Deformational plagiocephaly, also known as positional molding, is the most common cause of a misshapen skull in infants. Babies with deformational plagiocephaly usually have a flattened head on the back or one side, and sometimes a bulging forehead, ear displacement, and facial prominence on the same side. Deformational plagiocephaly is not serious and typically resolves without medical treatment. It is not a form of craniosynostosis, which is a condition that requires surgical intervention.
What Causes Deformational Plagiocephaly?
Most cases of deformational plagiocephaly occur in babies who spend a lot of time on their backs. The incidence of deformational plagiocephaly has increased dramatically since pediatricians started recommending that babies sleep on their backs to reduce the risk of Sudden Infant Death Syndrome (SIDS). In most cases, the flattening that is the hallmark of deformational plagiocephaly is simply caused by pressure on the back of the head while the child is sleeping, feeding, and engaging in play during the day.
In other cases, deformational plagiocephaly may be caused by a condition called muscular torticollis, which is present at birth and simply means that one or more of the neck muscles is tight, causing the head to tilt and/or turn to one side. Infants with muscular torticollis cannot turn to the opposite side, causing consistent pressure on one side of the head.
View/Download: A Parent's Guide to Plagiocephaly 
Premature infants, twins, and breech babies are also at increased risk for developing deformational plagiocephaly, since they may spend more time in one position during NICU admission, have less room to move during gestation, and are positioned in the womb in ways that can mold head shape respectively.
Deformational plagiocephaly affects only the cosmetic appearance of the skull and face. There is no involvement of the brain and no expectation of any developmental or intellectual impact.
If parents have any concerns about their child's head shape and would like to rule out craniosynostosis or other conditions, they may contact our Craniofacial Program to schedule an evaluation.
The Weill Cornell Medicine Neurological Surgery team offers a comprehensive plagiocephaly clinic. This clinic, run by our advanced provider team, provides comprehensive evaluation, management, and treatment for children with positional plagiocephaly. To make an appointment, please call 212-746-2363.
Reviewed by: Caitlin Hoffman, M.D.
Last reviewed/last updated: June 2023
Illustration by Thom Graves, CMI
