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BackgroundMandibular Sagittal Split Osteotomy (MSSO) is a popular technique in orthognathic surgery used both to advance and to retreat the mandible. However, MSSO may incur in important complications, such as bad splits and sensorineural injuries. Knowing the location of the fusion between the buccal and lingual cortical (FBLC) in the mandibular ramus and the bone thickness in the region where osteotomies will be performed is determinant in MSSO planning to avoid complications. The aim of this study was to document and evaluate possible differences between sexes regarding the location of the FBLC in relation to the superior cortical of mandibular foramen (MF) and bone thickness in the region of interest for MSSO in a Brazilian population.Material and MethodsEighty five cone-beam Computed Tomography (CBCT) scans were used to perform linear measurements to determine the location of the FBLC. Bone thickness from the mandibular canal (MC) to the cortical external surfaces and the diameter of the MC were measured at three different points: mandibular ramus (A), mandibular angle (B) and mesial of the second molar (C).ResultsThe FBLC was located at a mean distance of 8.3 mm from the superior cortical of the MF in males and 8.1 mm in females. There was no difference between males and females regarding the mean bone thickness from the MC to the buccal external surface at all the points investigated (p >>0.05). Bone thickness from the lingual external surface to the MC was bigger among females than males in regions B and C (p<0.05). The diameter of the MC was bigger among males in regions B and C.ConclusionsSexual dimorphism regarding mandibular bone thickness but not regarding the location of FBLC was present. This fundamental knowledge may assist to the panning of MSSO. Key words:Cone-Beam Computed Tomography, mandibular nerve, orthognathic surgery, sagittal split ramus osteotomy.

Aim To report the surgical management of bilateral mandibular coronoid processes hyperplasia and mandibular retrognathism associated with trismus and convex facial profile in an individual diagnosed with Nager syndrome (NS). Case report A 21 years old female was referred to the Department of Oral and Maxillofacial Surgery, presenting limited mouth opening and an unpleasant convex facial profile. The tomography exhibited hyperplasia of mandibular coronoid processes with no evidence of intracapsular ankylosis of the temporomandibular joint. The treatment objectives were to increase mouth opening through a bilateral coronoidectomy and gain chin projection using the double‐step advancement genioplasty technique. The 9‐month postoperative follow‐up revealed a 22.22% (6 mm) gain in jaw opening, improved masticatory function, and facial profile. Conclusions The NS is a complex craniofacial anomaly due to its clinical heterogeneity. Thus, treatment planning must be done individually, considering the patients' main complaints and respecting the limitations regarding anatomy and availability of proper surgical materials. In the present case, a bilateral coronoidectomy associated with immediate physiotherapy improved the patient's mouth opening, and the double‐step genioplasty promoted a much more significant chin advancement than would be obtained with the single‐step traditional osteotomy.

Objective To investigate the subjective risk for obstructive sleep apnea (OSA) in adolescents and young adults with isolated Robin sequence (IRS). Additionally, to investigate the association of OSA risk with respiratory signs/symptoms, and retrognathia. Design Prospective, observational, and cross-sectional study. Setting Tertiary reference hospital for the rehabilitation of craniofacial anomalies. Participants Adolescents and adults (n = 30) with IRS were clinically evaluated and screened through the Berlin Questionnaire (BQ) and Respiratory Symptoms Questionnaire. The maxillomandibular relationship was assessed on lateral cephalograms of those that reached skeletal maturity (n = 13). Polysomnography (PSG) was performed in a subgroup of 4 individuals. Results The mean age of the sample was 18.2 (±3.4) years, 17 (56.7%) were adolescents (14-19 years), and 16 were (53.3%) female, all presented a repaired cleft palate. Clinical Parameters Systemic arterial pressure (118.0 ± 4.1/76.3 ± 4.9 mmHg), body mass index (BMI) (20.9 ± 2.8 kg/m2), neck (33.2 ± 2.3 cm), and waist circumferences (72.0 ± 5.8 cm) were within normal ranges. A skeletal class I pattern was observed in 61.5% of the participants while a class II was seen in 15.4% of them. A high risk for OSA was detected in 16.7%, and it was associated with nasal obstruction, snoring and drowsiness, and a skeletal class II pattern ( P ≤ .05). One patient presented with mild OSA (apnea–hypopnea index [AHI] = 10.1 events/hour) at the PSG exam. Conclusions A high risk for OSA can be observed with a moderate frequency among adolescents and young adults with IRS, especially among those who are concurrently suffering from nasal obstruction, snoring and retrognathia.

This study aimed to evaluate the effects of the Nasal Alar Bases suture (N.A.B.S.) and V-Y lip suture (V-Y.L.S.) in the maintenance of the distance between the nasal alar bases (N.A.B.) and the red lips display (R.L.D.) in patients operated for correction of crossbite with maxillary atresia. We evaluated 9 patients, 4 who received the above mentioned sutures, and 5 who received simple sutures. It was evaluated the measures N.A.B. and R.L.D. in the preoperative phase, postoperative, and after 7 and 450 days. Measurements of N.A.B. were stable throughout the experimental period in N.A.B.S. and V-Y.L.S. group, while the group receiving simple sutures there was an increase of this measure in the postoperative period and a decrease after 450 days. The N.A.B.S. and V-Y.L.S. group showed a significant increase in R.L.D. in immediate postoperative period, reducing slightly after 7 days, and presenting a significant loss in the final assessment, showing an even lower value than the mean preoperative. N.A.B.S. was effective in the short and medium term in controlling unwanted nasal enlargement in patients undergoing E.M.C.A. In the immediate postoperative period, there is an increased R.L.D., but long-term reduction of the R.L.D. occurs in all E.M.C.A. patients, regardless of the type of suture used.