A technique for bite plane construction

A technique Jeremy Shulman, School of Dentistry,

for bite D.D.S. University

plane

construction

of Michigan,

Ann Arbor,

Mich.

B

asic indications for the use of bite planes have been discussed in a previous artic1e.l Though they can be of great value in both general and specialty practice, many dentists avoid their use due to time-consuming construction and adjustment procedures. A technique has been developed to circumvent these disadvantages so that minimal office time is needed prior to wax duplication procedures and for subsequent intraoral adjustment. TECHNIQUE

1. Make a maxillary arch impression, and pour a stone cast. 2. Paint the cast with a wax separating medium. 3. Heat and place a double tnickness of pink baseplate wax over the cast (Fig. 1). Apply gentle pressure so that sligilt cuspal indentations appear in the wax. 4. Remove the wax from the cast, and trim it with a sharp knife leaving f/8 inch of wax adjacent to the buccal indentations and f/2 inch adjacent to the lingual indentations. Round the posterior edges 1/8 inch distal to the last tooth (Pig. 2). 5. Soften the trimmed wax wafer, and manually adapt it to the cast (Fig. 3). 6. Flatten the occlusal surface of the wax on the cast with a hot spatula (Fig. 4). 7. Readapt and smooth the buccal and lingual surfaces of the wax with a hot spatula (Figs. 5 and 6). 8. Remove the wax from the cast while still slightly warm, and place it in the mouth. 9. Guide the lower jaw to force the teeth into the wax. The mandible should contact the wax as close as possible to the centric relation pathway, and the indentations in the wax should be no more than about 1/3e inch in depth. If all teeth do not contact the wax, add additional wax in the nonoccluding areas until contact is established (Figs. 7 and 8). Important: To facilitate later adjustment of the acrylic resin (steps 19, 20, and 21)) indentations in the wax should be of minimal depth, and the lower teeth must not be allowed to deeply penetrate or to perforate the wax. 10. Remove the wax bite plane from the mouth, and replace it on the master cast (Fig. 9). 334

ylm~r ‘u

‘3”

Technique

Fig. 1. Two thicknesses of baseplate wax adapted Fig. 2. The wax wafer

is trimmed

for

bite plane

to the maxillary

construction

335

cast.

to the desired width.

Fig. 3. The trimmed and reheated wax wafer is carefully adapted to the master cast. Fig. 4. The occlusal

surface of the wax is smoothed with

Figs. 5 and 6. The buccal

and lingual

a hot spatula.

surfaces of the wax are smoothed

with

a wax spatula.

11. Reduce the occlusal surface of the wax by smoothing it with a flat blade or by cutting it with a sharp instrument. Allow the slightest possible indentation to remain for at least one cusp of each lower tooth. Aside from these slight indentations, the resulting occlusal plane should be made as flat as possible (Figs. 10 and 11). 12. Return the wax to the mouth. 13. Check the lateral and protrusive excursions of the mandible against the wax (Figs. 12 and 13). Only the cuspids should contact in lateral excursions, and all of the incisor teeth and cuspids should contact in protrusion (or cuspids only if SO desired). Increase or decrease the thickness of the wax bite plane in the anterior region until the desired posterior clearance is obtained. To increase clearance? add wax anterior to the centric relation marks. To decrease the clearance, chill the wax

336

J. Prosthet. Dent. March, 1973

Shulman

Fig. 7. The wax bite plane is placed in the mouth, and the patient along the centric

relation

is guided

to close his jaws

pathway.

Fig. 8. The final closure of the mandibular

teeth into the wax wafer.

