Between 1932 and 1988, over 500 different toothbrush designs were patented in the United States, each professing to provide significant improvements in tooth cleansing. Among these, the Roc-B-Tween toothbrush, patented in Oakland in 1938, offered oscillatory movement with a “rack and pinion-like effect” occurring between the bristles of the toothbrush and the spaces between the teeth, effectively cleansing a “vital spot.”
Mattick, BE 2010 A guide to bone toothbrushes of the 19th and early 20th centuries. Bloomington, IN: Xlibris Corp;McMath, JF Dental Instrument. Patent 2122619. 5 July 1938. Print.
This Roc-B-Tween brush (A343.2) has a natural bristle head and a blue plastic handle.
University of the Pacific Permanent Collection. Donor: Dr. John D. Mann (’90)
The replaceable brush head is small, and the hinge is recessed between the handle and pivoting head to “avoid pinching of delicate mouth tissues or membranes.”
Roc-B-Tween toothbrush packaging
Marketing copy on the box proclaims thorough cleaning of every crevice.