Abstract: Rotary toothbrushes herein disclosed comprise an elongate horizontal tubular barrel with a depending rearward handle. At the barrel forward part is a pair of upright rotary brushes with the bristles extending transversely inwardly toward the barrel and revolvably secured thereto with a common axle means so that the twin-brushes rotate in co-angular unison. There are bi-directional powering means, and preferably manual, to cause the twin-brushes to move in alternating angular directions whereby bucal and lingual sides of upper and lower teeth are simultaneously swept. Specially arrayed bristles promote efficacious sweeping and cleaning to the teeth and gingival surfaces. Aptly positioned stationary brushes might be on the barrel between the rotary brushes. Dental hygiene liquids can be stored within the hollow handle and controllably deliverable therefrom along tubular plumbing having a lead-end extending toward one or both twin-brushes.