Internal maxillary distraction with a new bimalar device.
OBJECTIVE
Distraction osteogenesis of the Le Fort I segment is advocated for patients who require significant advancement of the maxilla or who have a soft tissue envelope compromised by scar tissue. We present a technique for maxillary distraction using an interconnecting intraoral device anchored to the malar prominences above the osteotomy and either the maxilla and/or the dentition below the level of the osteotomy.


METHODS
Ten patients with nonsyndromic cleft lip and palate, mean age of 18, underwent Le Fort I maxillary distraction osteogenesis for management of maxillary hypoplasia. A Le Fort I osteotomy is performed and a Spectrum Intraoral Midface Multi-Vector Distractor (OsteoMed, Addison, TX) is placed leaving a 1 mm to 2 mm distraction gap. After a 2 to 4 day latency period, distraction begins at a rate of 1 mm a day. Once the desired occlusion is achieved the device is left in place for a minimum of 2 months for consolidation.


RESULTS
Preoperative Sella-Nasion-A point measurements from lateral cephalograms averaged 74 degrees (range, 70-76 degrees). Postoperative Sella-Nasion-A point averaged 81 degrees (range, 75-89 degrees). Preoperative overjet averaged -7.4 mm (range, -3 to -13 mm). Postoperative overjet averaged 2.6 mm (range, 1-3 mm). Average distraction was 9 mm (range, 6-16 mm). The average vertical movement was 7.2 mm in an inferior direction (range, 0-15 mm). The results remained stable at a follow-up of 30 months.


CONCLUSIONS
We report on distraction of the Le Fort I segment using an internal device. The device design allows the forces of distraction to be shared across a larger surface area delivering a uniform and reliable vector of distraction with increased stability.
Kahn
David M
DM
Division of Plastic Surgery, Stanford University Medical Center, Stanford, CA, USA. David.Kahn@stanford.edu
Broujerdi
Joseph
J
Schendel
Stephen A
SA
D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D002971:Cleft Lip / Q000601:surgery; D002972:Cleft Palate / Q000601:surgery*; D005260:Female; D006801:Humans; D016268:Internal Fixators; D008297:Male; D008437:Maxilla / Q000601:surgery*; D008875:Middle Aged; D019857:Osteogenesis, Distraction / Q000295:instrumentation*; D019340:Osteotomy, Le Fort / Q000295:instrumentation*; D063173:Retrognathia / Q000601:surgery