An osteological assessment of cyclopia by micro-CT scanning.

PURPOSE

Imaging modalities such as micro-CT scanning and three-dimensional reconstruction are providing a mechanism for detailed analysis of skeletal components not only of normal specimens but also through revisitation of the abnormal. The aim of this study was to analyse the craniofacial skeleton of five human fetuses with cyclopia by means of micro-CT scanning and three-dimensional reconstruction.

MATERIALS AND METHODS

The study consisted of five cyclopean individuals from the paediatric collection of the School of Anatomical Sciences, University of the Witwatersrand. The specimens ranged in age from 22 to 42 weeks of gestation. The osteological features of each bone of the skull were analysed with the aid of micro-CT scanning and analysis using VG studiomax software.

RESULTS

A detailed analysis of all the bones of the skull revealed that the upper two-thirds of the viscerocranium and the anterior region of the basicranium were the most affected regions of the cyclopean fetuses. The ethmoid, nasal, inferior concha and the lacrimal bones were absent in all the cases of cyclopia. Major abnormalities were found in the premaxillary region which affected the development of the anterior dentition.

CONCLUSION

This study supports the suggestion that the malformations of the visceral bones are secondary to defective development of the presphenoid and mesethmoid cartilages. The ethmoidal bones are important midline struts during normal development and their absence in cyclopia leads to non-laterality of facial features.