Internal Maxillary Distraction With a New Bimalar Device

Purpose

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.

Materials and 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.