Background/Purpose: Chronic temporomandibular disorders develop with persistent pain in other areas of the body in some patients, suggesting a predisposition to a generalized pain phenotype. The objective of our study was to evaluate whether there is an association between temporomandibular joint (TMJ) pain, and pain in other joints, or a generalized pain phenotype.

Methods: The Osteoarthritis Initiative is a cohort study of participants with or at risk for knee osteoarthritis. TMJ pain was assessed via self-reported pain or aching across the face, cheek, or jaw, in the past 30 days at the 4-year visit.  Logistic regression was used to estimate the association between recent TMJ pain and knee pain on most days of the month in the past 30 days, as well as hand pain and hip pain. Depression was ascertained using the Center for Epidemiologic Depression Scales (CES-D), and the number of reported body areas with pain was assessed using a homunculus (see figure legend for locations). Mean CES-D scores and number of body areas with pain were compared between participants reporting recent TMJ pain and those without using a two-sample t-test.  All analyses were cross-sectional (n=3,852), and due to previously reported sex differences in TMJ pain, all analyses were conducted sex-stratified.

Results: Participants had a mean age of 61 years (SD 9.1), with 80% White and 17% African American. Recent TMJ pain was reported by 11% of females (n=2,225) and 5% of males (n=1,627). Females with TMJ pain had significantly higher odds of reporting knee pain (OR=1.40 [95%CI: 1.14, 1.72]), hand pain (OR=1.81 [95%CI: 1.39, 2.37]), and hip pain (OR=2.13 [95%CI: 1.62, 2.79]), compared to females without TMJ pain; and while the odds of knee, hand, and hip pain was higher among males with TMJ pain compared to males without TMJ pain, the associations were not significant (OR=1.23 [95%CI: 0.86, 1.77]; OR=1.37 [95%CI: 0.81, 2.32]; OR=1.26 [95%CI: 0.73, 2.17], respectively). Females reporting TMJ pain had higher levels of depression on average compared to those without TMJ pain (9.2 vs 7.0; difference of 2.2 [95%CI: 1.1, 3.4], p=0.0002) though we did not observe a significant difference among males (7.9 vs 6.2; difference of 1.7 [95%CI: -0.5, 3.8], p=0.13). Both females and males with TMJ pain had significantly higher mean counts of body pain areas compared to those without TMJ pain (4.2 vs 2.5; difference of 1.7 [95%CI: 1.3, 2.2], p< 0.0001, and 2.9 vs. 1.8; difference of 1.1 [95%CI: 0.4, 1.8], p=0.004, respectively; Figure 1)

Conclusion: Males and females reporting recent TMJ pain also reported pain in more body areas than those who did not have TMJ pain, suggesting a generalized pain phenotype. Females with TMJ pain were significantly more likely to have knee, hand, and hip pain. The management of patients with TMJ pain and pain in other joints may require a broader pain assessment and treatment strategies tailored to address a generalized pain phenotype.