First cases of Osteonecrosis of the Jaw in two Metabolic Bone Disease Services

MASTAGLIA SR; BAGUR A

Toronto ( Canada)

Congreso; 32nd Annual Meeting of The American Society for Bone and Mineral Research (ASBMR); 2010

The American Society for Bone and Mineral Research (ASBMR)

Bisphosphonates (BP) are the choice therapeutic agents for osteoporosis, bone metastasis, and Paget’s disease. They have been associated with a condition known as bisphosphonate related osteonecrosis of the jaw (BRONJ). We saw no case of osteonecrosis of the jaw related or unrelated to BP over our 25 years’ experience in BP use until 2009. We report the first two cases of BRONJ seen at two reference centers: a university hospital and a metabolic bone diseases center. Case 1: A 60-year old woman with a ten-year history of osteoporosis treated with oral alendronate for 5 years, calcium and vitamin D. She received 3 dental implants which were successful, but developed BRONJ after receiving another 2 in the maxilla. She exhibited exposed bone for over 8 weeks, which prompted consultation and immediate suspension of BP. Menopause occurred at age 50; dairy intake was 1000mg calcium/day. She reported regular exercising, hand fracture and colon cancer surgery 7 years earlier. She had no history of pathology or of taking medication affecting bone. Laboratory results were normal except for slight hypovitaminosis D: Ca 9.0 mg/dl, P 3.5 mg/dl, PTH 38 pg/ml, CTX 290 ng/L, 25OHD 27 ng/ml, BGP 23 ng/ml, Bone alkaline phosphatase 72 IU/L and Cr 0.7 mg/dl. Bone mineral density (BMD) on presentation of BRONJ was low (Hologic, DXA): Lumbar spine 0.866 (Tscore -1.6), Femoral neck 0.607 (Tscore -2.4) and Total femur 0.706 (Tscore -1.9). The jaw lesion improved with local dental treatment but failed to remit. Dietary calcium and Vitamin D were prescribed. Case 2: A 71-year old woman with severe osteoporosis (wrist and hip fracture), type II insulin-dependent diabetes with inadequate metabolic control, retinopathy, and diabetic foot. Physical examination: 158cm height; 62500 Kg weight; 25 Kg./m2 body mass index (BMI), dorsal kyphosis and scoliosis. She received 70mg/week of oral alendronate and 320mg/day of calcium. Four years later she suffered fractures in D7, L1, and L3, thus requiring a walking aid. The patient did not show for follow-up for 2 years, during which she developed a necrotic lesion in the jaw. Biopsy confirmed BRONJ. She received adequate treatment for the lesion and alendronate was suspended; 18 months later the lesion had not healed completely. Conclusion: 1- Though unusual, BRONJ is a complication that must be taken into account in BP treated osteoporosis patients. 2- Our patients had potentially associated factors, i.e. diabetes and invasive dental treatments.