The Association Between Temporomandibular-Related Quality of Life and Oral Behaviours: A Cross-Sectional Study in Patients With Temporomandibular Disorders.

Objectives: Oral behaviours (OB) are some oral overuse behaviours which could be observed in patients with temporomandibular disorders (TMD). This study aims to investigate the association between TMD-related quality of life and OB to enhance understanding of these behaviours.

Methods: A total of 319 participants diagnosed with TMD were included in this research. According to the diagnostic criteria for TMD, patients were divided into three subgroups: pain-related TMD (PT, n = 71), intra-articular TMD (IT, n = 91) and combined TMD (CT, n = 157). Participants completed the oral behaviour checklist (OBC), the oral health impact profile for TMD (OHIP-TMD), the generalised anxiety disorder 7-item (GAD-7) and the patient health questionnaire 9-item (PHQ-9), and demographic characteristics were collected from medical records.

Results: TMD patients with high OBC scores (25-84 points) had higher scores in six of the seven OHIP-TMD domains (all p < 0.05). Logistic regression analysis indicated that OHIP-TMD scores (OR = 1.03), younger age (OR = 0.95), education (OR = 2.80-3.10), and PHQ-9 scores (OR = 1.14) were significantly positively correlated with OBC scores (p < 0.05). After adjusting for confounding factors, the psychological discomfort (OR = 1.09) and psychological disability (OR = 1.10) domains of the OHIP-TMD were identified as independent factors associated with higher OBC scores.

Conclusions: Patients with more frequent OB exhibited a lower quality of life across nearly all OHIP-TMD domains. Higher OHIP-TMD scores and specific psychological domains were independently associated with a higher frequency of OB. The causal relationship between quality of life and OB in TMD patients requires further investigation.