Comparative study of normal, Crouzon, and Apert craniofacial morphology using finite element scaling analysis

Abstract

Finite element scaling analysis is used to study differences in morphology between the craniofacial complex of normal individuals and those affected with the syndromes of Apert and Crouzon. Finite element scaling quantifies the differences in shape and size between forms without reference to any fixed, arbitrary registration point or orientation line and measures the amount of form change required to deform one object into another. Two-dimensional coordinates of landmarks digitized from annual sets of cephalometric radiographs were used in the analysis. A simple tabulation shows no difference in variances between the normal and pathological samples. A test of mean differences depicts the Apert and Crouzon morphologies as significantly different from normal. The Apert palate differs from normal in shape in the older age groups analyzed, and palatal size differences are most common at the posterior nasal spine. The Apert pituitary fossa and basi-occiput are significantly larger than normal. The Crouzon pituitary fossa is also larger than normal, but the difference is not always significant. The typical morphology of the Crouzon nose is due more to differences in shape than size. The Crouzon basi-occiput is significantly smaller than normal. An age association of the differences between the normal and pathological craniofacies was found in Apert syndrome but not in Crouzon syndrome. Apert syndrome is characterized by a more homogeneous pattern of craniofacial dysmorphology from 6 months to 18 years of age than Crouzon syndrome.

Chiari malformation associated with craniosynostosis

“…4,11,20 Apert syndrome, however, which typically presents with a normal or larger than normal posterior fossa, is not associated with CM. 32 Hydrocephalus is frequently associated with craniofacial anomalies and may occasionally play a role in CM pathogenesis in these patients. 4,9,10,43 Children with craniofacial disorders as well as hydrocephalus are more likely to have a CM than children with a craniofacial disorder in the absence of hydrocephalus.…”

Craniofacial Growth in Apert Syndrome as Measured by Finite-Element Scaling Analysis

“…1985: Lozanoff and Diewart. 1986Moss el aL 1987;Richtsmeier. 1987], The FES methods used in this study were developed by Lewis et al [1980], and are based on principles from finite-element analysis and continuum mechanics.…”

A Genomewide Linkage Scan for Quantitative Trait Loci Influencing the Craniofacial Complex in Baboons (Papio hamadryas spp.)

“…However, as is the case with many systems, our primary understanding of the specific genes related to craniofacial morphology comes from animal models phylogenetically distant from humans, such as zebrafish, chick, or mouse (e.g., Alexandre et al 1996;Helms et al 1997;Leamy et al 1999Leamy et al , 2000Workman et al 2002;Helms and Schneider 2003;Albertson and Yelick 2004;Eames and Helms 2004), or from genetic disorders associated with human craniofacial anomalies (Slavkin 1983;Olsen 1998;Slavkin 2001;Cohen 2002). Many of these anomalies affect multiple tissue types and are often not restricted to cranial structures (Richtsmeier 1987;Cohen andKreiborg 1991, 1994a,b). Additionally, these disorders are frequently characterized by high degrees of genetic and phenotypic heterogeneity.…”