The shape of the human head is primarily determined by the underlying bone structure of the skull. The skull’s malleability is highly dependent on age, defining the possibility of changing one’s head shape. For infants, whose skulls are still developing, external forces can easily alter the shape, allowing for non-invasive correction. For adults, the skull is a rigid, fused structure, meaning any alteration requires invasive, surgical intervention.
The Biological Basis of Head Shape Fixity
The newborn skull is composed of several bony plates separated by fibrous joints called sutures. These sutures, along with soft spots known as fontanelles, allow the skull to compress during birth. This flexibility also provides necessary space for the brain’s rapid growth during infancy. The presence of these flexible joints makes the infant head susceptible to shape changes from external pressure.
The process that locks the skull into a permanent shape is called synostosis, where the flexible sutures gradually turn into solid bone. The fontanelles are the first to close, typically within the first two to nineteen months of age. As these spaces close, the individual bony plates begin to interlock tightly. This forms a rigid, protective shell for the brain.
While some cranial sutures may not fully ossify until early adulthood, the skull becomes structurally fixed soon after the fontanelles close. This maturation process explains why the adult skull is non-malleable. Once the skull bones are locked together, they form an unyielding structure that resists external pressures. Therefore, the adult skull cannot be reshaped through non-invasive means like massage, bracing, or posture changes.
Correcting Positional Molding in Infants
Infancy is the only time when significant, non-surgical head shape correction is naturally possible. This correction primarily addresses acquired conditions like positional plagiocephaly (asymmetrical flattening) and brachycephaly (symmetrical flattening). Both conditions are linked to consistent external pressure on the soft, developing skull. This often occurs because the baby spends extended time lying on their back, a practice recommended to reduce the risk of Sudden Infant Death Syndrome.
The initial and most recommended treatment involves repositioning techniques, which are effective because the infant skull is highly responsive to pressure changes. Parents are encouraged to increase “tummy time” when the baby is awake and supervised, which relieves pressure and strengthens neck muscles. Other strategies include alternating the direction a baby is placed in the crib or encouraging them to turn their head toward toys or light. These repositioning efforts are most effective when started early, ideally before the age of six months.
For moderate to severe cases that do not respond to repositioning, a cranial orthotic helmet or band may be prescribed. This customized device uses 3D imaging to apply gentle holding pressure to prominent areas while allowing flattened areas to round out as the brain grows. Helmet therapy is most effective when initiated between four and six months of age during the phase of rapid skull growth. This non-invasive approach addresses positional molding.
Adult Approaches to Changing Head Contour
Once the cranial sutures have fused and the skull has achieved its adult structure, the bone is fixed. Adults who seek to change their head contour must rely on invasive, aesthetic craniofacial surgery.
Skull Reduction
Skull reduction is a procedure used to smooth out or reduce high spots, bumps, or overly large areas, often at the back or sides of the head. This involves using specialized burring tools to carefully shave down the outer layer of the skull bone. To maintain the protective integrity of the skull, the amount of bone safely removed is limited, typically to a depth of five to seven millimeters.
Skull Augmentation
Skull augmentation is performed to round out flat spots or increase the projection of a specific area, such as the back of the head. Surgeons achieve this by applying biocompatible materials, most commonly bone cement, directly onto the skull. For larger or more complex contour changes, a custom-designed implant, created from a patient’s CT scan, may be inserted beneath the scalp. These procedures are considered major surgery, requiring extensive planning with 3D imaging. Patients must have a clear understanding of the limitations and risks involved in altering the permanent skeletal structure.