Designed By:
Wilfred Terrell and W. E. Van Dorn
Manufactured By:
Precision Dental Mfg. Co., Pasadena , California
US Patent:
2199896
Description:
The “Precision Coordinator” is an “arcon” type articulator. Coined by Gunner Bergstrom in the 1950's, “arcon” means that the condylar elements are on the mandibular member and the condylar paths are on the maxillary member of the articulator. The condylar controls are essentially universal joints with curvilinear condylar paths that can be independently set in a vertical and horizontal direction. This feature that allows changing the relative positions of the condyles to each other is known as a “split axis.” The controlling mechanism for this articulator is the incisal guide that features twin parabolic cams that control both the horizontal (gothic arch) and vertical (protrusive) movements. A milling device is built into the lower cast holder that produces a variable area of freedom in the centric position The movement can be varied from.02 to .08 inches. It mills circularly in the molar region, elliptically in the premolar region and laterally in the incisor region.
Mitchell DL, Wilkie ND: Articulators through the years. Part I. Up to 1940, j Prosthet Dent 1978; 39:330-338.
Sharry J (ed): Complete Denture Prosthodontics (ed. 2) New York, NY, McGraw-Hill Book Company, Inc. 1968, p.219.
Dr. Edgar N. Starcke's articles in the Journal of Prosthodontics have more information on the history of articulators.