A comparative study of facial growth following lip and palate repair performed in sequence and simultaneously: an experimental study in beagles.

Abstract

This study was designed to assess the effects of the commonly accepted sequence of cleft lip and palate repair on subsequent maxillofacial growth and to compare these effects with those resulting from simultaneous lip and palate repair. Using 62 eight-week-old normal beagles, we tested the hypothesis that sequential repair (lip first, palate second) of surgically induced lip and palate defects is less detrimental to maxillofacial growth than simultaneous repair of both surgically created defects. Animals were assigned to one of four groups: two control groups (unoperated and unrepaired) and two experimental groups. Defects simulating cleft of the lip, alveolus, and palate were surgically created in the unrepaired controls and in the experimental animals. In one experimental group, the lip and palate defects were repaired immediately and simultaneously. In the other experimental group--simulating current clinical practice--the lip defect was repaired first at the time that it was created, while closure of the palatal defect was delayed 4 weeks. After the animals were killed at 36 weeks of age, 11 maxillary variables were measured directly from cleaned skulls and analyzed by using univariate and multivariate techniques. Animals that had lip and palate defects closed in sequence had less severe maxillofacial aberrations than animals with simultaneously closed defects. Sequential closure of the defects also had identifiable effects on maxillofacial form. The growth aberrations observed among animals with sequential closure, however, are primarily attributable to surgical creation of the defects and not to the surgical repair. Delaying palate repair is less traumatic to the subsequent growth of the maxillary complex than simultaneous repair of lip and palate defects.