Analysis of Cranial Morphology of Healthy Infants Using Homologous Modeling.

OBJECTIVE: Data on cranial morphology of healthy individuals can be used as the guide in the treatment of cranial deformity. There are many reports analyzing the cranial morphology of healthy children in the past. But most of them focus on 2-dimensional values, and there are only a few reports, which analyzed the cranial morphology of Japanese healthy infants. We report a novel method that enables the comprehensive analysis of cranial morphology of Japanese healthy infants in 3D. METHODS: Craniofacial CT data of 20 healthy infants (9 males, 11 females) ranging in age from 1 to 11 months were collected. Based on the CT data, we created 20 homologous models of cranium using software specifically designed to support homologous modeling. We averaged vertex coordinates of the homologous models to create average model. We further performed principal component analysis, and created virtual models based on each principal component. The contribution rate was calculated, and the features described by each principal component were interpreted. RESULTS: We created the average cranial model of Japanese healthy infants. Seven principal components (cumulative contribution rate: 89.218%) were interpreted as to which part of the cranial shape each component was related to. The elements were extracted that may characterize the cranial morphology of some of the clinical conditions such as dolico/brachycephaly and deformational plagiocephaly. Some of these elements have not been mentioned in the past literature. CONCLUSION: Homologous modeling was considered to be valid and strong tool for comprehensive analysis of cranial morphology.