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Desktop mechanical 3D digitizer (MicroScribe 3D-G2X). The inset shows the stylus tip of the digitizer perpendicularly touching the cusp tip of the dental cast.
Source publication
The aim of this retrospective study on dental models was to compare the orthodontic outcomes of maxillary dentoalveolar protrusion treated with headgear, miniscrews, or miniplates for maximum anchorage.
The 40 subjects were diagnosed as having either Angle Class II malocclusion or Class I bimaxillary dentoalveolar protrusion. All patients were trea...
Context in source publication
Context 1
... and posttreatment dental models from each of the 40 patients were trimmed to keep the occlusal plane parallel to the horizontal. On each maxillary dental model, morphologic landmarks were marked with a sharp pencil on the following locations: the mesial and distal ends of the incisal edge of the bilateral central incisors, the cusp tip of the canines, the buccal and palatal cusp tips of the second premolars, and the mesiobuccal, mesiopalatal, distobuccal, and distopalatal cusps of the first molars (Fig 1). To superimpose the pretreatment and posttreatment dental models, at least 4 reliable points, mostly mesial and distal points of the third palatal rugae, were identified as references to analyze individual tooth movements. ...
Similar publications
To quantify the treatment effects of interradicular miniscrew anchorage and to confirm the validity of the clinical usage of interradicular miniscrews in the distal movement of maxillary molars in nonextraction treatment.
Twenty-four maxillary molars were moved to the distal using miniscrews placed in the interradicular space between the second pre...
Anchorage is a major concern in adult mutilated dentition. However, with the explosive development of Temporary Anchorage Devices (TADs) newer avenues in orthodontic treatment philosophy have opened up. Mini-screws are found to be stable during such treatments, demonstrating that they could provide absolute anchorage for tooth movement. The present...
Citations
... These findings align with those presented by Becker et al. [23], who reported no displacements exceeding 0.5 mm in the transverse and vertical directions for both molars and incisors. Lai et al. [37] reported slight bodily intrusion during upper molar protraction with skeletal anchorage. On the contralateral side, a distal displacement of molars by −2.4 mm ± 1.7 was observed, with transverse and vertical movements of −0.5 mm ± 1.5 and 0.2 mm ± 1.4, which indicate constriction and extrusion, respectively. ...
Aim:
The purpose of the present study is the three-dimensional (3D) analysis of molar and incisor movements that occur during the correction of the upper midline deviation by using the Mesial-Distalslider appliance.
Materials and methods:
A total of 20 consecutive patients (12 women and 8 men; mean age 19.6 ± 11.1 years) were selected from the Orthodontic Department of Heinrich-Heine University of Düsseldorf. To correct the upper midline deviation (>2 mm), the patients were treated with asymmetric mechanics (mesialization on one side and distalization on the contralateral side) with the aid of Mesial-Distalslider. Dental casts were taken for each patient before (T0) and after the treatment (T1). The casts were 3D digitized and the models were superimposed on the palatal anterior region. Three-dimensional molar movements and sagittal incisor movements (proclination and retroclination) were assessed for T0 and T1.
Results:
At the end of the treatment, the total movements of the molars resulted in 4.5 ± 2.2 mm (antero-posterior direction), -0.4 ± 2.4 mm (transverse direction) and 0.3 ± 0.9 mm (vertical direction) on the mesialization side, and -2.4 ± 1.7 mm (antero-posterior direction), -0.5 ± 1.5 mm (transverse direction) and 0.2 ± 1.4 mm (vertical direction) on the distalization side. Incisor displacement was 0.9 mm ± 1.7 (mesialization side) and 0.6 mm ± 0.7 (distalization side).
Conclusion:
The Mesial-Distalslider appliance could be considered a valuable tool in orthodontic treatment for upper midline correction. Within the limits of a retrospective study, asymmetric molar movements appeared possible without clinically relevant anchorage loss.
