Answer:
Trigonocephaly (Ax Head, Keel-Shaped Deformity)
Discussion-:
The metopic suture begins to close during the second year and is completely closed during the third year.
Premature metopic synostosis results in sharp, anteriorly directed ridging of the midline frontal contour.
Closure of the metopic suture restricts expansion of the frontal midline, so these patients manifest symmetric lateral sloping of the forehead, short anterior fossa, forward bowing of the coronal sutures, orbital hypotelorism, and ethmoid hypoplasia .
The crista galli remains intact. The nasal septum and facial midline are usually straight. The medial walls of the orbits are thickened and rise unusually high. Therefore, the superomedial corners form the highest points of the orbital roofs, and the lateral orbits fall away inferiorly. The degree of orbital deformity correlates with the wedging of the forehead. The frontal lobes, frontal sulci, and ventricles are usually compressed. There may be callosal dysgenesis, hydrocephalus, or other intracranial anomalies.
Reference: Head and Neck imaging- fourth edition- Peter Som and Hugh Curtin.
Contributed By:
Dr. Karunakaran M. Kalathi MD, Dr. Arun Chelladurai MD
Consultant Radiologists, Aarthi Scans, Thirunelveli, Tamilnadu, India
Trigonocephaly (Ax Head, Keel-Shaped Deformity)
Discussion-:
The metopic suture begins to close during the second year and is completely closed during the third year.
Premature metopic synostosis results in sharp, anteriorly directed ridging of the midline frontal contour.
Closure of the metopic suture restricts expansion of the frontal midline, so these patients manifest symmetric lateral sloping of the forehead, short anterior fossa, forward bowing of the coronal sutures, orbital hypotelorism, and ethmoid hypoplasia .
The crista galli remains intact. The nasal septum and facial midline are usually straight. The medial walls of the orbits are thickened and rise unusually high. Therefore, the superomedial corners form the highest points of the orbital roofs, and the lateral orbits fall away inferiorly. The degree of orbital deformity correlates with the wedging of the forehead. The frontal lobes, frontal sulci, and ventricles are usually compressed. There may be callosal dysgenesis, hydrocephalus, or other intracranial anomalies.
Reference: Head and Neck imaging- fourth edition- Peter Som and Hugh Curtin.
Contributed By:
Dr. Karunakaran M. Kalathi MD, Dr. Arun Chelladurai MD
Consultant Radiologists, Aarthi Scans, Thirunelveli, Tamilnadu, India