Temporomandibular Joint Ankylosis After Ramus Construction With Free Fibula Flaps in Children With Hemifacial Microsomia

Purpose: Patients with hemifacial microsomia (HFM) and Kaban-Pruzansky type III mandibular deformities require ramus construction with autologous tissue. The free fibula flap, an alternative to the costochondral graft, has favorable characteristics for this construction but may be associated with temporomandibular joint ankylosis. The purposes of this study were to present a series of patients with HFM who underwent free fibula flap ramus construction, to determine the incidence of ankylosis, and to identify perioperative factors associated with ankylosis.

Materials and methods: We performed a retrospective cohort study of patients with HFM who underwent ramus construction with a free fibula flap at Boston Children's Hospital from 2003 to 2015. Patients who had at least 1 year of follow-up and complete medical records were included. The predictor variables included demographic information, HFM severity, surgical history, and operative details. The primary outcome variable was the occurrence of ankylosis. Descriptive statistics were calculated, and significance was set at P < .05.

Results: We included 8 patients (75% of whom were female patients) in the study sample. Patients underwent construction at a mean age of 11.4 ± 5.9 years (range, 5 to 21 years). In 5 patients (63%), ankylosis developed during the follow-up period of 7.3 ± 4.8 years. The average time from construction to ankylosis was 4.2 ± 3.7 years. The only predictor variable statistically significantly associated with ankylosis was the use of a contralateral releasing osteotomy, which reduced the rate of ankylosis (P = .035). There was a trend toward a younger age in patients in whom ankylosis developed (8.8 ± 2.6 years) compared with those without ankylosis (15.5 ± 8.1 years, P = .392).

Conclusions: The free fibula flap can be associated with a high rate of ankylosis when used for ramus construction in patients with HFM. Passive flap insertion and/or use of a contralateral releasing osteotomy may reduce this risk.