Robust and least-squares orthogonal mapping: methods for the study of cephalofacial form and growth

A method is presented for the description and analysis of cephalofacial form and growth using two-dimensional coordinate data. The procedure permits the identification of shape differences at specific cephalofacial coordinate locations without reliance upon conventional cephalometric landmarks. The resulting size-standardized coordinates can be analyzed by statistical methods for further data exploration. Two methods of shape transformation--least-squares and robust fitting--are described and compared. An example of the utility of the technique for cephalofacial growth studies is provided.