... In studies comparing skeletal Class II correction with headgears, mini-screws, and mini-plates, the application of skeletal anchorage elicits greater changes within the anterior skeletal regions with less anchorage loss, and the application of mini-plates can be used to implement absolute intrusion of maxillary molars. [32] Because the mandible has an unfavorable anatomical structure compared to that of the maxilla for teeth movement, more stable skeletal anchorage such as a mini-plate should be considered preferentially for orthodontic treatment cases in which lower molar distalization and/or intrusion is being considered. [33] With these possibilities, appropriate force application and positioning combined with effective anchorage can favor teeth movement in the mandible. ...
BACKGROUND
To evaluate and compare the distribution of stress and displacement of teeth during mandibular arch distalization using buccal shelf screws.
MATERIALS AND METHODS
Three three-dimensional finite element models of mandibular arch were constructed with third molars extracted. Models 1, 2, and 3 were constructed on the basis of the lever arm heights of 0 mm, 3 mm, and 6 mm, respectively, between the lateral incisor and canine. A buccal shelf screw was placed at the area in the second molar region with the initial point of insertion being inter-dental between the first and second molars and 2 mm below the mucogingival junction. MBT pre-adjusted brackets (slot size 0.022 × 0.028”) were placed over the clinical crown’s center with a 0.019 × 0.025” stainless-steel archwire on three models. A retraction force of 300 g was applied with buccal shelf screws and a lever arm bilaterally using nickel-titanium closed coil springs. The displacement of each tooth was calculated on X, Y, and Z axes, and the von Mises stress distribution was visualized using color-coded scales using ANSYS 12.1 software.
RESULT
The maximum von Mises stress in the cortical and cancellous bones was observed in model 1. The maximum von Mises stress in the buccal shelf screw and the cortical bone decreased as the height of the lever arm increased. Applying orthodontic forces at the level of 6 mm lever arm height resulted in greater biomechanical bodily movement in distalization of the mandibular molars compared to when the orthodontic forces were applied at the level of 0 mm lever arm height.
CONCLUSION
Displacement of the entire arch may be dictated by a direct relationship between the center of resistance of the whole arch and the line of action generated between the buccal shelf screw and force application points at the archwire, which makes the total arch movement highly predictable.
... 5.2 The choice of anchorage: according to the specific situation of the patient choose appropriate anchorage, such as micro screw implant anchorage in the treatment of effective, orthodontic and periodontitis, abscess, loose teeth are superior to oral anchorage, safe, high efficiency, recovery of oral function and the overall beauty better, is widely used in orthodontic clinical work[10] [11]. And the microscrew implant anchorage can achieve a more stable effect, less anchorage loss [12] [13]. The effect of orthodontic treatment is significant, which can significantly improve the soft tissue, dentition and maxilla, improve the chewing function and bite force of patients, and have no obvious postoperative complications [14]. ...
This paper explores the clinical efficacy of orthodontic retention of third molars after extraction of the first or second molars. Studies show that the use of the second molar near the movement to replace the first molar, retain the third molar although need a long treatment time and higher treatment cost, but promote the gap of tissue regeneration, preserve healthy natural teeth, restore occlusal stability, but also can avoid the late repair of the first molar or second molar. In addition, the second molar after moving near the third molar is also conducive to the eruption of the third molar, maximizing the use of the third molar, to form a healthy and complete functional tooth line. Therefore, For patients with severe removal of the first or second molars, poor prognosis, severe periapical disease, and loss of the first or second molars, the treatment method of replacing the second molar for the first molar and the third molar for the second molar can be an effective treatment option.
... The use of skeletal anchorage can cause greater anterior teeth retraction and prevent the mesialization of the molar, whereas the use of TADs prevents deterioration of the profile with clockwise rotation of the mandible that can lead to an increase in the vertical dimension. 3 In certain borderline cases of Class II malocclusion en masse retraction of the anterior teeth can be brought about using the advantage of extra-alveolar mini-implants at the infrazygomatic crest (IZC) region. 4,5 There is often deepening of the overbite when retraction is carried out due to the extrusion of the maxillary anterior teeth. ...
Introduction:
The objective of this prospective study was to examine the efficacy of posterior interradicular and infrazygomatic crest mini-implants for en-masse anterior retraction.
