A cross-sectional study of temporomandibular joint coronal plane disk position: imaging reliability and clinical utility

OBJECTIVES: The aim of this study was to assess the reliability, frequency, and clinical significance of temporomandibular joint (TMJ) medial and lateral disk positions, observed in the coronal-oblique plane, to determine their importance in clinical diagnosis and for routine imaging.

STUDY DESIGN: This cross-sectional study involved secondary data analysis (clinical and imaging) of 401 participants of the TMJ Impact Study. We used the χ 2 statistic to evaluate the associations between coronal disk positions with (1) anterior disk displacements with reduction and without reduction; and (2) familiar TMJ pain resulting from excursive movements and palpation, range of motion, and joint sounds.

RESULTS: Anterior disk displacements of any type occurred in 67.5% of joints; in contrast, medial and lateral disk positions occurred in 16% and 24% of joints, respectively. Radiologist reliability was as follows: sagittal posterior band position: right κ = 0.68, left κ = 0.60, average 84% agreement; and medial or lateral disk position: right κ = 0.36, left κ = 0.32, average 70% agreement. Medial and lateral disk positions were associated with sagittal displacements (P < .001). However, there were no associations between medial and lateral disk positions and familiar pain, range of motion, and joint sounds.

CONCLUSIONS: Coronal disk position does not contribute to clinical symptomatology or findings and currently lacks sufficient evidence to support its inclusion into standard TMJ imaging protocols or into a clinical diagnostic category.