Delayed inflammation after biodegradable and osteoconductive osteofixation in orthognathic surgery

Objectives: This study aims to identify patterns and to describe the clinical course of delayed adverse tissue responses in patients who underwent orthognathic osteotomy with biodegradable osteofixation. Patients and Methods: Through a retrospective review of cases between 2013 and 2020, we identified three patients who underwent bimaxillary osteotomy and fixation with unsintered-hydroxyapatite/poly-L lactic acid (u-HA/PLLA) devices, after which they developed delayed inflammation. These lesions were treated with drainage and/or removal of the devices. Histological evaluations were conducted using H&E staining, and structural changes in the u-HA/PLLA devices were assessed by scanning electron microscopy (SEM). Results: Inflammatory lesions developed only in the mandible, with onset ranging from 12 to 35 months post-operation. Histological studies identified foreign-body granulomas or secondarily infected lesions. SEM analysis indicated biodegradation and tissue integration. Conclusion: Orthognathic patients treated using u-HA/PLLA devices should be informed about the potential for delayed inflammation and monitored for at least 3 years.