Like Jovial, to prevent head becoming flat, we place our daughter alternating left and right each time we put her to sleep in her playpen.

Alternate your baby’s head position each time you put him to sleep or every 2-3 hours during awake hours such as feeding time or diaper changing. Put her to sleep with her head at the head of the crib one night; with her head at the foot of the crib the next night. Vary the direction as babies tend to turn their heads toward the door (to look for caregiver coming into the room) or the window (to see the light). This will give her the practice to turn the head equally in both directions. Baby's skull is soft and pliable. Positional plagiocephaly, a flat spot where a baby's head rests will develop when she spends most of the time by lying on back. Torticollis, the neck or muscle spasms will develop too if baby keeps head turn to one side. Consult a doctor if this happens.

My mum alys rotate my baby head is to prevent the back of their head to become flat, hence every hour, she will tilt left and right. This is to allow them to have a round yet not flat head. I think its quite true cos baby head r soft hence its better to rotate to prevent Having a flat head. Same goes to baby nose, we tend to pinch their nose in order to achieve a sharper nose. :)

I didn't rotate my baby as I thought they will turn/rotate by himself. His head is not flat now.

It is important to keep changing your baby's sleeping position to prevent your baby developing a persistent flat spot, either in the back or on one side of the head, which is a sign of Positional Plagiocephaly, also known as flattened head syndrome. This condition can occur when your baby sleeps in the same position repeatedly. As baby's skull is very soft and pliable during the first 2 months of life, it is recommended to rotate the head sleeping position. From the day your baby is born, alternate the direction your baby's head is facing when you put him to sleep each night. After the first few weeks, when he's able to turn his head himself, put him to sleep with his head at a different end of the cot each night so that he can turn his head towards a different end of the cot each night.

I did rotate as my boy tend to sleep on the left side. I rotate him not only prevent his head to become flat also his ears. When carrying him, I will also rub him head in circular movement for a nice round head.