the long-term clinical implications of Herbst treatment on the masticatory system, and (2) to analyse the radiographic appearance of the temporomandibular joints at the time of follow-up using lateral tomography of the right and left TMJ. The sample consisted of 19 consecutive male subjects with a Class II, Division 1 malocclusion treated with the Herbst appliance for an average period of 7 months. The patients were reinvestigated at the end of the growth period (an average of 7.5 years after treatment). The anamnestic, clinical, and radiographic findings revealed that Herbst treatment did not seem to have any long-term adverse effects on the craniomandibular system.
This study was designed to investigate the biomechanical effect of protractive maxillary orthopedic forces on the craniofacial complex by use of the three-dimensional finite element method (FEM). The three-dimensional FEM model was developed on the basis of a dry skull of a young human being. The model consisted of 2918 nodes and 1776 solid elements. Eighteen cranial and facial sutural systems were integrated in the model. An anteriorly directed 1.0-kg force was applied on the buccal surfaces of the maxillary first molars in both a horizontal parallel direction and a 30 degree obliquely downward direction to the functional occlusal plane. The nasomaxillary complex showed a forward displacement with upward and forward rotation in a horizontal protraction case, whereas a downward force produced almost translatory repositioning of the complex in an anterior direction. High stress levels were observed in the nasomaxillary complex and its surrounding structures. However, the pattern of stress distributions within the complex was different in two force systems. A downward protraction force produced relatively uniform stress distributions, indicating the importance of the force direction in determining the stress distributions from various orthopedic forces.
The presumed relationship between occlusal disharmonies and temporomandibular disorders has been the cornerstone of traditional orthodontic thinking about these disorders. Current research, however, indicates that temporomandibular problems are actually medical orthopedic diseases or dysfunctions that have little to do with occlusal morphology or maxillomandibular relationships. Therefore, orthodontists must discard some of their traditional beliefs and practices, replacing them with modern concepts of musculoskeletal pain and dysfunction, in order to provide appropriate care for patients suffering from temporomandibular disorders.
Fifty-one individuals (28 girls and 23 boys) who had received orthodontic treatment were compared as to signs and symptoms of craniomandibular disorders with 47 individuals (19 girls and 28 boys) without such treatment. All were 19 years old. An average of 5 years had elapsed since the termination of the treatment. The examinations enabled calculations of the anamnestic, the clinical dysfunction, and the occlusal indices of Helkimo. There were no statistically significant differences between the groups except with regard to the anamnestic index. Subjects who had not received orthodontic treatment reported most symptoms, but none were severe. In conclusion, there were no substantial differences as to signs and symptoms of craniomandibular disorders in these two groups of individuals.
This chapter has discussed the important aspects of nocturnal bruxism and its relation to disorders of the masticatory system and headaches. Bruxism is believed to be a stress-related sleep disorder, occurring in both men and women, in children, and in adults. In most patients, bruxism results only in minor tooth wear; however, it can become extremely severe with damage occurring in essentially every part of the masticatory apparatus. Nocturnal bruxism should not be overlooked as an etiologic factor in muscular headaches. Short-term acute therapy may involve physical therapy, nocturnal electromyographic biofeedback, and medication to relieve anxiety and improve sleep. Long-term management usually includes some form of stress reduction, change in lifestyle, and an occlusal splint or nightguard to protect the teeth and masticatory system.
Timing of mandibular growth and orthodontic treatment are coincidental, not cause-and-effect. Comparison of cephalometric radiographic tracings made before, during, and after treatment has shown no evidence that orthodontic forces can either arrest or stimulate growth of the condyle. Conversely, the growth behavior of the condyles can have a profound effect on the time required to achieve an orthodontic correction and on the anatomic and functional relationships at the end of treatment and later. Mandibular growth at the moment of orthodontic force application can have important effects on facial growth and function. If there is no growth, the mandible may rotate downward and backward, and condyle displacement and clicking can occur. Future growth rarely leads to recovery of such alterations. With adequate growth at the moment of orthodontic force application, the freeway space is maintained and horizontal tooth movement does not alter mandibular position. The position of the maxillary incisors in the face must be based on many considerations going far beyond arbitrary conformity to some "standard" values based on averages. Functional relationships and their effects on the joints are one of those considerations, along with esthetics. Dynamic thinking requires that maxillary incisors not be over-retracted, anticipating continued growth of the condyle that can reposition the body of the mandible and lower incisors downward and forward. This can occur before, during, or many years after treatment. If a tight incisor relationship is established, or develops naturally, in the early or midteens, and the condyles later outgrow the maxilla, clicking may well develop. Anterior translation of the mandible with the new growth is impeded by the incisors, so posterior displacement of the condyles occurs instead. This is most likely to occur in straight ("good") faces. Facial morphology, or pattern, has an impact on function. In the straight facial pattern, these problems usually involve incisor interference. In convex faces, the problems more often involve vertical molar interferences. Each of these presents its own unique problems and treatment requirements.
