Objective: The purpose of the present study was to analyze histologically the midline structures in a human fetus with holoprosencephaly and a single median maxillary central incisor.
Methods: A human male fetus, CRL 137 mm, postconceptional age 18 weeks, with a diagnosis of holoprosencephaly, the cebocephalic type (one nostril), and alobar brain development, was investigated. After radiography, the cranial midline structures were examined histologically.
Results: The histological examination revealed partial absence of the intermaxillary suture (in the region anterior to the central incisor), absence of the internasal suture, and partial absence of the metopic suture (caudal part). A single midline nasal bone was observed instead of two bilateral nasal bones, and a midline maxillary central incisor was found instead of two bilateral incisors. A short nasal septum, absence of crista galli, and partial absence of cartilaginous tissue anterior to the sella turcica in the region of the presphenoid bone were recorded.
Conclusions: The study shows that in the affected fetus, there were malformations of midline structures anterior to the sella turcica comprising suture development and cartilage development.