[Evaluation of skull vault asymmetry using methods of analytical morphometry]

Some vertical frontal C.A.T. sections of 8 skull vaults were studied in evaluating shape asymmetry between left and right curves. Every profile was normalized by subdividing in 120 points and standardized by positioning the sagittal line of skull vault profile parallel to the ordinate axis of a Cartesian system. After these procedures, we tried to detect the asymmetry. In order to achieve these results we used a procedure that we named "Janus", a subset of S.A.M. (Shape Analytical Morphometry) software system, giving an artificial close curve by the mirror composition of left and right cranial vault profiles to match each other. This match was performed by a parabolic fitting for a standard positioning. The procedure was able to split the whole asymmetry information into the isometric and allometric components. We tried to detect allometry in terms of direction and versus with a numerical evaluator of its magnitude; this description was properly a vector. In this pilot study by using 24 sections, we found 20 left and 4 right predominance, expressed time by time by isometry, allometry or both.