title: Long-term changes in the masseter muscle following reduction gonioplasty.
abstract: Many plastic surgeons use mandibular osteotomy (reduction gonioplasty) without masseter resection to correct a square face. However, there is not enough long-term observation of the masseter after reduction gonioplasty, although some researches have already confirmed that the volume of masseter muscle does decrease shortly after reduction gonioplasty.
  
  
  METHODS
  The Plastic Surgery Hospital database was retrospectively reviewed for patients who underwent reduction gonioplasty. Fifty-six patients with both preoperative and 4 years postoperative 3-dimensional computed tomography (3DCT) were included. The changes in the volume and morphology of the masseter muscle after reduction gonioplasty were assessed quantitatively. The 3DCT data were analyzed using Mimics 10.01 software.
  
  
  RESULTS
  All patients were satisfied with the outcome. No complications happened. There were significant differences between the preoperative and 4 years postoperative volume and morphology.
  
  
  CONCLUSIONS
  After reduction gonioplasty, the masseter muscle atrophied (reduced 20.98% ± 8.75%), especially the lower part of the masseter muscle in the long-term follow-up. Most patients with prominent mandibular angles should be treated with reduction gonioplasty without approaching the masseter muscle.
authors.affiliation: From the *Department of CranioMaxilloFacial Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; †State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; and ‡Department of Hand, Plastic, and Reconstructive Surgery, Trauma Centre Ludwigshafen, Ludwigshafen, Germany; and §Department of Plastic and Hand Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Xi
authors.initials: X
authors.lastname: Fu
authors.forename: Lu
authors.initials: L
authors.lastname: Rui
authors.forename: JianFeng
authors.initials: J
authors.lastname: Liu
authors.forename: Christoph
authors.initials: C
authors.lastname: Hirche
authors.forename: Feng
authors.initials: F
authors.lastname: Niu
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.forename: RuoWei
authors.initials: R
authors.lastname: Su
authors.forename: Jia
authors.initials: J
authors.lastname: Xu
authors.forename: Lai
authors.initials: L
authors.lastname: Gui
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D063168:Mandibular Osteotomy / Q000379:methods*; D008406:Masseter Muscle / Q000000981:diagnostic imaging* / Q000502:physiology; D009133:Muscular Atrophy / Q000000981:diagnostic imaging*; D017060:Patient Satisfaction; D019651:Plastic Surgery Procedures / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult