Effect of Genioplasty on the Pharyngeal Airway Space Following Maxillomandibular Advancement Surgery

Abstract

Purpose: To evaluate the effect of genioplasty on the size of the pharyngeal airway space (PAS) in a sample of patients without obstructive sleep apnea syndrome (OSAS) undergoing maxillomandibular advancement (MMA) surgery.

Materials and methods: Lateral cephalometric radiographs of 52 patients who underwent orthognathic surgery for MMA were obtained before (T1) and after (T2) surgery. The radiographs were digitized and the anteroposterior dimensions of the PAS were measured at the nasopharynx, oropharynx, and hypopharynx levels. The sample was divided into 2 groups: MMA with genioplasty (n = 27; average age, 30.81 yr) and without genioplasty (n = 25; average age, 37.64 yr). Comparisons were made between T1 and T2 in patients with and without genioplasty. Horizontal and vertical changes of the maxilla, mandible, and chin were correlated to changes in the PAS.

Results: MMA resulted in an increased anteroposterior PAS at the 3 levels analyzed (P < .05), except in the hypopharynx, in cases without genioplasty (P = .141). When the groups with and without genioplasty were compared, there were no significant differences (P > .05) in the PAS. There was a statistically relevant correlation between horizontal mandibular change and the oropharynx (r = 0.484 and r = 0.509, respectively) and between vertical chin change and the hypopharynx (r = 0.434 and r = 0.455, respectively) for groups with and without genioplasty. There was a statistically relevant correlation between horizontal chin change and the hypopharynx (r = 0.586) for surgeries without genioplasty.

Conclusion: Considering the limitations inherent to retrospective study designs, the results suggested that MMA surgery, with and without advancement genioplasty, can promote immediate gains to the PAS. A larger gain was possible in the hypopharynx for MMA with genioplasty. MMA without genioplasty could represent a greater gain in the nasopharynx and oropharynx. Further studies should evaluate functional parameters in patients with OSAS to measure the possible benefits of this increase in the PAS.