This article reports a 10-year longitudinal investigation of symptoms attributed to temporomandibular joint dysfunction in orthodontically treated subjects. The study was designed to test the prevailing assumption that orthodontic therapy is an etiologic factor in inducing TMJ dysfunction. Although the study was prospective in design, several unexpected methodologic complications limited the data analyses. Presumed joint dysfunction symptoms were assessed in orthodontically treated subjects. The presumed symptoms were subsumed under three categories: subjective symptoms, objective symptoms, and x-ray findings. The prevalence of symptoms was analyzed before treatment, 4 years later subsequent to retention, and 10 years after the initiation of the study. Comparisons of symptom frequencies were made between Begg and activator-treated subjects. The results of this investigation led to the following conclusions. In studying temporomandibular joint dysfunction, subjective symptoms, objective symptoms, and x-ray findings should be analyzed separately. Registration of symptoms during orthodontic treatment should probably be attributed to age changes rather than to treatment procedures. Begg Class I and Class II treatments do not reduce the percentages of symptoms registered. Begg Class I and Class II treatments do not affect the incidence of subjective symptoms. Begg Class I and Class II treatments do not affect the incidence of x-ray findings. Begg Class I and Class II treatments create higher percentages of objective symptoms after retention, but not in the long run (10 years). Ten years after the beginning of treatment, the initial differences in symptomatology between activator and Begg children no longer exist.
The deformational effects on the human skull resulting from maxillary protraction were examined by means of strain gauges and displacement transducers. A maxillary protraction appliance was used that included a reverse headgear attached to the maxillary first molars. The protraction forces that were applied to this appliance were parallel to the occlusal plane at the following locations: the height of the maxillary arch, 5 mm above the palatal plane, and 10 mm above the Frankfort horizontal plane. The results indicated that protraction forces at the level of the maxillary arch produced an anterior rotation and forward movement of the maxilla, protraction forces 10 mm above the Frankfort horizontal plane produced a posterior rotation of the maxilla with a forward movement of nasion, and protraction forces 5 mm above the palatal plane produced a combination of parallel forward movement and a very slight anterior rotation of the maxilla. Moreover, constriction of the anterior part of the palate occurred in all cases.
The present study was designed to evaluate the true treatment effects of the maxillary protracting appliance with chincap for skeletal Class III cases and to evaluate the difference of true treatment effects between the cases in which the maxilla was protracted from the first molars and the cases protracted from the first premolars. Cephalograms of 63 cases (the first molar protraction group--27 cases protracted from the first molars, the first premolar protraction group--36 cases protracted from the first premolars) treated with the combined maxillary protraction and chincap appliance were used. Template analysis was performed to evaluate the estimated treatment effects without growth change. Forward movement of the maxilla and backward rotation of the mandible were characteristic features of the estimated treatment effects in 63 cases. In comparing the two groups, the maxilla was displaced more anteriorly and rotated more upward and forward in the first molar protraction group. Therefore, the intraoral site of protraction should be selected by considering vertical dimensions of skeletal and dental structures, and the amount of forward displacement of the maxilla required in the treatment of the individual patient.
A statistical comparison of cross-sectional cephalometric records of Class III malocclusion subjects from ages 5-15 with serial Class I controls, finding strong tendencies for early appearance of distinctive characteristics.
