RESUMEN
PURPOSE: The purpose of this systematic review was to describe and compare the different approaches of radiologic posterior airway space (PAS) assessment in obstructive sleep apnea (OSA) and analyze the correlations of PAS changes with polysomnographically evaluated parameters after orthognathic surgery. MATERIALS AND METHODS: For this systematic review, a PubMed query was designed to search for original studies radiographically evaluating the PAS in patients before and after orthognathic surgery for treatment of their OSA. To account for the clinical relevance of PAS changes after surgery, only studies providing pre- and postoperative polysomnographic (PSG) data were included. The authors investigated whether the predictor variables (PAS changes) would be correlated with the primary outcome variables (PSG parameters). RESULTS: The final sample included 15 publications in which the PAS was evaluated by lateral cephalography in 8 studies, cone-beam computed tomography in 3, conventional computed tomography in 5, and magnetic resonance imaging in 1. Most linear, areal, and volumetric PAS changes after surgery (predictor variables) were found to be statistically significant. Maxillomandibular advancement (MMA) was the only orthognathic procedure performed in all studies included and was combined with additional surgical procedures in 9 studies. Improvement (ie, decrease) of the apnea-hypopnea index (AHI) as the primary outcome variable was reported in all publications. CONCLUSION: After MMA (with or without additional surgical procedures), most linear, areal, and volumetric PAS parameters showed significant changes. The PAS changes correlated with clinical improvement in PSG parameters. In particular, decreased AHI was reported in all studies. For better inter-study comparability, internationally accepted standards regarding the methods used for PAS evaluation are needed. Moreover, statistical analysis should account for multiple testing when various PAS parameters are evaluated.