In the first 2 years of your baby's life, you will see many changes, including the shape of your baby's head as his brain grows. A newborn's skull is soft with gaps between the bones. The gaps close as the bones grow and the brain reaches its full size. As the brain gets larger, it pushes against the bones of the skull until the gaps start to close. This occurs approximately 18-24 months after birth.

The softness of the cranial bones (skull) and the flexibility of the gaps during that time allow your baby's head to form. In some cases, the head forms in unusual ways with flattened areas, swelling or portions that stick out. A misshapen head is called deformational or positional plagiocephaly.

Causes

Many newborns do not have a perfectly shaped head. This can be due to the trip down the birth canal. However, in most cases, the head becomes completely normal by 6 weeks of age. Abnormal head shape beyond this time may be a problem and something to ask your healthcare provider about.

Keeping an infant's head in one position for long periods of time is the main reason for skull flattening. Infants who spend lots of time on their backs or in car seats without changing positions are at higher risk. Sometimes, a baby is born with a flattened head because of a lack of space in the mother's womb, for example with twins or a breech birth.

A birth defect called muscular torticollis also can cause a baby to have an unusually shaped head. Torticollis causes one or more of the neck muscles to become extremely tight, which makes the head tilt or turn in one direction.

Premature infants are at higher risk for developing an unusually shaped head because the skull bones become stronger and harder in the last 10 weeks of pregnancy. Premature infants do not get the benefit of this growth in the uterus. Also, since many premature infants spend a lot of time in the hospital on special equipment, their heads may stay in the same position for a long time.

Tummy Time

In some cases, you can prevent or lessen the flattening by changing how much time your baby spends on his back. While babies should always sleep on their back, you can switch the direction of the baby's head from side to side. You also can vary in which direction the baby's body is placed in the crib so he is laying on different sides of his head to see outside the crib. When not sleeping, babies should enjoy time on their tummies.

Treatment Options

Healthcare providers typically spot a baby's misshaped head during a regular physical exam - X-rays are usually not necessary. They will look at the top of your baby's head, including the position of the ears and cheekbones.

Treatment generally includes placing the infant in a different position or reshaping the head with the assistance of a band or helmet. Some babies do not require any treatment, and the condition will correct itself when the infant begins to sit.

Reshaping Baby's Head

Your healthcare provider also may recommend a skull-molding helmet to reshape your baby's head. You can prepare your baby for the feel of the helmet by placing a cap or hat on his head several days before using the helmet.

The helmets usually have a hard shell and a foam lining. The helmet applies gentle pressure to the baby's head, slowing growth in the areas that are misshaped and allowing for growth in the flat parts. As the head grows, the helmet must be adjusted to fit correctly.

The average treatment with a helmet is usually 3-6 months, depending on the baby's age and the amount of head reshaping needed. The best age for this treatment is between 4 and 12 months.

Jill Rollet is senior associate editor at ADVANCE.