title: Maxillary distraction in patients with cleft deformity using a rigid external distraction device: a pilot study on the distraction ratio of the maxilla to the device.
abstract: We examined the ratio between actual maxillary distraction and the distraction of the rigid external distraction device (Rigid external distraction (RED) system) used for maxillary distraction in patients with a cleft deformity. Twelve patients were examined. The amount of maxillary advancement was measured on lateral cephalograms and divided by the activation amount on the RED system. The value obtained was represented as the distraction ratio of the maxilla to the system. The mean ratio in 10 patients with complete cleft lip, palate, and alveolus (complete cleft) was 0.24. However, the ratios in two patients with cleft lip and alveolus or soft cleft palate (incomplete cleft) were considerably higher than the mean ratios in patients with complete cleft. When the maxilla is distracted in patients with complete cleft using the RED system, the amount of activation on the system needs to be about four times the amount of planned maxillary distraction. However, the distraction ratio may be affected by the type of cleft.
authors.affiliation: Oral and Maxillofacial Surgery, Department of Oral Restitution, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo 113-8549, Japan. harada.osur@tmd.ac.jp
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Harada
authors.forename: Masaru
authors.initials: M
authors.lastname: Sato
authors.forename: Ken
authors.initials: K
authors.lastname: Omura
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002972:Cleft Palate / Q000175:diagnosis* / Q000601:surgery*; D004867:Equipment Design; D004869:Equipment Safety; D005115:Extraoral Traction Appliances; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008437:Maxilla / Q000601:surgery*; D019857:Osteogenesis, Distraction / Q000295:instrumentation* / Q000379:methods; D010865:Pilot Projects; D018570:Risk Assessment; D016896:Treatment Outcome