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14 Assessment of nostril show (a). Nasal projection (CB) to nasal length (AB), according to Goode's ratio: CB:AB = 0.55:0.6 is normal (b). Horizontal assessment of nasal projection: from nasal base (Nb), the Pn-Sn to Sn-Nb should be 2:1 (c). Nasal base ("worm's eye") view assessment of the nose. The general shape of the alar base should resemble an isosceles triangle (d)
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The clinical evaluation of the face is the most important aspect of evaluating patients with dentofacial deformities. The clinical examination is the primary determinant in making a diagnosis and developing a treatment plan. The basic treatment goals are: establishment of orofacial function, ensure stability of results, achieve facial esthetics and...
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Treatment of traumatic deep bite and hypodivergent skeletal pattern in patients with questionable or no growth potential has long been recognized as a clinical challenge. Concurrent presence of a sagittal jaw discrepancy and transverse incompatibility in some cases call for meticulous consideration of three-dimensional nature of the problem. As ort...
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... A meta-analysis suggested that BSSO and intra-oral vertical ramus osteotomy (IVRO) have good stability when used for mandibular setback, with results showing that IVRO statistically reduced the incidence of neurosensory dysfunction of the IAN after mandibular setback surgery compared with BSSO [95]. When planning orthognathic surgery, each case must be analyzed individually [96], considering the patient's expectations and individual anatomical characteristics through a good physical and complementary examination. The surgical technique chosen must be based on the most efficient result for the patient and not just the surgeon's personal choice of technique. ...
Craniofacial surgery is proposed and performed for a variety of reasons, ranging from congenital or acquired malformations to emotional disorders and parafunctions of the masticatory, respiratory, auditory, and visual systems. Surgery of the mandible and its orthostatic repositioning is the most common of these corrections of craniofacial anomalies. Throughout the history of these procedures, various techniques have been proposed and perfected, but always with a high rate of minor and major complications. The recurrence rate of mandibular malposition is high, as is the temporary loss of facial sensitivity and motor skills. These outcomes are often related to the choice of surgical technique rather than the skill of the surgeon, which is considered to be one of the most important factors in the final outcome. Surgical techniques involving direct manipulation of the vascular-nervous bundles, such as bilateral sagittal split osteotomy, clearly present the possibility of major or minor complications. In this study, an orthognathic surgical technique, performed by the same team for over 40 years and now available through a 20-year postoperative patient follow-up study, is presented with a literature review relating it to biomechanical concepts and bone remodeling to analyze the evolution of orthognathic surgery since it became common practice to correct maxillofacial discrepancies. In this review, we also present a case report in which previous orthodontic treatment prepared a patient for surgical correction of mandibular bone discrepancy without the need for combined maxillary and/or genioplasty, and we describe the most commonly used techniques today, as well as their advantages and disadvantages. The combination of established concepts together promotes favorable stability of mandibular osteotomies, functional anatomical positioning of the temporomandibular joint, reduced risk of injury to the mandibular vasculo-nervous bundle, and good aesthetics with positive patient acceptance and no relapse, thus these are the objectives for proposing innovative treatments that combine the technologies available today.
... Cephalometric measurements of the cranio-maxillofacial region are used to develop orthodontic treatment plans and to evaluate orthodontic effects and treatment results [5,6]. The traditional cranio-maxillofacial measurements mainly adopts a direct measurement approach, two-dimensional images and X-ray cephalometric measurements [7]. ...
Abstract Background Some female adults who received orthodontic treatment often complain about thinner faces, protruding cheekbones and sunken temples, even at the beginning of treatment. The present research aimed to explore facial soft tissue changes during and after orthodontic treatment, as well as the related factors affecting facial soft tissue changes. Methods This study used 3dMD stereo photography technology to compare facial soft tissue changes among adult females who received orthodontics. A total of 52 adult females (24 teeth extraction, 28 non-teeth extraction cases) were included and potential correlations between related factors (facial morphology features, the change of occlusal height and dental arch width) were evaluated during different treatment periods. Results Overall, 3D-negative soft tissue changes of the buccal region moderately correlated with distances of nasion-menton and subnasale-menton (both rs = 0.30, P
Cephalometric analysis is critically important and common procedure prior to orthodontic treatment and orthognathic surgery. Recently, deep learning approaches have been proposed for automatic 3D cephalometric analysis based on landmarking from CBCT scans. However, these approaches have relied on uniform datasets from a single center or imaging device but without considering patient ethnicity. In addition, previous works have considered a limited number of clinically relevant cephalometric landmarks and the approaches were computationally infeasible, both impairing integration into clinical workflow. Here our aim is to analyze the clinical applicability of a light-weight deep learning neural network for fast localization of 46 clinically significant cephalometric landmarks with multi-center, multi-ethnic, and multi-device data consisting of 309 CBCT scans from Finnish and Thai patients. The localization performance of our approach resulted in the mean distance of 1.99 ± 1.55 mm for the Finnish cohort and 1.96 ± 1.25 mm for the Thai cohort. This performance turned out to be clinically significant i.e., ≤ 2 mm with 61.7% and 64.3% of the landmarks with Finnish and Thai cohorts, respectively. Furthermore, the estimated landmarks were used to measure cephalometric characteristics successfully i.e., with ≤ 2 mm or ≤ 2° error, on 85.9% of the Finnish and 74.4% of the Thai cases. Between the two patient cohorts, 33 of the landmarks and all cephalometric characteristics had no statistically significant difference (p < 0.05) measured by the Mann-Whitney U test with Benjamini–Hochberg correction. Moreover, our method is found to be computationally light, i.e., providing the predictions with the mean duration of 0.77 s and 2.27 s with single machine GPU and CPU computing, respectively. Our findings advocate for the inclusion of this method into clinical settings based on its technical feasibility and robustness across varied clinical datasets.
