I know about plagiocephaly, which means flat head syndrome, but I don’t understand what happens with torticollis with frontal and occipital plane? Eg. If left torticolis happens it will lead to left frontal and right occipital regions flattening! How exactly does it happen?

The most common cause of a flattened head is a baby’s sleep position and usually occurs when a baby sleeps in the same position most of the time or because of problems with the neck muscles.

Babies with torticollis have difficulties turning their heads because of tight neck muscles on one side of the neck and as a result, they tend to keep their heads in the same position when lying down. Left torticolis presents as side bending of the neck to the left and rotation of the neck to the right.

When the baby sleeps in a prone position, left frontal flattening occurs. On the other hand, sleeping in the supine position can cause the right occipital regions to flatten.

Reference 1