A true understanding of occlusionand comprehensive dentistry is only im-portant if you want to become the bestdentist you can possibly be. The fact is, thepredictability and longevity of all thebeautiful dentistry that dentists create,and the overall comfort and functioningof their patients, is predicated on just howwell they understand and apply thesetwo principles.

A primary tenet of comprehensivedentistry is that all of the components ofthe masticatory system (teeth, soft tissues,skeletal structures, muscles, and joints)are intimately related and dependent onone another for ideal function.1-2 Thisinterrelationship is mediated by the cen-tral nervous system via the exquisite pro-prioceptive nerve network that permeatesthe entire gnathic system. Comprehensivedentistry is really about seeing, and un-derstanding, the “big picture.” This is a fardifferent approach than the “see the hole,fill the hole,” mentality often employed inrestorative dentistry. Addressing estheticconcerns is also an integral component ofcomprehensive dentistry. Creating “ideal”functional and masticatory relationships

and harmony without addressing esthet-ics often leads to patient disappointment.Conversely, esthetics without regard forfunction (or parafunction) often leads tocase failure and/or masticatory dishar-mony. The dentist who wants to practicetruly excellent dentistry must be able tothink comprehensively and address bothfunction and esthetics.3-5

An understanding of occlusion is essen-tial to practicing comprehensive dentistry.There are at least five occlusal philosophiesin use today (Classic Gnathology, Bioes-thetics, Dawson/Pankey, Neuromuscu-lar, and Maximum Intercuspation [MIP]).While an in-depth discussion of each ofthese philosophies is well beyond the scopeof this article, it is probably safe to saythe vast majority of dentists use MIP (hab-itual closure) as a starting and ending pointwhen developing an occlusal scheme. Thereason for this is probably because it re-quires the least thought, time, knowledge,and effort. The dentist simply works withthe occlusal relationship as it exists. Theproblem is that in many cases the patient’sexisting MIP and occlusal scheme is farfrom ideal. In fact, it may be a destructive

relationship, causing a problem, or prob-lems, somewhere in the masticatory system.These problems can manifest as muscularpain, joint problems, wear and/or chip-ping of teeth, tooth mobility, tooth sen-sitivity, an uncomfortable bite, and a varietyof other symptoms. By using the existingbite relationship in such a situation, den-tists are in fact placing restorations intoan occlusal scheme that is not workingwell for that patient. It would seem logi-cal to try and improve the occlusal/mastic-atory relationships in such a patient priorto, or in conjunction with, doing the re-storative dentistry.6 The questions toask are, when does the patient’s existingocclusal scheme need to be altered prior toperforming restorative/prosthetic proce-dures and when is it acceptable to workwith the occlusal scheme as it exists?

The following case presentation, inwhich both functional and esthetic issuesare addressed, demonstrates a compre-hensive approach to restorative dentistry.In this particular case, for reasons that will

become apparent, the existing occlusalscheme was altered prior to performingthe prosthetic dentistry. A detailed ration-ale and methodology is described. Thecase demonstrates just how the science ofocclusion and comprehensive dentistry canactually be applied to clinical dentistry.

CASE PRESENTATIONThe patient was a 37-year-old woman whowas referred for a consultation regardingthe replacement of congenitally missingmaxillary lateral incisors and improvingthe appearance of her teeth and smile(Figure 1 and Figure 2). She had previous-ly consulted with a number of other den-tists and had explored restorative optionsincluding implants, orthodontics, andfixed bridgework. At the age of 20 sheunderwent 15 months of orthodontictreatment to reposition the upper ante-rior teeth and to create space betweenthe central incisors and canines. Over thepast 15 years she had worn three differentMaryland-type fixed bridges to replace

32 INSIDE DENTISTRY—FEBRUARY 2007CONTINUINGeDucaTion

Is Occlusion and ComprehensiveDentistry Really That Important?Gary Alex, DMD

ABSTRACT

Patient demand for cosmetic dentistry has never been greater. This has led many dentists to invest considerable time, effort,and money mastering various cosmetic procedures and techniques. While this is commendable, it should be recognized thatit is one thing to be able to make beautiful teeth, and an entirely different thing to make beautiful teeth that actually lastand function in harmony with the rest of the masticatory system. An acceptable cosmetic result, without regard for functionand/or parafunction, will often result in premature case failure. What the truly successful clinician of today requires is a logical andsystematic methodology in approaching cosmetic/restorative cases that will lead to a reasonably predictable and durableend result. The following case presentation describes how a comprehensive approach to dentistry, one that integrates bothfunction and esthetics, can be used to successfully diagnose, treatment plan, and restore a cosmetic/restorative case.

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LEARNING OBJECTIVES

After reading this article, thereader should be able to:

n describe the benefits ofapproaching restorative/prosthetic cases in acomprehensive fashion.

n recognize when an alterationin the existing occlusalscheme might be beneficialprior to case treatment.

n possess a better under-standing of centric relation,how to use it, and ways tofind and record it.

n discuss the value ofearbow transfers andproperly mounted modelsfor case diagnosis.

