title: Subapical anterior maxillary segmental osteotomy: a modified surgical approach to treat maxillary protrusion.
abstract: BACKGROUND
  Anterior segmental osteotomy has become an established surgical technique to achieve functional occlusion and improve the facial profile in the treatment of maxillary protrusion. Postoperative nasal changes, however, are somewhat unpredictable. The here presented subapical anterior maxillary segmental osteotomy has been developed to avoid such unintended nasal changes.
  
  
  METHODS
  Thirty-two patients (29 women and 3 men; age range, 18-40 y; mean age, 22 y) with maxillary protrusion underwent subapical anterior maxillary segmental osteotomy. A horizontal osteotomy was carried out between the apices of the anterior teeth and the piriform aperture, maintaining a distance of approximately 2 to 3 mm to the apices. Lateral to both canines, this horizontal osteotomy was connected with vertical osteotomies carried out along the alveolar socket of the first premolar on the right and left sides. Lateral cephalograms and lateral and en face photographs were taken preoperatively and postoperatively for analysis. All patients were followed up for at least 6 months.
  
  
  RESULTS
  Significant changes were observed in hard tissue parameters except the anterior nasal spine. The nasal tip, the alar base, and the lip width remain to have no significant change. The ratio of the upper lip to the maxillary incisor retraction was 0.64:1. Whereas both the nasolabial angle and the philtrum length were significantly increased, the protrusion of the upper incisors and the vermilion length presented decreased. The intraoperative and postoperative courses were uneventful during the entire follow-up period.
  
  
  CONCLUSIONS
  Subapical anterior maxillary segmental osteotomy provides a suitable option in the treatment of maxillary protrusion. It provides improvement of the aesthetic profile without nasal changes.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Key Laboratory for Oral Biomedical Engineering of the Ministry of Education, Wuhan University, Wuhan, People's Republic of China. wzx789@hotmail.com
authors.forename: Zhong Xing
authors.initials: ZX
authors.lastname: Wu
authors.forename: Li Wu
authors.initials: LW
authors.lastname: Zheng
authors.forename: Zu Bing
authors.initials: ZB
authors.lastname: Li
authors.forename: San Jie
authors.initials: SJ
authors.lastname: Ye Weng
authors.forename: Xue Wen
authors.initials: XW
authors.lastname: Yang
authors.forename: Yao Jun
authors.initials: YJ
authors.lastname: Dong
authors.forename: Roger A
authors.initials: RA
authors.lastname: Zwahlen
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000601:surgery*; D008437:Maxilla / Q000002:abnormalities / Q000601:surgery*; D019647:Oral Surgical Procedures / Q000379:methods*; D010027:Osteotomy / Q000379:methods*; D018709:Statistics, Nonparametric; D016896:Treatment Outcome