Objective classification of lip in children with repaired cleft lip-palate

Aims: To classify 3-dimensional (3D) lip shape in children with repaired cleft lip-palate and to compare the lip shape of these children with those of non-cleft ‘control' children. Method: The study sample consisted of two groups of children: 1) A group with repaired cleft lip-palate (n=47), and 2) a group of non-cleft children (n= 25). Facial images of each child were recorded using a 3D camera. All facial images were standardized to a common head orientation. Statistics: A 46-dimensional feature vector that described each child's lip form was extracted from the data. Then, a vector quantization technique was applied to describe the optimum number of 3D lip shapes by means of mathematical codes. Results: Lip shapes in the total sample were described by eight codes. The differences in the feature vectors between the two groups were in the shape of the free edge of the upper lip vermillion border, protrusion of the upper and lower lips, and symmetry of the lips. In each Code, the percentages of children with and without a cleft lip-palate were as follows: Code 1=52.9% and 47.1%; Code 2= 85.7% and 14.3%; Code 3=16.7% and 83.3%; Code 4= 100.0% and 0.0%; Code 5= 71.4% and 28.6%; Code 6=100.0% and 0.0%; Code 7=100.0% and 0.0%; and Code 8=0.0% and 100.0%, respectively. Conclusion: Patients with cleft lip-palate were in the Codes 2, 4, 5, 6, and 7 categories and to a lesser extent in Codes 1 and 3. Non-cleft 'normal' children had lip shapes that were in the Codes 3 and 8 categories and to a lesser extent in Codes 1, 2, and 5. These findings imply that lip shape can be objectively categorized, and that there is greater variation in lip shape for the children with cleft lip-palate. (Supported by NIDCR Grant # R01DE13814)