Depression and somatization in patients with temporomandibular disorders

Psychological and behavioral traits may be important for the diagnosis and management of orofacial pain.

This study compared the levels of depression and somatization in patients in single and multiple research diagnostic criteria for temporomandibular disorders (RDC/TMD) diagnostic groups.

The RDC/TMD was established to allow standardization and replication of research into the most common forms of muscle- and joint-related research and is divided into 2 axes: axis I, clinical TMD, and axis II, pain-related disability and psychological status. One hundred seventeen patients (28 male and 89 female; mean age, 33.3 +/- 10.3 years) with RDC/TMD-defined clinical TMD were selected. The RDC/TMD history questionnaire and examination forms were input directly into computers with the use of a software program developed at the National University of Singapore (NUS TMDv1.1 software). Axis I and II variables were generated online and automatically archived for statistical analysis. Patients were subsequently classified into 7 groups based on the presence of the various RDC/TMD axis I diagnostic groups: group A, myofascial pain only (group I); group B, disk displacement only (group II); group C, other joint conditions such as arthralgia, osteoarthritis, and osteoarthrosis only (group III); group D, myofascial pain and disk displacement (groups I and II); group E, myofascial pain and other joint conditions (groups I and III); group F, disk displacement and other joint conditions (groups II and III); and group G, myofascial pain, disk displacement, and other joint conditions (groups I, II, and III). Differences in mean Symptom Checklist-90 scores between groups were compared by analysis of variance/Scheffé tests to contrast depression and somatization levels between the various axis I diagnostic groups (alpha=.05).

The frequencies of the different groups were as follows: group A, 26.5%; group B, 29.9%; group C, 12.8%; group D, 6.0%; group E, 13.7%; group F, 4.3%; and group G, 6.8%. Approximately 39% of patients were clinically depressed, and 55% had moderate to severe somatization. Differences in mean depression and somatization with pain item scores were significant between groups (P<.05).

Within the limitations of this study, patients diagnosed with myofascial pain and other joint conditions (group E) had significantly higher levels of depression (P=.03) and somatization (P=.03) than patients diagnosed with only disk displacements (group B).