A drill guide assembly used to guide a drill into the jawbone of a patient during dental surgery includes at least one through going guide bore for guiding the drill, at least one attachment for securing a part of the drill guide assembly to the jaw of the patient during surgery, wherein the drill guide assembly includes a first part including the at least one first through going guide bore, the at least one first attachment and at least a first reference area for referring the first part to a first anatomical feature of the patient, a second part including a second reference area for referring the second part to a second anatomical feature of the patient, and a guiding structure for guiding the first part and the second into a desired configuration.