Anterior disk displacement of the temporomandibular joint. Significance of clinical signs and symptoms in the diagnosis.

In order to examine the diagnostic significance of typical clinical symptoms in temporomandibular joint (TMJ) disorders for diagnosis of anterior disk displacement, clinical findings were compared with the degree of disk displacement in 84 TMJs of 59 patients with TMJ disorders, who were examined clinically and by means of magnetic resonance imaging (MRI). The control group consisted of 31 subjects with no TMJ symptoms. No significant correlation between the degree of anterior disk displacement and palpation pain of the masticatory muscles or clicking/crepitus of the TMJ could be found. Joint clicking was observed in 65% of patients with TMJ symptoms in normal disk position (NDP). The percentage of joint clicking was almost the same in patients with anterior disk displacement with reposition (ADWR) (68%). There were significant correlations between active mouth opening and disk position as well as between a history of pain and disk position. Patients with NDP and ADWR had almost identical mouth opening values: 48 (+/- 5) mm and 46 (+/- 5) mm respectively. In contrast to these groups the mean values decreased significantly to 42 (+/- 6) mm in patients with anterior disk displacement without reposition (ADWOR). There were no significant correlations between occlusal findings (centric relation and habitual relation, early occlusal contacts, abrasion facets) and disk position when viewed either collectively or individually.