Some parents have a gut feeling that there is something wrong with their child's head shape. Others are blind sided when a pediatrician or concerned friend suggests a cranial consult. While our babies all have different head shapes when they are born, we know that they should improve over the first year of life. If they aren't improving and remain moderately severe, a cranial helmet is required.
An "Elongated Head" is a head shape with a low cephalic index (see more info on measurements here). Cephalic index is calculated by measuring the width and length of the head and dividing the two for a ratio. While norms differ based on age, gender, and ethnic background, we generally aim for a cephalic index of .80-.90. Less than .80 is considered a low cephalic index and the head looks longer and narrow. Greater than .90 is considered high cephalic index and the head is flat and wide. For more information on head shapes, see our previous post.
But what if the head isn't flat? What if the head is elongated and narrow? How long is too long? Does an elongated head always require surgery to correct if it seems to be getting worse and worse? Is an elongated head something to helmet for?
In this post we will discuss conditions of head elongation that are positional and treated by cranial remolding helmets. We will then compare this to Sagittal Craniosynostosis and describe the causes and surgical treatments. Finally we will provide evidence regarding the elongated head and functional implications.
Okay, sounds like a lot to cover, right? Let's get started.
These terms refer to a head shape that has been elongated beyond the natural course of brain growth. The course is typically altered because the baby is being positioned on either side of their head. The head gets elongated because the baby is consistently placed on their left or right side and then the head only grows in the length direction. The width of the head is held by the mattress and stays the same.
This is common for babies that have a NICU or hospital stay. Traditionally, placing baby in left sidelying is through to promote digestions and decrease reflux. Because babies are being monitored in NICU they do not have to be positioned on their back like pediatricians recommend once baby goes home. Once a baby has an elongated head it is hard for them to roll onto the back of their head to help the skull shape become more proportional.
Scaphocephaly is sometimes synonymous with sagittal craniosynostosis. Sagittal craniosynostosis however is specifically caused by the premature closing of the sagittal suture which runs across the top of the head (more on that later).
Cranial Remolding Helmets are used to correct positional scaphocephaly/dolicephaly. They focus on holding the length (anterior/posterior) while the width (medial/lateral) grows. Helmets will work to correct the width to length ratio as long as the child is wearing the helmet, growing, and does not have sagittal craniosynostosis.
Other Benign Head Shapes: Bathrocephaly
Bathrocephaly is a skull shape, characterized by a "hook-like" protuberence of the occipital bone (specifically at the mendosal suture). This benign head shape can look concerning but is simply a variant of the occipital bone structure and non malicious. If this head shape persists, the skull should be imaged to rule out craniosynostosis.
Craniosynostosis is the premature closure of one or more cranial sutures. The cranial sutures are typically open at birth and as the brain growth is pushes the cranial bones into position. before they suture. With Sagittal Craniosynostosis, the sagittal suture has fused prematurely. This is the suture that runs along the top of the head in a straight line. When it closes prematurely, the brain grows and pushes the bones in the length direction so that the head becomes elongated.
Red flags for this include a very low cephalic index, a raised ridge along the top of the head, and a bulging occipital bone. Craniosynostosis can occur with other sutures and must be diagnosed with imaging such as MRI or CT scan (not the STARscanner) and read by a neurosurgeon.
Craniosynostosis can require surgical intervention to relieve pressure on the brain. If left untreated, Craniosynostosis can have serious long term side effects.