Editing Chewing (section)

==Chewing motor program==
[[File:Water buffalo chewing cud - 01.ogv|thumbnail|A [[water buffalo]] chewing cud]]
Chewing is primarily an unconscious ([[autonomic nervous system|semi-autonomic]]) act, but can be mediated by higher conscious input. The motor program for mastication is a hypothesized central nervous system function by which the complex patterns governing mastication are created and controlled.

It is thought that feedback from [[proprioceptive]] nerves in teeth and the [[Temporomandibular joint|temporomandibular]] joints govern the creation of neural pathways, which in turn determine duration and force of individual muscle activation (and in some cases muscle fiber groups as in the masseter and temporalis).

This motor program continuously adapts to changes in food type or occlusion.<ref>{{cite journal|last=Peyron|first=Marie-Agnès|author2=Olivier Blanc |author3=James P. Lund |author4=Alain Woda |date=2004-03-09|title=Influence of Age on Adaptability of Human Mastication |journal=[[Journal of Neurophysiology]] |volume=92|pages=773–779|url=http://jn.physiology.org/cgi/content/full/92/2/773|access-date=2008-07-02|doi=10.1152/jn.01122.2003|pmid=15277595|issue=2|url-access=subscription}}</ref> This adaptation is a learned skill that may sometimes require relearning to adapt to loss of teeth or to dental appliances such as [[dentures]].

It is thought that conscious mediation is important in the limitation of [[parafunctional habit]]s 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 habit]]s.

===Muscles===
{{Main|Muscles of mastication}}