Prevalence and risk factors of silent obstructive sleep apnea in patients with dentofacial deformities

Abstract Objective Prevalence of silent obstructive sleep apnea (OSA) in patients with dentofacial deformities is unknown, although OSA is severe risk of airway obstruction in perioperative orthognathic surgery or complication after surgery. The aim of this study was to investigate prevalence and risk factors of silent OSA in patients with dentofacial deformities. Methods We analyzed 72 patients (24 male, 48 female) with dentofacial deformities without previous OSA symptoms. Polysomnography was performed before orthognathic surgery. Prevalence and risk factors of silent OSA were statistically analyzed as related to Apnea hypopnea index (AHI). Results Mean AHI was 1.6 (range: 0-12.1) /h. Three patients of 72 patients (4.1%) were diagnosed silent OSA. AHI during REM sleep phase 3.7 (0-32.3) was higher than AHI during NREM sleep phase 1.0 (0-9.7). AHI of male patients was higher than that of female. AHI was increased according to high BMI. AHI was higher in deep bite than open bite, edge to edge bite and nomal bite. AHI of mandibular asymmetry cases were higher than that of symmetry cases. Conclusions The prevalence of silent OSA was 4.1%. Obesity, male, deep bite, mandibular asymmetry and REM sleep phase were risk factors of silent OSA.