7/29/2019 PROSTHETIC OPTIONS FOR EDENTULOUS CONDITIONS

1/5

DEVELOPMENT OF OCCLUSION WHERETOTAL RECONSTRUCTION IS CONTRAINDICATEDWILLIAM H. PRUDEN, II, D.D.S.Paterson, N. .I.

E MPHASIS on complete mouth treatment is altogether fitting and proper as longas the dentist remembers that the objective of restorative dentistry should beto do the least amount of dentistry required for a given patient. A comprehensivediagnosis including complete history, clinical examination, mounted diagnostic casts,and roentgenograms serves the best interests of our patients. However, it does notnecessarily follow that our treatment plans should include a restoration on everytooth. Striving for the ideal is a noble aim but a foolish one if the nonideal is alsofunctional and nonpathologic. Methods of developing an occlusion as it affects themouth that does not need full treatment will be presented in this article.

THE ONE TOOTH RESTORATIONA full mouth rehabilitation might consist of a single onlay or crown if this

were all the dental treatment needed in a specific situation. The patient with manylarge amalgam restorations, one of which fractures with the loss of a cusp, is anexample. If the diagnosis shows good functional occlusion with good alignment ofteeth, well carved and contoured restorations, and good periodontal health, wewould be foolish to suggest replacement of all restorations in an attempt to achievethe ideal. We would be assuming a great deal to presume to improve on an alreadyh.ealthy condition.

The occlusion of the one crown or onlay being constructed must receive asmuch care as would be given a full mouth restoration. A fine-fitting restoration withimporper occlusion could conceivably create a situation so unfavorable as torequire extensive restoration at a future date. A deflective contact of this restorationmight cause repositioning of the mandible with resulting new neuromuscular habits.This could lead to trauma and destruction in other parts of the mouth.FUNCTIONALLY GENERATED PATHS

The functional core technique for establishing the occlusal surface is idealvvhen one tooth must be restored and the remainder of the mouth shows good func-tional occlusion and is nonpathologic. A soft wax is placed in the inlay preparation

Read before the American Dental Association, Atlantic City, N. J.649

7/29/2019 PROSTHETIC OPTIONS FOR EDENTULOUS CONDITIONS

2/5

550 PRUDEN J. Pros. Den.May-June, 1966or over the crown preparation within a short copper band matrix. Then, the pa-tient carves the wax with the opposing teeth so that the pattern will be formedharmoniously with all functional and nonfunctional mandibular movements. A stonecore or index is obtained of this wax surface, and the core can be used as thecounter die for the wax pattern of the in1ay.l

As long as the core can be positioned on the adjacent teeth, the pattern andsubsequently the cast restoration will be in normal occlusion not only in the centricposition but in any other occlusal position.

The functionally generated path technique can be very successful in quadrantdentistry or even for total reconstruction where proper anterior guidance hasbeen previously established. However, this method should not be used to developthe occlusion in eccentric positions opposite an extruded tooth or to form lateralpathways in a pathologically involved dentition where centric occlusion is not inharmony with centric relation. In these situations, previous occlusal corrections orextensive restorations should be made to provide a harmonious functional occlusion.THE SINGLE POSTERIOR FIXED PARTIAL DENTURE

The handling of the occlusion is a diagnostic problem for a fixed partial den-ture, or for several individual tooth castings .in the same quadrant of the dentalarch. If the rest of the mouth is healthy, the quadrant requiring treatment shouldbe restored in harmony with the remaining dentition. Full working casts can beoccluded more easily and with greater accuracy than casts of a part of the dentalarch, and they also act as a guide for the technician when carving wax patterns.He can refer to the contours and occlusal anatomy of the teeth on the oppositeside.z

Periodontal problems in other parts of the mouth that cannot be explained bylocal irritation or systemic factors may be related to occlusion. Mounted diagnosticcasts will furnish valuable information in this region.3 When centric occlusion isnot in harmony with centric relation, the casts aid in determining whether equilibra-tion, reconstruction, or a combination of both will best serve to obtain a harmoniousrelationship. Occlusal equilibration is at best a gross procedure and strictly a nega-tive one. Any grinding procedure can only remove tooth structure. Equilibrationshould never be done prophylactically When it is employed, it should be done verycarefully with a method that most likely will harmonize the maximum intercuspationof teeth with centric relation (that position to which the closing muscles of mastica-tion would carry the mandible if the teeth were not in the way). Equilibrationprocedures should eliminate interferences on the balancing side at least whiledeveloping cuspid contacts on the working side.THE RESTORATION OF ONE DENTAL ARCH

Sometimes a harmonious occlusion can be established with a combination ofreconstruction in one dental arch and occlusal corrections on the other. Often, therestorations can be constructed in centric position because the opposing posteriorteeth are out of contact following completion of the preparations in the involved arch.Some equilibrating of the teeth in the opposing dental arch will probably be indi-

7/29/2019 PROSTHETIC OPTIONS FOR EDENTULOUS CONDITIONS

3/5

V&me 16Number 3 OCCLUSION DEVELOPMENT 551ca.ted. Usually these teeth will have extruded creating a poor plane of occlusionwhich, if not corrected, will result in traumatic or inefficient occlusion.

This principle of rebuilding the occlusion in centric relation can be employedwhen the teeth to be restored are in one dental arch or are in the right quadrant ofone jaw and left quadrant of the other. Any of these conditions eliminates all con-tacts of posterior teeth after the preparations are completed.

