Upper Airway Changes After Mandibular Setback and/or Advancement Genioplasty in Obese Patients.

[PURPOSE] Orthognathic surgeries, such as bilateral sagittal split ramus osteotomy (BSSO) and genioplasty, can influence the pharyngeal airway space (PAS) and this has been supported by previous studies. The purpose of this study was to assess changes of the PAS in patients with a high body mass index (BMI) likely to have narrow airways before and after setback BSSO with or without advancement genioplasty surgery by 3-dimensional computed tomography.

[MATERIALS AND METHODS] Thirty-five adults with a BMI of at least 24.0 kg/m were treated from 2010 to 2016. Samples were grouped mandibular setback (group A; n = 11), advancement genioplasty (group B; n = 12), and mandibular setback plus advancement genioplasty (group C; n = 12). Computed tomograms were obtained 1 week preoperatively (T0), 1 week postoperatively (T1), and at least 1 year postoperatively (T2). The area of the posterior nasal spine and posterior plane (PPA), the soft palate plane (SPA), the plane of the most posterior point of the tongue base (PTA), the plane of the root of the epiglottis (EA), and the volumes of the palatopharyngeal part (VP), oropharyngeal part (VO), glossopharyngeal part (VG), and laryngeal part (VL) were measured and compared within groups using analysis of variance. The P value was set at .05.

[RESULTS] In group A, all results showed statistically significant differences (P < .05) from T0 to T2 except for VO, VG, VL, SPA, PTA, and EA. In group B, VO, VG, VL, SPA, PTA, and EA showed statistically significant increases (P < .05) from T0 to T2. The hyoid at T2 showed significant advancement compared with T0 (P < .05). In group C, there were statistically significant decreases (P < .05) from T0 to T1 for VG, VL, PTA, and EA.

[CONCLUSION] In adults with a high BMI, mandibular setback BSSO could decrease the PAS, whereas advancement genioplasty could enlarge the PAS, after surgery. Therefore, undergoing advancement genioplasty concurrently with mandibular setback BSSO could help in lessening the negative effects of a PAS decrease.