Defect-Driven and Age-Related Patterns of Flap Selection in Pediatric Mandibular Reconstruction

Background: Pediatric mandibular reconstruction requires restoration of mandibular continuity while accounting for craniofacial growth, dental development, and long-term functional outcomes. Although vascularized osseous free flaps are widely used, the influence of defect characteristics and patient age on donor-site selection remains unclear. This study evaluated patterns of flap selection in relation to mandibular defect classification and patient age. Methods: This retrospective single-center cohort study included 75 patients aged 1-18 years who underwent microvascular mandibular reconstruction between 2011 and 2025. Donor sites included the fibula, iliac crest, and medial femoral condyle. Mandibular defects were classified according to the Brown classification. Associations between defect class, age, donor-site selection, and flap loss were analyzed. Results: The fibula flap was used most frequently (52.0%), followed by the iliac crest (44.0%) and medial femoral condyle (4.0%). Donor-site selection was significantly associated with Brown defect classification (p < 0.001). Age differed across donor-site groups, with fibula flaps used more often in younger patients and iliac crest flaps in older patients. However, after stratification by defect class, age-related differences were not statistically significant. Overall flap survival was 93.3%, and age was not associated with total flap loss. Conclusions: Donor-site selection showed a stronger association with defect characteristics than with patient age. Observed age-related patterns likely reflect differences in defect morphology. These findings support the clinical relevance of a defect-oriented framework for pediatric mandibular reconstruction; however, flap selection remains individualized and influenced by multiple patient- and surgeon-related factors.