Fig. 9. The wax bite plane is returned to the master cast. Fig. 10. The occlusal surface of the wax bite plane is trimmed

flat by using a cutting

instru-

ment.

bite plane and have the patient move his mandible in the appropriate excursions with gentle pressure until the wax is worn down to the desired level of posterior tooth clearance. 14. Remove the wax from the mouth and dismiss the patient. 15. Return the wax bite plane to the cast, and trim the excursive pathways so that only slight cuspal path indentations remain. 16. Sear the buccal and lingual edges of the wax to the stone cast. The finished buccal wax should be thin and festooned and should overlap the teeth about G inch. 17. Follow usual laboraory procedures to duplicate the wax bite plane in clear heat-cured acrylic resin. If this procedure is accomplished in a laboratory, the work authorization must caution the technician NOT to alter the occlusal surface in any way either before or after processing. However, the buccal and lingual surfaces may be polished. 18. Place the acrylic resin bite plane in the mouth. There may be problems in seating caused by processing changes or by undercuts. Make the necessary corrections to allow complete’seating of the appliance. If retention problems are anticipated, clasps can be added at the time of wax-up (steps 5,6, and 7). 19. Use blue articulating paper to check lower tooth contacts while guiding the

Volumr 29 Number 3

Technique

Fig. 11. The finished wax bite plane shows the correct Fig. 12. The lateral

interferences,

for bite plane

contours

construction

337

and surfaces.

if any, are checked in the mouth.

Fig. 13. The protrusive

relation

Fig. 14. The occlusion articulating paper.

of the finished

is being checked in the mouth. acrylic

resin bite plane is checked

in the mouth

with

jaw along the pathway to centric occlusion in the acrylic resin (Figs. l-1 and 15), Most of the original indentations will show marks. With a flat acrylic finishing bur, smooth the areas of blue markings just to the point where they no longer show (Fig. 16). Areas adjacent to cuspal contact must be as nearly flat as possible in all direction (especially mesiodistally) to allow unimpeded movement from the position of centric occlusion to the position of centric relation. 20. Recheck the centric relation in the mouth with articulating paper, and continue refining the acrylic resin until all identations are gone and all teeth leave one tiny blue mark on a flat occlusal plane (Fig. 17) . 21. Check the lateral and protrusive excursions in the manner described in steps 19 and 20 (Figs. 18, 19, and 20). 22. Lightly polish the occlusal surface of the acrylic resin bite plane. Care must be taken not to destroy the uniformity of cuspal markings. Following the polishing. recheck this uniformity in the mouth with articulating paper. APPOINTMENT

PLANNING

Using this technique, a bite plane can be made in either two or three appointschedule would involve impression making at the first, ments. A three-appointment fitting and adjusting the wax at the second, and finishing the appliance at the third.

330

Shulman

J. Prosthet. Dent. March, 1973

paper are shown on the acrylic resin bite plane be:fore Fig. 15. Markings from the articulating corr ections are made. Fig. 16. The occlusal surface of the acrylic resin plane is flattened and reduced until (each lowe ‘r tooth leaves at least one mark in centric occlusion and until excursive pathways are reco rded. Fig. 17. The finished acrylic resin bite plane with visible indelible centric occlusal mark .ings mad e by all lower teeth. Fig. 18. The contacts made in all lateral excursions are checked, and the necessary correct are made. Fig. 19. The protrusive relation of the mandibular teeth to the acrylic resin bite plar le is chec :ked. have been corFig. 20. The finished acrylic resin splint after eccentric occlusal relationships rectt :d is ready to be inserted in the mouth.

Technique

for bite plane

construction

339

Construction can be completed in two appointments if a recent cast is available or if the patient is asked to wait while a new cast is made. Either way, the total chair time should be no more than 30 minutes. This is possible since very little final adjustment is needed. This, in turn? is possible, because the mouth has served as an articulator while the proper form and thickness are established. SUMMARY

A technique has been described for bite plane construction. Time-consuming fabrication procedures and adjustments have been circumvented. It is hoped that, by making the entire procedure easy and quick, more use will be made of this valuable adjunct in various treatment situations where it is indicated. Reference 1. Shulman, J.: Bite Modification J. 49: 27-30, 1972. DEPARTMENT OF PERIODONTICS SCHOOL OF DENTISTRY 1011 N. UNIVERSITY UNIVERSITY OF MICHIGAN ANN ARBOR, MICH. 48104

Appliances:

Planes, Plates and Pivots, Va. State Dent. Assoc.