Spear-Approaches to Vertical Dimension

Approaches to Vertical Dimension CE

Abstract: Vertical dimension is a highly debated topic in dentistry. Differences of opinion over how vertical dimension should be established, whether it can be modified, and what the outcome of modification will be can become confusing for those dentists searching for the right treatment for their patients. The fact is that there are multiple different approaches because there are several correct ways to alter vertical dimension. This article will address the most common reasons dentists consider altering vertical dimension, their five top areas of concern, and the methods by which vertical dimension can be established.

n dentistry there are areas of inter- the gonial angle of the mandible, and Iest that provoke heated debate the eruption of the teeth. As the ramus among different groups of practi- grows, the teeth continue to erupt, main- tioners. Vertical dimension is one of taining the occlusion. There can be, those topics. There are practitioners however, significant differences in the who vehemently defend their position length of the ramus, which has a sig- as to how vertical dimension should nificant impact on anterior facial height be established, whether it can be mod- or “vertical dimension.” In what would ified, and what the outcome will be Frank M. Spear, DDS, MSD be considered normal or ideal ramus Founder and Director if it is modified incorrectly. Other development, the midface, measured Seattle Institute for Advanced practitioners hold the exact opposite Dental Education from glabella to the base of the nose, is Seattle, Washington beliefs with equal intensity. These dif- roughly equal in measurement to the ferences of opinion become confusing, Affiliate Assistant Professor lower face measured from the base of University of Washington because most clinicians are searching the nose to the bottom of the chin at School of Dentistry for the right answer with regard to Seattle, Washington the completion of growth. As ramus how patients should be treated. As a length varies, both anterior facial height Private Practice general rule, any time multiple dif- Seattle, Washington and tooth display vary. Differences in ferent approaches exist for a long ramus length are primarily influenced period of time in dentistry, it is proba- by genetic variations.1-11 A patient who bly because there are several correct has a short ramus with normal posterior answers to the same problem. As tooth eruption will have an increased we will see, that is the case with verti- anterior facial height and an anterior Learning Objectives cal dimension. open bite. Often, however, the anterior teeth in such a patient overerupt to After reading this article, the Understanding Occlusal maintain the occlusion, creating both reader should be able to: Vertical Dimension excessive tooth and gingival display. The Glossary of Prosthodontic Terms Commonly, the patient with a short • explain how vertical dimension defines “occlusal vertical dimension” as ramus shows a long lower facial height is established during growth the distance between any point on the when compared with their midfacial and development. maxilla and any point on the mandible height. This patient has excessive gingi- • discuss the five most common where the teeth are in maximum inter- val display and is often treated with a concerns of practitioners when cuspation. Commonly, nasion and men- maxillary impaction to decrease their 12-16 considering an alteration of ton are used for these points. vertical dimension (Figures 1 and 2). vertical dimension. A patient who has a long ramus with Vertical Dimension during normal posterior tooth eruption will • describe the different beliefs Growth and Development have the opposite facial appearance to about how vertical dimension Three factors affect the occlusal that of the person with a short ramus. should be established. vertical dimension during growth and Commonly, this patient will have a development: the growth of the ramus, very short lower face in comparison to

2 Advanced Esthetics & Interdisciplinary Dentistry Vol. 2, No. 3, 2006 V does notkeepup withtoothwear, the unchanged. If, however, theeruption cal dimensionofthepatient willbe the samerateastoothwear, theverti- any wear occursat occurs.If eruption dimensionif to maintainthevertical isnecessary completed, tootheruption dimension. Aftergrowthvertical is that canresult inalterationsfacial variations, however, intootheruption contact asthefacegrows. There canbe tomaintainocclusal dibular teetherupt andman- development, themaxillary dimension. In normalgrowth and development ofapatient’s vertical playsacriticalrole inthe eruption ramus lengthandgonialangles,tooth angle is(Figure 5). mor developed themassetermuscleis, masseter muscle. be influencedb the formationofgonialanglemay