The association between anterior crossbite, deep bite and temporomandibular joint morphology validated by magnetic resonance imaging in an adult non-patient group

摘要

The aim of this study was to determine whether associations exist between anterior edge-to-edge bite, anterior crossbite, deep bite and morphology of the temporomandibular joint (TMJ) in the vertical dimension, evaluated by magnetic resonance imaging (MRI) in adults.A total of 148 subjects (90 females, 58 males) were selected from the cross-sectional epidemiological population-based study " Study of Health in Pomerania" (SHIP) for this evaluation. In each person a clinical orthodontical examination was performed. Four linear measurements and one ratio from MRI scans of the TMJs were evaluated. To estimate the effects of anterior edge-to-edge bite, anterior crossbite and deep bite on TMJ variables, linear regression was applied. (Analyses were adjusted for sex, age, school education, and orthodontic treatment.). Anterior edge-to-edge-bite/crossbite had shorter mean eminence heights (eh) on both joint sides (p< 0.01). In deep bite without gingival contact the postglenoid process height (pgph) decreased significantly in left joints (p= 0.018) and there was a tendency to a decrease in right joints (p= 0.059). The ratio between eminence height and postglenoid process height (eh/pgph) was increased on both left (p< 0.001) and right (p= 0.002) joints.In conclusion, anterior edge-to-edge-bite/crossbite is connected to a reduced eminence height and deep bite without gingival contact with an increased ratio between eminence height and postglenoid process height. Therefore the condylar path in the anterior edge-to-edge bite and crossbite cases can be interpreted to be reduced and in the deep bite cases without gingival contact to be steepened.