Methods:
The 22 patients were divided into two groups. In group 1 (IZC n = 11), mini-implants were placed in the infrazygomatic crests and in group 2 (IR, n = 11), mini-implants were placed in the molar-premolar interradicular sites. Soft tissue, skeletal, and dental treatment effects between two groups were compared using lateral cephalometric measurements.
Results:
The average angle between the cranial base and A point was 1.01 degrees (P = .004), and the linear distance between the upper incisor and A point was 2.67 to 5.2 millimetres (P = .00). In IZC group the maxillary incisor to the palatal plane moved upward by a mean of -5.20 mm (P = .059), whereas in IR group the incisor movement changed by -2.67 mm (P = .068). There was no significant difference between groups IZC and IR while comparing overall treatment changes on upper incisor position change, angle, and overjet.
Conclusions:
Mini-implants placed in between the molar and premolar as well as the infrazygomatic crest can withstand the deepening of the bite during retraction. Mini-implants in IZC are capable of causing intrusion of the anterior teeth and preventing intrusion of the molars, thereby providing absolute anchoring in all planes. Placement of the mini-implants in the infrazygomatic crest resulted in more linear retraction.
... Studies have shown that while retracting incisors, mesial movement of molars could be reduced by approximately 2 mm using miniscrew anchorage instead of traditional anchorage [11]. Researchers studied both the retraction of incisal edges and the mesial movement of molars; these studies clearly illustrated changes in the sagittal direction of teeth [12,13]. However, it is much more di cult to understand the vertical changes in teeth due to the complex nature of these changes. ...
(1)Objectives:
To explore the vertical changes in the maxillary central incisor and the maxillary first molar and to investigate the changes in the mandibular plane angle during process space closure by miniscrew sliding mechanics.
(2) Methods:
A total of 20 adult patients were enrolled from the Department of Orthodontics of Peking University Hospital of Stomatology from 2008 to 2013. A digital dental model and craniofacial cone-beam computed tomography (CBCT) scan were taken at the beginning of the treatment(T0) and immediately after space closure(T1). Stable miniscrews were used to superimpose the maxillary digital dental models (T0 and T1), and the vertical changes in the maxillary first molar and the maxillary central incisor were measured. The changes in the mandibular plane were measured by CBCT superimposition in three dimensions.
(3) Results:
The average extrusion of the maxillary central incisor was 2.56±0.18 mm; the average intrusion of the maxillary first molar was 1.25±1.11 mm, with a distal movement of 0.97±0.99 mm; and the average mandibular plane angle decreased by 0.83±1.65°. The differences in the three indexes were statistically significant.
(4) Conclusion:
In the process of space closure with the miniscrew sliding method, the upper dentition changed significantly in both the sagittal and vertical directions. The maxillary central incisors were extruded, and the maxillary first molars were intruded. The mandibular plane was rotated slightly counterclockwise.
... However, in the first months of treatment after second molar extraction only a headgear was used, and hence treatment time with fixed appliances was reduced. Furthermore, treatment devices using skeletal anchorage may present a shorter treatment time in both interventions without anchorage loss [24][25][26]. Especially in group I orthodontic treatment duration was influenced by patient compliance, which is required for successful distalisation of the first molars by headgear. However, patients with bad compliance were excluded. ...
Background
This retrospective cohort study aimed to compare treatment results between bilateral extraction of upper second molars (M2) and first premolars (P1) in terms of treatment timing, cephalometry, upper third molar alignment and relapse in the long-term.
Methods
Fifty-three consecutively treated Caucasian patients with a brachyfacial pattern, skeletal class I and dental class II requiring extraction in the maxilla due to crowding were retrospectively divided into group I (M2 extracted; N = 31) and II (P1 extracted; N = 22). Fixed appliances were inserted after extraction and after distalisation of the first molars in group I. Post-treatment lateral cephalograms were digitally analysed and compared between groups. Six to seven years later relapse and success of upper third molar alignment were clinically evaluated as well as orthodontic treatment duration, pre-treatment age and gender recorded.