There appearstobesomeevidencethat having steepmandibularplaneangles. gonial anglesoftenar midface. P long lo siv heights, withalongnarrow face,exces- ramus appearance ofpatientswithshort more obtusegonialanglesmimicthe dibular planeangle.Patients whohave monly referred toashavingaflatman- their midface. These patientsare com- lowerface andshort facecompared to patient withalongramus,square dency tomimicthefacialfeatur with anacutegonialanglehasaten- dimension.Apatient anterior vertical angle alsohasanimpactonthepatient’s dimension. the ramusoroverall posteriorvertical same timemaintainingthelengthof patient’s dimensionwhileatthe vertical the overall faceandincreasing the hastheimpactoflengthening surgery toothdisplay.increase maxillary This la toincrease lower facialheightand the chininferiorlyaswell asthemaxil- torotate involves adoublejawsurgery ofthelong-ramuspatientoften sion and 4). squaremay have face(Figures a very 3 ramus patient,thelongpatient the long,slenderfaceofshort toothdisplay.quate maxillary Unlike their midfaceandmayhav ol. 2,No. 3, 2006 e e pr tooth andgingiv w Treatment dimen- ofthevertical onounced oracutethegonial er facewhencompar atients withmore obtuse 17-22 The stronger andmore y thestr The patient’s gonial 22,23 al display e r In additionto ength ofthe eferr ed totheir e inade- ed toas , anda es ofa reduce theexcessivetoothandgingivaldisplayverticaldimension. at rest,5mmmorethanwouldbenormalforherage. gingival display Figure 4 appearance. Figure 3 Figure 2 Figure 1 rotate themandible andthemaxillainferiorly —A patient with a long ramus. Note the reduced anterior facial height and very squarefacial —A patientwithalongramus.Notethereducedanteriorfacialheightandvery —Before and after photographs of the patient seen in Figure 1 after a maxillary impactionto —Before andafterphotographsofthepatientseeninFigure1amaxillary —A patientwithashortramusexhibitinglonganteriorfacialheight,excessivetoothand —Before andafterphotographsofthe patientseeninFigure3afterdouble-jawsurger , andasignificantlylonger, lowerfacethanmidface.Thepatientshows8mmoftooth Advanced Esthetics& , increasingtoothdisplay andanteriorfacialheight. Interdisciplinar y Dentistr y y to 3 CE Figure 5—The impact of ramus length and gonial angle on lower facial height and mandibular plane angle. Note the reduced lower facial height in the example with a long ramus and flat angle, and the exaggerated lower facial height in the example with the short ramus and steep angle. vertical dimension may decrease with Effects on the Temporal regarding muscle pain. When evaluating time. The question of whether eruption Mandibular Joint the literature it is prudent to examine keeps up with tooth wear to maintain To address these concerns, it is help- how the research was done. There are vertical dimension is one of the most ful to evaluate the literature on the several papers that have concluded that heated debates in dentistry.24-27 alteration of vertical dimension and its altering vertical dimension produces impact in each of the five areas. With symptoms such as headaches, muscle Clinical Alterations of regard to pain in the temporal mandibu- aches, and muscle fatigue.32-34 The Vertical Dimension lar joint, the literature is clear that if problem with several of these research Having described how vertical di- the joint is comfortable at the existing projects is that they altered vertical mension is established during growth vertical dimension, it is highly unlikely dimension by building up only the and development, it is now important that the joint will experience any discom- posterior teeth without any anterior to discuss why vertical dimension might fort at an altered vertical dimension. It contact or anterior guidance. At the be changed clinically. The most com- is possible, however, in the event of end of the study, several of the patients mon reasons dentists consider altering anterior disc displacement, that alter- reported muscle symptoms and it was vertical dimension are: 1) to improve ing vertical dimension may change the concluded that it was a result of the esthetics by altering facial form and/or relationship of how the condyle com- change in vertical dimension. In fact, tooth and gingival display; 2) to improve presses retrodiscal tissue posterior to the patients were left with an occlusal occlusal relationships, such as correcting the displaced disc (Figure 6). In some scheme that would not be created clini- anterior open bites; and 3) to gain space instances, increasing the vertical dimen- cally. If the articles regarding the impact for the restoration of short or worn teeth. sion may benefit the relationship of of vertical dimension changes on mus- Practitioners often mention five areas the condyle to the disc, whereas in oth- cles are limited to those that created of concern about altering