Dynamic Occlusion

Occlusion: Occlusion can be defined very simply:”it means the contact between teeth”. the concept can be further refined by defining those contacts between the teeth when the mandible is closed and stationary as the static occlusion, and those contacts between teeth when the mandible is moving relative to the maxilla as the dynamic occlusion. [1]

• there are few terms in occlusion which needs to be explained in ordr to understand occlusion in detail.

• Static Occlusion: static occlusion is the contact of upper and lower dentition when mandible is not moving.

• Centric occlusion (CO): can be described as the occlusion the patient makes when they fit their teeth together in maximum intercuspation. Also known as maximum Intercuspation Position

It is the position of the mandible to the maxilla, with the intra-articular disc in place, when the head of the condyle is against the most superior part of the distal facing incline of the glenoid fossa [1]

• Dynamic occlusion: Dynamic occlusion is the functional occlusion in which mandibular and maxillary teeth move relative to each other. other than the muscles of mastication there are two guidance systems which are the main determinates of functional occlusion.

• Posterior guidance: posterior guidance is determined by the temporomandibular

Canine-protected occlusion lessens the odds of temporomandibular disorders, since it diminishes the chances of interfering during lateral excursion.

Teeth that are used in guidance are loaded laterally during excursions that is why heavily restored teeth maybe at risk of fracture. Number of problems can arise if a weak tooth is in guidance. Teeth having canine protected occlusion have significantly lower periodontal indices [3]

The purpose of canine guidance is protective in nature, it protects the posterior teeth in lateral excursive and protrusive movements. Lateral forces placed on posterior teeth can bring about a fracture or extreme wear. Strong vertical forces are the least harming to posterior teeth because the force will be absorbed by the greatest surface area of the periodontal ligament.[4]

Canines have longer root length and due to its location in the mouth i.e away from the joint makes it eligible to withstand lateral forces. Canine-protected occlusion reduces lateral tooth contact and the possibility of interfering contacts. Without canine protected occlusion posterior teeth can undergo wear severly and restorations placed in posterior region may undergo francture or