The invention discloses a modular surgical bone screw assembly having a threaded base portion and a screw head adapted to attach a variety of structures to bone. The features of the screw include a modular design for the assembly that separates the function of anchorage to the recipient bone to one of the modules of the device (threaded portion) from the other function of attaching another element (such as bone block, membrane, orthodontic wires, elastics etc) to a second module (the screw head). The design also allows the head to be exchanged after the implant has been placed.
