Neonatal distraction surgery for micrognathia reduces obstructive apnea and the need for tracheotomy.

The objective of the study was to assess the effectiveness of neonatal mandibular distraction in treatment of obstructive sleep apnea in the perinatal period in preventing a tracheotomy. This was a prospective study of 17 infants at two centers with severe micrognathia who demonstrated obstructive sleep apnea refractory to conservative therapy. Age at surgery varied from 5 to 120 days. Distraction was performed at a rate of 2 mm/d. After distraction, callus consolidation was allowed for 4 to 6 weeks, and the device was then removed. Each child underwent a three-dimensional computed tomography scan before surgery and approximately 3 months after surgery. Of the 17 patients, 14 successfully underwent extubation and demonstrated significant improvement in the obstructive sleep apnea. Postoperative horizontal ramus length increased from 23.3 to 34.8 mm after surgery. Mean maxillary mandibular discrepancy was 8.28 mm before surgery and 2.2 mm after surgery. Ten infants who underwent pre- and postoperative polygraphic studies showed improvement in obstructive apnea. Three patients had postoperative polysomnographic studies only; the results were also within the normal range. The mean follow-up interval was 16.5 months (range: 8-48 months). Neonatal distraction is an effective method for treatment of micrognathia with obstructive sleep apnea in the perinatal period in preventing a tracheotomy.

Alterations in apoptosis and epithelial-mesenchymal transformation in an in vitro cleft palate model.

The processes of apoptosis and epithelial-mesenchymal transformation have been identified as two major mechanisms by which secondary palatal shelves achieve fusion. The aim of this study was to investigate alterations in these mechanisms by changing the physical distance between paired palatal shelves in an in vitro model of palatogenesis. Wild-type palatal pairs were dissected from E13.5 CD1 mouse embryos and allowed to grow in tissue culture for 48 hours at various intershelf distances. During the fusion process, medial edge epithelial cell fate was assessed using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining, to evaluate apoptosis, and carboxyfluorescence (carboxy-2,7'-dichlorofluorescein diacetate succinimidyl ester) labeling, to measure transformation to mesenchymal cells. Palatal pairs separated in culture greater than or equal to 0.4 mm failed to fuse. TUNEL staining showed that the number of apoptotic cells in the palatal shelves increased as the intershelf distance increased, becoming marked in shelves that did not achieve fusion. The amount of epithelial-mesenchymal transformation, however, decreased with increasing intershelf distance. These results suggest that the contribution of epithelial-mesenchymal transformation and apoptosis to palatal shelf development and fusion can be altered by physical proximity. Therefore, one mechanism behind clefting in utero may result from an imbalance in epithelial-mesenchymal transformation and apoptosis as observed in vitro where palatal shelves are challenged to fuse by physical separation. This effect could be significant in the understanding and treatment of developmental palatal abnormalities. Perhaps in utero manipulation of intershelf spacing or epithelial-mesenchymal transformation and/or apoptosis could reverse the clefting paradigm.