Chewing

The muscles of mastication move the jaws to bring the teeth into intermittent contact, repeatedly occluding and opening.

It is thought that conscious mediation is important in the limitation of parafunctional habits as most commonly, the motor program can be excessively engaged during periods of sleep and times of stress.

It is also theorized that excessive input to the motor program from myofascial pain or occlusal imbalance can contribute to parafunctional habits.

[6] A 2015 systemic review found evidence that chewing can decrease self-reported hunger and therefore food intake.

[7] Eating food which does not require chewing, by choice or for medical reasons as tooth loss, is known as a soft diet.

[12] Other animals such as cows chew their food for long periods to allow for proper digestion in a process known as rumination.

[13] Ornithopods, a group of dinosaurs including the Hadrosaurids ("duck-bills"), developed teeth analogous to mammalian molars and incisors during the Cretaceous period; this advanced, cow-like dentition allowed the creatures to obtain more nutrients from the tough plant life.

This may have given them the advantage needed to compete with the formidable sauropods, who depended on their massive gastrointestinal tracts to digest food without grinding it.