Association between the degree of Parkinson's disease progression and the oral environment.

Introduction: Aim of this study was to examine the relationship between the degree of Parkinson's disease (PD) progression and the oral environment in patients with PD.

Material and methods: Fifty patients with PD [mean age, 64.9 ± 8.5 years old; mean Hoehn and Yahr (HY) stage, 3.2 ± 0.8] were recruited. The patients were divided into a mild/moderate group (HY stage 2-3) and a severe group (HY stage 4-5), and the oral environment was assessed using the Oral Health Assessment Tool (OHAT) score.

Results: The OHAT scores for all participants were positively correlated with the age (rho = 0.27, p < 0.05), disease duration (rho = 0.28, p < 0.05), and MMSE score (rho = -0.28, p < 0.05). Multiple linear regression analyses showed that, among the OHAT items, "tongue," "saliva," and "lips" were associated with the age, disease duration, and MMSE, respectively (β = 0.021, p = 0.008; β = 0.027, p = 0.010; β = -1.974, p = 0.041, respectively).

Conclusions: The results of this study suggest the possibility of an association between the degree of PD progression, such as age and disease duration, and the deterioration of the oral environment. These results encourage specialized personnel to pay attention to the tongue and dry mouth condition, especially for older PD patients with a long disease duration.