WBR0767

Author	[[PageAuthor::Rim Halaby, M.D. [1] (Reviewed by Will Gibson)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pharmacology
Sub Category	SubCategory::Musculoskeletal/Rheumatology
Prompt	[[Prompt::A 58-year-old female presents to the physician's office for a mandibular lesion. Her past medical history is significant for breast cancer. She is currently receiving zoledronic acid for her osteoporosis. The physician suspects the patient is having bisphosphonate-related osteonecrosis of the jaw. What additional predisposing factor is most likely to be present that led to this patient's condition?]]
Answer A	AnswerA::Personal history of dental problems
Answer A Explanation	AnswerAExp::History of dental problems, such as dental extractions or tooth infections, is the main risk factor for BRONJ.
Answer B	AnswerB::High-grade breast cancer on pathological analysis
Answer B Explanation	AnswerBExp::A history of breast cancer is not a risk factor for the development of BRONJ. However, breast cancer often metastasizes to bone where it causes osteolytic lesions.
Answer C	AnswerC::History of corrosive esophagitis
Answer C Explanation	[[AnswerCExp::Corrosive esophagitis may be an adverse effect of bisphosphonates. To prevent corrosive esophagitis, patients are asked to take bisphosphonates in the morning in a standing position while drinking plenty of water. Patients are instructed to stay standing for several minutes before lying in a supine position.]]
Answer D	AnswerD::History of heavy smoking
Answer D Explanation	AnswerDExp::Smoking is not a risk factor for BRONJ.
Answer E	AnswerE::Caucasian race
Answer E Explanation	AnswerEExp::While caucasian race is a risk factor for the development of osteoporosis, it is not an independent risk factor for BRONJ.
Right Answer	RightAnswer::A
Explanation	[[Explanation::Bisphosphonates are pyrophosphate analogues that bind to hydroxyapatite in the bone, thereby inhibiting osteoclast activity. Bisphosphonates are indicated for the treatment of osteoporosis, as inhibiting osteoclast-driven breakdown of bone can increase bone strength. Bisphosphonates are used for Paget's disease to stop the cycling of osteoblastic and osteoclastic activity. Finally, bisphosphonates can be used to treat hypercalcemia by slowing the release of calcium from the bone. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is an adverse drug reaction during bisphosphonate use. The main risk factor for BRONJ is a history of dental procedures and/or poor dental hygiene. In particular, patients with BRONJ have often undergone dental extractions, or surgery of the maxillofacial region. Other secondary factors that also seem to be associated with BRONJ are corticosteroid therapy, radiotherapy, diabetes mellitus, and peripheral vascular disease. These other risk factors are not high-yield for the USMLE. Educational Objective: Bisphosphonate-related osteonecrosis of the jaw is associated with a personal history of poor dental problems. References: Maerevoet M, Martin C, Duck L. Osteonecrosis of the jaw and bisphosphonates. N Engl J Med. 2005; 353(1):99-102. First Aid 2015 page 445]]
Approved	Approved::Yes
Keyword	WBRKeyword::Dental procedures, WBRKeyword::Tooth extraction, WBRKeyword::Dental, WBRKeyword::Mandible, WBRKeyword::Osteoporosis, WBRKeyword::Tooth, WBRKeyword::Teeth, WBRKeyword::Ostenoecrosis, WBRKeyword::Jaw, WBRKeyword::Bisphosphonate, WBRKeyword::Zoledronic acid, WBRKeyword::Mandible, WBRKeyword::Mandibular, WBRKeyword::Risk factor
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::