vertical dimen- er circumstances it is possible that a an ideal occlusal scheme simply at dif- sion. Will the vertical alteration have a change in vertical dimension may have ferent vertical dimensions, it is clear negative effect on the temporal mandibu- a negative effect. If the patient is having that altering vertical dimension does not lar joint? Will muscle pain be a side significant joint symptoms, it will be produce muscle pain. In fact, less than effect of the change in vertical dimen- necessary to try out any vertical changes 5% of the patients had any short-term sion? Will the vertical dimension be in an appliance to predict the impact of muscle awareness, which disappeared stable in its new position? Will muscle the vertical dimension on the patient’s 2 weeks after the vertical alteration.35-40 activity levels be altered, increasing symptoms. It is critical that when the bite force and potentially increasing vertical dimension is altered, there are Stability of Altered the failure rate of restorations? Will stable posterior occlusal contacts, be- Vertical Dimensions speech be affected in a negative way? cause a lack of posterior occlusion can Another area of concern that gen- significantly increase the load on the erates heated debate is the stability of the joints. Alterations in vertical dimension vertical dimension after any changes. do not have a negative impact on tem- Two basic schools of thought exist. One poral mandibular joints unless the joint believes that any change in vertical suffers from an internal derangement. dimension will be followed by a return Even then there is a high likelihood to the previous vertical dimension that a vertical alteration will not nega- through tooth intrusion or tooth erup- tively affect the joint.28-31 tion. This group believes that the length of the masseter muscle and medial Muscle Pain pterygoid are fixed and, therefore, any Figure 6—This illustration shows how the condyle compresses retrodiscal tissue after The next area of concern in alter- alteration in the vertical dimension of anterior disc displacement. ing vertical dimension is the impact occlusion will revert back to the previous

4 Advanced Esthetics & Interdisciplinary Dentistry Vol. 2, No. 3, 2006 out thepatientor clinicianrealizingit,andwiththeocclusion remainingthesame. this patientbeenmonitored withcephalometricradiographs forsomerelapsetohaveoccurred inthedistancebetweenmaxillaand themandiblewith- the 4.5yearsbetweenmiddlephotograph andtherightphotographnochangehastakenplaceintermsofvertical relapse.However, itispossiblehad middle showstheprovisionalrestorations 6monthspostinsertion.Thefarrightshows5yearsafterseatingofthe finalrestorations.Itappearsthatduring Figure 10 V ing thelengthofmuscles(Figure 8). display andfacialheightwhilemaintain- are rotated inferiorlytoimprove tooth body ofthemandibleandmaxilla altered duringthesurgery. Instead, the and medialpter including theinser posterior por withdouble-jawsurgery, becausethe ed r significant r statistically thesepatientsexperience v face. patient withalongramusandsquare tooth displayandfacialheightinthe down-fracturing themaxillatoincrease withsignificantrelapse, suchas ciated clinicalprocedurescertain maybeasso- change thatoccurred. only asmallpercentage oftheactual relapse inthesecircumstances maybe lar sion, which mightoccuraftermaxil- dimen- significant closingofthevertical increase dimensionaftera invertical dimension. This relapse couldbean occurring afteranalterationinvertical toward dimension theoriginalvertical definitely shows examplesofarelapse rect someofthetime. The literature regarding stability. give ussome clueastotheconfusion groups have goneonfordecadesshould that theseargumentsbetween thetwo in thelengthofmuscles. The fact ar dimensionofocclusion in thevertical dimension isadaptableandthatchanges second group believes thatvertical nature ofthemuscles(Figure 7). The v eason thattodaythesepatientsar er ertical dimensionbecauseofthefixedertical ol. 2,No. 3, 2006 e maintainedbecauseofanalteration y impactionsurgery. However, the tical changemaylookex It maybethatbothgroups are cor- I mmediately aftersurger —Three stagesinthetreatmentofapatient whoseverticaldimensionwasincreased.Atthefarleftispretreatment verticaldimension.The elapse. tion ofthemandible, ygoid muscle,isnot tion ofthemasseter 44-46 41-43 I t isforthis Conversely, cellent, but e tr y , the eat - change inmusclelengthwouldhave dimensionwasincreased,vertical a position ofthecondyleasanterior if ther tation ofrelapse (Figure 9).However, length, andther masseter ormedialpter ther dimensionisincreased,anterior vertical possible thatifthecondyleisseatedas r v for eachmillimeterthecondyleisseated mandibular jointduringtr seated inthefossaoftemporal length. Additionally, ifthecondyleis ofchangeinmassetermuscle mm 1 tical dimensionresulting