Department of Pathology and Anatomical Sciences, University of Missouri at Columbia
Saturday All day, Plaza Level
The anterior fontanelle (AF) of the infant cranium is an integral element in growth of the craniofacial system, with variation in its size indicative of altered growth patterns. Traditionally, surface area of the AF in fetal and newborn crania has been estimated using linear measures of the longitudinal and transverse diameters. Although this method has the advantage of being applicable to both dry crania and digital image data, it does not provide an accurate measure for crania with irregularly-shaped fontanelles. Additionally, this method assumes the AF borders to be smooth curves, while naturally-occurring undulations may be present due to variable rates of bone deposition. In this study we test a new method of estimating AF surface area (AFSA).
Our sample consisted of CT data of cadaveric human fetal crania between 30-36 weeks gestation (N=5). Three-dimensional surfaces of the crania were reconstructed using Amira 5.2©. We collected longitudinal and transverse diameters of the AF. We also calculated AFSA from the 3D cranial surface reconstructions through labeling of individual voxels of the CT images. We then statistically compared the two measures of AFSA.
Results show that the two estimates of AFSA are statistically significantly different. We hypothesize that the differences are the result of the highly variable shape of the AF, which cannot be taken into account by the traditional measures. Thus, this novel method of estimating AFSA may be more accurate, particularly when the fontanelle is irregularly shaped, due either to natural variation or pathology in bone deposition.