Gary Alex, DMDPrivate Practice

Huntington, NY

Log on now to www.insidedentistryCE.com to take the FREE CE quiz!

THIS CE LESSON IS MADE POSSIBLE THROUGH AN

EDUCATIONAL GRANT FROM

Figure 1 Preoperative full smile. Figure 2 Preoperative MIP retracted view withteeth apart. Note the lingual thinning of theupper anterior teeth, chipping and wear of thelower anterior teeth, and abfraction-type lesionson teeth Nos. 8, 11, 24, and 25. All of these arepotential signs of potential occlusal instability.

34 INSIDE DENTISTRY—FEBRUARY 2007

the lateral incisors; at least one of thosefixed bridges had composite or ceramicwings. She stated she was never happywith how any of them looked and thatthey would fall out occasionally. She hadbeen evaluated for dental implants butthere was insufficient space for restora-tions of this nature (Figure 3 and Figure 4).At the time of her initial visit she was wear-ing a flipper-type removable partial den-ture that she was very dissatisfied with,both because of the esthetics and becauseit caused her discomfort (Figure 5). Shestated that she was very self-conscious ab-out her teeth and smile, and often avoidedsmiling in photographs. Quite significant-ly, she also mentioned that she was notcomfortable with her teeth touching andthat her bite “felt off ” and that some-times it felt like she had “two bites.” Shewas not aware of any grinding or clench-ing habits. Her periodontal status wasexcellent. The medical history was non-remarkable. When she was asked whatshe would like as far as her teeth and smilewere concerned, her reply was: “a whiter/brighter smile, something that looks reallynice and I feel good about, somethingthat will last, nothing I can take in andout, and I would like my bite to feel com-fortable because it has never felt right.”

TREATMENT PLANNING The concept of comprehensive dentistryand the comprehensive exam was ex-plained and discussed with the patient ather initial visit. It is often helpful to showthe patient another case that has alreadybeen worked up comprehensively to helpthem better understand what is involvedand the advantages of such an approach.A typical comprehensive exam requiresabout 60 to 90 minutes and includes afull set of radiographs, full maxillary andmandibular alginate impressions, diag-nostic digital photographs, an earbowtransfer, and centric relation (CR) and/or MIP bite records. In addition to this, atemporomandibular joint (TMJ), rangeof motion, and muscle screening exami-nation is performed. Stable and comfort-able joints are essential prior to definitivetreatment. Input from other dental spe-cialists and/or other diagnostic imaging(eg, CAT scan, MRI, tomogram, etc) inaddition to conventional dental x-raysmay also be required. The informationfrom the comprehensive exam is used toformulate a concise written narrative de-scribing, among other things, just what itis the patient is looking to do, clinical find-ings, one or more treatment options, ad-vantages and disadvantages of each option,time frames involved, and anticipatedfees for treatment.

Diagnostic photographs are an integralpart of any comprehensive exam and theauthor believes it is imperative that den-tists be adept with digital photography.Quality digital photographs are essentialfor a number of reasons, including com-munication with the patient, laboratory,and the patient’s insurance company;

legal protection; and documentation of thecase before and after treatment. Dentistsshould also know how to use a basic edit-ing program for cropping and editing asrequired. This author will typically take aseries of digital photographs, includingvarious smile, occlusal, lips in repose, fullface, and retracted views. These are thenstored in individual patient folders thatcan be recalled at any time.

It is also essential that dentists under-stand how to take an earbow transferand just why it is so important. The ear-bow is used to record the relationship ofthe patient’s maxillary arch relative to theTMJ, and then transfer this relationshipto an articulator (Figure 6 and Figure 7).An earbow transfer is absolutely essentialwhenever an open bite record is taken, asis the case with most CR bite records.The correct axis of condylar rotation(actually a close approximation) is record-ed by the earbow, which is then used tomount the upper cast to this hinge axisposition. If the correct hinge axis is not

recorded via an earbow or hinge axis re-cording when taking an open bite record,then the casts will not meet properly whenthe models are closed together. In addition,the starting hinge axis position will havean effect on excursive pathways. An incor-rect hinge axis position during fabrica-tion of the restorations will often resultin considerably more time spent adjust-ing the case once it is placed.

Even if the dentist chooses to take aclosed MIP bite record, it is advantage-ous to take an earbow transfer and mountthe case on an articulator. For one thing,a properly taken earbow transfer and up-per cast mounting will enable the dentistand technician to visualize any cant ofthe maxillary teeth as they relate to thefacial midline and horizon. In other words,the earbow transfer relates the “estheticplane” (line from upper canine to cani-ne) to the articulator just as it appears inthe patient’s mouth with the head heldstraight and erect (Figure 8 through Figure10). In the author’s opinion, a properly

taken earbow transfer is more accuratethan “stick bite” type registrations for eval-uating horizontal and vertical planes. Theauthor also prefers to use a level to helpdetermine the esthetic plane. This is achie-ved by having the patient sit in a chairand orienting the head so it appears leveland straight relative to the horizon. Theanterior bow is then moved in the hori-zontal plane until the bubble in the levelis centered (Figure 11). One of the treat-ment goals is to create an esthetic planeof occlusion that is parallel to the horizon,with the head straight and erect, regard-less of any facial discrepancies.7 Althoughmany dentists use the interpupilary lineto orient the bow to determine the esthe-tic plane, this is often incorrect becauseone eye is frequently higher or lower thanthe other (Figure 11).