inlessthan with a3-mmalterationinanteriorver- sion are measured attheanteriorteeth, teeth. Most dimen- alterationstovertical muscle,andanterior medial pterygoid mandibular joint,massetermuscle, ofthetemporal do withthegeometry regarding stabilitymayinfacthave to dimension. vertical that hadthesmallestactualchangein est percentage ofrelapse were those instances, thepatientswithhigh- significant relapse occurring.In some ring, whereas othersindicateamore show littleornorelapse occur- very with regard tostability. Some articles tistry, donotshow clearconclusions as through theuseofrestorative den- dimension,such ofalteringvertical ods atur dimension.Liter- alterations tovertical andsignificant surgery orthognathic stable. very This surgicalappr educed almost1mm.I ertically themassetermusclelengthis ertically The reason somuchconfusionexists The twoprevious examplesinvolved e searches on more traditionalmeth- e willbeminimal,ifany e wasnoalterationinthev e wouldbenoexpec- 47-52 oach hasproven t is,ther ygoid muscle , changein eatment, ertical efor Advanced Esthetics& e, from theseatingofcondyle. to decreasesinposteriorverticaldimension relating increasesinanteriorverticaldimension and themandible. dimension viaitsinsertionpointsonthemaxilla seter muscleisrelatedtoanteriorvertical Figure 7 Figure 9 Figure 8 posterior verticaldimension. or verticaldimensionwithoutchangingthe movement ofthechinhasincreasedanteri- change inmolarpositionbuta5-mminferior patient inFigures3and4.Therehasbeenno after cephalometricradiographsfromthe —This illustrationshowshowthemas —This illustrationshowsthegeometry —A superimpositionofthebeforeand Interdisciplinar y Dentistr y 5 - CE dimension, the muscle activity is similar to pretreatment levels. This is a critical finding because any treatment that attempts to modify muscle activity levels by altering vertical dimension can only be successful on a short-term basis because of the body’s natural neuromuscular adaptability.

Effects on Speech The final area of concern when altering vertical dimension concerns Figure 11—Patients use different methods to create sibilant sounds. On the far left is the intercuspal position. In the middle, a patient makes sounds using the lingual of the maxillary incisors. On the far phonetics, particularly the sibilant or right is a patient who postures the mandible forward, making sibilant sounds between the maxillary “S” sounds. As a general rule, there is a and mandibular incisal edges. high level of adaptability by most patients with regard to speech. After a short period of time, usually 1 week to 4 weeks, most patients will learn to reprogram their speech patterns to any alterations that have been made den- tally. There are, however, patients in whom this adaptation does not occur. To understand how this might be related to vertical dimension it is important Figure 12—On the left is the patient seen in Figure 10, 1 month after the provisional restorations had to understand the differences in how been placed, increasing the vertical dimension. On the right is this patient saying “66” and lisping during sibilant sounds. It was necessary to reduce the mandibular incisors to correct phonetics. patients make sibilant sounds. The majority of people make “S” sounds occurred, and may be responsible for is clenching. As the vertical dimension by moving their mandible forward so any relapse. is increased, resting muscle activity that the incisal edges of the mandibular Because none of the studies47-52 actually decreases. The more open the incisors are end-to-end with the incisal assessed the change in condylar posi- vertical dimension is, the less activity edges of the maxillary incisors (Figure tion and related it to the alteration in is present in the muscles in a postural 11). For these patients, it is the incisal anterior vertical dimension, it is impos- position. This decrease in muscle activi- edge position of the teeth that can cre- sible to make that conclusion. The real ty occurs until there is approximately ate phonetic problems if a significant question concerning stability is what 10 mm to 12 mm of anterior vertical increase in incisal ledge length occurred clinical impact any relapse would have opening. Opening beyond 10 mm to to either the maxillary or mandibular on the patient. It would appear that 12 mm starts to increase elevator muscle incisors. The teeth may now collide even in the studies where some relapse activity. Interestingly enough, if the during the “S” sounds, generally result- occurred, the patients involved were vertical change is maintained for 3 to ing in a whistling or slurring any time basically unaware of the relapse and 4 months, the resting muscle activity a sibilant sound is made. This can be experienced no symptoms. Unless an returns to a level closely matching the evaluated clinically by simply having