A photo of a Motodent electric toothbrush. The toothbrush was on display at the the <a href="https://en.wikipedia.org/wiki/Museum_of_American_Heritage" class="extiw" title="w:Museum of American Heritage">Museum of American Heritage</a> and the photo was taken during a visit to the museum. The museum display mentioned an inventor, Tomlinson Moseley. There is a <a rel="nofollow" class="external text" href="http://patft.uspto.gov/netacgi/nph-Parser?patentnumber=2196667">US patent</a> that appears to cover the depicted electric toothbrush. The patent was filed for in 1937 and it indicates that the patent rights were assigned from Moseley to Motodent, Inc., of Los Angeles, California, USA.
<a href="//commons.wikimedia.org/wiki/User:Gazebo" title="User:Gazebo">Gazebo</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>