3-dimensional analysis of cleft palate casts.

It is the aim of presurgical infant orthopedics (PSIO) to reduce the width of the cleft and to achieve optimal alignment of the cleft palate segments within the first few months of infancy prior to any surgical cleft closure. The question about the amount that PSIO can stimulate and steer the growth of the maxilla using a Hotz and Gnoinski passive appliance has not yet been satisfactorily answered. In this study, a 3-dimensional digital computer-aided procedure was developed to analyze metrically and to visualize the growth of the edentulous maxilla of cleft lip and palate in infants. In a pilot study, a series of digital scans of consecutive plaster casts was carried out. 5 infants with complete unilateral cleft lip and palate (UCLP), who had been treated with passive appliances were evaluated. Impressions were taken at the age of one week and after 3, 6 and 12 months. Following digitizing, the casts were computer-reconstructed and segmented perpendicular to the alveolar crest, the reference points being C1, C1', C2, C2' and I. The volume of the resulting segments was ascertained. Computer superimposition of reconstructed consecutive casts was employed to facilitate a visualization of the extent and direction of morphological changes. Our first results have shown that with our method it is possible to quantify the growth rate of defined segments of the maxilla. The 3-dimensional analysis presented here will be the basis for further studies to objectify PSIO.