Three-dimensional (3D) printing refers to a wide range of additive manufacturing processes that enable the construction of structures and models. It has been rapidly adopted for a variety of surgical applications, including the printing of patient-specific anatomical models, implants and prostheses, external fixators and splints, as well as surgical instrumentation and cutting guides. In comparison to traditional methods, 3D-printed models and surgical guides offer a deeper understanding of intricate maxillofacial structures and spatial relationships. This review article examines the utilization of 3D printing in orthognathic surgery, particularly in the context of treatment planning. It discusses how 3D printing has revolutionized this sector by providing enhanced visualization, precise surgical planning, reduction in operating time, and improved patient communication. Various databases, including PubMed, Google Scholar, ScienceDirect, and Medline, were searched with relevant keywords. A total of 410 articles were retrieved, of which 71 were included in this study. This article concludes that the utilization of 3D printing in the treatment planning of orthognathic surgery offers a wide range of advantages, such as increased patient satisfaction and improved functional and aesthetic outcomes.
Introduction:
This study aimed to identify a simple yet reliable soft-tissue parameter for the clinical determination of esthetic lip position by investigating the most consistent reference lines and assessing their sensitivity and specificity.
Methods:
A total of 5745 records from Chinese patients aged >18 years were screened. In part I of the study, lateral view photographs of 96 subjects (33 males, 63 females) with esthetic facial profiles were selected. The profile esthetics of each photograph was first scored by 52 dental students, followed by 97 laypeople on a 5-point attractiveness scale. For the top 25% of photographs with the highest score for each sex (8 males, 16 females), the consistency of 6 commonly used reference lines were assessed to determine the esthetic lip position. In part II of the study, lip positions relative to Steiner's (S) and Ricketts' (E) lines in the profile photographs of 86 patients (43 males, 43 females) deemed to have an esthetically unpleasing profile were compared with those in 86 Chinese movie star idols (43 males, 43 females).
Results:
In part I of the study, the S, E, and Burstone's (B) lines exhibited the lowest standard deviations for the upper and lower lips. B line was excluded from further analysis because of its higher mean absolute values, and S and E lines were used for the subjective assessment in part II of the study. In part II, the S line showed a sensitivity of 86.0% and 86.0% and a specificity of 81.4% and 83.7% for males and females, respectively. In contrast, the E line presented a sensitivity of 88.4% and 93.0% and a specificity of 79.1% and 74.4% for males and females, respectively.
Conclusions:
S, E, and B lines were the most consistent soft-tissue parameters among both sexes; however, because of the smaller absolute values, the S line would be more convenient among the 3 for a quick clinical assessment of lip position. Moreover, the performance of both S and E lines was similar among both sexes, which supports using these lines in assessing the esthetic lip position.
Introduction:
Smile analysis provides data on the positive and negative elements of a patient's smile. We aimed to develop a simple pictorial chart to record relevant parameters of the smile analysis in a single diagram and to investigate the reliability and validity of this chart.
Methods:
A panel of 5 orthodontists developed a graphical chart, which was reviewed by 12 orthodontists and 10 orthodontic residents. The chart comprises facial, perioral, and dentogingival zones analyzing 8 continuous and 4 discrete variables. The chart was tested on frontal smiling photographs of 40 young (aged 15-18 years) and 40 old (aged 50-55 years) patients. All measurements were performed twice with an interval of 2 weeks by 2 observers.
Results:
Pearson's correlation coefficients for observers and age groups varied from 0.860 to 1.000 and between observers from 0.753 to 0.999. Minor significant mean differences were found between the first and second observations, which were not clinically relevant. The kappa scores for the dichotomous variables were in perfect agreement. To test the sensitivity of the smile chart, differences between the two age groups were assessed as differences because aging is expected. In the older age group, philtrum height and visibility of mandibular incisors were significantly larger, whereas the upper lip fullness and buccal corridor visibility were significantly lesser (P <0.001).
Conclusions:
The newly developed smile chart can record essential smile parameters to aid diagnosis, treatment planning, and research. The chart is simple and easy to use, has face and content validity and good reliability.