This article describes the construction of the FR-3 appliance classically used in cases of Class III malocclusion characterized by maxillary skeletal retrusion. Included is a description of proper impression technique, construction bite registration, preparation of the work models, and a complete description of the fabrication of the FR-3 appliance. Specific steps in the clinical management of this appliance are also presented. The cephalometric records of three patients treated with the FR-3 appliance are then presented.
An interview and a clinical examination of signs and symptoms of functional disturbances and diseases in the stomatognathic system were performed on 309 adolescents 15-18 years old. Relationships and differences between data from this investigation were analyzed. Statistically significant correlations were found between headaches, bruxism, and tenderness to palpation of the attachment of the temporal muscle. There were also correlations between occlusal interferences in the retruded position (RP) and clickings and between mediotrusion interferences and clickings. The occlusal interferences were correlated to tenderness to palpation of the TMJ and TMJ muscles. Young people with distal occlusal relation were more frequently conscious of symptoms from the stomatognathic system than those with neutral or mesial occlusal relation. Deep bite was correlated to clenching and frontal dental wear.
To identify the skeletal and dental relationships of adults who have class III malocclusion, lateral cephalograms of 302 adult patients who had a class III molar and cuspid relationship were traced. Ninety-four of the patients had had presurgical orthodontic treatment and 208 had not. The tracings were digitized, and the following sets of measures were analyzed: maxillary skeletal position; maxillary dentoalveolar position; mandibular dentoalveolar position; and mandibular skeletal position. In addition, the mandibular plane angle and lower anterior facial height were measured as an indicator of vertical facial dimensions. None of these values demonstrated significant gender differences except lower anterior facial height; therefore, the subjects were treated as a group. Although there was considerable variation among patients, the most common combination of variables was a retrusive maxilla, protrusive maxillary incisors, retrusive mandibular incisors, a protrusive mandible, and a long lower facial height.
The prevalence of temporomandibular (TM) disorders and the status of the functional occlusion in former orthodontic patients many years after treatment were evaluated in two independent clinical studies. In each study, the former orthodontic patients were compared to similar groups of adults with untreated Class I and Class II malocclusions. Both studies reported similar findings with regard to TM disorders; there was no statistically significant difference (p greater than 0.05) between the orthodontic and control groups in either study. The illinois study found a high prevalence of nonfunctional (balancing) contacts in both groups, while the Eastman study found a somewhat lower prevalence. Differences for most of the occlusal parameters between the orthodontic and control groups were not statistically significant in either study. The findings for these two studies are similar and suggest that orthodontic treatment performed during adolescence does not generally increase or decrease the risk of developing TM disorders in later life.
This paper describes a method of cephalometric analysis which is currently used by the author in the evaluation and treatment planning of orthodontic and orthognathic surgery patients. In the analysis of a single film, the positions of the maxilla and mandible are related to cranial structures and to each other. Criteria for evaluation of the anteroposterior and vertical positions of the upper and lower incisors are provided, as is the documentation of the standards for each of the measures. In addition, the analysis of serial films is considered and a step-by-step outline of the cephalometric procedure is presented.
The effect of continuous bite jumping on masticatory muscle activity was investigated in ten growing boys with Class II, Division 1 malocclusion treated with the Herbst appliance. Integrated EMG recordings from the temporal and masseter muscles were analyzed quantitatively during maximal biting in intercuspal position and during chewing of peanuts. The results of the investigation revealed the following: (1) Before treatment the EMG activity from the masseter muscle was less than from the temporal muscle, especially during maximal biting in the intercuspal position. After treatment no difference in EMG activity was found between the two muscles, during either maximal biting or chewing. (2) During insertion of the Herbst appliance, the mandible was jumped anteriorly to an incisor edge-to-edge position with no occlusal contacts present in the posterior dental arch segments. The EMG activity from the two muscles during maximal biting and chewing was markedly reduced. (3) When the Herbst appliance was removed after 6 months of treatment, normal occlusal relations were found in all patients. The EMG activity in the two muscles exceeded pretreatment values. The increase in EMG activity seen was greater for the masseter than for the temporal muscle. The results of this investigation suggest that the increased muscle activity seen in the Class II, Division 1 cases during bite jumping with the Herbst appliance was due to an altered sagittal jaw base or dental relationship.