A TMJ and muscle-screening examshould be part of any comprehensive exam.The simple fact is that any change in con-dylar position and/or morphology willaffect the way the teeth come together. It

Figure 3 Occlusal view of the upper anteriorteeth showing lack of sufficient interproximalspace for implants.

Figure 6 and Figure 7 The earbow is used to record the relationship of the maxilla relative to theTMJs. The data is then transferred to an articulator. The correct hinge axis starting position (or closeapproximation) is essential when taking an open bite record.

Figure 8 Try-in of a denture with a cantedesthetic plane. An earbow transfer was taken andthe denture was mounted on a semi-adjustablearticulator (also see Figure 9).

Figure 9 A properly taken earbow and uppercast mounting will enable the technician to visu-alize the cant as it actually appears in the patient’smouth, with the head straight and erect, allowingfor easy correction (also see Figure 10).

Figure 10 Denture with the corrected estheticplane after adjustment on the articulator.

Figure 11 The author prefers to use a level toalign the earbow parallel to the horizon to deter-mine the esthetic plane. In this example, it is easyto see that if the interpupilary line was used todetermine the esthetic plane, the final restorationswould be canted relative to the horizon once theywere placed in the patient’s mouth. This is becauseone eye is significantly higher than the other.

Figure 4 Radiographic appearance of theanterior teeth showing insufficient space for den-tal implants.

Figure 5 Photograph of the removable partialdenture (“flipper”) that the patient was wearingon her initial visit.

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simply makes sense that we ascertain thecondition of the joints prior to definitivetreatment. The author uses a simple andconcise TMJ- and muscle-screening examform as a guide during this aspect of thecomprehensive exam. It is important to es-tablish baseline parameters in terms ofjoint and muscle health prior to treatment.If significant problems are suspected thenother diagnostic information, such as anMRI, may be required. Stable and comfor-table joints are vital to overall case com-fort, stability, and predictability.

In this particular case several “red flags”were evident regarding the stability ofthe patient’s existing occlusal scheme.The patient had stated that she was “notcomfortable with her teeth touching”and her bite “felt off.” She had also men-tioned that it felt like she had “two bites.”During the TMJ screening exam, consis-tent reciprocal clicking (clicking on open-ing and closing) of the left joint was noted.In addition, the patient reported discom-fort to direct palpation of the left TMJ.Lingual thinning of the upper anteriorteeth and chipping and wear of the lo-wer anterior teeth also was evident (re-fer back to Figure 2). Both joints could beloaded comfortably with light and firmpressure via bilateral manipulation (see

Figure 12 and Figure 13 for examples) buta very significant “hit and slide” from CRto MIP was noted. A “hit and slide” is theterminology used to describe the slideseen as patients squeeze their teeth to-gether from the first point of tooth con-tact, with the joints in CR, to an MIPposition (Figure 14 and Figure 15).

Centric relation (CR) is a joint-basedposition where the condyles (medial poles)are fully seated in their most superior po-sition in the glenoid fossa and the disks

are in their proper position and orienta-tion on the heads of the condyles. PeterDawson defines CR as “the relationship ofthe mandible to the maxilla when the pro-perly aligned condyle/disc assemblies arein the most anterior superior position ofthe glenoid fossa.”1 What clinicians needto understand is that CR is a repeatablejoint-based axial position found inde-pendently of the teeth.8-11 In fact, CR biterecords are typically taken with the teethapart. In the author’s experience, CR has

proven to be a very repeatable, reliable, anduseful position for case diagnosis and de-sign, as well as in the management of manyocclusal-muscular disharmonies.

Because there was clear evidence ofocclusal disharmony in this case, theauthor felt a CR bite record and mount-ing was essential to properly diagnosethe existing occlusal relationships. In theauthor’s experience, CR can be foundfairly easily in the vast majority of pa-tients without prolonged splint therapy

(Circle XX on Reader Service Card)

INSIDE DENTISTRY—FEBRUARY 2007 35

Figure 12 Frontal view of proper finger posi-tion for bilateral manipulation. Bilateral manipu-lation uses a gentle, unforced hinging movementof the mandible to seat the condyles upward intothe glenoid fossa.

Figure 13 Sagittal diagrammatic view of bilat-eral manipulation demonstrating proper fingerpositioning and how the mandible is rotated tofully seat the condyles in their respective sock-ets. (Illustration courtesy of Dr. Peter Dawson.)

