MON-397 Potential Relationship Between Hypothyroidism and Bone Loss at Dental Implants

Introduction: Hypothyroidism (HT) is an endocrine condition with autoimmune and inflammatory etiologies. Studies have shown that both periodontal disease and peri-implant bone loss are bidirectionally influenced by systemic inflammatory conditions, such as diabetes, adverse pregnancy outcomes, cardiovascular disease, and osteoporosis.(1) There also is evidence that HT is associated with decreased bone metabolism, depressed bone turnover, and a prolonged bone remodeling cycle.(2) Consequently, the objective of this study was to determine if the severity of bone loss around dental implants is related to the presence of HT. Methods: Following IRB approval, medical, dental, and radiographic records of patients who received dental implant placement at a university-based postgraduate program in periodontics from 2000–2017 were reviewed (1480 implants; 635 patients). Rate of bone loss in mm/year was calculated from surgical implant placement and subsequent re-evaluation radiographs, with correction for radiographic distortion. Presence of HT was confirmed by review of patient medical records, clinical diagnosis of HT, and history of thyroid hormone supplementation. Populations were adjusted for smoking, diabetes, use of systemic steroids, presence of autoimmune disease (other than HT), and systemic inflammatory conditions. Calculations were performed using IBM SPSS Statistics v25. Results: Patients with HT had a decreased rate of crestal alveolar bone loss around dental implants. Specifically, patients with HT experienced peri-implant bone loss at a rate of 0.42 mm/year, while bone loss from patients without HT was 1.34 mm/year (68.7% decrease; mean difference = 0.92 mm/year, 95% confidence interval = 0.39–1.50 mm/year, P<0.002). There were no significant differences in patient oral hygiene, or in implant service time, among any of the groups studied (P>0.05). Conclusions: The results suggest that the rate of marginal alveolar bone loss at dental implants is significantly decreased in patients with HT, and occurs independently of any of the systemic conditions noted above. The findings imply that potential changes in bone metabolism and remodeling associated with HT might result in less peri-implant alveolar bone loss following implant placement surgery. As a result, there does not appear to be an increased risk of peri-implant crestal bone loss in patients with HT. References: (1)Kim J., Amar S., Odontol. 94(1):10–21, 2006. (2)Tuchendler D., and Bolanowski M.,Thyroid Res. 7:12, 2014.