Results
After debonding patients with second molar extraction showed significantly smaller values for the Wits-appraisal, but higher values for index and facial axis. Extracting first premolars caused significantly more retroinclination/−position of anterior teeth and an increased profile concavity, more relapse and less successful alignment of upper third molars. Orthodontic treatment duration, pre-treatment age and gender were not significantly different between groups.
Conclusions
Bilateral extraction of upper first premolars or second molars may solve dental crowding in skeletal class I dental class II patients with a brachyfacial growth pattern. Upper second molar extraction seems to affect maxillary third molar alignment, long-term stability and dental and soft-tissue cephalometric parameters positively, but no intervention proved to be clearly superior.
... However, for many of these patients, surgery is not a viable option because of medical or financial concerns [2]. Therefore, camouflage therapy can sometimes be an alternative method of treatment [3][4][5][6]. ...
Background:
Patient satisfaction with facial appearance at the end of orthodontic camouflage treatment is very important, especially for skeletal malocclusion. This case report highlights the importance of the treatment plan for a patient initially treated with four-premolar-extraction camouflage, despite indications for orthognathic surgery.
Case summary:
A 23-year-old male sought treatment complaining about his unsatisfactory facial appearance. His maxillary first premolars and mandibular second premolars had been extracted, and a fixed appliance had been used to retract his anterior teeth for two years without improvement. He had a convex profile, a gummy smile, lip incompetence, inadequate maxillary incisor inclination, and almost a class I molar relationship. Cephalometric analysis showed severe skeletal class II malocclusion (A point-nasion-B point = 11.5°) with a retrognathic mandible (sella-nasion-B point = 75.9°), a protruded maxilla (sella-nasion-A point = 87.4°), and vertical maxillary excess (upper incisor to palatal plane = 33.2 mm). The excessive lingual inclination of the maxillary incisors (upper incisor to nasion-A point line = -5.5°) was due to previous treatment attempts to compensate for the skeletal class II malocclusion. The patient was successfully retreated with decompensating orthodontic treatment combined with orthognathic surgery. The maxillary incisors were repositioned and proclined in the alveolar bone, the overjet was increased, and a space was created for orthognathic surgery, including maxillary impaction, anterior maxillary back-setting, and bilateral sagittal split ramus osteotomy to correct his skeletal anteroposterior discrepancy. Gingival display was reduced, and lip competence was restored. In addition, the results remained stable after 2 years. The patient was satisfied with his new profile as well as with the functional malocclusion at the end of treatment.
Conclusion:
This case report provides orthodontists a good example of how to treat an adult with severe skeletal class II malocclusion with vertical maxillary excess after an unsatisfactory orthodontic camouflage treatment. Orthodontic and orthognathic treatment can significantly correct a patient's facial appearance.
... In skeletal Class III cases, it is challenging to obtain an esthetically and functionally sound occlusal outcome, only with orthodontic treatment. Furthermore, owing to its high rate of relapse it is difficult to maintain a constant post treatment occlusion [4]. Three treatment modalities have been curated to manage skeletal Class III malocclusion, they are: 1. ...
Research conducted to identify the etiologic features of Class III malocclusion showed that this type of deformity involves not only jaws, but the total cranio-facial complex, making it a difficult anomaly to understand. Majority of patients presenting with Class III malocclusions have a combined skeletal and dental discrepancy, making the factors contributing to this anomaly, complex. In skeletal Class III cases, it is challenging to obtain an esthetically and functionally sound occlusal outcome, only with orthodontic treatment. Furthermore, owing to its high rate of relapse it is difficult to maintain a constant post treatment occlusion. The clinical success of orthodontic mini-screws is dependent on many factors such its material characteristics, biomechanics, surgical technique, clinician's experience, bone depth and quality, primary stability of the mini-screw and oral hygiene of the patient. However, despite its large-scale application in routine orthodontics, its success rate can be further improved. The present article demonstrates the effect of mini-screws on skeletal class III treatment.
