Cephalometric evaluation of the craniofacial complex in hemifacial microsomia treated with an internal distraction osteogenesis device: A case series of 3 patients with a ≥12-year follow-up.

Introduction: Distraction osteogenesis has been the preferred treatment modality for patients with hemifacial microsomia. Although an immediate improvement in facial asymmetry is noted at the completion of the procedure, long-term data regarding postdistraction stability is rare. In this study, a ≥12-year follow-up was conducted on patients who underwent distraction osteogenesis to examine the long-term stability of the surgical procedure. This study aimed to evaluate the cephalometric distraction relapse tendency after ≥12 years.

Methods: Three patients with hemifacial microsomia who underwent distraction osteogenesis were recalled, and their records were taken. Multiple measurements, such as mandibular length, ramus height, maxillary height, occlusal height, and chin position, were made to record the changes in the mandible and maxilla from posteroanterior and 45° lateral oblique cephalograms after ≥12 years.

Results: Mandibular length, ramus height, maxillary height, chin deviation, occlusal cant, and the interantegonial plane angle showed immediate improvements after distraction. After ≥12 years of distraction, the mandibular length, maxillary height, and occlusal height remained relatively stable, but the ramus height and chin deviation were unstable, resulting in an increase in facial asymmetry.

Conclusions: A combination of decreased growth and postsurgical relapse on the affected side contributes to the continuous worsening of facial asymmetry. Dentoalveolar remodeling contributed to even more facial asymmetry into adulthood. Thus, overcorrection was needed to reduce and overcome the degree of long-term facial asymmetry after growth completion.