CRANIOFACIAL GROWTH AFTER IATROGENIC CLEFT-PALATE REPAIR IN A FETAL OVINE MODEL

Controversy exists over the impact of scar formation on craniofacial g rowth after cleft palate repair. The fetal ovine model presents an opp ortunity to study a group of animals with little or no scar using ceph alometric studies of craniofacial growth after iatrogenic cleft palate repair. Grossly evident scar is formed in the palates of lambs repair ed at 118 days or later in gestation, while those animals operated at 70 and 77 days' gestation exhibited no scar grossly and minimal scar h istologically in the submucosa with normal nasal and oral mucosal surf aces. For this study, 15 lambs were studied: four were unoperated, thr ee were operated at 70 days, one at 77 days, and seven had clefts prod uced and repaired at 118 to 133 days' gestation. The animals were euth anized at 1 month of age and the heads removed and frozen until analyz ed. Computerized tomography of the heads was used to create voxel (vol ume pixel) data sets, and volume rendering and measurement software (V oxblast) was used to create a three-dimensional reconstruction of the skull. Palate measurements were obtained by selecting points on the up per deciduous premolars. A plane was set through the palate and upper deciduous premolars using standard points on the skull to maintain con sistent visualization and point selection. The measurements were norma lized to skull size measured by the distance between points on the rig ht and left zygomatic bones. Using one-way analysis of variance, follo wed by a protected t test, no significant differences were found betwe en the means of any measurement in the three treatment groups, Fetal p alate repair, with or without scarping, resulted in normal craniofacia l growth in the 1-month-old lamb.