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Objective: To explore the decision-making patterns among expert and novice orthodontists and oral maxillofacial surgeons in the management of adults with Class III malocclusions and moderate skeletal discrepancies., Design: Self-administered questionnaire survey., Setting: Faculty of Dentistry, National University of Singapore and the University Dental Cluster, National University Hospital, Singapore., Participants: A total of 55 clinicians, comprising 13 expert orthodontists, 20 novice orthodontists, 10 expert oral maxillofacial surgeons and 12 novice oral maxillofacial surgeons., Methods: Clinicians assessed six adults with a Class III malocclusion and moderate skeletal discrepancy. They were asked to decide who could be managed exclusively by orthodontic camouflage, who would require combined orthodontic-orthognathic surgery as the only viable treatment, or who could be offered both treatment options., Results: The study found variable decision-making patterns among the clinicians in each case. Only 18.2%-40.0% of clinicians agreed that the cases selected were of moderate skeletal discrepancies and could be offered both treatment options whereas the rest were either more inclined to recommend orthodontic camouflage or orthognathic surgery. Intra-clinician agreement (n = 20) was only fair (Kappa value = 0.31). There was only slight inter-clinician agreement (n = 55) on their clinical decisions (Kappa value = 0.10). Clinical experience and dental specialty did not significantly influence clinicians' decisions. Oral and maxillofacial surgeons were 1.98 times more likely to indicate orthognathic surgery as the only viable treatment compared to the orthodontists (95% confidence interval = 1.15-3.42)., Conclusion: Variability in the patterns of decision-making for adults with a Class III malocclusion and moderate skeletal discrepancy was observed among the clinicians with low repeatability and agreement., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

With the advancement of digital technology over the last few decades, the use of virtual surgical planning and fabrication of surgical guides have tremendously improved the outcomes of various maxillofacial surgical procedures. The intraoral vertical ramus osteotomy (IVRO) is an orthognathic surgical procedure largely employed for mandibular setback in correcting dentofacial deformities. This study describes the design and application of a surgical cutting guide for IVRO. The guide can also be used to facilitate the placement of miniplate fixation. The initial experience at the authors' centre suggests that the guide has allowed the osteotomy to be performed with increased precision and confidence. Furthermore, the use of miniplate fixation decreased the period of maxillomandibular fixation. However, a larger series is required to evaluate the utility of this system more thoroughly., (Copyright © 2022 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Bimaxillary protrusion is a dentofacial deformity common in the East Asian population. It is often difficult to decide between orthodontic and surgical retraction to treat patients with bimaxillary protrusion, especially if surgery to correct skeletal base discrepancies is also required. The objective of this study was to investigate the treatment outcomes of surgical versus orthodontic retraction in patients with bimaxillary protrusion undergoing orthognathic surgery. A retrospective cohort study was conducted, where the medical records and radiographs of 51 patients with bimaxillary protrusion who had an anterior segmental osteotomy concomitant with orthognathic surgery were examined. Patients who had bimaxillary anterior segmental osteotomies were more likely to achieve an inter-incisal angle of 135 ± 5° at the end of treatment, when compared to patients who had orthodontic retraction (P < 0.01). The total treatment duration of patients who had bimaxillary anterior segmental osteotomies was significantly shorter as compared to that of the patients who only had these osteotomies in the maxilla (P < 0.001) or mandible (P = 0.012). Complications and permanent long-term sequelae following anterior segmental osteotomies were uncommon. It is concluded that bimaxillary anterior segmental osteotomies are a viable alternative for patients with concomitant bimaxillary protrusion and skeletal base discrepancies. This allows for a significantly shorter treatment time and greater correction of inter-incisal angles, without a significant increase in complications., (Copyright © 2022 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: The asymmetric mandible presents the clinician with unique anatomic challenges in orthognathic surgery correction. This study aims to investigate these characteristics of the asymmetric mandible: mandible bone thickness, soft tissue thickness, and the proximity of the bone cortex to the inferior alveolar nerve (IAN) canal., Study Design: Three-dimensional virtual models were created of 35 participants of Asian descent with mandibular asymmetry. Mandibular bone thicknesses and soft tissue thicknesses were measured at certain landmarks. Statistical analysis of the thicknesses of both sides of the mandible was performed. Comparison of thicknesses between patients with minor and major asymmetry were also performed., Results: The bone was significantly thinner at the longer side at all 4 mandible landmarks (P < .001). The bone lateral to the IAN was significantly thinner at the longer side, as well (P < .001). The soft tissue thickness did not differ significantly across sides, except at 1 landmark. These findings were even more exaggerated in the major asymmetry group., Conclusions: The longer side of the asymmetric mandible bone was thinner, and the bone lateral to the IAN was also thinner as a result. This asymmetric thinness was exaggerated in patients with severe asymmetry, which may predispose the longer side to IAN injury and unfavorable fractures. The differences in bone thickness in the asymmetric mandible may also result in residual postoperative asymmetry., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: A widely used guide of 2 mm incisal show at rest is used as an esthetic guide in treatment planning for many patients. However, this does not consider the lip form at rest. This study aimed to investigate the most esthetic incisal show at rest, at varying lip forms, perceived by dental professionals and laypeople., Methods: Three volunteers of each gender and type of lip form (straight, moderate, and high) were recruited. For each volunteer, 6 images of their perioral region with a variable incisal display at rest were generated. A survey was conducted whereby respondents were asked to grade the attractiveness of each image using a numerical visual analog scale from 0-10., Results: A survey sample of 107 respondents participated in the study (male-to-female ratio = 37 to 70; dental professionals-to-laypeople ratio = 50 to 57). Mann-Whitney U-test was used to analyze the differences in preferences between the various groups (P <0.05). Both dental professionals and laypeople responded that 2 mm incisal show at rest is only suitable for patients with straight lip form. However, for patients with moderate or high lip forms, an incisal show of 4-5 mm was preferred. There was also no significant difference between the perceived ideal incisal show of dental professionals and laypeople, except for the ideal incisal show of models with straight lip form., Conclusions: The guide of 2 mm incisal show at rest is appropriate only for patients with straight lip form. Patients with moderate or high lip form should have a greater incisal show. This finding was agreed on by both dental professionals and laypeople, regardless of their gender., (Copyright © 2022. Published by Elsevier Inc.)

Patients requesting treatment for mandibular prognathism seek functional and aesthetic improvements. Improvements in bite force and efficiency are generally used as measures of better function. It is unclear what effect the surgical correction of mandibular prognathism will have on the patient's occlusal forces. The literature was searched using medical subject heading (MeSH) and key word terms 'bite force', 'osteotomy', 'orthognathic surgery', and 'prognathism'. A total of 17 articles were included in this review. These included a total of 697 patients, who ranged in age from 15 to 44 years. Male patients outnumbered female patients in only one study. Five hundred and thirty-two patients underwent bilateral sagittal split osteotomy, 108 patients underwent intraoral vertical ramus osteotomy, and 24 patients underwent extraoral vertical ramus osteotomy (approach unspecified). In general, masticatory efficiency at 3 months after surgery was greater than that found pre-surgically; the increase was significant at 6 months after surgery. The occlusal contact area and points tended to increase from 3 months after surgery, and there was a significant increase at 12 months after surgery. Occlusal forces, although improved, will be lower in corrected prognathic patients than in normognathic patients even at 2 years after surgery., (Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)