June 2010 Archives
1Department of Anthropology, The Pennsylvania State University, PA, USA.
3St. John's Mercy Children's Hospital, St Louis MO, USA
4Washington University School of Medicine, Saint Louis MO, USA
5Department of Neurological Surgery, University of California Davis, Sacramento CA, USA
Premature closure of the sagittal suture occurs as an isolated (nonsyndromic) birth defect, or as a syndromic anomaly in combination with other congenital dysmorphologies. The genetic causes of sagittal nonsyndromic craniosynostosis (NSC) remain unknown. Though variation of the dysmorphic (scaphocephaly) skull shape of sagittal NSC cases has been acknowledged, this variation has not been quantitatively studied in 3D. We have analyzed the computed tomography skull images of 43 infants (aged from 0.9 to 9 months) with sagittal NSC using anatomical landmarks and semilandmarks to quantify and characterize the within-sample phenotypic variation. Suture closure patterns were defined by dividing the sagittal suture into three sections (anterior, central, posterior) and coding each section as "closed" or "fused". Principal components analysis of the Procrustes shape coordinates representing skull shape of 43 cases of NSC did not separate individuals by sex, chronological age, or dental stages of deciduous maxillary first molar. However, analysis of suture closure pattern allowed separation of these data. The central section of the sagittal suture appears to be the first to fuse. Then, at least two different developmental paths towards complete fusion of the sagittal suture exist; either the anterior section or the posterior section is the second to fuse. Results indicate that according to the sequence of sagittal suture closure patterns, different craniofacial complex shapes are observed. The relationship between craniofacial shape and suture closure indicates not only which suture fused prematurely (in our case the sagittal suture), but also the pattern in which the suture closes. Whether these patterns indicate differences in aetiology cannot be determined with our data and requires analysis of longitudinal data, most appropriately of animal models where prenatal conditions can be monitored.
Look for cool baboon graphics from this project on the cover of the September issue of AJPA!
See http://www.hominid.psu.edu for additional information on this project.
The Economist commented on the paper in their May 20 issue through their article "To Get the Girl - Fighting off Rivals May be Responsible for Masculine Traits". See link to this article
Dr. Puts replies to the comments received by the publication in the May 24 issue of The Economist. See link below for his comments.
Penn State Live also reported on the paper in their May 13 issue. See link below: