Scaphocephaly

This 9-month-old infant was brought for evaluation of anteroposterior elongation of the cranium. The infant was born at term via uncomplicated vaginal delivery. His mother had noticed that his head was more elongated and narrower than his sibling's. He had achieved appropriate motor and social milestones for his age. Neither parent had a family history of abnormal head shape. The rest of the examination findings were unremarkable.

Christian Sonnefeld, MD, and Atiya Khan, MD, of Morgantown, WVa, diagnosed scaphocephaly (boat-shaped head). A noncontrast CT scan of the head with 3-D reconstruction revealed early sutural synostosis of the posterior portion of the sagittal suture as the cause of the dolichocephalic configuration of the cranium.

Premature closure of 1 or more of the cranial sutures--craniosynostosis--can be associated with various anomalies and genetic disorders.¹ Apert, Chotzen, Pfeiffer, Carpenter, and Crouzon syndromes all have extracranial manifestations, such as syndactyly, polydactyly, dysmorphic facies, midfacial hypoplasia, beaklike nose, and proptosis. This patient had none of these extracranial findings.

The type of craniosynostosis depends on the suture or sutures involved. The most common type is sagittal synostosis, also known as scaphocephaly (or dolichocephaly), which accounts for about 60% of all cases of craniosynostosis.² It is characterized by an elongated anteroposterior diameter of the skull and a decreased transverse diameter. Palpable ridging over the sagittal suture may be noted at birth. The cranial index approaches 60 (normal cranial index is about 80). However, recent data suggest that measurements of internal skull planes, surface landmarks, and skull base planes may produce more reliable indices than the traditional cranial index.³

Boys are more commonly affected than girls, and 2% to 8% of cases are familial.² Isolated sagittal synostosis is rarely associated with deformity of the skull base or facial bones. Neurologic findings are usually normal. In premature infants, scaphocephaly develops because of positional molding of the poorly mineralized skull.

Craniosynostosis is managed surgically to allow normal brain growth and to prevent increased intracranial pressure and compromise of visual and auditory function. In infants with scaphocephaly, the shape of the skull may become normal with maturity. For those with mild scaphocephaly, such as this patient, reassurance and clinical follow-up may be all that is needed. Molding helmets may be tried. For infants with severe scaphocephaly, surgery may be indicated for cosmesis. Early surgery is optimal and can provide an excellent cosmetic result.⁴ In sagittal craniosynostosis, surgery within 3 to 6 months permits restoration of near-normal skull contour.⁵