Centric relation: Difference between revisions

Latest revision as of 17:55, 11 December 2024

Centric Relation[edit]

Centric relation (CR) is a fundamental concept in dentistry, particularly in the fields of prosthodontics and occlusion. It refers to the maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective discs with the complex in the anterior-superior position against the shapes of the articular eminences. This position is independent of tooth contact and is clinically discernible when the mandible is directed superiorly and anteriorly. It is restricted to a purely rotary movement about the transverse horizontal axis.

Definition and Importance[edit]

Centric relation is a bone-to-bone relationship, not influenced by the teeth. It is considered a repeatable and reproducible position, which makes it a critical reference point in dentistry for:

Diagnosing occlusal conditions
Planning and executing restorative and prosthetic treatments
Fabricating dental prostheses such as dentures and dental crowns

CR is used as a starting point for developing an optimal occlusion, as it provides a stable and reproducible position for the mandible.

Clinical Application[edit]

In clinical practice, centric relation is used to:

Establish a reference position for mounting dental casts on an articulator
Diagnose occlusal disharmonies
Plan comprehensive dental treatments

The determination of centric relation is crucial for the success of full mouth rehabilitation and the construction of complete dentures. It ensures that the occlusal forces are distributed evenly, minimizing the risk of TMJ disorders and other complications.

Methods of Recording Centric Relation[edit]

Several techniques are used to record centric relation, including:

Bimanual manipulation: The dentist uses both hands to guide the mandible into the centric relation position.
Leaf gauge: A series of thin plastic strips are used to deprogram the muscles and guide the mandible into CR.
Lucia jig: A device placed on the anterior teeth to separate the posterior teeth and allow the mandible to move freely into CR.

Each method aims to achieve a consistent and repeatable position for accurate diagnosis and treatment planning.

Controversies and Challenges[edit]

Despite its importance, centric relation can be challenging to determine accurately. Some controversies include:

Variability in techniques and practitioner skill
Differences in patient anatomy and muscle tone
Debate over the exact definition and clinical relevance of CR

These challenges necessitate a thorough understanding of the concept and careful clinical practice to ensure accurate results.

Also see[edit]

Template:Dental anatomy

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-== Definition ==
+== Centric Relation ==
-The maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective disks with the complex in the
-anterior-superior position against the shapes of the articular eminencies. This position is independent of tooth contact. This position is clinically discernible when the mandible is directed superior and anteriorly. It is restricted to a purely rotary movement about the transverse horizontal axis (GPT-5).
-== Importance of Centric Relation ==
+Centric relation (CR) is a fundamental concept in dentistry, particularly in the fields of [[prosthodontics]] and [[occlusion (dentistry)|occlusion]]. It refers to the maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective discs with the complex in the anterior-superior position against the shapes of the articular eminences. This position is independent of tooth contact and is clinically discernible when the mandible is directed superiorly and anteriorly. It is restricted to a purely rotary movement about the transverse horizontal axis.
-Proprioceptive impulses (impulses of three-dimensional spatial orientation) guide the mandibular movements. In dentulous patients the proprioceptive impulses are obtained from the periodontal ligament.
-Edentulous patients do not have any proprioceptive guidance from their teeth to guide their mandibular movements. The source of the proprioceptive impulses for an edentulous patient is transferred to the temporomandibular joint. The centric relation position acts as a proprioceptive centre to guide the mandibular movements.
+== Definition and Importance ==
-The centric relation has the following salient features:
+Centric relation is a bone-to-bone relationship, not influenced by the teeth. It is considered a repeatable and reproducible position, which makes it a critical reference point in dentistry for:
-* It is learnable, repeatable and recordable position which remains constant throughout life.
-* It is a definite learned position from which the mandible can move to any eccentric position and return back involuntarily. It acts as a centre from which all movements can be made.
-* If the mandible has to move from one eccentric position to another it should go to the centric relation before advancing to the target eccentric position.
-Functional movements like chewing and swallowing are performed in this position, because it is the most unstrained position.
-* The muscles that act on the temporomandibular joint are arranged in such a way that it is easy to move the mandible to the centric position from where all movements can be made.
-* The casts should be mounted in centric relation because it is the point from which all the movements can be made or simulated in the articulator.
-* It is helpful in adjusting condylar guidance in an articulator to produce balanced occlusion.
-* It is a definite entity, so it is used as a reference point in establishing centric occlusion.
-Centric relation is a learned position (not a default position) and the dentist should teach the patient with patience to move his mandible from the centric relation position.
+* Diagnosing occlusal conditions
+* Planning and executing restorative and prosthetic treatments
+* Fabricating dental prostheses such as [[dentures]] and [[dental crowns]]
-<youtube>
+CR is used as a starting point for developing an optimal occlusion, as it provides a stable and reproducible position for the mandible.
-title='''Documentary Film - {{PAGENAME}}'''
-movie_url=http://www.youtube.com/v/WTi-0eg8nI0
-&rel=1
-embed_source_url=http://www.youtube.com/v/WTi-0eg8nI0
-&rel=1
-wrap = yes
-width=750
-height=600
-</youtube>
-{{stub}}
+== Clinical Application ==
-{{dictionary-stub1}}
+In clinical practice, centric relation is used to:
+* Establish a reference position for mounting dental casts on an [[articulator]]
+* Diagnose occlusal disharmonies
+* Plan comprehensive dental treatments
+The determination of centric relation is crucial for the success of full mouth rehabilitation and the construction of complete dentures. It ensures that the occlusal forces are distributed evenly, minimizing the risk of [[temporomandibular joint disorder|TMJ disorders]] and other complications.
+== Methods of Recording Centric Relation ==
+Several techniques are used to record centric relation, including:
+* '''[[Bimanual manipulation]]''': The dentist uses both hands to guide the mandible into the centric relation position.
+* '''[[Leaf gauge]]''': A series of thin plastic strips are used to deprogram the muscles and guide the mandible into CR.
+* '''[[Lucia jig]]''': A device placed on the anterior teeth to separate the posterior teeth and allow the mandible to move freely into CR.
+Each method aims to achieve a consistent and repeatable position for accurate diagnosis and treatment planning.
+== Controversies and Challenges ==
+Despite its importance, centric relation can be challenging to determine accurately. Some controversies include:
+* Variability in techniques and practitioner skill
+* Differences in patient anatomy and muscle tone
+* Debate over the exact definition and clinical relevance of CR
+These challenges necessitate a thorough understanding of the concept and careful clinical practice to ensure accurate results.
+== Also see ==
+* [[Occlusion (dentistry)]]
+* [[Prosthodontics]]
+* [[Temporomandibular joint disorder]]
+* [[Dental articulator]]
+* [[Dental prosthesis]]
+{{Dental anatomy}}
+{{Dentistry}}
+[[Category:Dentistry]]
+[[Category:Prosthodontics]]
+[[Category:Occlusion (dentistry)]]