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(as is advocated by some). CR can be de-termined in any number of ways, in-cluding bilateral manipulation (BLM),leaf gauge, central bearing point andGothic arch tracing, and various typesof anterior deprogrammers such as aLucia jig.12-16 The technique used most

often by the author is to use BLM in con-junction with a modified Pankey depro-grammer. The Pankey deprogrammer isfilled with a very firm and quick settingpolyvinyl siloxane (Futar® D Occlusion,Kettenbach GmbH & Co, KG) and placedover the upper anterior teeth. The sur-face of the deprogrammer should be keptparallel to the occlusal plane. The patientis reclined to a horizontal position, withthe deprogrammer in place, for 5 to 15minutes. The idea is to keep the teethapart for a time to assist in muscle relax-ation (deprogramming). Some patientscan be deprogrammed very quickly whileothers require more time. Muscle relax-ation, especially of the lateral pterygoids, isone of the keys to locating a correct CRposition.17 To paraphrase Frank Spear,DDS, MSD (various lectures): “CR is nota position you have to put people in, it isa position the condyles go when the lat-eral pterygoids relax.”

After deprogramming, BLM is usedto gently hinge the mandible while hold-ing the condyles up in the glenoid fossa(CR). Using this hinging motion, the low-er anterior teeth are guided through a thinlayer of composite that has been placed on

Figure 14 TMJ illustrator demonstrating thefirst point of tooth contact (arrow) with thecondyles in CR.

Figure 15 As the “teeth” close/slide togetherinto MIP the condyles are no longer in CR but aredown and forward from that position. This move-ment, from the first point of tooth contact withthe condyles in CR (see Figure 14) to an MIPtooth-based position, is called a “hit and slide”from CR to MIP.

INSIDE DENTISTRY—FEBRUARY 2007

(Circle XX on Reader Service Card)

Figure 16 View of a Pankey deprogrammerthat has been filled and seated over the upperanterior teeth. The surface of the deprogrammerhas been roughened and coated with a Bis-GMAresin that facilitates adhesion to a subsequentlyplaced thin layer of composite.

Figure 17 Bilateral manipulation is used tohinge the mandible in CR until the lower incisaledges penetrate the soft composite and contactthe hard surface of the deprogrammer. The com-posite is then light-polymerized, resulting in avery precise incisal index. A very firm-setting PVSis injected between the separated posterior teethwhile the patient is closed into the index to takethe CR bite record.

Figure 18 After the upper cast is mountedwith the earbow transfer, the lower model ismounted to the upper cast using the CR biterecord and incisal index.

the surface of the Pankey deprogrammer(Figure 16). As the incisal edges of the low-er anterior teeth penetrate the soft com-posite, they contact the hard surface of thedeprogrammer. At this point the compo-site is light-polymerized, creating a veryprecise incisal index of the lower anteriorteeth on the surface of the deprogrammer(Figure 17). It is important to roughenthe smooth surface of the deprogrammerand brush on an unfilled resin prior toplacing the thin layer of composite (to en-sure it sticks). If CR has been properly de-termined, then each and every time themandible is hinged using BLM, the lowerincisal edges will fit precisely into theincisal index. In fact, once the patient is de-programmed no external manipulation isrequired as the patient, on command,will consistently close into the index with-out any external guidance. If everythingwas done correctly, the condyles will bein CR when the patient is closed into theindex. All that remains to be done is toinject a very firm-setting PVS between theseparated posterior teeth while the patientis closed into the index. The resulting biterecord and index is then used to mountthe case in CR on a semi-adjustable ar-ticulator (Figure 18 and Figure 19). Hav-ing taught this technique to hundredsof dentists, the author finds that mostwill pick up the technique relatively quick-ly. For those not comfortable with bilater-al manipulation, the use of a leaf gaugeor Lucia Jig offers a viable alternative forfinding CR; however, one loses a certaindegree of “tactile” information obtain-ed from a more hands-on technique likebilateral manipulation.

In this CR-mounted case, the only pointof tooth contact when the models wereclosed together was the mesiolingual cuspof tooth No. 16 (Figure 20 through Figure22). This was the same first and only pointof contact seen in the patient’s mouthwhen bilateral manipulation was used tohinge the mandible in CR (Figure 23).The fact that what we see in the mouthis duplicated precisely on the articula-tor confirms the accuracy of the mount-ing. The patient’s hit and slide from CRto MIP can be easily demonstrated byunlocking the articulator hinges andsliding the models together into an MIPposition. Basically, the same thing is oc-curring in the patient’s mouth. In orderfor the patient to bring his or her teethtogether into MIP, one or both of thecondyles must translate out of CR, andmove down the eminence to some de-gree. It should be pointed out that thismay not be a clinical problem and that itis often acceptable to place restorationsinto an occlusal scheme such as this. Spe-cifically, if no signs or symptoms of oc-clusal disharmony exist, and the patientis comfortable and has no difficulty chew-ing, then a change in the existing occlusalrelationship may be unwarranted. Evena seriously flawed occlusion may notcause clinical problems if the patientdoes not bring his or her teeth together

very often, or brings them together withlittle intensity, or just has a high adaptivecapacity. In the author’s opinion, it is amistake to alter an existing occlusal schemethat is already working solely to satisfythe philosophical occlusal “ideal” of a par-ticular occlusal philosophy. Having saidthat, there are many patients that havean occlusal scheme that is NOT working

well for them, and dentists need to con-sider a change before placing definitiverestorations. The trick is to know whena change is required and when it is not.18

The clinical findings and history in this caseclearly indicated a problem with the exist-ing occlusal scheme and the decision wasmade to modify the occlusion prior to do-ing the clinical dentistry.

