J Korean Soc Plast Reconstr Surg.  1998 Jun;25(4):581-586.

Distraction osteogenesis of mandible in hemifacial microsomia

• Kim S

Abstract

Gradual distraction on living tissues creates stress that stimulates growth and regeneration. Timing and rate of distraction are one of the major factors affecting callus distraction. Slow rate of distraction often led to premature consolidation of the lengthening bone, while rapid rate of distraction often resulted in undesirable change within lengthening bone. Since Dr. McCarthy reported the successful lengthening of mandible in hemifacial microsomia, most of craniofacial bone lengthening has been done at a rate of 1.0 mm per day. The purpose of this study is to present my experience of rapid and multidirectional distraction of mandible in hemifacial microsomia. I have performed distraction osteogenesis of mandible in 33 patients of hemifacial microsomia with an age of 2-9 years from November, 1995 to October 1997. A complete osteotomy was made at the angle of mandible posterior border of the ramus proximal to the osteotomy and two threaded wires were inserted aling the lower border of the body distal to the osteotomy. Long PennigMinifixator(Orthofix, Bussolengo, Italy) maintained the mandible in fixation for 4 days. Following this period, the device was lingthened serially 1 mm every 12 hours by turning the nut. After the period of active lingthening was complicated, the mandible was maintained in external fixation until the radiological consolidation of the bone was confirmed. According to a study protocol, photographs, cephalograms(lateral and frontal), and panoramic view of mandible were obtained preoperatively, just before the active lengthening, at the time of removal of the device, and at 6 months intervals thereafter. The amount of vertical distraction along the posterior border of the ramus was from 19 to 32 mm and horizontal distraction along the lower border of the body was from 3 to 18 mm. The total amount of distraction was from 25 to 47 mm. The period of rapid distraction was from 13 to 27 days. Following the period of rapid distraction the mandible was maintained in external fixation for an average of 8.5 weeks(ranging from 7 to 11 weeks). There was no preoperative complications, and the length of clinical follow-up tangles from 3 to 26 months. Early reconstruction with minimal morbidity of rapid and multidirectional mandibular distraction in the hemidacial microsomia was successful without relapse. Orthodontic treatment can begin as soon as possible after gradual distraction in order to establish normal dental occlusion.

MeSH Terms

Bone Lengthening
Bony Callus
Dental Occlusion
Follow-Up Studies
Goldenhar Syndrome*
Humans
Mandible*
Nuts
Osteogenesis, Distraction*
Osteotomy
Recurrence
Regeneration