Soft-tissue facial angles in individuals with ectodermal dysplasia : a three-dimensional non invasive study

OBJECTIVE: To supply quantitative information about the facial soft tissues of patients with hypohidrotic ectodermal dysplasia. DESIGN: Prospective assessment. SETTING: National meetings of hypohidrotic ectodermal dysplasia patients and families. PATIENTS AND MAIN OUTCOME MEASURES: Facial and mandibular corpus convexities in the horizontal plane; facial convexity in the sagittal plane; interlabial, naso-labial, nasal convexity, and left and right soft tissue gonial angles were calculated from the three-dimensional coordinates of 11 soft tissue facial landmarks obtained in 18 male and 17 female hypohidrotic ectodermal dysplasia patients aged 3 to 41 years and in 504 reference healthy individuals. In addition, z-scores were computed and the patients were grouped by cluster analysis. RESULTS: Male and female z-scores did not differ. In the pooled group, facial convexities in the horizontal and sagittal planes were significantly (Student's t, p < .01) increased (flatter) in hypohidrotic ectodermal dysplasia patients, compared with normal controls. The naso-labial angle was significantly reduced (more acute). Upper and lower facial convexity and mandibular corpus convexity in the horizontal plane deviated less from the norm with increasing age. Facial convexity in the horizontal and sagittal planes, soft tissue gonial angles, and naso-labial and interlabial angles deviated less from the norm with increasing number of teeth present in the mouth. Cluster analysis identified three homogeneous groups, all characterized by a peculiar facial phenotype. Modifications in facial convexity and gonial and interlabial angles differentiated each cluster. CONCLUSIONS: Patients with hypohidrotic ectodermal dysplasia had flatter faces in the horizontal and sagittal planes than normal controls had. Cluster analysis revealed patterned differences in facial phenotype.