To use the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis II and additional pain-related and psychosocial variables to identify subtypes of TMD patients in a primary health care setting based on pain-related disability.

Consecutive TMD pain patients (n = 399) seeking treatment in a primary care setting completed a multidimensional pain questionnaire. Subtyping was based on the Graded Chronic Pain Scale (GCPS), and the patients were divided into a no-disability group (0 disability points), lowdisability group (1-2 disability points), and high-disability group (3-6 disability points). Psychosocial variables included RDC/TMD Axis II variables, anxiety, tension and stress, worry, catastrophizing, coping ability, general health, and other pain problems. Subtype differences were analyzed with t test, Wilcoxon rank-sum test, ANOVA, or Kruskal-Wallis test. A further analysis with multivariable logistic model was applied. All P values from pairwise comparisons were Bonferroni adjusted.

Most (61%) of the patients belonged to the no-disability group, 27% to the low-disability group, and 12% to the high-disability group. When subtypes were compared, patients in the no-disability group appeared psychosocially well-functioning, with fewer symptoms related to psychosocial distress, better ability to control pain, and fewer jaw functional limitations and other pain problems. Patients in the high-disability group reported the highest levels of symptoms of depression and somatization, sleep dysfunction, worry, and catastrophizing thoughts. The low-disability patients formed an intermediate group between the no-disability and high-disability groups.

The results suggest that GCPS-related disability scoring can be used as a simple screening instrument in primary care settings to identify individuals with different, clinically relevant psychosocial subtypes.