An oral care implement body to which a replacement head can be detachably coupled. In one embodiment, the oral care implement body includes a gripping portion having a shoulder, a stem extending from the shoulder along a longitudinal axis, and a boss protruding from an outer surface of the stem. The boss may have a locking rib section having an undercut surface that is axially spaced from the shoulder and a positioning rib section extending from the locking rib section to the shoulder. The undercut surface may circumferentially protrude from a first side surface of the positioning rib section. The locking rib section may extend along a first rib axis and the positioning rib section may extend along a second rib axis, the first rib axis oriented obliquely to the second rib axis.