Hypothyroidism is Related to Less Bone Loss at Dental Implants

Objectives: Hypothyroidism (HT) is an endocrine disorder having autoimmune and inflammatory etiologies. Periodontal and peri-implant disease might be bidirectionally related to a variety of systemic inflammatory conditions. The objective of this study was to determine if the severity of bone loss around dental implants also might be related to the presence of HT.
Methods: This retrospective study was reviewed and approved by the SUNY Buffalo (SUNYAB) IRB. We examined medical and dental history records, and radiographic data, of patients receiving dental implants at the SUNYAB School of Dental Medicine from 2000-2017 (1480 implants; 635 patients). Rate of bone loss (mm/year) was calculated from implant placement and evaluation radiographs, with correction for radiographic distortion. Presence of HT was confirmed by review of patient medical records and use of thyroid hormone supplementation. Populations were adjusted for smoking and diabetes. Calculations were performed using IBM SPSS Statistics v25.
Results: Patients with HT had a lower rate of bone loss around dental implants. Specifically, patients with HT experienced peri-implant bone loss at a rate of 0.53 mm/yr, while bone loss from patients without HT was 1.63 mm/yr. (67.5% decrease, mean difference= 1.1 mm/yr confidence interval= 0.47-1.73 mm/yr, P=0.0007). Among non-smokers and non-diabetics, that relationship persisted with HT patients experiencing 0.37 mm/yr bone loss, and patients without HT experiencing 1.71 mm/yr. (78.2% decrease, mean difference= 1.34 mm/yr, 95% confidence interval= 0.58-2.10 mm/yr, P=0.0006).There were no significant differences in patient oral hygiene among any of the groups (P>0.05).
Conclusions: Our data indicate that the rate of bone loss around dental implants might be related to HT or HT treatment. Prospective and retrospective studies are currently underway to determine whether our findings are due to the disease process, or to thyroid hormone supplementation. Our data further suggest that clinicians should consider thyroid disease as a component of patient evaluation