Editing Bruxism (section)

===Occlusal factors===
[[Occlusion (dentistry)|Occlusion]] is defined most simply as "contacts between teeth",<ref name="Davies 2001B">{{cite journal |vauthors=Davies S, Gray RM |title=What is occlusion? |journal=British Dental Journal |volume=191 |issue=5 |pages=235–8, 241–5 |date=September 2001  |pmid=11575759 |doi=10.1038/sj.bdj.4801151a}}</ref> and is the meeting of teeth during biting and chewing. The term does not imply any disease. [[Malocclusion]] is a medical term referring to less than ideal positioning of the upper teeth relative to the lower teeth, which can occur both when the upper jaw is ideally proportioned to the lower jaw, or where there is a discrepancy between the size of the upper jaw relative to the lower jaw. Malocclusion of some sort is so common that the concept of an "ideal occlusion" is called into question, and it can be considered "normal to be abnormal".<ref name="Wassell 2008" /> An occlusal interference may refer to a problem which interferes with the normal path of the bite, and is usually used to describe a localized problem with the position or shape of a single tooth or group of teeth. A ''premature contact'' is one part of the bite meeting sooner than other parts, meaning that the rest of the teeth meet later or are held open, e.g., a new dental restoration on a tooth (e.g., a crown) which has a slightly different shape or position to the original tooth may contact too soon in the bite. A ''deflective contact/interference'' is an interference with the bite that changes the normal path of the bite. A common example of a deflective interference is an over-erupted upper [[wisdom tooth]], often because the lower wisdom tooth has been removed or is [[tooth impaction|impacted]]. In this example, when the jaws are brought together, the lower back teeth contact the prominent upper wisdom tooth before the other teeth, and the lower jaw has to move forward to allow the rest of the teeth to meet. The difference between a premature contact and a deflective interference is that the latter implies a dynamic abnormality in the bite.