Temporomandibular Joint Disorder in Parkinson's Disease Patients

BACKGROUND: Recent studies suggested that Temporomandibular joint disorder (TMD) may be more prevalent in patients with Parkinson's disease (PD), but lack international standardized clinical assessment. OBJECTIVES: This study aimed to investigate the correlation between the Diagnostic Criteria for TMD (DC/TMD) diagnosis and PD motor symptoms, and to investigate the presence of TMD in PD patients. METHODS: 419 participants from the outpatient clinic of the Department of Neurology were enrolled. Patient's TMD status was diagnosed with DC/TMD. PD motor symptoms and severity were assessed by the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III and Modified Hoehn and Yahr scale (HY). RESULTS: 45.6% of PD participants were diagnosed with TMD, with Anterior Disc Displacement with Reduction being the most common TMD subtype (27.4%), followed by Degenerative Joint Disease (6.9%). Compared to PD patients without TMD, those with TMD exhibited more advanced motor dysfunction (p = 0.043). Occurrence of Pain-related TMD was correlated with bradykinesia (rho = 0.135, p = 0.006) and axial symptoms (rho = 0.125, p = 0.010), while Intra-articular joint disorder was correlated with tremor (rho = 0.097, p = 0.047). PD patients with longer disease duration were associated with higher odds of TMD diagnosis (OR = 1.064, p = 0.010). CONCLUSIONS: TMD subtypes are associated with specific motor manifestations in PD: pain-related TMD correlated with bradykinesia and axial impairment, whereas intra-articular joint disorders correlated with tremor. Multidisciplinary collaboration between dentists and neurologists is essential and may benefit the management for both PD and TMD.