Abstract
Objectives: Maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) is considered
the useful treatment; however, its wide effectiveness is unclear. Thus, this study aimed to explore
factors affecting the efficacy of MMA for OSA using a 3-D morphological and computed fluid
dynamics (CFD) analysis of the upper airway (UA).
Design: Retrospective study
Settings and participants: Twenty consecutive patients (six women, mean age 34.2 ± 12.4 years)
who underwent MMA because of persistent OSA at our center.
Main outcome measures: Cone-beam computed tomography images were captured before and after
MMA. We assessed the maxilla and mandibular positions, cross-sectional areas of the nasal airway
(NA) and pharyngeal airway (PA), and PA space (PAS). The negative pressure of the PA, NA, and UA
were measured at inspiration using CFD. We performed paired t-tests and Wilcoxon signed-rank test
to compare values before and after MMA. The relationship between the airway size and pressure was
evaluated using Spearman correlation coefficients and a non-linear regression analysis.
Results: PAS significantly expanded from 6.5 ± 3.4 mm to 12.2 ± 3.8 mm. NA obstruction
significantly improved from -312.6 ± 265.0 Pa to -76.2 ± 129.0 Pa. Moreover, the patients were
divided into four types according to the PAS size and presence of NA obstruction, namely narrow PAS
with NA obstruction, narrow PAS, NA obstruction, and wide PAS and without NA obstruction.
Conclusions: We identified variations in the OSA types. However, MMA substantially improved
NA obstruction and PA expansion. Thus, we considered that MMA for OSA was effective for various
types.