One of the goals in a CR-based occlu-sion is the harmonization of MIP withCR. In other words, when the patient clo-ses into MIP the condyles are also in CR. Inthis case, the only point of tooth contact,with the condyles in CR, was the ML cuspof tooth No. 16. This was essentially anonfunctional tooth that also had mes-ial caries. It was decided to “extract” this

Figure 22 In CR, the teeth on the right sideare completely out of occlusion, as are all theteeth on the left side with the exception of toothNo. 16.

Figure 23 The fact that the same (and only)point of contact we see in the mouth using bilat-eral manipulation is exactly the same as what wesee on the articulator confirms the accuracy ofthe mounting.

Figure 24 Tooth No. 16 is “extracted” on themodel with a heatless stone.

Figure 25 and Figure 26 Removing tooth No. 16 eliminated almost all of the “hit and slide” fromCR to MIP, and bilateral posterior contacts are now evident from the premolars back.

Figure 27 Anterior coupling (tooth contact)was achieved by minor equilibration of the mod-els after tooth No. 16 was removed.

Figure 28 The TMJ illustrator is used to demon-strate the occlusal scheme created on the mod-els that resulted in a new MIP position that isnow coincident with CR.

Figure 29 Diagnostic wax-up of teeth Nos. 4through 13. The diagnostic wax-up should beviewed as our “best guess” as to what the caseshould look like in its final form. It must be test-ed in provisionals. A matrix for provisionals, facialreduction guide, and incisal reduction guide areall fabricated from the diagnostic wax-up.

Figure 30 As was done on the models, toothNo. 16 was extracted in the patient’s mouth, andthe teeth equilibrated to CR. The patient’s “hit andslide” from CR to MIP was completely eliminated.

INSIDE DENTISTRY—FEBRUARY 2007 37

Figure 19 Properly trimmed and polished CR-mounted models on a semi-adjustable articulator.

Figure 20 and Figure 21 When the models are closed together with the hinges locked in CR, theonly point of tooth contact is the mesio-lingual cusp of tooth No. 16 (compare with Figure 23).

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38 INSIDE DENTISTRY—FEBRUARY 2007

tooth on the upper model to ascertain whateffect this would have on the occlusion(Figure 24). The tooth was removed with aheatless stone and the models closed to-gether with the hinges locked in a CRposition. Just removing this one tootheliminated almost all the hit and slidefrom CR to MIP and bilateral posteriorcontacts were now evident (Figure 25 andFigure 26). Anterior coupling (anteriortooth contact) was subsequently achievedby minor equilibration of the models (Fi-gure 27). The occlusal scheme created onthe models resulted in a new MIP positionthat was now coincident with CR (Figure28). By doing the occlusal correction onthe models first, it was determined thatthe same process could easily be repeat-ed in the patient’s mouth without exces-sive removal of tooth structure.

In addition to the aforementioned oc-clusal issues, a number of other factors wereconsidered in developing a treatment planfor this patient. She was not a candidate fordental implants. She would not accept a re-movable appliance of any type. She hadnegative experiences with three differentfixed Maryland-type bridge replacements.She had very high esthetic expectations, andspace management was a significant con-cern because of the insufficient room in thelateral incisor areas for replacement withteeth of appropriate width. After con-sidering all of these factors and carefullyevaluating the information obtained fromthe comprehensive exam, the followingtreatment plan was presented to the patient:

1. Perform a diagnostic wax-up of teethNos. 4 through 13 on CR-equilibratedmodels (tooth No. 16 was removed).The wax-up would be used to fabri-cate a matrix for provisionals and alsoto fabricate reduction guides that wouldbe used during tooth preparation. Theplan would call for porcelain veneerson teeth Nos. 4, 5, 12, and 13 along withtwo three-unit Lava™ (3M ESPE, St.Paul, MN) bridges from teeth Nos. 6through 8 and Nos. 9 through 11, withpontics at teeth No. 7 and No. 10.2. At the first appointment, extracttooth No. 16. Equilibrate patient to CR.3. Before the preparation appoint-ment, the lower teeth are whitenedwith a take-home system (Nite White®,Discus Dental, Culver City, CA). Thiscould be done at any time in the treat-ment plan, but usually it is done be-fore the preparation appointment.4. At the second appointment, adjustand even out the lower incisal edges.Prepare teeth Nos. 6, 8, 9, and 11 fortwo all-ceramic Lava bridges. Prepareteeth Nos. 4, 5, 12, and 13 for porcelainveneers. Take final impressions andfabricate provisional restorations us-ing the matrix fabricated from the di-agnostic wax-up.5. At the third appointment, evaluatethe patient in provisionals 1 to 2 daysafter the preparation appointment andmake changes as required. Evaluatethe provisionals for esthetics, phone-tics, occlusion, and function. Once the

