OBJECTIVE. Jaw pain may occur in rheumatoid arthritis (RA), osteoarthritis (OA), and fibromyalgia (FM). We investigated the prevalence and correlates of jaw pain, and whether jaw pain is increased in RA, where intrinsic articular disease can be noted radiographically, or is a manifestation of a generalized pain problem.
We analyzed data from 22,720 patients participating in a longitudinal outcome study of rheumatic diseases, including 17,683 with RA, 4,011 with OA, and 1,026 with FM. Jaw pain was considered to be present if a patient indicated it in either the left or right jaw. In addition to standard rheumatic disease measures, we also obtained self-report assessments that included a count of painful nonarticular regions (the regional pain score, RPS), a joint count, and a count of symptoms.
The age and sex adjusted rate of jaw pain was 18.7% in RA, 18.6% in OA, and 35.4% in FM. Jaw pain was best predicted by joint count, RPS, and a count of somatic symptoms in univariate analyses. In multivariate analyses jaw pain was predicted by joint count, RPS, symptom count, and fatigue. The ROC area under the curve for this model was 0.79, and 82.8% of patients were correctly classified. There was little difference in predictor variables for RA and OA patients. Covariate adjusted analyses controlling for age, sex, symptom count, fatigue, RPS, and joint count predicted jaw pain in 14.7% (95% CI 14.1 to 15.3) of RA and 11.6% (95% CI 10.6 to 12.7) of OA patients. This difference, 3.1%, may represent the increment in jaw pain attributable to RA.
Jaw pain is present in about 19% of patients with RA and OA, and is primarily a marker for a general pain increase and symptom sensitivity problem. Patients who have jaw pain have worse outcomes manifested by decreased functional ability, lower household income, and decreased quality of life. Variables not usually formally measured in clinical practice best identify this problem: self-reported joint count, symptom count, count of painful regions (RPS), and a visual analog scale for fatigue.