Regeneration of the Neocondyle After Free Fibular Flap Reconstruction of the Mandibular Condyle

Purpose: Shifting of the flap position after condylar reconstruction with free fibular flaps is known to occur, but its long-term effects on postoperative esthetic outcomes have not been sufficiently reported. Therefore, in this study, we evaluated the long-term morphologic stability of the free fibular flap neocondyle. Patients and Methods: This was a retrospective cohort study. The primary outcome variables were neocondyle regeneration and neocondyle position including the distance between the glenoid fossa and the initial neocondyle (Fo-Co), the distance between the glenoid fossa and the stable neocondyle (Fo-Co'), and shifting of the neocondyle (defined as the distance between the stable neocondyle and the initial neocondyle). The primary predictor variable was time. The other variables were age, gender, diagnosis, and number of fibular segments. Correlation analysis between the predictor variables and outcome variables was performed. Results: The sample was composed of 26 patients (11 male and 15 female patients) with a mean age of 31 years. Diagnosis and number of fibular segments were significantly associated with Fo-Co and Fo-Co' (P < .05). Among the 26 patients, only 11 showed neocondyle regeneration at follow-up (group A) whereas 15 did not (group B). Neocondyle regeneration was significantly associated with patient age (P < .01). Stable Fo-Co and stable time were significantly associated with neocondyle regeneration (P < .05). The mean stable time was significantly shorter in group A (3.64 +/- 1.12 months) than in group B (6.67 +/- 3.85 months) (P < .05), and the mean Fo-Co' was significantly shorter in group A (13.65 +/- 3.94 mm) than in group B (20.68 +/- 8.87 mm) (P < .05). Conclusions: The possibility of neocondyle regeneration is higher in pediatric patients than in adults. Neocondyle regeneration could result in the movement of the neocondyle toward the glenoid fossa with a shorter stable time, which could improve neocondyle repositioning. Repositioning of the neocondyle with free fibular flaps for mandibular condyle defects is a self-adaption process for temporomandibular joint function. (C) 2019 American Association of Oral and Maxillofacial Surgeons