Sleep Bruxism Is a Significant Risk Factor for the Recurrence of Temporomandibular Disorder: A Single‐Center Retrospective Study

ABSTRACT Background Oral behaviours are risk factors for temporomandibular disorder (TMD), but the associations between oral behaviours and TMD prognosis remain unclear. Objective To assess the effect of oral behaviours on TMD prognosis. Methods This single‐centre retrospective study included 99 TMD patients (12 males and 87 females, median age: 28 years) who received physical therapy between January and August 2022 and completed a 6‐month follow‐up. Pain intensity, mouth opening, jaw function and oral behaviours were assessed at baseline. At follow‐up, disease recurrence and the abovementioned indicators were assessed. Paired‐samples t tests were used to compare pain, mouth opening and jaw function before and after treatment. Chi‐squared tests were used to assess changes in oral behaviours. Multivariate logistic regression analyses were used to identify risk factors for TMD recurrence. p < 0.05 indicated statistical significance. Results TMD recurrence was reported by 25 patients, yielding a recurrence rate of 25%. After physical therapy, the patients' pain, mouth opening and jaw function significantly improved ( p < 0.001). The oral behaviour during waking hours was effectively corrected ( p < 0.05); however, it was difficult to improve nocturnal oral behaviour ( p > 0.05). Multivariate logistic regression analysis revealed that sleep bruxism was an independent risk factor for TMD recurrence (OR = 4.411, p = 0.023). Conclusion Sleep bruxism is a significant risk factor for TMD recurrence. Close attention should be given to whether TMD patients have a habit of sleep bruxism.