ABSTRACT
OBJECTIVES: To analyze the effects of primary hyperparathyroidism on oral health and to investigate if the effects are linked to severity of the disease. SUBJECTS AND METHODS: This prospective cohort study involved 6151 primary hyperparathyroidism patients registered in the Scandinavian Quality Registry of Thyroid, Parathyroid, and Adrenal surgery and the National Cancer Register after parathyroidectomy (exposure) during 2011-2017 (patient cohort) and 60,654 individuals without primary hyperparathyroidism (reference cohort), matched by age, gender, and county of resident at the date of parathyroidectomy. The outcomes were tooth extractions and periodontal interventions. The risk for the outcomes was assessed by Poisson regression models. RESULTS: After adjusting for covariates, the patient cohort had a higher incidence rate of tooth extraction during the two-year period after parathyroidectomy (IRR = 1.15; 95% CI = 1.01-1.31), but a lower incidence rate of periodontal interventions during the four- to six-year period after parathyroidectomy (IRR = 0.88; 95% CI = 0.79-0.99). Furthermore, patients with more severe primary hyperparathyroidism were more likely to have tooth extractions and periodontal interventions after parathyroidectomy. CONCLUSIONS: The risk of tooth extraction increased slightly during the first two years after parathyroidectomy. Thereafter, the oral health effects subsided. Pre-surgical serum ionized calcium levels and adenoma weight may indicate negative dental outcomes after parathyroidectomy.