operator was evaluating vertical dimen- pretreatment resting muscle activity the patient say “66” or “77” and watch- sion using radiography, the clinician level, although the vertical dimension ing to see if the anterior teeth touch would not see any changes posttreat- has not been decreased.53-56 during the sibilant sound. If they do, ment (Figure 10). The conclusion con- The impact of increasing vertical and the patient has been given 2 to 4 cerning stability is that it is an unknown dimension on clenching muscle activity weeks to adapt and has not, it will be entity; that is, the patient may or may is the opposite; as the vertical dimension necessary to shorten either the upper or not experience some relapse, but the is increased, the electrical activity level the lower incisor. If the upper incisor treatment will remain successful. in the elevator muscles increases during can be shortened it is possible to cor- clenching beyond their pretreatment rect the phonetics and not alter the Impact on Muscle Activity Levels level. Again, however, if the vertical centric occlusal contacts at all. However, The fourth area of concern when dimension is maintained for 3 to 4 although it is possible to shorten the altering vertical dimension is the impact months, this increased level of clenching lower incisor to correct speech, it is on muscle activity levels. There are electrical activity similarly reduces to necessary to remove the centric con- two components to the activity levels pretreatment levels.57-60 In summary, tact on the lingual of the maxillary of muscles: the muscle activity level although there is an initial change both incisor. If the centric contact can be when the mandible is at rest and the in resting and clenching activity levels, gained by adding material to the lin- muscle activity level when the patient after 3 to 4 months at the new vertical gual of the maxillary incisor, vertical

6 Advanced Esthetics & Interdisciplinary Dentistry Vol. 2, No. 3, 2006

dimension will not be affected. However, lips, swallow, and relax. Most schools and a mild, cyclic electrical current is if it is not possible to add material on the advise a 2-mm to 4-mm freeway space generated to stimulate contraction of lingual of the maxillary incisor, it will as normal, so if there is a desire to the muscles of mastication by way of the be necessary to either close the vertical increase the vertical dimension on a cranial nerves. The surface electrical dimension to regain centric contact denture it is necessary that the patient activity of the temporalis, masseter, and restoratively or leave the patient with an have more than 4 mm of freeway space digastric muscles are recorded elec- anterior open bite, risking secondary with their existing dentures. The free- tromyographically, and a jaw-tracking eruption and instability (Figure 12). way space then determines how much device evaluates the position of the The second method by which the vertical dimension can be increased. mandible relative to the maxilla. A base- patients make sibilant sounds is between This method of using freeway space to line electromyographic reading is taken the mandibular incisal edge and the determine vertical dimension has been before any muscle relaxation. The TENS lingual contour of the maxillary inci- used for decades in denture prostho- unit is then started to relax the muscles sors. If vertical dimension has been dontics. It is important to note, how- of mastication and the electrical activity increased restoratively in these patients, ever, that freeway space is only being of the muscles evaluated. Neuromus- any problems with phonetics will be used to mount the models and set the cular rest is achieved when the elevator between the mandibular incisal edge teeth for the denture try-in. At the try- muscles are at their lowest level of activ- and the lingual contour of the maxil- in, phonetics and esthetics are used to ity without an increase in the electrical lary incisors. Again, if after 2 to 4 weeks refine final incisal edge position and activity of the digastric muscles. This of adaptation the patient is still having vertical dimension. The challenge of neuromuscular rest position is thought difficulty making “S” sounds, it will using freeway space for patients who to be the starting point for the building be necessary to provide a speaking space. still have their natural teeth is that as of the occlusion. The operator closes This can be done by shortening the low- the vertical dimension is changed; mul- up from this position for the “new” er incisor or removing material from tiple studies have found that freeway amount of freeway space, effectively the lingual of the maxillary incisor. In space recreates itself within the subse- using the combination of neuromuscu- either case, however, it is highly likely quent 4 