Abstract: Support and guide apparatus (1) for a dental drill (2) comprises an articulated arm (3) which can be attached to a fixed support member (4) and provided with an attachment member (88) for a tail (20) of the drill (2); the arm (3) is provided with a device (70) which acts to maintain the axis of rotation (A) of the drill turbine orthogonal to a predetermined working plane (.tau.) and a counterweight (108) which balances the weight of the movable parts in any position of the arm itself.The apparatus (1) further includes stabilization apparatus (201) for the head (203) and jaw (205) comprising a side bracket (241) lockable with respect to the headrest of a dental chair, which (241) carries a transverse element (246) projecting therefrom to maintain the patient's jaw in the open position.