The status of temporomandibular joint (TMJ) function and functional occlusion was evaluated by means of a questionnaire and a detailed clinical examination in a group of seventy-five subjects between 25 and 55 years of age who had been treated orthodontically with full fixed appliances at least 10 to 35 years previously, during adolescence. The findings were compared to those of a control group of adults with untreated malocclusions. The findings indicate that in patients who underwent orthodontic treatment many years previously the prevalence of TMJ signs/symptoms is similar to that of a control group of adults with untreated malocclusions. However, a trend exists which suggests that subjects who have undergone extensive fixed appliance orthodontic treatment many years previously may possibly have a lower prevalence of TMJ problems than a similar group of adults with untreated malocclusions. A similar high prevalence of nonfunctional occlusal contacts occurred in the orthodontically treated and control groups. Also, a high prevalence of mandibular shift from the retruded contact to the intercuspal position was evident in both groups, with the shift being significantly greater in the control group than in the orthodontic group. When subjects in the orthodontic and control groups were combined, no relationship was evident between subjects exhibiting signs or symptoms of TMJ dysfunction and the presence of nonfunctional occlusal contacts and mandibular shifts.
The choice of treatment of children with developing skeletal Class III malocclusions has always posed a dilemma. Chin cups and various types of reverse headgears with elastics have been used in the past to minimize the growth and development discrepancy of the midface and the mandibular bones. In the present article, a critique of commonly used protraction devices is presented. A modified protraction headgear design and the biomechanical considerations of its clinical use are presented in this study. The clinical results show that a modified protraction headgear with a chin cup helps in the correction of moderately severe Class III malocclusions by the anterior displacement of the maxilla and maxillary dentition, and possibly restricting or changing the direction of the growth of the mandible. This headgear can also be used to correct axial inclinations and/or mesial displacement of posterior teeth.
The purpose of ttu's project was to determine whether functional posterior crossbites in children influence the position of the mandibular condyle and assess the effect of crossbite correction on condylar position. Ten children from four to nine years of age with functional posterior crossbites were treated by maxillary expansion. Standardized transcranial temporomandibularjoint radiographs were taken prior to treatment and following crossbite correction. Pretreatment radiographs were taken with the child's teeth occluded in the crossbite relationship. Post treatment radiographs were made with the teeth in centric occlusion. Prior to treatment, there were significant differences in the horizontal and vertical joint space measurements between the crossbite and noncrossbite sides. There were no significant differences between the two sides following crossbite correction.
The study was based on 23 patients aged between 24 and 28 years who had undergone extensive orthodontic treatment 10 years earlier and were investigated for symptoms of temporomandibular dysfunction. The investigation was carried out according to a standardized schedule which has been described by Carlsson and Helkimo (1972) and Helkimo (1974). The results presented by Helkimo (1974) were used as a standard of reference.
The prevalence of mandibular dysfunction symptoms is consistently lower than the reference values. No association between extensive tooth movement and the occurrence of symptoms could be discerned, but a tendency to a higher prevalence of symptoms in patients treated with fixed appliances in both jaws than in those treated with fixed appliances in the upper jaw only was noted. There seems little reason to fear an increased occurrence of mandibular dysfunction symptoms in patients subjected to orthodontic treatment. Special attention should be paid, however, to the torque on the molars, in order to avoid mediotrusive interferences.
Functional problems in the stomatognathic system have become a painful experience for many patients today. If these patients have previously undergone orthodontic treatment in childhood this is often claimed to be a cause of the symptoms, although this statement is frequently made only on the basis of ‘clinical experience’.
An investigation was undertaken on 60 patients who had had treatment for Angle's Class II, Division 1 malocclusion and were, on average, five years out of retention. Thirty of the patients had been treated without extraction and the other 30 after extraction of four premolars. The functional and dysfunctional conditions of the stomatognathic system were compared with an untreated control group of the same age. The material (mean age 21 years) was sub-divided according to the anamnestic (AiO-AiII) and clinical (DiO-DiIII) dysfunction indices of Helkimo (1974).
The cases treated without extractions showed significantly less anamnestic and clinical disturbances than both the extraction and the control group (P<0.05). Clinically, however, fewer extraction cases appeared in the class with moderate (DiII) and severe (DiIII) disturbances, but more with slight (DiI) disturbances compared to the control group.
