The fetal cleft palate: IV. Midfacial growth and bony palatal development following in utero and neonatal repair of the congenital caprine model.

BACKGROUND: Midfacial hypoplasia and growth disturbances following cleft palate repair are well-known consequences of the maxillary scarring inherent with each repair technique. The present study investigated the influence of in utero palatoplasty, and cleft repair in 6-week-old goats, on midfacial growth and bony palatal development in the authors' congenital caprine cleft palate model in an effort to identify an inherent component of facial growth impairment associated with the cleft anomaly.

METHODS: At 85 days' gestation, eight clefted fetuses underwent in utero cleft palate repair using a modified von Langenbeck technique; eight fetuses remained as unrepaired controls. At 6 weeks of age, eight goats underwent cleft palate repair using the same technique. All goats were euthanized at 6 months of age; dry skull measurements and cephalometric analyses were performed.

RESULTS: Fetal Repairs: Both repaired and unrepaired clefted goats demonstrated significant evidence of maxillary hypoplasia compared with unclefted controls. Repaired goats showed a decrease of 15.7 percent in maxillary length, and unrepaired clefted goats showed a decrease of 18.0 percent in maxillary length, compared with unclefted controls. There was no significant difference in maxillary growth between the repaired and unrepaired clefted groups. Bony cleft width was reduced by 48 percent anteriorly and 60 percent posteriorly. Thirty-seven percent of repaired congenital clefts demonstrated partial bony fusion involving 10 to 70 percent of the palatal length. This was accompanied by an 8.8 percent decrease in maxillary width at the level of the third molar crown compared with unclefted controls and an 18.3 percent decrease in maxillary width compared with unrepaired clefted goats. Unrepaired clefted goats demonstrated neither a decrease in maxillary width nor any narrowing or fusion of the bony cleft. Newborn Repairs: Significant midfacial growth impairment was seen in animals that underwent cleft palate repair at 6 weeks of age compared with those repaired in utero and with unclefted controls. Repaired clefted goats demonstrated a significant decrease in maxillary length by 29.5 percent compared with unclefted controls and 16.4 percent compared with the group repaired in utero. Repaired goats also demonstrated a significant decrease in maxillary width in the transverse dimension at the level of the third molar. A decrease in maxillary width of 25.3 percent was seen compared with the unclefted controls and 18.1 percent compared with the fetal repairs. Bony cleft width was reduced by 32 percent anteriorly and 27 percent posteriorly following repair at 6 weeks of age. Although all goats demonstrated narrowing following repair, partial bony palatal fusion was not seen in this group.

CONCLUSIONS: In utero cleft palate repair does not contribute to impairment of midfacial growth. The authors attribute this finding to the scarless nature of mucoperiosteal healing in the privileged fetal environment. However, the cleft palate anomaly does have an inherent component of facial dysmorphology that is evidenced as maxillary hypoplasia or retrusion in unrepaired clefted animals. Cleft repair in the newborn period, or thereafter, results in midfacial growth impairment in a manner similar to that seen clinically. The authors attribute this finding to the scarring that routinely accompanies conventional palatoplasty. The combination of the growth impairment inherent in the cleft anomaly and that attributable to postnatal repair scarring yields the midfacial retrusion commonly associated with cleft palate.