Long-Term Outcomes and Growth Analysis of Costochondral Grafts for Hemifacial Microsomia: 24-Year Experience of a Single Surgeon.

ABSTRACT

BACKGROUND: Costochondral grafts (CCGs) can be used in mandibular reconstruction of Kaban-Pruzansky IIB/III hemifacial microsomia (HFM). Their growth is variable, occasionally necessitating secondary surgery. This study examined one surgeon's 24-year experience to better quantify long-term outcomes and surgical care required in CCG reconstruction of HFM mandibles. METHODS: Serial three-dimensional computed tomography scans, from preoperative to most recent, were analyzed in patients with minimum four years of clinical follow-up following CCG reconstruction. Graft/ramus height, length, volume, bilateral mandibular body length, and chin deviation were measured. Changes in measurements were analyzed at preoperative, immediate postoperative, most recent imaging prior to secondary surgery, and most recent imaging overall. Growth rates per measure were calculated utilizing scans after CCG, but before secondary surgery. RESULTS: Thirteen patients were analyzed. Median clinical follow-up was 10.0 (5.1) years. One patient developed temporomandibular joint ankylosis secondary to stacked-graft malposition, which was repaired without further complications. CCG reconstruction led to immediate improvement in graft/ramus height (p=0.03), length (p=0.002), and volumetric symmetry (p=0.02). No difference was found between graft and native ramus height (p=0.4) and length measures (p=0.5), while graft volume and affected mandibular body grew significantly more slowly. By latest imaging, 63% of patients required secondary surgery, including distraction osteogenesis and/or orthognathic surgery due to differential graft/hemimandible growth behavior. By most recent clinical follow-up, this proportion increased to 93%. CONCLUSION: CCGs provide significant short-term mandibular and facial symmetry improvement in HFM IIB/III. Long-term analysis reveals frequent undergrowth requiring secondary intervention to promote and maintain symmetry.