Sunday, October 28, 2007
13039

Distraction Rate and Latency: Factors in the Outcome of Pediatric Maxillary Distraction

Patrick Cole, MD, Stephen Higuera, MD, and Larry H. Hollier, Jr, MD.

BACKGROUND/PURPOSE: Over 50 years ago, current tenets of distraction osteogenesis were developed through work on the lower extremity; however, the application of these tenets to the pediatric craniofacial skeleton remains questionable. Prompted by concern that traditional aspects of distraction osteogenesis may lead to higher rates of premature consolidation in the pediatric maxilla, we retrospectively evaluated maxillary distraction protocol utilizing a 24-hour latency period in conjunction with a distraction rate of 2mm/day. METHOD(S): Following maxillary advancement via distraction protocol consisting of a 24-hour latency period and distraction rate of 2 mm/day, 7 consecutive pediatric cases were evaluated. Standard profile photos and cephalometric films taken pre-operatively, at device removal, and at one year follow up were compared. With the sella as the point of registration, pre- and postdistraction films were superimposed on the sella-nasion plane. Sella-nasion-subspinale, the angle of convexity, the distance from incisal edges to the y axis, and angulation of the upper incisor to the sella-nasion plane were analyzed to evaluate hard tissue changes. RESULTS: Patient age ranged from 3 years to 14 years (mean=7.43 years). Maxillary distraction length averaged 11 mm (range=10-12 mm). Interval from device application to removal averaged 98 days (range=75-180 days). The interval of the active distraction ranged from 11 to 65 days (mean=24 days). From distraction completion to device removal averaged 85 days (range=60-150). Follow up intervals ranged from 52 to 24 months (mean=34 months). All patients demonstrated substantial clinical advancement of the maxilla with correction of midfacial deficiencies. A single patient developed mild cellulitis at one skin-device interface; no other complications were noted. Cephalometric and clinical evaluations at one year post-distraction demonstrated stable results, and parental satisfaction was qualitatively high. CONCLUSIONS: Our results demonstrate effective maxillary correction following application of a 24-hour latency period coupled with rapid distraction at 2 mm/day. Our success with a short latency period and more rapid device expanse may be a product of the significant vascularity and improved healing potential of the pediatric maxilla.
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