What is the difference between teats with a round hole and those with a Y or cross cut hole?

The difference between the round hole teats and cross cut or Y teats is essentially the shape of the opening at the tip of the teat.

Round hole teats have a ‘round hole’. If the bottle is held upside down, milk will drip out without any sucking needed. This is perfect for young babies who have little jaw development as they don’t have to work too hard to get their milk.

Cross cut or Y teats have an opening shaped like a ‘Y’. Unlike the round hole teat, milk is only released when the baby sucks on the teat. The Y cut is perfect for babies as they get older and have stronger jaw muscles. With a Y cut, the baby is able to vary the flow of milk themselves. The harder they suck, the larger the cross cut opening.

Cross cut or Y teats can be used across a wide age range due to the opening being able to expand and contract.