title: Measurement of Distraction Force in Cleft Lip and Palate Patients During Le Fort I Maxillary Advancement With Rigid External Distraction.
abstract: OBJECTIVE
  Maxillary distraction osteogenesis (DO) is a mainstream surgical technique for patients who have severe maxillary hypoplasia associated with craniofacial syndromes and cleft-related deformities. However, limited information about the biomechanical aspects of maxillary DO is available limiting broad utilization and improvements to the procedure. The objective of this study was to analyze force levels during the active distraction process and to investigate the relationship between distraction force and maxillary movement during Le Fort I maxillary DO using a rigid external distraction (RED) system.
  
  
  METHODS
  Microtension gauges were integrated into the distraction wires on each side of the RED system. Six patients with cleft lip and palate aged 12.8 to 23.5 years underwent strain gauge measurements during maxillary advancement with DO using an RED system. Lateral cephalograms were taken to measure maxillary horizontal, vertical, and linear movements after DO.
  
  
  RESULTS
  The average linear maxillary movement was 11.2 mm (range 8.5-15.9 mm). The applied forces ranged from 13.4 to 26.8 N. The distance of maxillary movement was proportional to the distraction force.
  
  
  CONCLUSIONS
  The measurement of distraction forces during DO provides important information with which to establish appropriate protocols. Patients requiring more advancement may require more distraction force. However, other factors such as scarring, patient anatomy, surgical freedom of the osteotomized maxilla, and the like, may affect the required force during DO with the RED system.
authors.affiliation: *Maxillofacial Orthognathics, Graduate School, Tokyo Medical and Dental University, Tokyo †Department of Oral and Maxillofacial Functional Rehabilitation, Graduate School of Medicine, University of the Ryukyus, Okinawa ‡Division of Pedodontics/Orthodontics, Department of Surgical Subspecialties, National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Sawada
authors.forename: Takuya
authors.initials: T
authors.lastname: Ogawa
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kataoka
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Baba
authors.forename: Keiji
authors.initials: K
authors.lastname: Moriyama
mesh_terms: D000293:Adolescent; D002508:Cephalometry / Q000379:methods; D002971:Cleft Lip / Q000601:surgery; D002972:Cleft Palate / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000254:growth & development / Q000601:surgery; D019857:Osteogenesis, Distraction / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D019340:Osteotomy, Le Fort / Q000379:methods*; D011183:Postoperative Complications / Q000517:prevention & control*; D011859:Radiography / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult