Shape changes in the cleft palate maxilla: a longitudinal study

The purpose of this study was to compare the shape of the maxilla in Norma lateralis of cleft lip and palate (CLP) patients with non-CLP controls matched for sex and age. This study utilized elliptical Fourier functions to assess the presence of residual shape changes in the cleft palate maxilla after treatment, compared with controls.

Longitudinal data (n = 25) were available from the Miami Craniofacial Anomalies Foundation. From these data, two samples were selected: group I (mean age and SD, 5.06 +/- 1.82 years) after lip surgery and the initiation of palate surgery and group II (16.58 +/- 2.42 years) well after the conclusion of surgery. Twenty-two of these patients were matched with controls (5.11 +/- 1.33 and 15.91 +/- 2.25 years, respectively). The maxillary outline as seen on the lateral radiograph was (1) traced, (2) fitted with a series of 48 closely placed points, (3) digitized, and (4) submitted to a specially written routine that computes elliptical Fourier functions (EFFs). These EFFs are close analogs of the bounded maxillary outline as judged by the residual or difference between the observed points and the predicted points generated by the Fourier function. Each maxillary outline was subsequently standardized for size and corrected for positioning in two-dimensional space.

Utilizing a three-way multivariate analysis of variance, statistically significant shape differences were obtained for both young and older groups, as well as between the CLP and controls. No significant gender differences were found. Morphological differences consisted of a posterior repositioning of the nasal crest aspect in the CLP cases. These results suggest that although a clinically satisfactory treatment result was obtained, differences in maxillary shape remain.