In this type of procedure, locating and transferring the hinge-axis to thearticulator and obtaining proper centric registrations will lead to increased ac-curacy.2+6 However, remounting procedures are not as effective as in the fullmouth reconstruction situation because wear on the stone counter cast is likely to0c:cur.REXTORING THREE QUADRANTS

Occasionally extensive restorative treatment is necessary in three quadrantsof the mouth and yet the fourth quadrant is sound. If the periodontal condition ishealthy, the alignment of the teeth adequate, and caries activity controlled, thisquadrant need not be involved. The patient would be treated in much the same wayas for complete restoration of all posterior teeth except that the teeth of the fourthquadrant would only be involved with reshaping or recontouring procedures. Hereagain the use of the hinge axis, proper centric relation records, and remountingprocedures are a decided aid. Frosting or sand blasting the occlusal surfaces andtemporary placement of the restorations can be of value in refining the occlusion. Acareful analysis of the marks on the occlusal surfaces of the castings must be madebefore alteration is begun.OCCLISION FOR ANTERIOR TEETH

The anterior teeth must harmonize with the remainder of the occlusion. Ananterior fixed partial denture, for example, must not prevent contact of the posteriorteeth nor must it overload any tooth in the anterior segment either during closure,in centric position, or in any eccentric excursion.

Some confusion exists regarding the role of the cuspids. Some dentists feelthat these teeth shou!d be slightly out of contact when the mandible is in centricrelation while others feel they should contact simultaneously with the posterior teeth.Clinical observation indicates that they must at least function in the working excur-sion and many believe that they should support the occlusion at this time. When thecuspid is out of contact in the lateral excursion, the premolars often become mobile.Whether the increased root length of the cuspid, its increased proprioception, orevolutionary factors are responsible for the protective maintenance that it provides isnot completely clear.7,s

Crowns should not be placed on lower anterior teeth if they can be avoided.The size of these teeth makes esthetics and proper contours of the restorations diffi-cult problems. Where fixed prostheses or stabilization are necessary, pin-ledge re-tainers are preferred.If both posterior and anterior restorations are indicated, the posterior restora-tions are completed first, with an arbitrary incisal guidance which is later fabricated

7/29/2019 PROSTHETIC OPTIONS FOR EDENTULOUS CONDITIONS

4/5

552 PRUDEN J. Pros. Den.May-June, 1966in the anterior teeth. However, the anterior guidance or at least cuspid guidancemust be established first when the generated path technique is used, because thecuspids must support the occlusion during the subsequent operative procedures.nSPLINTING IN OCCLUSAL DEVELOPMENT

Splinting of teeth is merely an adjunct to occlusion. Splinting is not a sub-stitute for good occlusion. However, in a harmonious occlusal relation, splintingcan be of great aid in supporting fixed restorations and/or periodontally weakenedteeth.

Most dentists tend to think of splinting as being developed by solder jointsonly. However, perfectly adequate splinting can be obtained where parallelism is aproblem or might jeopardize the pulp by dove-tailing one casting into another. Like-wise, the use of cemented copings with telescopic crowns may achieve a form ofsplinting. Two or more fixed partial dentures can be connected to develop completearch splinting by the use of underlying connected copings on adjacent teeth.THE IMPORTANCE OF PRECISION IN DEVELOPMENT OF OCCLUSION

The fabricating of an occlusion presupposes precise techniques. Anything thatincreases accuracy is worth doing. The vacuum mixing of die stones before pouringcasts, proper measuring of all materials, vacuum investing procedures, and the useof modern equipment to eliminate as much of the human factor as possible areall important adjuncts, Their use will help to insure not only accurately fittingrestorations but restorations with harmonious occlusion. Nonetheless, all patientsfor whom restorations have been made, be they large or small, should be recalledfor observation of the occlusion. Proper adjustment of wear facets may save troublefor both the dentist and the patient.SUMMARY

Methods of development of harmonious occlusion for patients who do notrequire complete mouth reconstruction were described. Treatment procedures rangedfrom single tooth restorations to three quadrants requiring dental reconstruction.By practicing the basic tenents of gnathology in treatment of the simple restorationsin conjunction with proper periodontal care, the complex, time consuming, patientfatiguing, full mouth rehabilitation can be avoided for many patients.REFERENCES1. Benfield, J. : in Kilpatrick, H. : Work Simplification in Dental Practice; Applied Time andMotion Studies, Philadelphia, 1963, W. B. Saunders Company.2. Pruden, W. H., II: Occlusion Related to Fixed Partial Denture Prosthesis, D. Clin. NorthAmerica, p. 121-136, March, 1962.3. Pruden, W. H., II: The Role of Study Casts in Diagnosis and Treatment Planning, J.

PROS. DENT. 10:707-710, 1960.4. Wilson, W. H., and Lang, R. L.: Practical Crown and Bridge Prosthodontics, New York,1962, McGraw-Hill Book Company, Inc.5. Lucia, V. 0.: Modern Gnathological Concepts, St. Louis, 1961, The C. V. Mosby Company.6. Granger, E. R.: Practical Procedures in Oral Rehabilitation, Philadelphia, 1%2, J. B.Lippincott Company.

7/29/2019 PROSTHETIC OPTIONS FOR EDENTULOUS CONDITIONS

5/5

Volume 16Number 3 OCCLUSION DEVELOPMENT 5537. DAmico, A. : The Canine Teeth-Normal Functional Relation of the Natural Teeth of Man,J. Southern California D.A. 26:6-23, 19.58.8. Alexander, P. C.: Analysis of Cuspid Protective Occlusion, J. PROS. DENT. 13:309-317, 1963.9. Mann, A. W., and Pankey, L. D.: Oral Rehabilitation. Part I. Use of the P-M Instrument

in Treatment Planning and in Restoring the Lower Posterior Teeth. Part II. Re-construction of the Upper Teeth Using a Functional Generated Path Technique, J.PROS. DENT. 10:135-162, 1960.

44 CHURCH ST.PATERSON, N. J. 07505