title: Meta-analysis of mandibular distraction osteogenesis: clinical applications and functional outcomes.
abstract: BACKGROUND
  Mandibular distraction osteogenesis has been used effectively to treat syndromic craniofacial deformities. In recent years, its scope of application has widened to include treatment of airway obstruction in adults and children and nonsyndromic class II mandibular hypoplasia. So far, there has been no evidence-based review of mandibular distraction osteogenesis for mandibular lengthening.
  
  
  METHODS
  Two rounds of searches were performed by two independent assessors. The first-round PubMed search used the keywords "mandible" and "distraction osteogenesis." In the second-round search, the reference lists of the articles were retrieved. For both rounds, abstracts and then full articles were reviewed and selected on the basis of a set of inclusion and exclusion criteria.
  
  
  RESULTS
  The 178 retrieved articles yielded 1185 mandibular distraction osteogenesis patients: 539 received unilateral mandibular distraction osteogenesis and 646 received bilateral mandibular distraction osteogenesis. Mandibular distraction osteogenesis was reported to improve facial asymmetry and retrognathia (50.1 percent), correct the slanted lip commissure (24.7 percent), and improve or level the mandibular occlusal plane (11.1 percent) in unilateral asymmetry cases, whereas bilateral mandibular distraction osteogenesis was shown to be effective in preventing tracheostomies for 91.3 percent of neonates or infants with respiratory distress, and in relieving symptoms of obstructive sleep apnea for 97.0 percent of children and 100 percent of adult patients.
  
  
  CONCLUSIONS
  Mandibular distraction osteogenesis is effective in treating craniofacial deformities, but further clinical trials are required to assess the long-term stability and to compare the treatment with conventional treatment methods, especially in cases of obstructive sleep apnea or class II mandibular hypoplasia.
authors.affiliation: Hong Kong From the Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Hong Kong, Prince Philip Dental Hospital.
authors.forename: Andrew T C
authors.initials: ATC
authors.lastname: Ow
authors.forename: Lim K
authors.initials: LK
authors.lastname: Cheung
mesh_terms: D000293:Adolescent; D000328:Adult; D001171:Arthritis, Juvenile / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D019465:Craniofacial Abnormalities / Q000601:surgery*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008334:Mandible / Q000601:surgery*; D008336:Mandibular Diseases / Q000151:congenital / Q000601:surgery*; D008338:Mandibular Injuries / Q000601:surgery*; D019857:Osteogenesis, Distraction; D020181:Sleep Apnea, Obstructive / Q000601:surgery*; D016896:Treatment Outcome