Editing Bruxism (section)

===Tooth wear===
Many publications list tooth wear as a consequence of bruxism, but some report a lack of a positive relationship between tooth wear and bruxism.<ref name="Shetty 2010" /> Tooth wear caused by tooth-to-tooth contact is termed [[attrition (dental)|attrition]]. This is the most usual type of tooth wear that occurs in bruxism, and affects the occlusal surface (the biting surface) of the teeth. The exact location and pattern of attrition depends on how the bruxism occurs, e.g., when the [[canine tooth|canines]] and [[incisor]]s of the opposing arches are moved against each other laterally, by the action of the medial pterygoid muscles, this can lead to the wearing down of the [[Commonly used terms of relationship and comparison in dentistry|incisal]] edges of the teeth. To grind the front teeth, most people need to posture their mandible forwards, unless there is an existing edge to edge, class III incisal relationship. People with bruxism may also grind their [[Commonly used terms of relationship and comparison in dentistry|posterior]] teeth (back teeth), which wears down the [[cusp (dentistry)|cusps]] of the occlusal surface. Once tooth wear progresses through the [[Tooth enamel|enamel]] layer, the exposed [[dentin]] layer is softer and more vulnerable to wear and [[caries|tooth decay]]. If enough of the tooth is worn away or decayed, the tooth will effectively be weakened, and may fracture under the increased forces that occur in bruxism.

[[Abfraction]] is another type of tooth wear that is postulated to occur with bruxism, although some still argue whether this type of tooth wear is a reality.<ref name="Neville 2001" /> Abfraction cavities are said to occur usually on the facial aspect of teeth, in the cervical region as V-shaped defects caused by flexing of the tooth under occlusal forces. It is argued that similar lesions can be caused by long-term forceful toothbrushing. However, the fact that the cavities are V-shaped does not suggest that the damage is caused by toothbrush [[Abrasion (dental)|abrasion]], and that some abfraction cavities occur below the level of the gumline, i.e., in an area shielded from toothbrush abrasion, supports the validity of this mechanism of tooth wear. In addition to attrition, [[Acid erosion|erosion]] is said to synergistically contribute to tooth wear in some bruxists, according to some sources.<ref name="Pettengill 2011">{{cite journal |author=Pettengill CA |title=Interaction of dental erosion and bruxism: the amplification of tooth wear |journal=Journal of the California Dental Association |volume=39 |issue=4 |pages=251–6 |date=April 2011  |doi=10.1080/19424396.2011.12221893 |pmid=21675679|s2cid=12323562 }}</ref>