Beyond ONJ – A review of the potential uses of bisphosphonates in dentistry

Untreated osteoporosis and higher FRAX as risk factors for tooth loss: a 5-year prospective study

INTRODUCTION

Studies have shown that an impaired bone condition, represented by osteoporosis and increased fracture risk, may potentially aggravate periodontal disease and, consequently, the risk of tooth loss. This 5-year prospective study aimed to investigate whether systemic bone condition represents risk factor for tooth loss due to periodontal disease amongst elderly women.

MATERIAL AND METHODS

Seventy-four participants, aged ≥ 65 years, who attended the 5-years recall for periodontal evaluation were involved. Baseline exposures were osteoporosis and fracture risk probabilities (FRAX). Women were grouped according to bone mineral density (BMD) and years of bone treatment for osteoporosis. The primary outcome at a 5-year follow-up was the number of tooth loss due to periodontal disease. Periodontitis staging and grading, and causes of tooth loss were recorded.

RESULTS

The multivariate Poisson regression models showed that women with untreated/shortly treated osteoporosis were 4 times more likely to present higher number of tooth loss due to periodontal disease than those with normal BMD or treated for ≥ 3 years (risk ratio (RR) = 4.00, 95% CI 1.40-11.27). Higher FRAX was also linked to tooth loss (RR = 1.25, 95% CI 1.02-1.53). Receiver-operating characteristic (ROC) curve suggested that women with history of ≥ 1 tooth losses have higher chances of worse major FRAX (sensitivity = 72.2%; specificity = 72.2%).

CONCLUSION

In this 5-year study, higher FRAX and untreated osteoporosis were risk factors for tooth loss. Women with normal BMD or treated for osteoporosis for ≥ 3 years did not show increased risk. Management of skeletal conditions should be emphasized with periodontal care for the prevention of tooth loss in elderly women.

Bisphosphonates in dentistry: Historical perspectives, adverse effects, and novel applications

Studies of the potential role of bisphosphonates in dentistry date back to physical chemical research in the 1960s, and the genesis of the discovery of bisphosphonate pharmacology in part can be linked to some of this work. Since that time, parallel research on the effects of bisphosphonates on bone metabolism continued, while efforts in the dental field included studies of bisphosphonate effects on dental calculus, caries, and alveolar bone loss. While some utility of this drug class in the dental field was identified, leading to their experimental use in various dentrifice formulations and in some dental applications clinically, adverse effects of bisphosphonates in the jaws have also received attention. Most recently, certain bisphosphonates, particularly those with strong bone targeting properties, but limited biochemical effects (low potency bisphosphonates), are being studied as a local remedy for the concerns of adverse effects associated with other more potent members of this drug class. Additionally, low potency bisphosphonate analogs are under study as vectors to target active drugs to the mineral surfaces of the jawbones. These latter efforts have been devised for the prevention and treatment of oral problems, such as infections associated with oral surgery and implants. Advances in the utility and mechanistic understanding of the bisphosphonate class may enable additional oral therapeutic options for the management of multiple aspects of dental health.

Is implant surgery a risk factor for osteonecrosis of the jaw in older adult patients with osteoporosis? A national cohort propensity score-matched study

OBJECTIVES

This study aimed to investigate the association between dental implant therapy and osteonecrosis of the jaw (ONJ) in osteoporotic patients and the relationship between tooth extraction, dental implantation, and ONJ.

MATERIAL AND METHODS

This retrospective cohort study used the Customized Health Information Data from the National Health Insurance Corporation in South Korea. The study population included patients older than 70 years with a history of osteoporosis; the cases included patients who had undergone dental implant surgery between July 2014 and July 2016 with specific procedure codes. The case and control cohorts were stratified by tooth extraction because it was the strongest risk factor to consider in this study. Each group of patients was matched using the propensity score. To investigate the relationship between dental implants and ONJ, a Cox proportional hazard model was applied to socio-economic factors, comorbidities, and bisphosphonates (BPs). All analyses were conducted using SAS statistical software.

RESULTS

Based on the fully adjusted model, the propensity score-matched osteoporosis patients with dental implants had a 0.51 times hazard ratio of osteonecrosis. On the contrary, tooth extraction was associated with a higher risk of ONJ (HR = 5.89). The patients with rheumatoid arthritis (RA) and those using BPs had a higher HR, respectively, 6.80 and 4.09 HR (p < .001).

CONCLUSIONS

Dental implantation was not a risk factor and patients with implants show rather lower ratios. However, older osteoporotic Korean patients who had undergone tooth extraction had higher risks of ONJ. A significantly higher risk of ONJ was associated with RA and BPs as well.

Off-label uses of denosumab in metabolic bone diseases

Denosumab (Dmab), a monoclonal antibody against the receptor activator of nuclear factor-κB (RANK) ligand (RANKL) which substantially suppresses osteoclast activity, has been approved for the treatment of common metabolic bone diseases, including postmenopausal osteoporosis, male osteoporosis, and glucocorticoid-induced osteoporosis, in which the pathway of the RANK/RANKL/osteoprotegerin is dysregulated. However, the imbalance of RANKL/RANK/osteoprotegerin is also implicated in the pathogenesis of several other rare metabolic bone diseases, including Juvenile Paget disease, fibrous dysplasia, Hajdu Cheney syndrome and Langerhans cell histiocytosis, thus rendering Dmab a potential treatment option for these diseases. Dmab has been also administered off-label in selected patients (e.g., with Paget's disease, osteogenesis imperfecta, aneurysmal bone cysts) due to contraindications or unresponsiveness to standard treatment, such as bisphosphonates. Moreover, Dmab was administered to improve hypercalcemia induced by various diseases, including primary hyperparathyroidism, tuberculosis and immobilization. The aim of this review is to summarize existing evidence on off-label uses of Dmab in metabolic bone diseases and provide opinion for or against its use, which should be always considered on an individual basis.