Temporomandibular joint click sound and magnetic resonance-depicted disk position: which relationship?

The aim of this work was to evaluate the agreement between temporomandibular joint click sound and MR diagnoses of different disk positions.

One hundred ninety-four (N=194) patients seeking treatment for temporomandibular disorders at the TMD Clinic, Department of Maxillofacial Surgery, University of Padova, Italy, underwent a bilateral magnetic resonance of the temporomandibular joints. The presence of click sounds was clinically assessed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and put into relation with different magnetic resonance (MR) diagnoses of disk-condyle position by means of permutation tests.

The proportion of joints with reducing and non-reducing disk displacement which provided a click sound during the clinical assessment was similar (45.6% vs. 48.9%, respectively), while the prevalence of the two MR diagnoses in joints with click sound were strongly different (25.3% vs. 40.1%, respectively. Thus, the MR diagnosis which appears to be more positively associated with click sounds is disk displacement without reduction.

There is a weak form of dependence between click and MR diagnosis, and the MR diagnosis of DDNR seems to be more positively associated with the presence of click sounds than the other categories, which did not show significant positive associations with click (i.e. there is negative association between click presence and normal disk position and no association between click presence and DDR joints.