title: Relationship of the hyoid bone and posterior surface of the tongue in prognathism and micrognathia.
abstract: In order to study relationship of the hyoid bone and posterior surface of the tongue in prognathism and micrognathia, we focused on the effect of the tongue on the upper airway lumen in 16 patients with Angle's Class II and 51 patients with Angle's Class III, and assessed the position of the hyoid, the depth from the posterior surface of the tongue, from the bottom of the vallecula and from hyoid bone to the posterior pharyngeal wall using lateral cephalograms. We were able to assess significant correlations between the posterior surface of the tongue and hyoid position in Angle's Class III. However, we found no association between them in Angle's Class II. This could be an adaptive feature of the genioglossus in response to hyoid localization to serve a compensatory role to prevent respiratory impairment in micrognathia at risk of apnoea.
authors.affiliation: Departments of Oral and Maxillofacial Surgery and Orthodontics, Matsumoto Dental University School of Dentistry, Nagano, Japan. yamaoka@po.mdu.a.jp
authors.forename: M
authors.initials: M
authors.lastname: Yamaoka
authors.forename: K
authors.initials: K
authors.lastname: Furusawa
authors.forename: T
authors.initials: T
authors.lastname: Uematsu
authors.forename: N
authors.initials: N
authors.lastname: Okafuji
authors.forename: D
authors.initials: D
authors.lastname: Kayamoto
authors.forename: S
authors.initials: S
authors.lastname: Kurihara
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D006928:Hyoid Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008297:Male; D008312:Malocclusion, Angle Class II / Q000000981:diagnostic imaging; D008313:Malocclusion, Angle Class III / Q000000981:diagnostic imaging; D008334:Mandible / Q000033:anatomy & histology; D008844:Micrognathism / Q000150:complications / Q000000981:diagnostic imaging; D011378:Prognathism / Q000150:complications / Q000000981:diagnostic imaging*; D011859:Radiography; D014059:Tongue / Q000033:anatomy & histology*