[The link between canine guidance and masticatory muscle activity: fact or fiction? 1].

The relationship between occlusal and articulation concepts and masticatory muscle activity, especially during lateral articulation, has been discussed for decades. A distinction is made between canine guidance and group function. One theory suggests that mechanoreceptors in the periodontal ligament can trigger a muscle shutdown reflex when only the canine receives the lateral force. However, more recent theories suggest that muscle activity is centrally regulated and is not influenced by occlusion or articulation. An extensive literature review showed only limited reduction of masticatory muscle activity when canine guidance was applied, which also recovered to the previous level over time. In this part of the two-part article, the literature review is discussed.