TIPS FROM OUR READERS A device for establishing J. A. Chrystie, I’ara
Vista.
SoJth
the occlusal plane for complete dentures
B.D.Sc., B.Sc.Dent. Australia
A modified Fox plane guide is used to locate the occlusal plane in treatment of edentulous patients. Two hinged perspex wings, each ruled with parallel lines, are added to the Fox guide (Fig. 1). In addition a jig with a fixed anterior pin and two vertically adjustable posterior pins is required (Fig. 2). TECHNIQUE 1. Adjust the lines of the perspex sheet parallel to the Fox plane guide. Place the occlusion rim, on the upper cast, on the Fox plane guide. Place the jig on the upper surface of the cast and adjust the screws until the plane of the jig is parallel to the lines on the perspex sheet (Fig. 2). Place pencil marks on the cast where each of the jig’s three legs rest. 2. Place the upper rim in the patient’s mouth, and insert the
Fig. 1. Fox guide attached.
THE
JOURNAL
plane
OF PROSTHETIC
with
hinged
DENTISTRY
perspex
wings
Fox plane guide. Adjust the perspex lines parallel to the ala-tragus line. 3. Replace the occlusion rim and cast on the Fox plane but rotated through 180 degrees. Reseat the jig on the cast using the pencil marks for positioning. 4. Adjust the wax rim until the jig is parallel to the lines on the perspex wings. When the rim is returned to the mouth the occlusal plane will be parallel to the ala-tragus line.