title: Soft tissue profile changes after maxillary advancement with distraction osteogenesis by use of a rigid external distraction device: a 1-year follow-up.
abstract: OBJECTIVE
  This study was conducted to evaluate the soft tissue profile changes after maxillary advancement with distraction osteogenesis (DO).
  
  
  METHODS
  Sixteen subjects underwent maxillary advancement with rigid external distraction after a high Le Fort I osteotomy. There were 11 male and 5 female patients, ages 5.2 to 25.7 years. The subjects included 9 with unilateral cleft lip and palate (UCLP), 4 with bilateral CLP, 2 with facial clefts and bilateral CLP, and 1 with cleft palate. Pretreatment and posttreatment lateral cephalograms were compared to evaluate the changes in soft tissue profile. A line 7 degrees below the SN plane was used as the horizontal coordinate, and a perpendicular line through Sella was used as the vertical coordinate in an XY coordinate system.
  
  
  RESULTS
  The preoperative facial concavity (N'SnPg') was reduced by 15.59 degrees, and the nasal tip moved 3.75 mm forward and 2.05 mm upward. These changes were positively correlated with the change of ANS position. The soft-tissue-to-hard-tissue ratio was 0.53:1 for nasal tip and ANS. The ratio was negatively correlated with the age of the patient. The ratio of soft tissue A point to skeletal A point was 0.96:1 and for the incisal edge to vermilion border of the upper lip it was 0.8:1. The soft tissue B point and Pg did not change significantly with maxillary distraction. However, the nasolabial angle increased by 4.96 degrees, the upper lip curvature flattened by 0.65 mm, and the lower lip curvature was accentuated by 0.89 mm after distraction. The amount of upper incisal exposure increased from 1.1 to 5.01 mm in the rest position.
  
  
  CONCLUSIONS
  Maxillary DO improved the soft tissue profile by increasing nasal projection, normalizing the nasolabial angle, and making the upper lip more prominent. More upper anterior tooth show in the rest position was obtained, but the upper lip length did not change. The concave facial profile became convex, with improved facial balance and aesthetics.
authors.affiliation: Craniofacial Center, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors.forename: E
authors.initials: E
authors.lastname: Wen-Ching Ko
authors.forename: A A
authors.initials: AA
authors.lastname: Figueroa
authors.forename: J W
authors.initials: JW
authors.lastname: Polley
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D002648:Child; D002675:Child, Preschool; D002971:Cleft Lip / Q000601:surgery; D002972:Cleft Palate / Q000601:surgery*; D004955:Esthetics, Dental; D016267:External Fixators; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008046:Lip / Q000033:anatomy & histology; D008297:Male; D008437:Maxilla / Q000002:abnormalities / Q000601:surgery*; D009666:Nose / Q000033:anatomy & histology; D019647:Oral Surgical Procedures / Q000295:instrumentation*; D019857:Osteogenesis, Distraction / Q000295:instrumentation*; D019340:Osteotomy, Le Fort; D018709:Statistics, Nonparametric; D016896:Treatment Outcome