Rudolph Hanau received a patent for his first articulator, the Model “A”, over five years after the application was submitted in February 1921. The Model “B”, dated March 1921, similar to this articulator, the ultimately manufactured Model “C” that was introduced to the dental profession in August 1921. The Model “C” preceded the highly popular Model “H” that was introduced in about 1923 and was patented in 1928.
The Model “C” articulator was introduced during a time when articulator design was dominated by a variety of arbitrary or geometric theories of mandibular movement such as Monson’s Spherical theory and Hall’s Conical theory. Hanau questioned these theories and suggested that articulators should be designed to be adjusted according to records taken from the patient. His requirements were that articulator movement must be directed by three adjustable guiding surfaces, two condylar paths and one incisal path. The direction and magnitude of the condyle movement must be adjustable to comply with anatomical requirements and the incisal guidance must conform with technical requirements.
The Model “C” articulator embodied these attributes but lacked practicality with its complicated mechanism and inconvenient in its application. Therefore, it was not generally accepted by the profession.
Beu Richard A.: The Chronicles of Hanau Products, 1920-1989, Teledyne, Hanau, Buffalo, NY, 1993.
Dr. Edgar N. Starcke's articles in the Journal of Prosthodontics have more information on the history of articulators.