Palate dimensions in six-year-old children with unilateral cleft lip and palate: a six-center study on dental casts.

Objective: To compare palatal dimensions in 6-year-old children with unilateral cleft lip and palate (UCLP) treated by different protocols with those of noncleft children.

Design: Retrospective intercenter outcome study. Patients : Upper dental casts from 129 children with repaired UCLP and 30 controls were analyzed by the trigonometric method.

Setting: Six European cleft centers. Main outcome measures : Sagittal, transverse, and vertical dimensions of the palate were observed.

Statistics: Palate variables were analyzed with descriptive methods and nonparametric tests. Regarding several various characteristics measured on a relatively small number of subjects, hierarchical, k-means clustering, and principal component analyses were used.

Results: Mean values of the observed dimensions for five cleft groups differed significantly from the control (p < .05). The group with one-stage closure of the cleft differed significantly from all other cleft groups in most variables (p < .05). Principal component analysis of all 159 cases identified three clusters with specific morphologic characteristics of the palate. A similar number of treated children were classified into each cluster, while all children without clefts were classified in the same cluster. The percentage of treated children from a particular group that fit this cluster ranged from 0% to 70% and increased with age at palatal closure and number of primary surgical procedures.

Conclusion: At 6 years of age, children with stepwise repair and hard palate closure after the age of two more frequently result in palatal dimensions of noncleft control than children with earlier palatal closure and one-stage cleft repair.