The need for a simple, routinely applicable method for morphologic analysis of maxillary arch in cleft patients resulted in development of a new original, objective and computerized method. The authors present the rationale and procedure of this method which is extremely suitable for clinical documentation, follow up and clinical investigation of cleft patients. The descriptive factors are expressed in relative numbers--rations of asymmetry and segment displacement. The relative numbers enable comparative analysis between arches of different size.