Bone Resorption After Microvascular Osseous Free-Flap Reconstruction in Pediatric Patients: A Retrospective Study.

Background Bone resorption is an important consideration following microvascular osseous reconstruction. However, data regarding clinically significant bone resorption in pediatric patients remain limited. This study aimed to assess the occurrence of clinically significant bone resorption six months after reconstruction with vascularized bone-containing free flaps in pediatric patients and to evaluate whether the occurrence of major bone resorption differed according to flap type. Methods This retrospective observational study included 46 pediatric patients who underwent 54 microsurgical free-flap procedures between 2013 and 2017. After exclusion of five soft-tissue flaps and 13 necrotic bone-containing flaps, 36 viable osseous free flaps were included in the bone-resorption analysis. Clinically significant bone resorption was assessed on computed tomography performed six months after reconstruction using a modified radiographic bone-height assessment based on the adjacent dentition. Major bone resorption was defined as insufficient reconstructed bone height to accommodate a dental implant of a length typically used for the corresponding anatomical region. The occurrence of major bone resorption at six months was compared according to free-flap type using Fisher's exact test. Results Major bone resorption was observed in 8 of 36 evaluable flaps (22.2%), whereas 28 flaps (77.8%) showed no major resorption. Major resorption occurred in 6 of 25 fibular flaps (24.0%) and two of nine iliac crest flaps (22.2%). No major resorption was observed among the two medial femoral condyle flaps. No statistically significant association was found between flap type and major bone resorption (Fisher's exact test, p = 1.000). Conclusion Clinically significant bone resorption may occur during the early postoperative period following microvascular osseous reconstruction in pediatric patients. Postoperative radiological assessment of reconstructed bone may be particularly valuable when future dental rehabilitation is anticipated.