A detailed functional and morphological evaluation of the pharynx, especially its relationship with the mandible, is essential for the surgical orthodontic treatment and diagnosis of sleep apnea syndrome. The present study assessed the correlation between pharyngeal and mandibular morphology in 45 adult Japanese women (average age, 27.9 years). Nine measurements in the pharynx, hyoid bone, and epiglottis were analyzed by conebeam computed tomography (CBCT), and six parameters of mandibular morphology were analyzed using lateral cephalograms. A positive correlation was found between pharyngeal space volume and gonial angle, and between pharyngeal vertical length and the mandibular plane. In addition, the results suggested that both antero-posterior position of the hyoid bone and epiglottis width are related to mandibular size. This study suggested that CBCT is a useful tool for three-dimensional evaluation of the pharynx. The results provide clinically valuable information for the diagnosis and treatment of surgical orthodontics, and enhance our understanding of sleep apnea syndrome.
