Surgery-first orthognathic approach for the correction of facial asymmetry

Abstract

We aimed to compare the reliability of the surgery-first approach and the traditional orthodontic-first approach for the correction of facial asymmetry based on the new classification of facial asymmetry. Patients with facial asymmetry who underwent orthognathic surgery between January 2016 and January 2019 were included. Cephalometric changes and relapse ratios were analyzed 12 months before and after surgery. Patients were divided into horizontal and vertical asymmetry groups based on the asymmetry vector, and subgroup analysis was conducted. The surgery-first approach without presurgical orthodontic treatment and the orthodontic-first approach showed a similar degree of asymmetry correction and skeletal stability. The relapse ratios of the maxilla height in the surgery-first and orthodontic-first groups were 0.25 ± 0.21 and 0.27 ± 0.25, respectively (p = 0.63), the relapse ratios of the maxilla width were 0.31 ± 0.32 and 0.21 ± 0.2, respectively (p = 0.14), the mandibular height relapse ratios were 0.34 ± 0.58 and 0.29 ± 0.36, respectively (p = 0.69), and the mandibular width relapse ratios were 0.12 ± 0.22 and 0.26 ± 0.31, respectively (p = 0.058). The treatment period of the surgery-first group (18.5 ± 5.3 months) was significantly shorter than that of the orthodontic-first group (22.9 ± 7.5 months, p = 0.024). Among the surgery-first group, patients with vertical asymmetry (15.0 ± 3.2 months) had a shorter treatment than those with horizontal asymmetry (21.6 ± 6.8 months, p = 0.006). Although contesting traditional standards is always challenging, the surgery-first orthognathic approach may lead to a new era in traditional orthognathic approaches. This new classification of facial asymmetry could be useful and practical when treating patients with facial asymmetry regardless of the etiology.

Keywords: Cephalometry; Dentofacial deformities; Facial asymmetry; Orthodontics; Orthognathic surgery; Retrospective studies.