Does Dental Arch Size Affect Obstructive Sleep Apnea?

Introduction:An excessive constricted maxillary dentition as observed in patients with congenital anomaly including Marfan's syndrome and Treacher Collins syndrome is considered to be related to the pathogenesis of Obstructive Sleep Apnea (OSA). Even in individuals without such anomalies, however, a narrowed upper dental arch appears to increase the vulnerability of OSA since dental arch narrowing decreases the tongue space, leading to upper airway constriction. Accordingly, we hypothesized that dental arch size is involved in the development of OSA.

Methods:The study protocol was approved by the ethics committee of the Neuropsychiatric Research Institute, Tokyo, Japan. Patients with dental prostheses and/or missing teeth at the target teeth for dental arch measurement were excluded. A total of 169 Japanese male OSA patients agreed to participate in the study and subsequently provided written informed consent. The study models for each patient were fabricated for analyses. With the use of multiple logistic regression analysis, we investigated the association between moderate OSA (Apnea Hypopnea Index >15/hour) and the patients' characteristics including age, Body Mass Index (BMI), the ratio of upper and lower dental arch width (i.e., upper dental arch width/lower dental arch width), overjet, and overbite.

Results:The ratio of upper and lower dental arch width (OR=0.008, 95%CI=0.000-0.967, p<0.05) and age (OR=1.052, 95%CI=1.017-1.089, p<0.01) were found to be statistically significant risk factors of OSA.

Conclusion:The more constricted upper dental arch in relation to lower dentition would increase OSA development. These findings may partially explain why orthodontic expansion of maxillary dentition is often effective as a fundamental treatment of OSA.

This work was supported by Grant-in-Aid for Young Scientists (B) 21792107 from The Ministry of Education, Culture, Sports, Science and Technology and by Grant-in-Aid for Scientific Research (B) 21406033 from Japan Society for the Promotion of Sciences.