A Potential Anatomic Cause of Mandibular Osteonecrosis in Patients Receiving Bisphosphonate Treatment

Abstract

To the Editor: The recent Mayo Clinic consensus statement for the use of bisphosphonates in patients with multiple myeloma1Lacy MQ Dispenzieri A Gertz MA et al.Mayo Clinic consensus statement for the use of bisphosphonates in multiple myeloma.Mayo Clin Proc. 2006; 81: 1047-1053Abstract Full Text Full Text PDF PubMed Scopus (212) Google Scholar noted that in one series of 22 patients, 91% of cases of osteonecrosis of the jaw (ONJ) occurred posterior to the canine teeth.2Badros A Weikel D Salama A et al.Osteonecrosis of the jaw in multiple myeloma patients: clinical features and risk factors.J Clin Oncol. 2006; 24: 945-952Crossref PubMed Scopus (494) Google Scholar In addition, 45% of the lesions in that study were spontaneous and occurred on the lingual surface of the mandible.2Badros A Weikel D Salama A et al.Osteonecrosis of the jaw in multiple myeloma patients: clinical features and risk factors.J Clin Oncol. 2006; 24: 945-952Crossref PubMed Scopus (494) Google Scholar Postulated causes, including failure of mineralization of newly formed osteoid, inhibition of angiogenesis, and impaired wound healing, are systemic, and therefore ONJ should not have a predilection for a particular anatomic site. We performed multislice computed tomography with orthoradial cuts at 2-mm intervals of the mandible of a woman with metastatic breast cancer who had received sequential pamidronate and zoledronic acid for 4 years (Figure 1).3Kelleher FC McKenna M Collins C Brady GM Crown JP Is bisphosphonate-induced osteonecrosis of the jaw (BONJ) an ischemic manifestation of pseudo-osteopetrosis? biochemical, densitometric, and imaging evidence [abstract].J Clin Oncol. 2006; 24 (Abstract 18621.): 698sGoogle Scholar She had developed ONJ after 2 dental extractions performed on her right hemimandible (Figure 1, A). The right mental foramen (Figure 1, B) and inferior alveolar canal (Figure 1, C) were patent, but lateral lingual canals in the right hemimandible could not be visualized. A solitary left lateral lingual canal (Figure 1, D) appeared narrow secondary to periosteal reactive bone and was visualized in 2 contiguous orthoradial cuts 2 mm apart, suggesting a low likelihood of missed canals using a 2-mm imaging distance (Figure 1, D and E). Healthy individuals may have from 1 to 5 lateral lingual canals. These canals penetrate the lingual surface of the mandible typically in the premolar region. They admit branches of the sublingual artery, travel in a mesial direction, and have a diameter of 0.6±0.2 mm.4Gahleitner A Hofschneider U Tepper G et al.Lingual vascular canals of the mandible: evaluation with dental CT.Radiology. 2001; 220: 186-189Crossref PubMed Scopus (97) Google Scholar We hypothesize that an iatrogenic pseudo-osteopetrotic state caused by bisphosphonate treatment constricts and occludes these canals, leading to pain, ischemia, and impaired wound healing after dental extraction. A Potential Anatomic Cause of Mandibular Osteonecrosis in Patients Receiving Bisphosphonate Treatment–Reply–IMayo Clinic ProceedingsVol. 82Issue 1PreviewI thank Dr Kelleher et al for their interesting letter regarding a potential anatomic cause of mandibular osteonecrosis. They postulate that in patients receiving bisphosphonate therapy, the lateral lingual periosteal perforating canals within the mandible undergo osteopetrosis and sclerosis, leading to avascular necrosis and impaired wound healing. Full-Text PDF