The effect of continuous bite jumping on the masticatory system was investigated in 20 boys with Class II, Division 1 malocclusion treated with the Herbst appliance for six months. The range of mandibular movement and dysfunction symptoms in the TMJ and associated musculature were examined clinically. Masticatory function was evaluated by a masticatory efficiency test combined with EMG registrations of temporal and masseter muscle activity.
Lateral mandibular movement capacity was reduced by an average of 1.9 mm during six months of bite jumping, but increased to the pre-treatment level twelve months after appliance removal. The frequency of joint muscle tenderness increased during the first three months of bite jumping. After six months of treatment most symptoms had subsided.
Masticatory efficiency and temporal and masseter muscle activity were markedly reduced during the first three months of bite jumping but increased, on average, to pre-treatment values after six months of treatment. Subjectively, the patients experienced chewing and biting difficulties only during the first 7–10 days of treatment.
It was concluded that treatment of Class II malocclusions by continuous bite jumping with the Herbst appliance resulted in minor functional disturbances in the masticatory system. These disturbances were temporary, appearing mainly at the beginning of treatment.
The present study aimed to analyze the surface remodeling of the maxilla by the method of metallic implants. The sample comprised 14 series of lateral cephalometric films of girls, and was derived from the files of the implant study of Björk. Implants had been inserted below the anterior nasal spine and on the lower anterior surfaces of the zygomatic arches. Various types of malocclusion were represented in the sample, but records during periods of orthodontic treatment and retention were excluded from the analysis. No subjects with craniofacial anomalies were included. The final sample comprised 155 radiographs in the age range 8 to 25 years. In addition to the anatomically defined reference points, six fiducial points and two implant points in the maxilla were digitized from each film. Data were debugged by comprehensive numerical and graphical procedures. The average relocation of the reference point subspinale (ss, Down's A point) was about 4.5 mm down and 0.5 mm forward from 8 to 25 years, whereas the reference point spinal (sp, ANS) was relocated about 4.5 mm down and 1 mm forward. The reference point pterygomaxillare (pm, PNS) was relocated 6 mm backward and 1.5 mm down by surface remodeling. The relocation of the sp and pm points resulted in an angular remodeling of the palatal plane of 2.5 degrees (backward). At the same time the maxillary complex rotated -1.5 degrees (forward) in relation to the anterior cranial base, resulting in a 1 degrees increase in the inclination of the palatal plane to the anterior cranial base. The orbital floor showed an average relocation of about 2.5 mm up and 2 mm backward by surface apposition, partly masking both the downward and forward sutural translation and the average forward growth rotation of the maxilla. Because of the angular remodeling of the palatal plane and the surface apposition on the hard palate, it is recommended that great caution be exerted in the interpretation of clinical treatment analyses based on superimposition on lines or structures defined by the anatomy of the bony palate during the period of growth.
A new analysis, the Projective Invariant Analysis, was developed for the evaluation of magnetic resonance images of the temporomandibular joint. This method was used because it takes into account factors such as linear and angular measurements that simple Euclidean geometric methods fail to address. Forty "normal" joints (20 subjects) and 65 "abnormal" joints were analyzed. Joints were defined as normal if they had a Class I skeletal pattern and a Class I occlusion. In addition, a history was obtained and a clinical examination was performed on each of these subjects to rule out any temporomandibular joint dysfunction, masticatory muscle myalgia, or cervicalgia. The images of the 40 normal joints were compared with 65 previously taken images of 53 patients with conditions that had been diagnosed as anteriorly displaced disks with reduction. These two groups were compared with the use of the analysis method described by Drace and Enzmann that uses angular measurements. The groups were also analyzed with the use of a new method in which the structural relationships of the articular eminence, gleniod fossa, mandibular condyle, and articular disk were related to each other using projective geometry. For the projective invariant analysis, a 95% confidence ellipse was constructed on the basis of the normal data. All but one of the 40 normal points fell within this ellipse, and only three of the 65 abnormal points were inside the ellipse. Both analyses showed a significant difference between the normal and abnormal groups.(ABSTRACT TRUNCATED AT 250 WORDS)
