Abstract

Focal osteoporotic bone marrow defect is an asymptomatic condition characterized by localized areas of de creased trabecular bone density within the jaw and is often detected incidentally on radiographic examination. Although it generally does not require treatment, it may increase the risk of complications during dental implant placement due to insufficient primary stability in areas of low bone density. This report describes three clinical cases of implant fixture displacement into focal osteoporotic bone marrow defects in the posterior mandible. Radiographic examinations revealed ill-defined radiolucent lesions without cortical expansion at the implant sites. One patient experienced inferior alveolar nerve injury following displacement, whereas no postoperative complications were observed in the remaining cases. These findings indicate that focal osteoporotic bone mar row defects may represent an underrecognized risk factor for implant displacement, and highlight the importance of careful preoperative radiographic assessment and cautious surgical planning in areas of suspected low bone density.(J Korean Dent Assoc 2026; 64(5): 157-162)