Oral health-related behaviors and prevalence of thyroid diseases in Iranian patients

Abstract Objective. Thyroid disorders can affect the general health-related quality of life with complications such as fatigue, anxiety, depression, and systemic manifestations. The aim of this study was to investigate the relationship between the oral health-related behaviors, the prevalence of thyroid diseases, and the oral health-related quality of the life. Methods. This cross-sectional and descriptive-analytical study was conducted on 419 patients with a history of thyroid disease and 100 healthy subjects with no thyroid disease as a control group. Demographic information including age, gender, BMI, smoking, alcohol consumption, and medical history was collected through questionnaires and interviews. An assistant of oral diseases evaluated the oral health-related behaviors and objective conditions of oral health status. The objective periodontal evaluation was based on the community periodontal index (CPI) and probing by WHO. The plaque index was examined by giving dental plaque disclosing tablets and chewing them for 30 seconds. Thyroid disease was based on the endocrinologist’s opinion and triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) criteria. In this study, to evaluate the oral health-related quality of life, the Oral Health Impact Profile (OHIP-14) questionnaire was used. The obtained results were analyzed using T-test, Multivariate logistic regression analysis, Chi-Square test, and SPSS-21 software. The significance level in data analysis was p<0.05. Results. Among the 419 patients with a history of thyroid disorders included in the study, 82 (15.8%) had hyperthyroidism (TSH <0.4 mIU/L), 261 (50.3%) had normal thyroid (TSH <5.0 mIU/L), and 76 (14.6%) had hypothyroidism (TSH >5.0 mIU/L). Regarding the observation of the oral and dental health status in the group of participants with no history of thyroid disorder, 64% of subjects with thyroid disorders observed their oral and dental health well, while in the group of subjects with no history of thyroid disorder, 46.9% observed oral health well (p<0.001). The results revealed a significant relationship between the presence of periodontitis and a history of thyroid disorder (p<0.021). During the study, 11% of hyperthyroid patients, 4.6% of participants with normal thyroid status, and 1.3% of hypothyroid patients suffered from periodontitis. The score of oral health-related quality of life in participants without a thyroid disorder history was significantly lower than that with a history of thyroid disorder indicating that their oral healthrelated quality of life is better (p=0.049). Conclusions. The results revealed a significant relationship between the presence of periodontitis and a history of thyroid disorder. However, there was no significant difference between two experimental groups regarding the presence of microbial plaque. The score of oral health-related quality of life in participants without a history of thyroid disorder was significantly lower than that with a history of thyroid disorder indicating that their oral healthrelated quality of life is better.