Evaluation of pharyngeal airway volume, soft-tissue changes, and risk of obstructive sleep apnea after bimaxillary orthognathic surgery in patients with skeletal Class III malocclusion using cone-beam computed tomography and the STOP-BANG questionnaire: A long-term study.

INTRODUCTION

Bimaxillary surgery is increasingly used for Class III malocclusion, but concerns about potential airway narrowing and its role in obstructive sleep apnea (OSA) remain. This study aimed to evaluate the long-term effects of bimaxillary surgery on the upper airway and soft tissues and the risk of OSA development in patients with skeletal Class III malocclusion using cone-beam computed tomography (CBCT) and the STOP-BANG (snoring, tiredness, observed apnea, high blood pressure, body mass index, age, neck circumference, and gender) questionnaire.

METHODS

In this retrospective descriptive-analytical study, 50 female patients with Class III malocclusion were treated with LeFort I advancement and bilateral sagittal split osteotomy. They all scored 0-2 on the STOP-BANG questionnaire. CBCTs were performed preoperatively and 5 years postoperatively with standardized head and neck positioning. They filled out the questionnaire in the follow-up. Confounding factors were minimized as much as possible. CBCTs were evaluated using OnDemand 3D software (version 10.0.1; Cybermed, Seoul, South Korea). Data were analyzed using an independent-samples t test, Pearson correlation, and chi-square test.

RESULTS

In the long-term, bimaxillary surgery statistically significantly increased the nasopharyngeal volume by 14.06% (P = 0.015) and decreased hypopharyngeal and upper airway volumes by 20.13% (P <0.001) and 7.71% (P = 0.015), respectively. Although there was a decrease in the oropharynx and the position of the soft palate, the changes were not statistically significant. The tongue moved backward (P = 0.005). No significant differences in STOP-BANG scores were observed (P >0.05).

CONCLUSIONS

Although bimaxillary surgery with the studied method significantly alters airway volume parameters, it may not increase the risk of OSA in healthy individuals. Our results can aid orthodontists and surgeons in selecting the proper treatment plans.