The Quality of Life for People with Parkinson’s Disease in Relation to Their Oral Health

The present study aimed to evaluate the correlation between the oral health status and the quality of life for people with Parkinson’s disease. The Decayed, Missing, Filled (DMFT) index and the quality of life questionnaire for people with Parkinson’s disease (Parkinson’s Disease Questionnaire-39) were used as evaluation instruments. Sixty-two people with a clinical diagnosis of Parkinson’s disease between stages 1 and 3, age between 46 and 86 years, of both sexes, with an average time of disease evolution of 7 years, participated in the study. Data were evaluated using the Pearson’s correlation test, and one-way ANOVA (p < 0.05). The mean DMFT obtained was 23; there was no correlation between the DMFT values and the total score of the Parkinson’s Disease Questionnaire-39 neither in its domains, nor between the DMFT and the stages of Parkinson’s disease (p = 0.61). We found that the oral health of parkinsonians is deficient due to the high number of missing teeth, but their perception of quality of life is favorable despite their motor limitations related to mobility, and activities of daily living.

system, which presents itself as the main pathological finding degeneration in the compact portion of the substance nigra in the midbrain, which promotes nigrostriatal pathway dysfunction, with a decrease in dopamine production at dopaminergic receptors' level, located on the striated body [2] [3] [4]. Changes in motor control become noticeable in the patient characterized by: tremor, muscular rigidity and bradykinesia. In advanced clinical forms, postural alterations and balance and gait disorders usually occur [5] [6].
The treatment of the disease can be pharmacological, surgical and/or through non-pharmacological therapies (occupational therapy, physiotherapy, speech therapy, psychology, among others). In drug therapy, Levodopa is the most widely used substance and its prescription may be isolated or associated with dopaminergic agonists, anticholinergics, COMT (catechol-O-methyltransferase) inhibitors, and dopamine carboxylase inhibitors [7].
The effects of drugs of dopaminergic or anticholinesterase action affect the oral cavity promoting the reduction of saliva production, causing microflora imbalance, and increasing predisposition to periodontal diseases and caries. This fact, associated with physical limitation and function impairment, affects daily activities. Also, there is difficulty or even inability in the performance of their daily tasks. In this study, we will focus on the social and economic development of the population, which will limit their activity and social participation, often leading to social isolation, harming quality of life [8].
In PD, the quality of life can be assessed by a specific questionnaire: the Parkinson's Disease Questionnaire-39 (PDQ-39), which allows to inform with sufficient precision the negative impact of the disease on the quality of life of these people [9]. Few studies are found on the literature regarding the real impact of this disease on oral health; thus this study aimed to evaluate the existence of any association between the oral condition and quality of life for people with Parkinson's disease.

Location of the Study
The study was developed in the Pro-Parkinson Extension Project: Dentistry, lo-

Type and Study Population
This is an analytical, quantitative, descriptive, cross-sectional study. These studies visualize the health status of the population at a given time, as snapshots of reality. It presents as advantages: to be adequate to test association hypotheses, their low cost, rapidness and ease of execution and analysis [10].

Sample Calculation and Selection
The sample calculation was based on a non-probabilistic sample (convenience), based on the number of patients who were attended at the Pro-Parkinson Extension Project: Dentistry's clinic between 2014 and 2016, by the following criteria: Inclusion Criteria-Parkinson's patients in stages 1 to 3 according to the Hoehn and Yahr [11] Scale who had at least sextant from the mouth with teeth; Exclusion criteria-Unsatisfactory communicative and cognitive level, verified through the Mini Mental State Exam.

Data Collection
The data in the medical records, collected from the information, was related to disease time since diagnose, the Hoehn and Yahr scale, the Decayed, Missing,

Statistical Analysis
The data was + compiled into Microsoft Excel spreadsheets and expressed as mild and standard deviation. Analysis of the correlation between DMFT and

Results
The sample consisted of 62 people with Parkinson's disease clinical diagnosis, being 39 men (62.9%) and 23 women (37.1%); in the stages HY1 = 20, HY2 = 29 and HY3 = 13 people. General characteristics of the sample studied are expressed in Table 1.
Regarding the dental health condition of the studied population, an average DMFT of 23 (±6) was observed, and a high degree of severity was noticed, due to the expressive number of losses; reaching almost 4 times the number of dental restorations. As the disease worsens, there is an increase in the number of missing teeth and a relatively small increase in the number of decayed teeth, with a decrease in the number of restored teeth (Figure 1).
The minimum and maximum values and the average score obtained in each dimension of the PDQ-39 are presented in Table 2. Numerically, individuals presented a worse perception of the QL in the dimensions "Body discomfort", "Mobility" and "Day Life Activities", and a better perception in the dimension "Social support". However, no correlation was observed between the DMFT values and the total PDQ-39 score in their domains (Figure 2), and no significant differences were noticed in the DMFT between the PD stages (p = 0.61).

Discussion
The oral health condition found in the parkinsonians studied in this research was precarious, especially due to the high prevalence of edentulism, which is a serious problem of oral health that refers to a mutilating dental practice and the difficulty in accessing specialized dental services, contributing to other studies that evaluated the DMFT index [13] [14] [15]. With the worsening of the disease, it was also observed a greater loss of teeth. However, the scarcity of studies in the dental literature with this type of analysis limited the discussion of this association, making it difficult to identify a relationship between the disease and the condition of oral health in individuals with PD.
The concept of quality of life is multidimensional and reflects a subjective perspective of the personal satisfaction in relation to several aspects of his life, involving the person's family, functional, spiritual, social, occupational and financial issues [9]. In this context, oral health has a decisive role, because when it  [17].
Although there is a concern about the maintenance of the elderly's oral health status in the dental literature, there is a lack of content regarding the oral health care of people with PD [18]. Despite of the limitations in this research due to the lack of publications about oral health and quality of life for people with Parkinson's disease, another limitation is related to self-reporting because it involves social and psychological components. As well as PDQ-39 presents more specific assessment dimensions for general health signs and symptoms.

Conclusion
New studies are important in order to contribute to the improvement of oral health care and assistance of this group of people, seeking to establish programs that meet specific needs, both preventive and curative, so that the oral health conditions necessary to live with quality of life are maintained, despite the motor limitations imposed by the disease.