The relationship between arch dimensions and the 5-year index in the primary dentition of patients with complete UCLP

To compare dental arch dimensions of children in the primary dentition with repaired unilateral clefts of the lip and palate (UCLP) to a noncleft group of a similar age and determine how the dimensions of the cleft arches relate to an index of treatment outcome.

Dental study casts of 44 5- to 6-year-olds with complete UCLP (22 boys and 22 girls) from a single center, whose primary surgery had been carried out by one surgeon, were matched for age, sex, and ethnicity with dental study casts from a longitudinal growth study. Analysis of variance was used to ascertain differences in arch dimensions between the two groups. The cleft group casts were then assessed with an established index of surgical outcome, the 5-year-old index. Spearman's rank correlation coefficient was used to see how the arch dimensions of the cleft group related to the categories of the index.

Maxillary arch dimensions were significantly smaller in the cleft group than in the noncleft group, irrespective of sex (p < .05). In the mandibular arch, there was no difference between the cleft and noncleft groups (p > .05). Maxillary arch dimensions of the cleft group correlated significantly with the 5-year-old index for arch length and intercanine width (p < .05) but not intermolar width (p = .842). This would suggest that the 5-year-old index is a suitable tool for assessing the outcome of treatment in the primary dentition for anteroposterior and anterior transverse arch dimensions.