Chin Lifters aim to keep the chin up and away from the chest. This is usually done using a pillow that provides bulk under the chin.

There is some merit in this. With the chin raised as far as possible, the airway is as open as it can be. This position is used for resuscitation.

Unfortunately, to get a substantial airway opening effect you really need the chin quite high indeed - higher than most people could tolerate sleeping in, and certainly higher than most pillows achieve.

But still, you would get a slight improvement even with a small lift of the chin, so this would certainly work for a small percentage of people.