... If the patient fails to cooperate, unfavorable effects like anchor loss and mesialization of molars are seen. 11 Even with orthodontic mini-implants, certain unwanted side effects might occur, such as distal crown tipping accompanying molar distalization, periimplantitis, close proximity to roots, and an additional procedure to remove the implants. 12 TPA has been most commonly used in the maxillary arch as an adjunct in clinical orthodontics to correct molar rotations, molar expansion, molar distalization, vertical molar control, and most common among all, anchorage reinforcement. ...
Background. Although there are various intraoral and extraoral appliances for anchorage management in orthodontics, most fail to preserve the anchorage efficiently. Thus, there is a need for an appliance that can preserve anchorage in the sagittal, vertical, and transverse directions with good patience compliance and cost-effectiveness. This study compared the efficacy of butterfly arch and transpalatal arch (TPA) as an anchorage reinforcing unit during orthodontic space closure using a linear finite element model.
Methods. A 3D model of the maxilla and associated structures was developed from CT images of an individual’s skull at a slice thickness of 1 mm. The magnitude of movements of anchor teeth in vertical, horizontal, and transverse directions was calculated in first premolar extraction cases during anterior retraction using a linear finite element model analysis and compared in two situations―butterfly arch and TPA attached to maxillary first molar for anchorage.
Results. The anterior teeth had similar movements in the case of TPA and butterfly arch. There was more mesial and lingual movement in the first molars with TPA than in the butterfly arch, which had buccal but no mesial movement. The anterior teeth showed extrusion and the second premolars showed intrusion with TPA. Also, the von Mises stress and maximum principal stress were maximum with TPA at the cervical region of anterior and posterior teeth compared to the butterfly arch, where both stresses were uniformly distributed all over the teeth.
Conclusion. A butterfly arch with its unique design, configuration, and biomechanical properties can be used as a device that can maintain the posterior anchorage efficiently.
... Over the past decade, the use of microimplants is becoming a standard practice in orthodontics. Their potential has been demonstrated repeatedly during orthodontic treatment for different types of movement: molar distalization [1][2][3][4], molar protraction [5,6], incisor or molar intrusion [7,8], incisor or molar extrusion [9,10], en-masse retraction of anterior teeth [11,12], and maintaining anchorage in extraction cases [13][14][15]. Microimplant-based distalization of maxillary molars can help facilitate correction of class II malocclusions by avoiding premolar extraction, decreasing the need for surgery in specific cases, and reducing patient compliance while keeping usual goals of treatment [ 16,17]. ...
Introduction:
Orthodontic treatment of class II malocclusion with conventional treatment modalities can be challenging for the clinician. The use of microimplants to obtain absolute anchorage has become very popular in recent years especially in noncompliant patients. Microimplants are convenient, save time, and produce good treatment results with no need for patient cooperation. A special approach for class II correction with microimplant supported molar distalization has been developed by the authors and is illustrated through two clinical cases. Description. For each clinical case, 0.022" preadjusted brackets were bonded on both arches except on the maxillary first and second premolars with bands on the first and second molars. After leveling and alignment, a 0.017" × 0.025" stainless steel wire was fitted on the upper arch, and two microimplants were placed bilaterally between the maxillary second premolar and the first molar. Open coil springs were inserted in the upper archwire on both sides and compressed via a steel ligature on sliding hooks to the microimplants pushing distally simultaneously the first and second maxillary molars. En-masse retraction of the maxillary anterior teeth was then carried out on a 0.019" × 0.025" stainless steel closing loop archwire while the posterior segment was anchored to the microimplant with a steel ligature to the first premolar.
Results:
Class I canine and molar relationship were achieved, and an ideal occlusion was established. Both ANB and FMA angles decreased by 1° due to the counterclockwise rotation effect of the maxillomandibular complex. Skeletal and dental results remained stable three years later.
Conclusion:
Maxillary molar distalization using coils and buccal microimplants can be regarded as an effective technique in a relatively short time and might be considered a breakthrough in the treatment of class II malocclusions. Microimplants enable the clinician to perform a nonextraction treatment in noncompliant patients who would alternatively be treated only with extractions.
