Dental Occlusion Concepts

Centric Relation

• Independent of tooth contact.
• Condyles articulate in the anterior-superior position against the posterior slopes of the articular eminences.
• The patient can make vertical, lateral or protrusive movements from this position.
• Clinically useful, repeatable reference position.

Centric Occlusion

• Maximum planned contact or intercuspation of opposing occlusal surfaces.
• It is a term used to denote any contact of the denture teeth other than centric occlusion.

Eccentric Occlusion

• Any contact of the denture teeth other than centric occlusion.

Differences Between Natural and Complete Artificial Occlusion

• Natural Dentition:
  • Teeth are attached to bone by periodontal ligaments.
  • Teeth receive individual pressure of occlusion and can move independently to adjust.
  • Horizontal (lateral) forces exerted on natural teeth during mastication affect only the teeth involved.
  • Occlusion in centric relation can initiate interferences and responses that direct the mandible into centric occlusion.
• Complete Artificial Dentition:
  • Bilateral balance is considered necessary for denture base stability.
  • Incising with artificial teeth affects all the teeth on the base.
  • Proprioceptors impulses created by closure into centric occlusion establish a memory pattern that permits the mandible to return to this centric occlusion position away from centric relation.

Axioms of Artificial Occlusion

• The wider and larger the ridge, the narrower the teeth and closer the teeth are to the ridge, the greater the lever balance.
• The more centered the force of occlusion anterior-posteriorly, the greater the stability of the base construction.

Types of Occlusion

• Bilateral Balanced Occlusion: Maximum contact in working and non-working sides.
• Unilateral Balanced Occlusion (Group Function): Maximum contact in working side and no contact in non-working side.
• Mutually Protected Occlusion:
  • Also known as canine protected occlusion, or organic occlusion.
  • Maximum contact at centric occlusion.
  • No posterior contact during protrusion.
  • The anterior teeth prevent the posterior teeth from contacting on either the working or the non-working sides during mandibular excursions.

Denture Occlusion

• Bilateral Balanced Occlusion in Natural Dentition:
  • Sliding movement of the mandible as it moves from retruded contact position to intercuspal position (a combination of forward and lateral movements, as well as vertical components).
  • Subject natural teeth on the balancing side to destructive obliquely directed forces.
• **Unilateral Balanced Occlusion (Group Function) **
  • Two or more teeth, other than canines, in contact on the working side and no balancing contacts.
• **Mutually Protected Occlusion **
  • Overlap of anterior teeth prevents posterior teeth from making any contact during mandibular excursions.
  • Posterior teeth are separated from contact during mandibular excursions.
  • This separation is termed disclusion.

This quiz covers key concepts in dental occlusion, including centric relation, centric occlusion, and eccentric occlusion. It also highlights the differences between natural and complete artificial occlusion, focusing on how these concepts apply to dental practice. Ideal for dental students and professionals looking to deepen their understanding.