Screening Survey of Pain Intensity in Patients with Temporomandibular Disorders

Objective: Pain tends to be the chief complaint in patients suffering temporomandibular disorders (TMD). Previous studies on pain and psychosocial factors have reported on the relationship between presence of pain and mental disorders. To date, however, few studies have addressed the relationship between intensity of pain and psychosocial factors. In this study, we investigated the relationship between intensity of pain and age, gender, palpation scores (PPS), tendencies toward depression, anxiety, and somatization, and oral parafunctional habits. Methods: This screening survey encompassed 104 patients (70 women and 34 men; mean age of 46.1 ± 19.3) who visited our clinic. We gathered the following data: age; gender; PPS included in Axis I diagnosis; and characteristic pain intensity (CPI), depression, anxiety, somatization, and oral parafunctional habits (assessed by the Oral Behavior Checklist) included in Axis II diagnosis. Based on the results of CPI, we divided patients into two groups: those experiencing low pain intensity (LP group) and those experiencing high pain intensity (HP group). The statistically significant level was set to below 5%. IBM SPSS Statistics V25 was used to perform all statistical analyses. Results: We observed no gender differences between LP and HP groups. The HP group included significantly more patients with higher scores for depression, anxiety, somatization, and oral parafunctional habits than the LP group. While no gender differences were observed in CPI, depression, anxiety, somatization, and oral parafunctional habits were significantly more common in women than in men. We observed no differences in age or PPS between the LP and HP groups. However, scores for depression, anxiety, somatization, and oral parafunctional habits were significantly higher in the HP group than in the LP group. We performed multiple regression analysis using the CPI score as the dependent variable and scores for depression, anxiety, somatization, and oral parafunctional habits as independent variables in both the LP and the HP groups. We identified no significant predictors for the LP group, but extracted depression as a significant predictor in the HP group. On evaluating the correlation of PPS with depression, anxiety, somatization, and oral parafunctional habits in both the LP and the HP groups, we found no correlation between the PPS and the seven-item generalized anxiety disorder (GAD-7) scale in the LP group but identified a significant correlation between the PPS and GAD-7 scores in the HP group. Moreover, the correlation coefficient between the patient health questionnaire (PHQ)-9 and GAD-7 scores was higher in the HP group than in the LP group. Conclusion: In those reporting more intense pain, we found a stronger correlation among psychological factors in patients diagnosed with TMD. Greater tendency toward depression was directly associated with pain intensity. The results point to the need to consider differences in psychosocial factors associated with pain intensity when treating TMD.