Definition of Dental Articulator:
A mechanical device which represents the temporomandibular joint and the jaw members to which maxillary and mandibular casts may be attached to simulate jaw movements.
Uses of Dental Articulators:
- To hold opposing casts in a predetermined fixed relationship.
- To open and close
- To produce border intraborder diagnostic sliding motions
- To diagnose dental occlusal conditions in both natural and artificial dentition’s
- To plan dental procedures that involve positions ,contours and relationships of both natural and artificial teeth as they relate to each other.
- To aid fabrication of dental restoration and the lost dental parts.
- To correct and modify completed dental restorations.
- Helpful in teaching and studying of occlusion and mandibular movements.
Ideal Requirements of Dental Articulators:
- It should hold casts in correct horizontal and vertical relationships.
- It should provide a positive anterior vertical stop (incisal pin).
- It should accept a face bow transfer record.
- It should open and close in a hinge movement.
- It should allow protrusive and lateral motion.
- The moving parts should move freely and be accurately machined.
- The non-moving parts should be a rigid construction.
Additional Requirements of Dental Articulators:
- Adjustable horizontal and lateral condylar guide elements.
- The condylar elements as a part of lower frame and condylar guides as a part of upper frame.
- A mechanism to accept a third reference point from a face bow transfer record.
- A terminal hinge motion locking device.
- Removable mounting plates that can be repositioned accurately.
- An adjustable incisal guide table.
- Adjustable intercondylar width of condylar elements, when graphic tracing to be used to set and / or select condylar guidance.
Advantages of Dental Articulators:
- Properly mounted casts allow the operator to visualize the patients occlusion especially from lingual view.
- Patient co-operation is not a factor when using an articulator once the appropriate interocclusal records are obtained from patient.
- The refinement of complete denture occlusion in mouth is extremely difficult because of shifting denture bases and resiliency of supporting tissues .This difficulty is eliminated when articulators are used.
- Reduced chair time ,patients appointment time.
- The patients saliva , tongue and cheeks are not factors when using an articulator.
Limitations of Dental Articulators:
- An articulator may be made of metal or plastic. Metal articulators show errors in tooling (manufacture) or errors resulting from metal fatigue.
- The articulator may not exactly simulate intraborder and functional movements of mandible
- Errors in jaw relation procedures are reproduced as errors in denture occlusion. Articulators do not have any provision to indicate or correct these errors.