Is maxillary dental arch constriction common in Japanese male adult patients with obstructive sleep apnoea?

OBJECTIVES Little is known about the contributions of a narrow maxillary dental arch and maxillary skeletal constriction to the development of obstructive sleep apnoea (OSA). Therefore, the purpose of this study was to clarify the relationships between maxillary dental arch width and OSA and between maxillary skeletal constriction and OSA in Japanese male patients.METHODS Study models for 164 Japanese male OSA patients were fabricated for dental arch analyses. We compared the patients' dental arch widths with the standard value for Japanese males. Moreover, the associations between the upper dental arch width and the apnoea-hypopnoea index (AHI), body mass index, skeletal pattern (SNA, SNB, and ANB), cross-sectional area of tongue obtained from an upright lateral cephalogram, lower dental arch width, overjet, and overbite were also examined.RESULTS Although a narrower upper dental arch was associated with severer OSA, the upper dental arch in OSA patients was not significantly narrower than the Japanese standard value. However, the results of a multiple regression analysis revealed that the upper dental arch became narrower as the mandible was positioned more rearward relative to the maxilla.CONCLUSIONS We conclude that dental arch constriction in the maxilla could be associated with the development of OSA but is not a typical feature of our sample of Japanese OSA patients. Moreover, the factor that aggravates OSA is not maxillary skeletal constriction but rather maxillary dental arch constriction related to antero-posterior skeletal discrepancy.