An articulator is a mechanical instrument used in dentistry to represent the temporomandibular joints (TMJ) and the jaw members, to which maxillary and mandibular casts may be attached to simulate some or all mandibular movements.

Description

In essence, an articulator acts as a “patient surrogate” in the dental laboratory. By mounting gypsum models of a patient’s teeth onto the device, clinicians and technicians can study the occlusion (bite) and fabricate prosthetics (like crowns, bridges, or dentures) that harmony with the patient’s natural jaw movements.

Classification & Features

Articulators are generally classified based on their adjustability and how closely they mimic human anatomy:

1. Non-Adjustable (Simple Hinge)

• Features: Only allows for a simple opening and closing motion. It does not account for lateral or protrusive movements.
• Limitation: Often leads to “high spots” on restorations that require significant adjustment in the mouth.

2. Semi-Adjustable

• Features: These are the most common in clinical practice. They can be adjusted for:
  • Condylar Guidance: The angle at which the jaw slides forward.
  • Bennett Angle: The lateral (side-to-side) movement of the jaw.
• Benefit: Uses a Facebow Transfer to record the spatial relationship of the maxillary arch to the TMJ, ensuring a much higher degree of accuracy.

3. Fully Adjustable

• Features: Can be programmed to replicate the exact complex paths of a specific patient’s mandibular movement.
• Benefit: Highest precision; typically reserved for full-mouth reconstructions or complex TMJ cases.

Usage and Workflow

The clinical and laboratory application of an articulator follows a specific sequence:

Step	Action
Impression Taking	Accurate Alginate or VPS impressions are taken to create stone models of the upper and lower teeth.
Facebow Record	A facebow is used on the patient to record the position of the upper jaw relative to the skull’s hinge axis.
Bite Registration	A VPS or wax bite registration is taken to show how the upper and lower teeth interlock.
Mounting	The dental technician uses the facebow and bite registration to “mount” the stone models onto the articulator using dental plaster.
Fabrication	The prosthetic (e.g., a bridge) is built on the models. The articulator allows the technician to check that the teeth don’t “clash” during side-to-side chewing motions.

Arcon vs. Non-Arcon Articulators

A common technical distinction in professional dentistry:

• Arcon (Articulator Condyle): The condylar elements are on the lower member (mimicking human anatomy). These are generally preferred for ease of use.
• Non-Arcon: The condylar elements are on the upper member.

Key Features Summary

• Stability: High-quality articulators are made of rigid metal (aluminum or stainless steel) to prevent flexing.
• Incisal Pin: Allows the technician to maintain a constant “Vertical Dimension” (the distance between the jaws).
• Magnetic Mounting: Many modern articulators use magnetic plates for quick removal and replacement of models.