[Therapeutic alternatives for drug-associated maxillary osteonecrosis (MRONJ): reports of two clinical cases and review of the literature]. / Alternativas terapéuticas de osteonecrosis maxilar asociada a medicamentos (ONMAM): reportes de dos casos clínicos y revisión de la literatura.

Introduction: Drug-associated Maxillary Osteonecrosis is one of the most relevant adverse effects in treatment with antiresorptive drugs such as bisphosphonates and denosumab. Oncological conditions such as multiple myeloma, breast cancer, prostate, and bone-metabolic disorders such as osteoporosis lead the indications for these antiresorptive therapies. Treatment is complex because the disease is often refractory. Pharmacological, conservative and surgical treatments are described. Objective: The aim of this study is to report two clinical cases of MRONJ treated with two different therapeutic protocols and the analysis of the available literature on these aspects based on the clinical classification defined by the American Association of Oral and Maxillofacial Surgeons (AAOMS). Conclusion: Patients who develop clinical signs of great morbidity associated with MRONJ, may see their quality of life conditioned and suffer a worsening of their underlying pathology. MRONJ treatment is conditioned by the stage of the disease, its success depends on interdisciplinary management and strict medical and dental clinical follow-up, as well as rigorous monitoring to prevent or detect future recurrences early.

Introducción: La Osteonecrosis Maxilar asociada a Medicamentos (ONMAM) constituye uno de los efectos adversos más relevantes en el tratamiento con drogas antirresortivas como bifosfonatos y denosumab. Patologías oncológicas como mieloma múltiple, cáncer de mama, próstata, y alteraciones óseas-metabólicas como la osteoporosis lideran las indicaciones para estas terapias antirresortivas. El tratamiento es complejo debido a que muchas veces, la enfermedad es refractaria a la terapéutica aplicada. Se describen tratamientos farmacológicos, conservadores y quirúrgicos. Objetivo: El objetivo de este trabajo es reportar dos casos clínicos de ONMAM tratados con dos protocolos terapéuticos diferentes y el análisis de la literatura disponible en la actualidad sobre estos aspectos en base a la clasificación clínica definida por la American Association of Oral and Maxillofacial Surgeons (AAOMS). Conclusión: Los pacientes que desarrollan cuadros clínicos bucales de gran morbilidad como lo es ONMAM, pueden ver condicionada su calidad de vida y sufrir un agravamiento de su patología de base. El tratamiento de ONMAM está condicionado al estadio de la enfermedad, el éxito del mismo depende del manejo interdisciplinario y de un estricto seguimiento clínico médico y odontológico, así como también un riguroso monitoreo para evitar o detectar precozmente futuras recurrencias.

The effects of icariin on wound healing of extraction sites with administration of zoledronic and dexamethasone: A rat model study.

OBJECTIVE: This study was intended to investigate the effects of icariin on the healing of tooth extraction sites under the systemic administration of zoledronic and dexamethasone. METHOD: Thirty female rats underwent bilateral ovariectomy and were randomly assigned to 5 groups: SS group received a weekly injection of saline, while ZD, ZD + LICA, ZD + MICA, and ZD + HICA groups received zoledronic with dexamethasone for 8 weeks. One week later, mandibular first molars were extracted in all groups. Then, 30, 60, and 120 mg/kg icariin were intragastrically given to ZD + LICA, ZD + MICA, and ZD + HICA groups daily for 10 weeks, while saline was given to SS group and ZD group. Blood samples and mandibles were harvested for examinations after 10 weeks. RESULTS: Significantly smaller wound area was noted in SS and ZD + HICA groups, but the incidence of bisphosphonate-related osteonecrosis of the jaws (BRONJ) was not significantly different. Groups injected with zoledronic and dexamethasone had higher C-terminal cross-linked telopeptide of type 1 collagen (CTX-1), tartrate-resistant acid phosphatase 5b (TRACP 5b), and the number of osteoclast cells, with less vascular endothelial growth factor (VEGF) and osteocalcin (OCN). In contrast, CTX-1, TRACP 5b, and the number of osteoclast cells declined after using icariin and promoted VEGF and OCN were noted and the effects were in a dosage-dependent manner. CONCLUSION: Concurrent use of zoledronic and dexamethasone inhibits the expression of VEGF, OCN, and wound healing and increases the number of osteoclast cells, serum CTX-1, and TRACP-5b after discontinuation for 10 weeks. Icariin weakens those effects in a dose-dependent manner but does not influence the onset of BRONJ.

Effects of bisphosphonates on mandibular condyle of ovariectomized osteoporotic rats using micro-ct and histomorphometric analysis.

OBJECTIVE: To evaluate microarchitectural changes in condylar cartilage and associated subchondral bone after bisphosphonates treatment using an ovariectomized (OVX) osteoporosis rat model. METHODS: Thirty six-month-old female Sprague-Dawley rats were randomly divided into sham, OVX, and risedronate (RIS)-treated groups. Both OVX and RIS groups received bilateral ovariectomy. OVX group was treated subcutaneously with saline, whereas RIS group received risedronate treatment (2.4 µg/kg) subcutaneously for 3 months. At the end of 3 months, animals were sacrificed and the entire condyles were harvested for micro-CT and histological analyses. Immunohistochemistry (IHC) was performed to assess the expression of type I/II collagen protein by semiquantitative imaging analysis. RESULTS: Micro-CT analysis showed OVX group had significant condylar subchondral bone loss compared to sham as shown by significant decrease in bone volume fraction (P = 0.028), trabecular thickness (P = 0.041), and significant increase in trabecular spacing (P = 0.003). In RIS group, partial inhibition of OVX-induced bone loss was detected. HE staining showed proliferative layer of condylar cartilage reduced, while hypertrophic chondrocyte layer increased significantly in RIS group compared to sham and OVX groups. IHC showed reduced expression of Col I in both the OVX and RIS groups, whereas expression of Col II was reduced in the OVX group but increased in the RIS group. CONCLUSION: Our findings suggest that systemic bisphosphonate treatment influences the structure and ossification of condylar cartilage and it has a dual action on condyle in a postmenopausal osteoporosis rat model which raises the concerns for the potential side effects of BPs on condyle to elder patients.