Medication-related osteonecrosis of the jaw (MRONJ) is area of exposed bone, or bone that can be probed through an intraoral or extraoral fistula, in the maxillofacial region > 8 weeks, without history of radiation to the jaw or obvious metastatic diseases, and is or has been treated with antiresorptive or antiangiogenic agents.
Dental extractions, most common predisposing event (45% to 61%). Other risk factors: implants, periodontal and periapical disease, removeable prostheses and intraoral trauma. Spontaneous MRONJ ranging from 17% to 70%, including tori, exostoses and mylohyoid ridges.
Dental screening prior to initiation of antiresorptive therapy.
Case Report 1
52-year-old male for assessment prior to an autologous stem cell transplant for treatment of his IgA kappa myeloma. 4 rounds of chemotherapy, 15 cigarettes per day, regularly consumed alcohol, 12 4 mg intravenous infusions of Zoledronate.
Ulcer on the lingual aspect of his lower right first molar (46) adjacent to the mylohyoid ridge. Stage 1 MRONJ Txt: saline and 0.2% Chlorhexidine mouth rinses after every meal, avoid oral trauma.
4 month later, exposed bone had increased, uncomfortable and mobile. A sequestrectomy was completed. Histopathology, necrotic bone with Actinomyces and inflammation. Two weeks postoperatively complete epithelialization of the previous osteonecrosis with mild signs of erythema.
Intraoral image of the right lingual mucosa over the mylohyoid ridge: (a) initial presentation ; (b) prior to sequestrectomy; (c) immediately post sequestrectomy; (d) two weeks post sequestrectomy with complete epithelialization.
Case Report 2
76-year-old female with a “hard palate tumor”, history of osteoporosis, Alendronate 70 mg orally once a week for 2 years. Bisphosphonate was ceased immediately.
Palatal torus covered by irregular mucosa concerns of malignancy. Mucosa biopsied and imaging organized, no malignancy. Biopsy show “focally ulcerated squamous mucosa with hyperplasia, spongiosis, and active inflammation”. (CT) scan showed maxillary torus necrosis.
(a) Axial computed tomography (CT) slide through maxillary torus showing lucency and erosion; (b) initial presentation pre-biopsy
Diagnosed with Stage 2 MRONJ, manage with avoidance of oral trauma, saline and 0.2% Chlorhexidine mouth rinses after every meal and ongoing review.
1 × 2 cm area of exposed bone of the palatal torus left of the midline, mobile and slightly tender. Sequestrectomy. Histology- necrotic bone.
(a)exposed palatal tori; (b)immediately post sequestrectomy (c) sequestered bone; (d) 2 weeks post sequestrectomy with epithelialization.
2 weeks postoperatively, completely asymptomatic.
Review of Literature
83% of reported cases women. Average age “spontaneous” MRONJ was 68.2 years (range: 50–87 years). 42% had osteoporosis, 23% had metastatic bone disease, 14% osteopenia, 13% multiple myeloma. 56% had oral bisphosphonates, 50% of these treated with Alendronate. 36% treated with IV BPs, most common Zoledronate (27%). Average duration of antiresorptive treatment in “spontaneous” MRONJ was 4.4 years (range: 0.3-10 years). 80% cases in mandible, 19% in maxilla. Of cases involving mandible, 58% in posterior region. 34% in mylohyoid and/or lingual area.