Bisphosphonate related osteonecrosis of the jaws: a review

Medication-related osteonecrosis of the jaw after long-term bisphosphonate treatment in a cat

A 12‐year‐old, neutered female, domestic medium hair cat was evaluated for a nonhealing, oral mucosal ulceration. The cat had a history of idiopathic hypercalcemia that had been treated with a bisphosphonate for 41 months. Oral examination identified exposed maxillary bone adjacent to a previous extraction site. Histopathology of the exposed bone and associated mucosa was most consistent with medication‐related osteonecrosis of the jaw. Treatment involved both medical and surgical interventions. Oral mucosal healing occurred after 6 months of treatment.

Evaluation of Mandibular Bone After Dental Extraction in Rats Treated With Antiresorptive Drugs

PURPOSE

Zoledronic acid (ZOL) and denosumab (Dmab) are commonly used to treat bone pathologies. Because these drugs suppress bone metabolism, this study sought to compare their effect on bone repair after tooth extraction.

MATERIALS AND METHODS

Four-week-old male Wistar rats were randomly assigned to 1 of 3 groups: ZOL 0.125 mg/kg, Dmab 0.25 mg/kg, or saline solution 10 mL/kg (control). After 1 week of treatment, the first left molar was extracted; the rats were euthanized at 28 days. The jaws were removed and photographed for macroscopic analysis of wound healing and then subjected to tomographic and histologic analyses. Immunohistochemistry was carried out against the receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG).

RESULTS

No difference in wound healing, presence of inflammatory infiltrate and bone sequestration, or osteocyte expression of RANKL and OPG was found among groups. Tomographic analysis showed that the ZOL group had less alveolar resorption and more complete alveolar repair compared with the other groups. There was a statistically significant difference in the OPG marker in the control (P = .008) and ZOL (P = .05) groups when comparing the extracted and non-extracted sides.

CONCLUSION

Systemic use of ZOL can improve alveolar bone healing; however, the potential risk for the development of osteonecrosis should be considered. Higher expression of OPG seems to be associated with the control of osteoclastogenesis during bone repair.

Cryptococcal Maxillary Osteomyelitis and Osteonecrosis in a 18-Month-Old Dog

An 18-month-old neutered male labradoodle was treated with surgical debridement for maxillary osteomyelitis and sequestrum formation. Histopathologic findings of the necrotic bone were consistent with Cryptococcus subspecies, confirmed with latex agglutination serum titer testing. The patient responded to a combination of fluconazole and surgical debridement and was titer negative after 8 months of medical therapy. The patient never exhibited signs of systemic illness which is commonly reported with cryptococcosis. Cryptococcus subspecies infection in dogs in the Pacific Northwest is part of an ongoing outbreak in the region, first reported in 2001, and is associated with specific risk factors. This is the first published case of oral cryptococcosis from primary inoculation.

Endodontic therapy of a mandibular canine tooth with irreversible pulpitis secondary to dentigerous cyst

Dentigerous cysts are uncommon, yet are being reported with increasing frequency in the veterinary literature. Dentigerous cysts are a type of benign odontogenic cyst associated with impacted teeth, most commonly the mandibular first premolar tooth. Significant bone destruction can occur secondary to the expansion of a dentigerous cyst. The expanding cyst can lead to pathology of neighboring teeth, which can include external root resorption or pulpitis. Intraoral dental radiographs are imperative to properly assess the presence and extent of a dentigerous cyst, as well as the status of the neighboring teeth. This case report describes treatment for dentigerous cyst including cyst lining curettage, mandibular bone regeneration, and endodontic therapy for a canine tooth with irreversible pulpitis.

Distinctive role of 6-month teriparatide treatment on intractable bisphosphonate-related osteonecrosis of the jaw

The administration of teriparatide (TPTD) in conjunction with periodontal care could provide faster and more favorable clinical outcomes in previously refractory bisphosphonate-related osteonecrosis of the jaws (BRONJ) cases compared to conventional dental care, combination of surgery and antimicrobial treatment. We also found that underlying vitamin D levels might influence the response to TPTD treatment.

INTRODUCTION

Treatment of BRONJ is quite challenging and there are no standard treatment modalities. In this retrospective, longitudinal study, we examined whether additional TPTD administration could be beneficial for the resolution of BRONJ lesions compared to conservative management, such as antimicrobial treatment with or without surgery, and also studied the factors influencing the response to TPTD.

METHODS

Twenty-four cases of intractable BRONJ were included: 15 subjects were assigned to the TPTD group and the other 9 subjects, who refused TPTD administration, were assigned to the non-TPTD group. All subjects in both groups continued calcium and vitamin D supplementation and the TPTD group additionally received a daily subcutaneous injection of 20 μg TPTD for 6 months.

RESULTS

While 60.0% of the non-TPTD group showed one stage of improvement in BRONJ, 40.0% of the group did not show any improvement in disease status. In the TPTD group, 62.5% of the treated subjects showed one stage of improvement and the other 37.5% demonstrated a marked improvement, including two stages of improvement or complete healing, and there was not a single case that did not improve. The clinical improvement of BRONJ was statistically better in the TPTD group after the 6-month treatment (p < 0.05). Moreover, patients with higher baseline serum 25(OH)D levels showed better clinical therapeutic outcomes with TPTD.

CONCLUSIONS

We observed the beneficial effects of TPTD on BRONJ, and subjects with optimal serum vitamin D concentrations seemed to reap the maximum therapeutic effects of TPTD. A prospective, randomized, controlled trial should be needed to further evaluate the therapeutic efficacy of TPTD in the resolution of BRONJ.