A computer-aided method of measuring nasal symmetry in the cleft lip nose

Objective assessment of the results of cleft lip and nose surgery is necessary to quantify differences between alternative surgical techniques. A previously described method of measuring facial asymmetry has been modified to allow a comparison of differently treated cleft noses (radical nasal correction versus no nasal correction). Standardised, inferior view photographs of 10-year-olds were obtained from patient records. These were projected, traced, digitised and analysed using a BBC microcomputer. A method of excluding the ill-defined nasal baseline by obtaining a mirror-image of the upper nasal perimeter is described. The method has a high degree of inter and intra observer reproducibility.