Designed By:
Rupert E. Hall
Manufactured By:
S.S. White Dental Manufacturing Company, Philadelphia, PA
US Patent:
1218178
Description:
This articulator is unique because it was the model for the patent and was never on the market.. It was constructed to conform to Hall's "conical" theory of mandibular movement. The theory stated that, if two equilateral (Bonwill) triangles were placed back to back, they would share the condylar (opening/closing) axis as a common base. The apex of the anterior triangle would be located at the incisal point and the apex of the posterior triangle would be located in the region of the external occipital protuberance. The “conical” theory states that the maxillary teeth conform to the surface of an 8-inch cone. Finally, the posterior point would be the lateral rotation center of the mandible. This is the first articulator to have an incisal guide table with adjustable lateral wings.
Detail of the incisal pin and guide. First patented in incisal table with adjustable lateral wings.
Lateral view, closed position
Open view, the hinge axis is the common base of the Bonwill triangles.
Anterior-lateral view, closed position. The posterior point of the articulator is the axis of lateral rotation.Dr. Edgar N. Starcke's articles in the Journal of Prosthodontics have more information on the history of articulators.