A toothbrush (101) includes a handle (103) and a head (105) connected to an end of the handle (103). The head (105) has a surface (111). A plurality of bristles (107) are mounted on the head (105) so the bristles (107) extend from the surface (111) on only one side of the head (105). The plurality of bristles (107) are arranged in a plurality of sets including first, second, and third sets (121, 123, 125). The bristles (107) of each of the first, second, and third sets (121, 123, 125) are substantially parallel to other bristles (107) in the same respective set. The bristles (107) in the first and third sets (121, 125) are oriented to angle outwardly from the bristles (107) in the second set (123) as they extend away from the surface (111).
