Abstract: Apparatus capable of use by unskilled hands for scribing, including marking and cutting, a tubular sleeve to produce a contoured end corresponding to the contour of the sub-gingival shoulder of a patient's tooth which has been prepared for a jacket crown, which apparatus comprises a mount for a scribing instrument and a body supporting same which is a snug fit within the bore of the sleeve of a pre-prepared jig used to assist the dentist in the tooth preparation, and said scribing instrument is carried by a rotatable portion of the mount to engage and follow a surface on the sleeve which has a contour corresponding to the contour of the sub-gingival shoulder.

Abstract: A dental surveyor to be used by a mechanic for the preparation of a jig carrying a cutting-bur guide sleeve to assist a dental surgeon in tooth preparation for the anchoring of a bridge, the surveyor comprising a pair of parallel traversing arms carrying a stylus and a sleeve holder, respectively, a worktable on an adjustable universal mount at an upper end of a stem also supported for universal movement in an intermediate clamping housing, and a floor beneath the stem and having two concentric tracks selectively engageable by the end of the stem, the inner track when engaged confining the worktable to rotation about a fixed fulcrum and the outer track when engaged confining the worktable to rotation and swivelling at a predetermined inclination to the axis of the fixed fulcrum, thus enabling the mechanic to vary the axes of the sleeves of successively prepared jigs so that tooth reduction by the surgeon on the patient may be achieved.