This study evaluated the reliability of jaw positions, the existence of distinct jaw positions, and condyle-disk-fossa relationships in a symptom-free population by using articulator mountings and magnetic resonance imaging (MRI). The subjects examined included 28 men, 22 to 35 years of age, all having Angle Class I molar relationships and no discernible TMJ dysfunction. Records taken included the following: an axiographic face-bow to locate retruded hinge axis position, an interocclusal registration of retruded position (RE), a series of interocclusal registrations for centric occlusion (CO), a leaf gauge-generated centric relation (CR), a series of interocclusal registrations for CR, and MRI. The mandibular position indicator of the SAM articulator (Great Lakes Orthodontics, Ltd., Tonawanda, N.Y.) was used to determine reliability and existence of distinct jaw positions. Magnetic resonance imaging also evaluated jaw positions and anatomic relationships. The results indicate: (1) The articulator analysis of CO and CR is statistically replicable. (2) A distinct jaw position could be demonstrated for CO that was separate from RE and CR. It was not possible to discriminate between RE and CR. (3) Condylar concentricity was observed in half of the sample and remained consistent in RE, CO, and CR. (4) Of the sample 13% demonstrated anteriorly displaced disks that were not influenced by posterior condyle placement. (5) The clinical concept of treating to CR as a preventive measure to improve disk-to-condyle relationships was not supported by this study.
The purposes of this study were to develop a classification system for disk displacement in the temporomandibular joint (TMJ) and to study the prevalence of the various types of TMJ disk displacement in patients and symptom-free volunteers. The study was based on bilateral MRIs of 243 patients and 57 symptom-free volunteers. Eight different types of disk displacements were identified in addition to the superior disk position and a tenth indeterminate category. Superior disk position was observed bilaterally in 18% of the patients and bilaterally in 70% of the symptom-free volunteers.
Centric relation records of 19 dental students were obtained with leaf gauges and by mandibular manipulation. The condyle/fossa relationships were subsequently evaluated with enhanced sagittal cephalometry. Both clinical methods of obtaining centric relation revealed considerable variation of the condyle location within the glenoid fossa. Only 10% of the patients showed a condyle position "upward and forward" in the fossa with the leaf gauge method. In the mandibular manipulation technique of obtaining centric relation, 10% of the patients showed an "upward and rearward" position of the condyle.
The objective of this study was to develop and test a quantifiable method of temporomandibular (TM) joint space analysis (JSA) unaffected by head rotation. Sixteen female TM joints were imaged using multidirectional axially corrected tomography. Lateral, central and medial image slices were obtained from each joint, traced three times each, and triplicated for drafting. Tracings and draftings were randomized, blinded, and measured manually with digital calipers. Simulated head rotations of +/-10 degrees were applied and the process repeated. Multiple comparisons were done within and between patients by analysis of variance. Based on this study, we found there was no difference for tracing, drafting, and measurement error within and between patients. There were no significant differences between -10, 0, and +10 degrees of head rotation. Our conclusion is that this method for TM-JSA has a high level of reliability as determined by analysis of tracing, drafting, and measurement error for each joint space position and simulated rotation.
The purpose of this investigation was to determine a possible association between disc displacement and temporomandibular disorders (TMD). Fifty-six Brazilian asymptomatic volunteers (25 males and 31 females) and 181 symptomatic TMD patients (112 females and 69 males) participated. Volunteers did not have temporomandibular joint pain, limited jaw opening, joint sounds, or previous TMD treatment. Bilateral temporomandibular joint magnetic resonance imaging scans were obtained from all subjects. Joints were classified as normal or having disc displacement. Asymptomatic volunteers had 28 (25%) joints with disc displacement; 10 (18%) had unilateral and 9 (16%) had bilateral disc displacement. Of the TMD patients, 25 (13.8%) had bilateral symptomatic but normal joints. Fifty-one (28.2%) had unilateral and 105 (58%) had bilateral disc displacement. Odds ratios (12.2 [95% confidence interval = 6.1 to 24.4, P = .001]) suggest a strong association between disc displacement and TMD. This study suggests that disc displacement is relatively common (34%) in asymptomatic volunteers and is highly associated with patients (86%) with TMD.