Validation of a fully automatic three-dimensional assessment of orthognathic surgery.

The aim of the present study was to propose and validate FAST3D: a fully automatic three-dimensional (3D) assessment of the surgical accuracy and the long-term skeletal stability of orthognathic surgery. To validate FAST3D, the agreement between FAST3D and a validated state-of-the-art semi-automatic method was calculated by intra-class correlation coefficients (ICC) at a 95 % confidence interval. A one-sided hypothesis test was performed to evaluate whether the absolute discrepancy between the measurements produced by the two methods was statistically significantly below a clinically relevant error margin of 0.5 mm. Ten subjects (six male, four female; mean age 24.4 years), class II and III, who underwent a combined three-piece Le Fort I osteotomy, bilateral sagittal split osteotomy and genioplasty, were included in the validation study. The agreement between the two methods was excellent for all measurements, ICC range (0.85-1.00), and fair for the rotational stability of the chin, ICC = 0.54. The absolute discrepancy for all measurements was statistically significantly lower than the clinical relevant error margin (p < 0.008). Within the limitations of the present validation study, FAST3D demonstrated to be reliable and may be adopted whenever appropriate in order to reduce the work load of the medical staff.

Assessment of soft-tissue vs hard-tissue changes after isolated functional genioplasty / Évaluation des modifications des tissus mous par rapport aux tissus durs après une génioplastie fonctionnelle isolée

Introduction: This study aimed to determine the vertical and horizontal soft-tissue vs hard-tissue changes after isolated functional genioplasty and to revisit hard-tissue remodeling at the symphysis. Methods: Seventy-five patients who underwent genioplasty as an isolated procedure at the end of their orthodontic treatment were divided into three groups on the basis of their age at surgery: < 15 years (group 1), 15-18 years (group 2) and ≥ 19 years (group 3). Patients were evaluated at three time points: immediately before surgery (T1), immediately after surgery (T2) and two years after surgery (T3). In addition, 25 patients who did not accept genioplasty, were age-matched with group 1, and had a follow-up radiograph two years after the end of their orthodontic treatment were used as a control group. Results: From T2 to T3, group 1 showed less forward horizontal hard-tissue and soft-tissue changes at pogonion (Pg) than the control group; however, no difference was noted for vertical changes at Me & Me'. From T1 to T3, the horizontal hard-tissue and soft-tissue changes at Pg were 6.39 mm and 6.72 mm, respectively, for surgical groups. Vertical hard-tissue change at menton (Me) showed a reduction of 1.63 mm (95% confidence interval [CI], -3.37 to 0.11) and 3.89 mm (95% CI, -5.83 to -1.95) in nongrowing female and male patients, respectively. The vertical soft-tissue change reduction was similar for nongrowing male and female patients (1.7 mm [95% CI, -2.96 to -0.45]). Soft-tissue thickness change at Pg (0.33 mm) was not significant. In contrast, a small but significant increase in soft-tissue thickness was noted at Me (0.54 mm). Linear regressions were calculated for all groups and allowed for predicting long-term soft-tissue changes (T3-T1) using the amount of surgical displacement (T2-T1). Conclusions: The horizontal hard-tissue change was stable for nongrowing patients, and the horizontal soft-tissue change was 92% of hard-tissue. Vertical soft-tissue change is less predictable. Variation of soft-tissue thickness after genioplasty can be explained by skeletal changes and the achievement of an unforced labial occlusion. These results support the functional and esthetic benefits of this surgery. Comparison with the control group showed that genioplasty does not change the growth pattern, and bone remodeling is likely to explain the difference noted at Pg.

Introduction: Cette étude avait pour but de déterminer les modifications verticales et horizontales des tissus cutanés par rapport aux tissus osseux après une génioplastie fonctionnelle isolée et d'évaluer le remodelage des tissus osseux au niveau de la symphyse. Méthodes: Soixante-quinze patients qui ont subi une génioplastie comme procédure isolée à la fin de leur traitement orthodontique ont été divisés en trois groupes sur la base de leur âge au moment de la chirurgie : moins de 15 ans (groupe 1), de 15 à 18 ans (groupe 2) et de 19 ans et plus (groupe 3). Les patients ont été évalués à trois moments : immédiatement avant la chirurgie (T1), immédiatement après la chirurgie (T2) et deux ans après la chirurgie (T3). En outre, 25 patients qui n'ont pas accepté la génioplastie, dont l'âge correspondait à celui du groupe 1 et qui ont subi une téléradiographie de profil de contrôle deux ans après la fin de leur traitement orthodontique ont été utilisés comme groupe témoin. Résultats: De T2 à T3, le groupe 1 a montré moins de changements horizontaux des tissus durs et mous vers l'avant au niveau du pogonion (Pg) que le groupe témoin ; cependant, aucune différence n'a été notée pour les changements verticaux au niveau de Me & Me'. De T1 à T3, les changements horizontaux des tissus osseux et cutanés à Pg étaient respectivement de 6,39 mm et 6,72 mm pour les groupes chirurgicaux. La modification verticale des tissus osseux au niveau du menton (Me) a montré une réduction de 1,63 mm (IC 95 %, -3,37 à 0,11) et de 3,89 mm (IC95 %, -5,83 à -1,95) chez les patients féminins et masculins sans croissance, respectivement. La réduction verticale de la modification des tissus mous était similaire chez les patients homme et femme qui ne sont pas en croissance (1,7 mm [IC 95 %, -2,96 à -0,45]). La modification de l'épaisseur des tissus mous à Pg (0,33 mm) n'était pas significative. En revanche, une augmentation faible mais significative de l'épaisseur des tissus cutanés a été observée à Me (0,54 mm). Des régressions linéaires ont été calculées pour tous les groupes et permettent de prédire les changements à long terme des tissus cutanés (T3-T1) en utilisant la quantité de déplacement chirurgical (T2-T1). Conclusions: Le changement horizontal des tissus osseux est stable pour les patients qui ne grandissent pas et le changement horizontal des tissus mous représente 92 % des tissus durs. Le changement vertical des tissus cutanés est moins prévisible. La variation de l'épaisseur des tissus cutanés après une génioplastie peut s'expliquer par les changements squelettiques et l'obtention d'une occlusion labiale non forcée. Ces résultats confirment les avantages fonctionnels et esthétiques de cette chirurgie. La comparaison avec le groupe témoin a montré que la génioplastie ne modifie pas le schéma de croissance et le remodelage osseux est susceptible d'expliquer la différence constatée à Pg.

