Abstract: A support device for a dentist's drill comprising a support, an articulated arm comprising two articulated quadrilateral devices disposed in series with one another, and an adjustment device operable to vary the direction of the working axis of the drill. The support is provided with a fixing device for connecting it to a seat back of a dentist's chair and the articulated arm can assume a working condition in which the two articulated quadrilateral devices are disposed at 90.degree. to one another.

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.