In dentistry, a mutually protected

occlusion Occlusion may refer to: Health and fitness * Occlusion (dentistry), the manner in which the upper and lower teeth come together when the mouth is closed * Occlusion miliaria, a skin condition * Occlusive dressing, an air- and water-tight trauma ...

is an occlusal scheme in which the anterior teeth protect the posterior teeth, and vice versa. The anterior teeth protect the posterior teeth by providing for a plane of guidance during excursions, thus allowing the cusps of the posterior teeth to disclude rather than strike one another during lateral or protrusive movements from centric relation. In other words, the posterior teeth have much larger crowns and more cusps than the anterior teeth. Because posterior crowns are wider and possess cuspal projections in various configurations, the cusps of the maxillary teeth and those of the

mandibular In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

teeth have an opportunity to bang into each other during chewing, speech or simply meeting together when one bites down. To prevent this from happening, the anterior teeth of each arch will, ideally, be situated so as to come into contact ''before'' the cusps of the posterior teeth do, thus preventing wear on the posterior teeth. This requires less force because the anterior teeth are further from the joint (analogous to stopping a door further from its hinge). The posterior teeth protect the anterior teeth by providing a stable

vertical dimension of occlusion Vertical dimension of occlusion, or VDO, also known as occlusal vertical dimension (OVD), is a term used in dentistry to indicate the superior-inferior relationship of the maxilla and the mandible when the teeth are occluded in maximum intercusp ...

. While anterior teeth may retain their natural position even after loss of posterior teeth, the

masticatory Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, t ...

forces will eventually cause the single-rooted anterior to splay, thus leading to a collapsed bite.

References

* Davis Henderson, Victor L. Steffel. McCRACKEN's Removable partial prosthodontics, 4th Edition, 1973. {{Prosthodontology Dentistry Restorative dentistry