Assessment of soft-tissue vs hard-tissue changes after isolated functional genioplasty.

INTRODUCTION: This study aimed to determine the vertical and horizontal soft-tissue vs hard-tissue changes after isolated functional genioplasty and to revisit hard-tissue remodeling at the symphysis. METHODS: Seventy-five patients who underwent genioplasty as an isolated procedure at the end of their orthodontic treatment were divided into 3 groups on the basis of their age at surgery: <15 years (group 1), 15-18 years (group 2), and ≥19 years (group 3). Patients were evaluated at 3 time points: immediately before surgery (T1), immediately after surgery (T2), and 2 years after surgery (T3). In addition, 25 patients who did not accept genioplasty, were age-matched with group 1, and had a follow-up radiograph 2 years after the end of their orthodontic treatment were used as a control group. RESULTS: From T2 to T3, group 1 showed less forward horizontal hard-tissue and soft-tissue changes at pogonion (Pg) than the control group; however, no difference was noted for vertical changes at Me & Me'. From T1 to T3, the horizontal hard-tissue and soft-tissue changes at Pg were 6.39 mm and 6.72 mm, respectively, for surgical groups. Vertical hard-tissue change at menton (Me) showed a reduction of 1.63 mm (95% confidence interval [CI], -3.37 to 0.11) and 3.89 mm (95% CI, -5.83 to -1.95) in nongrowing female and male patients, respectively. The vertical soft-tissue change reduction was similar for nongrowing male and female patients (1.7 mm [95% CI, -2.96 to -0.45]). Soft-tissue thickness change at Pg (0.33 mm) was not significant. In contrast, a small but significant increase in soft-tissue thickness was noted at Me (0.54 mm). Linear regressions were calculated for all groups and allowed for predicting long-term soft-tissue changes (T3-T1) using the amount of surgical displacement (T2-T1). CONCLUSIONS: The horizontal hard-tissue change was stable for nongrowing patients, and the horizontal soft-tissue change was 92% of hard-tissue. Vertical soft-tissue change is less predictable. Variation of soft-tissue thickness after genioplasty can be explained by skeletal changes and the achievement of an unforced labial occlusion. These results support the functional and esthetic benefits of this surgery. Comparison with the control group showed that genioplasty does not change the growth pattern, and bone remodeling is likely to explain the difference noted at Pg.

Effects of Hat-Shaped Mortised Genioplasty with Genioglossus Muscle Advancement on Retrogenia and Snoring: Assessment of Esthetic, Functional, and Psychosocial Results.

BACKGROUND: An increasing number of patients undergo genioplasty for esthetic purposes to correct micrognathism or retrognathism. However, these conditions are considered an important risk factor for snoring. The purpose of this study was to evaluate both esthetic improvement and functional changes of snoring symptoms in patients who underwent hat-shaped mortised advancing genioplasty with genioglossus muscle advancement. MATERIALS AND METHODS: This retrospective study enrolled 25 patients. We evaluated scores for subjective snoring classification (Stanford scale) and questionnaire findings for esthetic results. RESULTS: Most people (96%) were satisfied with the esthetic improvement after surgery. The grade of subjective snoring classification (Stanford scale) improved from 8.68 (range 0-10) to 4.08 (range 0-10) after surgery. Twenty-four patients had an improved snoring grade. All patients reported a positive impact on their daily activity and self-confidence, and they were willing to recommend the same operation to someone with the same clinical problems. CONCLUSION: We conclude that hat-shaped mortised advancing genioplasty with genioglossus muscle advancement can relieve the symptoms of snoring for patients with hypoplastic chin or retrogenia. Patients were satisfied with the functional and esthetic results. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Strategies of Mandibular Revision: A Retrospective Study of Revisional Mandibular Surgery for Unaesthetic Results of Previous Mandibular Reduction.