provisionals are deemed acceptable, analginate will be taken of the provisionalsand a solid model will be fabricated. Thesolid model will be sent to the labora-tory along with various photographs ofthe patient in the provisionals to assistthe ceramist in the fabrication of thefinal restorations.6. At the fourth appointment, try inand evaluate the final restorations. Oncethe case is approved, the veneers willbe bonded in and the bridges cement-ed in place.7. Fabricate and insert a Durasoftnightguard/retainer at case comple-tion (Great Lakes Orthodontics, Ton-awanda, NY).The patient accepted the treatment

plan as presented and was anxious to begin.The equilibrated models were sent to thelaboratory and a diagnostic wax-up wasreturned along with a matrix for provi-sional restorations and reduction guidesto be used during the preparation phaseof treatment (Figure 29). The diagnosticwax-up should be viewed as a “best guess”as to what the case should look like in itsfinal form. The only way to ascertain thatthis “guess” is correct is to actually try thecase out in provisionals that mimic thewax-up.

The treatment began by essentially du-plicating what was done on the mountedmodels. As on the models, tooth No. 16was extracted and the teeth equilibratedto CR (Figure 30). The patient’s hit andslide from CR to MIP was completely

eliminated. The following week, the pa-tient was re-evaluated and she reportedthat she was very comfortable with hernew bite. In her own words: “This is thefirst time since I can remember that mybite has felt comfortable and I know howmy teeth should fit together.” Once theocclusion had been addressed, the teethwere prepared as treatment planned. First,the incisal edges of the lower anteriorteeth were evened out to create a more es-thetic profile (Figure 31 and Figure 32).Great care should be taken whenever low-er incisal edges are altered. It is very im-portant to preserve the proper incisalinclination and maintain a sharp buccal-incisal line angle (Figure 33). In this case,there was a degree of latitude in reshap-ing the lower incisal edges because thelingual contours of the upper anteriorLava bridges could be designed as requiredto ensure proper occlusion with the alter-ed lowers. After the lower incisal edgeswere reshaped, the upper canines and cen-trals were prepared for Lava bridges andthe premolars for porcelain veneers. Thereduction guides, fabricated from the di-agnostic wax-up, were used to ensure ad-equate removal of tooth structure (Figure34). Final impressions were taken with apolyether impression material (Impreg-um™ Penta™ Soft Quick Step heavy bodyand light body, 3M ESPE) along with aclosed bite record. It should be pointed outthat the closed MIP bite record was nowalso a CR bite record because the patienthad been equilibrated to an MIP posi-tion that was now coincident with CR.

Provisional restorations were fabri-cated using the matrix fabricated fromthe diagnostic wax-up in conjunction withZenith/DMG Luxatemp® Fluorescence(Zenith/DMG Brand Division ForemostDental LLC, Englewood, NJ) B-1 shade.The matrix was filled with the Luxatemp

Figure 31 through Figure 33 The incisal edges of the lower anterior teeth were evened out to create a more esthetic profile. Great care should be takenwhenever lower incisal edges are altered. It is very important to preserve the proper incisal inclination and maintain a sharp buccal-incisal line angle.

Figure 34 Photograph of the facial reductionguide in place. It is evident that more facialreduction is required on teeth Nos. 8 and 9.

Figure 35 Matrix fabricated from diagnosticwax-up being filled with Luxatemp (DMG).

Figure 36 and Figure 37 The patient was seen 1 day after the preparation appointment so thatthe provisionals could be evaluated for comfort, esthetics, phonetics, and function.

Figure 38 Model showing preparations for the Lavabridges on teeth Nos. 6 through 8 and 9 though 11.

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“THIS IS THE FIRST TIME SINCE I CAN REMEMBER

THAT MY BITE HAS FELT COMFORTABLE AND

I KNOW HOW MY TEETH SHOULD FIT TOGETHER.”

and seated over the prepared teeth (Fig-ure 35). Once the material was set, theprovisionals were removed in three sec-tions (the veneers on teeth Nos. 4 and 5,the veneers on teeth Nos. 12 and 13, andthe bridge on teeth Nos. 6 through 11) sothat they could be smoothed and polishedoutside of the mouth. The occlusion wasadjusted and the provisionals were pla-ced by spot-bonding in the veneers andcementing the anterior bridge of teethNos. 6 through 11 with TempBond® (KerrCorporation, Orange, CA). The patient re-turned the day after the preparation ap-pointment so that the provisionals couldbe evaluated for comfort, esthetics, pho-netics, and function (Figure 36 and Fig-ure 37). Once the case had been workedout in provisionals, an incisal index wasfabricated to precisely record the incisaledge position. In addition to this, variousdigital photographs were taken along withan alginate of the provisional restora-tions. A solid model of the alginate im-pression was fabricated and sent to thelaboratory along with the photographsand incisal index. With this information,a good laboratory can duplicate every-thing that was right with the provisionalsin the final restorations and/or make mod-ifications as required. Using the provi-sionals as a guide19-20 is a much morepredictable approach then simply havingfinished restorations returned and “hop-ing” the case looks good, feels good, andfunctions well.

