A drill alignment apparatus for a drill adapted for osteoplastic surgery comprises an alignment rod mounted thereto and a clamp element. The alignment rod is parallel to and disposed a predetermined distance (D) from a shaft of the drill. The clamp element includes an aperture which permits passage of...http://www.google.es/patents/US4860735?utm_source=gb-gplus-sharePatente US4860735 - Drill alignment guide for osteoplastic surgery