weeks. Because of this, the use lar rest and freeway space to determine that the centric contact will be removed of freeway space to determine whether the new occlusal vertical dimension. and since the “S” sound is now made vertical dimension can be altered is not The primary flaws of this approach on the lingual of the maxillary anterior supported by research for patients who relate to the neuromuscular adaptability teeth, the only method to regain anteri- still have natural teeth.66-77 of patients. As discussed earlier, the rest- or contact is to close the vertical dimen- ing electrical activity of muscles, as well sion.61-65 In summary, with regard to Trial Appliances as freeway space, relapse toward pretreat- the five major concerns about altering Another method of determining ver- ment levels from 1 month to 4 months vertical dimension, it is obvious from tical dimension is the use of a trial splint posttreatment. Also, this approach often reviewing the literature that changes in or appliance. The patient is asked to results in a vertical dimension more vertical dimension are well tolerated in wear an acrylic appliance, typically for open than the patient’s existing vertical the majority of patients and there is no 3 months, to evaluate if the new vertical dimension, which can lead to the need evidence that there is only one correct dimension can be tolerated. The theory for an extensive amount of restorative vertical dimension. behind this is that the patient will expe- dentistry and extremely large teeth, sim- rience pain if the vertical dimension is ply to accommodate the vertical dimen- Determining a New not acceptable, but the challenge of sion that was dictated by the equipment. Vertical Dimension this approach is that outside of a few The next question that clinicians patients with temporal mandibular joint Measurements Using the frequently ask is how to determine a problems, altering vertical dimension Cementoenamel Junction new vertical dimension. Historically, does not produce pain. Although the Another methodology that has several techniques have been used, appliance may be very useful to deter- been described78,79 to determine ver- many from denture prosthodontics. mine other elements of treatment or tical dimension is to measure from the to aid in muscle deprogramming, it cementoenamel junction (CEJ), or gin- Using Freeway Space does not provide specific information gival margins of the maxillary central The first technique most dentists are regarding vertical dimension. incisors to the CEJ, or gingival mar- exposed to concerning vertical dimen- gins of the mandibular central inci- sion is the use of freeway space. Freeway Transcutaneous Electrical sors. This distance is then compared to space is defined as the distance between Neural Stimulation the 18-mm to 20-mm average distance the maxillary and mandibular teeth A third methodology that has also seen in a dentition of unworn teeth when the mandible is in its postural been used for decades to determine and a class I occlusion. If this distance is position. Several different techniques vertical dimension is the use of tran- less than 18 mm, it probably indicates have been used to reproduce this pos- scutaneous electrical neural stimulation a loss of vertical dimension and is, tural position, from having the patient (TENS). In this approach, electrodes therefore, a rationale for increasing it. say “M,” to having them lick their are applied over the coronoid notch The primary flaw of this approach is

8 Advanced Esthetics & Interdisciplinary Dentistry Vol. 2, No. 3, 2006 V changes weremade tothepatient’s verticaldimension. incisorsandfourmandibular incisor fullcrowns.No treated withorthodontics andfourmaxillary Figure 15 Figure 14 because oftheovereruptionwornanteriorteeth. rior teethmakesitappearasthoughthepatienthaslostaverticaldimensionbutthisisanillusion wear Figure 13 there isalackofspacetorestore the patient haslostverticaldimension.If occlusion, itishighlyunlikelythatthe rior teethare present, unworn,andin iftheposte- and 15).Asageneralrule, dimension(Figures vertical 14 existing els thepatientcouldbetr ening them tocorrect thegingival lev- the wornanteriorteethorcrown length- restoration, wheninfactby intruding decide toopenthebitegainspacefor examine thewornanteriorteethand wear (Figure 13). rior toothwear andnoposteriortooth commonly inpatientswithsevere ante- dimension ofocclusion. This canoccur normalvertical anterior andaperfectly diminished CEJ-to-CEJdistanceinthe It isinfactpossibletohave anextremely dimensionofocclusion. not thevertical the amountofanteriortootheruption, CEJ orgingiv Measuring thedistancebetween the oftheposteriorteeth. and theeruption is establishedby thelengthoframus dimensionofocclusion;it the vertical that theanteriorteethdonotestablish rior teethhavebeenbuiltupandthenorthodonticallyintruded,creatingspace