title: Retrospective magnetic resonance imaging study of risk factors associated with sideways disk displacement of the temporomandibular joint.
abstract: As part of our ongoing investigation of risk and predictive factors associated with temporomandibular disorders, we used magnetic resonance imaging (MRI) to identify risk factors for sideways disk displacement of the temporomandibular joint in 26 patients with MRI-confirmed unilateral pure sideways disk displacement (medial or lateral disk displacement) and normal positioning of the contralateral temporomandibular joint. Coronal morphologic harmonization between the condyle and fossa, angle between the axis of the ramus and condyle, and angle between the lateral pterygoid muscle (LPM) and condyle were evaluated. Only angle of the LPM related to the condyle was significantly correlated with mediolateral disk position; the angles of joints with medial, normal, and lateral disk positions were 70.2°, 66.7°, and 60.1°, respectively. These results suggest that a greater angle of the inferior head of the LPM to the axis of the condyle on axial MRI images may cause medial disk displacement, while a smaller angle may result in lateral disk displacement. (J Oral Sci 58, 29-34, 2016).
authors.affiliation: Department of Oral and Maxillofacial Radiology, Nihon University School of Dentistry.
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Kohinata
authors.forename: Kunihito
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Mari
authors.initials: M
authors.lastname: Tsunoda
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Masao
authors.initials: M
authors.lastname: Araki
authors.forename: Koji
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Kazuya
authors.initials: K
authors.lastname: Honda
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging* / Q000473:pathology