Medication-related osteonecrosis of the jaw secondary to peri-implantitis: Report of a case with a unique clinical course

The number of older adults with systemic conditions who have undergone dental implant treatment is increasing. Peri-implantitis is a local factor associated with medication-related osteonecrosis of the jaw (MRONJ). Treatment methods for severe MRONJ with pathological fracture remain controversial. An 86-year-old woman with dementia and osteoporosis was referred to our department with a chief complaint of left mandibular peri-implantitis. We diagnosed her with MRONJ secondary to peri-implantitis and performed conservative surgery in which the sequestrum was completely excised. Although a pathological fracture occurred approximately 2 months after surgery, we observed the patient conservatively because of the minimal deviation and absence of active inflammation. Spontaneous bone regeneration had occurred by approximately 1 year postoperatively. Our findings suggested that dental implants placed in older adults with dementia who are receiving antiresorptive therapy should be carefully monitored to prevent peri-implantitis and peri-implant MRONJ. In patients with severe MRONJ and pathological fracture, favorable bone healing can be achieved with conservative surgery if the remaining bone has remodeling capability.