Relationships between personality factors and DC/TMD Axis II scores of psychosocial impairment among patients with pain related temporomandibular disorders

This cross-sectional analytical study aimed to assess the relationship between personality factors and the DC/TMD Axis II scores of psychosocial impairment among patients with pain related temporomandibular disorders (TMD). 120 participants (60 females and 60 males) who were diagnosed with pain related TMD according to the Axis I DC/TMD protocol were recruited. The participants were requested to complete four tests including the NEO Five Factor Inventory (NEO-FFI) to assess personality factors and three Axis II DC/TMD tools; the Graded Chronic Pain Scale (GCPS) Version 2.0 to assess TMD pain intensity and pain-related disability, Patient Health Questionnaire-4 (PHQ-4) to assess psychological distress due to TMD pain, and Generalized Anxiety Disorder-7 (GAD-7) to assess patients' stress reactivity. Results showed that 49.2% of the participants experienced high intensity of characteristic pain, 14.2% reported pain related disability more than 30 days (grade 3 disability days) and had disability scores of 70 or above (grade 3 disability scores), 16.7% demonstrated severe distress, and 18.3% reported severe anxiety due to TMD pain. Females scored higher on all these variables than males (P < .05). Multiple regression analyses indicated that higher extraversion scores, higher agreeableness scores and being a female were associated with higher intensity of characteristic pain (p < .05). Also, higher neuroticism and agreeableness scores were associated with more disability days (p < .05). In addition, higher agreeableness scores were associated with higher disability scores and disability point values (p < .05). Furthermore, lower neuroticism scores and being a female were associated with higher PHQ total scores, while being a female and having a lower level of education were associated with higher GAD total scores (p < .05). In conclusion, personality profiles and gender significantly impact the DC/TMD Axis II scores of psychosocial impairment among patients with pain related TMD.