Cranial index of symmetry: an objective semiautomated measure of plagiocephaly. Technical note.

Object. The prevalence of deformational, or positional, plagiocephaly has increased during the last decade. Treatments vary among centers, ranging from expectant management to orthotic helmet therapy to craniofacial remodeling. This management variability is partially due to a lack of objective methods with which to measure the severity of plagiocephaly, as well as procedures that are not cumbersome or require radiographic studies. A simple and objective method of determining the degree of cranial deformation has been developed. Methods. A headband placed around the head was marked with two adjustable points—one denoting the nasion and the other, the inion. A digital camera was used to image the head from a vertex view. The shape of the headband and the area of each hemisphere were then determined by analyzing the image on a personal computer in a semiautomated fashion. A cranial index of symmetry (CIS) was calculated and, by definition, equaled 100% for a perfectly symmetrical head. In this preliminary s...