The master models and finished re-storations were inspected after they werereceived from the laboratory (Figure 38and Figure 39). The restorations were sub-sequently evaluated in the patient’s mouthto ensure proper fit, occlusion, and esthe-tics. Once approved by the patient, therestorations were placed by first bondingin the porcelain veneers (Figure 40) follow-ed by cementation of the anterior Lavabridges (Figure 41). The veneers werebonded in using the total-etch adhesive

system One-Step® Plus (BISCO, Inc, Sch-aumburg, IL) in conjunction with a wet-bonding protocol.21-24 The veneers weresandblasted, etched with hydrofluoric acid,and treated with hydrolyzed silane be-fore placement. There are many good res-in cements that can be used for placement.Once the veneers had been placed, theLava bridges were sandblasted with 50-µmaluminum oxide and cemented with aresin-modified glass ionomer cement(RelyX™ Plus, 3M ESPE).25-26 After all therestorations were placed, final finishingand polishing was performed under highmagnification. The occlusion was checkedin centric closure and excursive move-ments, and the patient was given writtenand oral instructions on proper home careand maintenance. The lower teeth hadbeen whitened prior to tooth preparationwith the Nite White® Excel 3 system. Thepatient returned 1 week after the case wasplaced for final adjustments, photographs,and the insertion of a flat-plane Durasoftacrylic upper night guard. The author rou-tinely provides nightguards in cases suchas this, both for protection of the porcelainand opposing natural teeth and to act as aretainer maintaining tooth position. Thepatient was delighted with the final results(Figure 42 through Figure 45).

What is needed when approaching acosmetic/restorative case such as the onepresented here is a logical and systematicmethodology that will lead to a reason-ably predictable final result. The place tostart should always be the comprehen-sive exam. It is up to clinicians, throughcomprehensive diagnostic examinationand evaluation, to develop a treatmentplan that fulfills not just the estheticbut the functional requirements of acase. While an excellent cosmetic resultis always a desirable goal, it was the re-cognition and treatment of the occlusalissues prior to doing the definitive re-storative dentistry that made this case atrue success.

ACKNOWLEDGMENTSThe author would like to thank FrontierDental Lab in San Francisco, CA, for theircontributions to the success of this case.

REFERENCES1. Dawson P. Evaluation, Diagnosis, and Treatment

of Occlusal Problems. 2nd ed,C.V. Mosby; 1989.

2. Dawson PE. Want a thriving practice? Con-

centrate on clinical excellence. Dent Econ.

1992;82(10):78-79.

3. Alex G, Polimeni A. Comprehensive dentistry:

the key to predictable smile design. AACD

Monograph. 2006;15-20.

4. Spear FM. The business of occlusion. J Am

Dent Assoc. 2006;137(5):666-667.

5. Miller L. Symbiosis of esthetics and occlusion:

thoughts and opinions of a master of esthetic

dentistry. J Esthet Dent. 1999;11(3):155-165.

6. Tarantola GJ, Becker IM, Gremillion H, Pink

F. The effectiveness of equilibration in the

improvement of signs and symptoms in

the stomatognathic system. Int J Periodontics

Restorative Dent. 1998;18(6):594-603.

7. Lee RL. Standardized head position and ref-

erence planes for dento-facial aesthetics.

Dent Today. 2000;19(2)82-87.

8. Tarantola GJ, Becker IM, Gremillion H. The

reproducibility of centric relation: A clinical

approach. J Am Dent Assoc. 1997;128(9):

1245-1251.

9. McKee JR. Comparing condylar position re-

peatability for standardized versus nonstan-

dardized methods of achieving centric relation.

J Prosthet Dent. 1997;77(3):280-284.

10. The glossary of prosthodontic terms. J

Prosthet Dent. 2005;94(1):10-92.

11. Spear FM. Occlusion in the new millenni-

um: the controversy continues. Signature.

2000;7(2):18-21.

12. McKee JR. Comparing condylar positions a-

chieved through bilateral manipulation to

condylar positions achieved through mastica-

tory muscle contraction against an anterior

deprogrammer: a pilot study. J Prosthet Dent.

2005:94(4):389-393.

13. Lucia VO. A technique for recording centric

relation: J Prosthet Dent. 1964;14:492-505.

14. Long JH. Locating centric relation with a leaf

gauge. J Prosthet Dent. 1973;29(6):608-610.