BACKGROUND: Mandibular reduction has been developed and popularized in Asia for decades. Despite the technical advancement and experience accumulation, complications and unaesthetic results still occur, and some need a revision surgery. This study aims to introduce the experience of revision surgery to reshape the unaesthetic mandibular contour after previous mandibular reduction. METHODS: From May 2011 to September 2017, patients dissatisfied with the result of previous mandibular reduction and who received a secondary mandibular revision were retrospectively reviewed and analyzed. RESULTS: Twenty-five patients were included in this study. Under-correction (88%, 22/25) was the most common aesthetic problem requiring revision, followed by asymmetry (56%, 14/25), broad chin (40%, 10/25), second mandibular angle (32%, 8/25), and over-correction (8%, 2/25). As revision techniques, long-curve mandibular reduction, simple mandibular reduction, and mandibular grinding were performed on 60% (15/25), 36% (9/25), and 4% (1/25) of the patients, respectively. All the patients were satisfied with the results. Cephalometric measurements indicated a significant bone removal after revision. CONCLUSIONS: When performing a revision surgery to reshape the mandibular contour, the surgeon should have a clear surgical plan based on comprehensive evaluation, focus on the balanced harmony of the entire face, use proper technique and instruments, and avoid concomitant injury and complications. The one-staged technique that treats the whole mandible as an entirety is superior than multistaged techniques to improve the aesthetic outcomes to the largest extent. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Combined surgical-orthodontic treatment: how did it evolve and what are the best practices now?

It has been 50 years since the landmark presentation by Hugo Obwegeser at Walter Reed Army Hospital. At that conference, Professor Obwegeser offered American surgeons techniques to correct facial skeletal deformities with access through intraoral incisions. As important advances in surgical technique and anesthesia evolved for the surgical procedures, a major contribution by American orthodontists in collaboration with surgeons was the creation of a common diagnostic, planning, and treatment scheme for use by both clinician groups in the treatment of dentofacial deformities, the skeletal and dental problems of the most severely affected 5% of the population. This article summarizes what American orthodontists and surgeons have learned in the late 20th and early 21st centuries, and forecasts what might be the future of treatment for patients with dentofacial deformities.

Assessment of skeletal stability after counterclockwise rotation of the maxillomandibular complex in patients with long-face pattern subjected to orthognathic surgery.

BACKGROUND: The aim of this study was to evaluate the long-term skeletal stability of counterclockwise maxillomandibular complex rotation in patients undergoing orthognathic surgery for long-face pattern. METHODS: This retrospective study consisted of 10 patients who underwent the procedure between September 2002 and April 2008. To assess the skeletal stability, 30 preoperative (T1), recent postoperative (T2), and late postoperative (T3) cephalometric radiographs of the 10 patients were digitized and traced. To measure the stability in the occlusal plane and mandibular plane, the cephalometric points and planes were determined 3 times. RESULTS: In the long term, on average, the A-point moved 0.21 mm backward (AYT3-AYT2), the B-point moved 0.57 mm backward (BYT3-BYT2), and the posterior nasal spine moved 0.31 mm backward (PNSYT3-PNSYT2). On average, the anterior maxillary area (A-point) moved 0.14 mm downward (AXT3-AXT2), the mandible (B-point) moved 0.07 mm downward (BXT3-BXT2), and the posterior nasal spine moved approximately 0.18 mm upward (PNSXT3-PNSXT2). The occlusal plane increased by 0.75 degrees (OPT3-OPT2), and the mandibular plane increased by 0.45 degrees (MPT3-MPT2). CONCLUSIONS: It was observed that the counterclockwise rotation of the maxillomandibular complex produces stable results in patients with long-face pattern undergoing orthognathic surgery.

Angloplasty revision: importance of genioplasty for narrowing of the lower face.

BACKGROUND: Angloplasty is the most common procedure in facial contouring surgery among Asians. However, to achieve satisfactory results during procedures aimed at altering the lower facial contour, the shape of the mandible and the chin area in particular is an important consideration. In cases of reoperation for further improvement after angloplasty, surgeons should consider performing a genioplasty to improve the shape of the chin. METHODS: From March of 2010 to August of 2012, 52 women who were dissatisfied with results of angloplasty and wanted a slimmer lower face underwent genioplasty and revision angloplasty. The procedures included narrowing genioplasty and contouring of the lower border of the mandible from the parasymphysis area to the previously resected area. RESULTS: All patients were satisfied with their facial appearance, which had become slender when viewed from the front. There were no notable complications. No patient experienced permanent sensory numbness of the lower lip. Two patients complained of submental bulges and were treated postoperatively using laser-assisted liposuction. CONCLUSION: When performing revision surgery to restore the contour of the mandible, the surgeon should consider the shape of the mandible as a whole to create a slender face, which is achievable by simultaneous narrowing genioplasty and contouring of the lower border of the mandible. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.