An orthodontic mini-screw comprises a screw head arranged to be coupled to an ancillary member. A threaded body couples to the screw head and has a first portion arranged to locate in a cortical bone layer of a patients jaw bone. A second portion of the threaded body is arranged to extend a predefined distance beyond the cortical bone layer and into an adjacent cancellous bone layer, such that a channel extends through the threaded body and out of at least one void located in the first portion. In use the channel is arranged to deliver a settable bio-compatible material into the cancellous bone layer to assist with anchorage of the mini-screw.