15. Carroll WJ, Woelfel JB, Huffman RW. Simple

application of anterior jig or leaf gauge in rou-

tine clinical practice. J Prosthet Dent. 1988;

59(5):611-617.

16. Dawson PE. Centric relation: Its effect on

occluso-muscle harmony. Dental Clinics of

North America. 1979;23(2):169-179.

17. Spear FM, Kokich VG. Interdisciplinary man-

agement of anterior dental esthetics. J Am

Dent Assoc. 2006;137(2):160-169.

18. Yaffe A, Hochman N, Ehrlich J. Physiologic oc-

clusion vs pathologic occlusion and ration-

al for treatment. Compend Contin Educ Dent.

1996;17(11):1093-1098.

19. Fondriest JF. Using provisional restorations

to improve results in complex aesthetic re-

storative cases. Pract Proced Aesthet Dent.

2006;18(4):217-224.

20. Terry DA, Moreno C, Geller W, Roberts M. The

importance of laboratory communication in

modern dental practice: stone models with-

out faces. Pract Periodontics Aesthet Dent.

1999;11(9):1125-1132.

21. Kanca J III. Improving bond strength through

acid etching of dentin and bonding to wet

dentin surfaces. J Am Dent Assoc. 1992;123

(9):35-43.

22. Alex G. Adhesive dentistry: where are we

today? Compend Contin Educ Dent. 2005;

26(2):150-155.

23. Tay FR, Gwinnett AJ, Pang KM, Wei SH. Res-

in permeation into acid-conditioned, moist,

and dry dentin: a paradigm using water-free

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1034-1044.

24. Gwinnett AJ. Moist versus dry dentin: its

effect on shear bond strength. Am J Dent.

1992;5(3):127-129.

25. Raigrodski AJ, Chiche GJ, Potiket N, et al.

The efficacy of posterior three-unit zirconium-

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26. Palacios RP. Retention of zirconium oxide

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40 INSIDE DENTISTRY—FEBRUARY 2007

Figure 39 Definitive restorations (veneers onteeth Nos. 4, 5, 12, and 13 and two Lava bridges).

Figure 40 The porcelain veneers on the premo-lars have all been bonded in using a total-etch adhe-sive system protocol (One-Step Plus, BISCO).

Figure 41 Cementation of Lava bridges with aRMGI cement (Rely X Plus, 3M ESPE).

Figure 42 through Figure 44 Finished case 2 weeks after placement. Figure 45 Patient at 14-month recall. Thepatient is “delighted” with her new smile and hasa comfortable and stable bite relationship.

CONTINUINGeDucaTion

1. A primary tenet of comprehensive dentistry is that:a. all cases should be built in centric relation.b. all components of the masticatory system

are intimately related and dependent on oneanother for ideal function.

c. it is only applicable in a Dawson/Pankeyocclusal philosophy

d. it is never applicable in a Dawson/Pankeyocclusal philosophy.

2. A destructive occlusal relationship can causeproblems somewhere in the masticatory sys-tem, such as:

a. joint pain.b. muscular pain.c. tooth sensitivity.d. all of the above

3. An earbow transfer is used to:a. transfer the “esthetic plane” to the articulator.b. record the correct axis (or a close approxima-

tion) of condylar rotation.c. record the relationship of the maxillary arch

relative to the TMJ.d. all of the above

4. Any change in condylar position and/or morphology:a. should be closely watched for 6 months.b. will affect the patient’s sense of taste.c. will affect the way the teeth come together.d. is potentially dangerous and should be

aggressively treated.

5. Stable and comfortable joints are vital to:a. case comfort.b. stability.c. predictability.d. all of the above

6. A “hit and slide” is the terminology used to describe:a. the movement of the condyles when using bi-

lateral manipulation.b. the movement seen from the first point of tooth

contact, with the joints in CR, to an MIP position.c. the mandibular movement when using a leaf

gauge.d. the force used to put the patient into CR.

7. Centric relation:a. is a joint-based position where the condyles

are fully seated in their most superior posi-tion in the glenoid fossa and the disks are intheir proper position and orientation on theheads of the condyles.

b. can be found by pushing the condyles back.c. cannot be found without prolonged splint therapy.d. can be identified by the clicking of the TMJ.

8. An anterior deprogrammer can be used to:a. assist in muscle relaxation.b. keep the teeth apart.c. locate the correct CR position.d. all of the above

9. In the case presented in this article, the patient's "hitand slide" was demonstrated by:

a. taking radiographs.b. manipulating the jaw.c. unlocking the articulator hinges and sliding

the models together.d. taking an impression with a high-viscosity

PVS material.

10. When adjusting lower incisal edges:a. there is no need to maintain centric stops.b. great care should be taken to maintain a

sharp buccal-lingual line angle.c. the jaw should be forced into centric relation.d. first determine the curve of Spee.

Is Occlusion and ComprehensiveDentistry Really That Important?Gary Alex, DMD

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42 INSIDE DENTISTRY—FEBRUARY 2007