Does Bilateral Gap Arthroplasty Increase the Severity of Obstructive Sleep Apnea in Patients With Temporomandibular Joint Ankylosis?

Abstract

Obstructive sleep apnea (OSA) is common in patients with bilateral temporomandibular joint ankylosis (TMJA). The purpose of this study was to compare the preoperative and postoperative apnea-hypopnea index (AHI) in patients with TMJA undergoing bilateral gap arthroplasty (BGA). The investigators implemented a prospective cohort study on patients with bilateral TMJA treated with BGA. The primary predictor variable was time (before and after BGA). The primary outcome variable was AHI and secondary outcome variable included posterior airway space, skeletal changes, Epworth sleepiness scale, minimum oxygen, average oxygen saturation, and maximal incisal opening at preoperative time (T0), 1 month (T1), and at 6 months (T2). The statistical test used were Greenhouse-Geisser test, repeated measure ANOVA (1 way), followed by post hoc Bonferroni test. The P-value was taken significant when <0.05 at a confidence interval of 95%. The study sample included 12 (m:f=1:2) patients of bilateral TMJA with a mean age of 14.9±4.8years and mean follow-up of 6 months. Mean duration of ankylosis was 10.5±6.9years (median=12). Trauma was the main etiological factor in 11 (91.7%) patients followed by infection in 1 (8.3%) patient. The mean increase in AHI was 8.6 (T0 to T1) with P-value=.002 and 23.4 (T1 to T2) and was statistically significant (P=.001). The mean decrease in posterior airway space was 4.5±1.0 to 3.5±0.5 (T0 to T2) and was statistically significant (P=.02). Mean difference in minimum oxygen was 6.8 (P-value=.015). Skeletal changes are consistent with clockwise rotation of the mandible and statistically significant changes in horizontal and vertical dimension. The mean change in average oxygen was statistically insignificant (P=1.0). The present study concludes that gap arthroplasty in patients with bilateral TMJA can lead to development or worsening of pre-existing mild to moderate OSA. Ramus-condyle reconstruction should be performed to prevent the retropositioning of mandible and worsening of OSA.