forrestoration. ol. 2,No. 3, 2006 . Ontherightissamepatientinocclusion.Measuringfromgingivalmarginsofante- —Initial andtreatmentphotographsofthepatientseeninFigure13.Themandibular ante- —On theleft,a29-year-oldpatientwithminimalornoposteriorwearbutsevereanterior —Before andafterphotographsofthe patientseeninFigures13and14.Thewas al marginssimplyevaluates 80 Most clinicians eated atthe dimension thatwouldinfluencefacial tist tomakelargevariations invertical for anor dibular position,itisextremely difficult making significantalterationsinman nathic surgeonwhohastheabilityof entirely appropriate for anorthog- teeth. Althoughthisappr midface b face tocorrespond tothelengthof altersthelengthoflowerproportion equal inheight. The methodoffacial and thelower faceare approximately Inproportion. anidealface,themidface be created inawaythatcorrects facial dimensionofocclusionshould vertical isthatthe this approach, thetheory dimension.Infor determiningvertical has beendescribedintheliterature isanothermethodthat facial proportion The MethodofFacialProportion the needtotreat theirposteriorteeth. allow thepatienttobetreated without orcrown lengtheningwould dontics anterior teethitisalsolikelythator As discussedintheintroduction, thodontist orr y alteringthelengthof estorativ oach maybe e den Advanced Esthetics& 81,82 tho- - - Gross sions of2mm,46or8 caused by dimen- changesinvertical capable ofseeingthefacialdifferences study evaluating whetherdentistswere sion needstobeclosed.F excessively dimen- longandthevertical ifthepatient’sproportion lower faceis or restorative dentisttocorrect facial almost impossiblefortheorthodontist fundamental flawregarding overjet, itis class IIIocclusion.In additiontothis outwitha unless thepatientstarted to have correct anteriorocclusalcontact overjet, makingitalmostimpossible in 6 mmwillresult ina4-mmincrease toincrease dimensionby thevertical ing alteration inoverjet. Therefore, attempt- dimension. This 2-mmchangeisan horizontal changeinananteroposterior or changeintheanteri- each 3-mmvertical overjet isalsoaltered significantly;for dimension isincreased ordecreased, occlusal relationship. Asthevertical pr v tensive reconstruction, several different justified. If thepatientdoesneedanex- not needtr do reconstruct teeth whichotherwise dimensionastherationaleto vertical sion. there isnosinglecorrect dimen- vertical isahighlyadaptableposition,and sion decades. used successfully, manyofthemfor all ofthem,andyet theyallhave been dimension itiseasytoseetheflawsin techniques fordeterminingvertical Dimension forthePatient Choosing theRightVertical patient This isquitelogical,astheonlytimea assess thedifference infacialfeatures. reached 8mm,dentistswere unableto cal the changeintoothdisplaywhenv In fact,itistheauthor’s beliefthatitis v facial changebecauseofthein cally altersapatient ther life teeth ar sion isgenerallyev ertical dimensionscould besuccessful. ertical er oportion andstillallowoportion acorrect teeth, there isapproximately a2-mm tical dimension. ’ After reviewing manyofthe different dimension isopenedthatdramati s activitiestheteethar efor F 83 urthermore, using aparticular ’ e notaffectingfacialpr e together;typicallyinmostof s v This meansthatv found thatuntilthechange Interdisciplinar er eatment isnotscientifically tical dimensionofocclu aluated iswhentheir ’s esthetics,notthe y Dentistr ertical dimen- ertical e apar inally, ina opor y t and tion. er ti 9 - - - CE This ultimately leaves us with the question of which one to choose. In answer- ing that question, and because many different vertical dimensions may be successful, it makes the most sense to the author to choose the one that sat- isfies the patient’s esthetic goals and the clinician’s functional goals. In many ways this is the simplest of all methods Figure 16—The initial presentation of a 65-year-old man with severe anterior tooth wear desiring esthetic improvement. for determining vertical dimension: The first step is to mount the patient’s existing models with the seated condyle. The second step is to establish on the maxillary model the ideal maxillary central incisor incisal edge position, either in wax or composite. This position is arrived at by evaluating the patient’s maxillary central incisor display with Figure 17—On the left of the full-smile photograph, the white line illustrates the desired incisal posi- the upper lip at rest and in a full smile. tion of the maxillary anterior teeth. On the right is a lip at rest, illustrating that the existing teeth are The third step is to determine if any 2.5 mm under the upper lip. alteration to the lingual contour of the maxillary incisors is necessary, and if so, to perform that alteration in wax or composite as well. Essentially, the desired changes to the maxillary central incisors have now been transferred to the model. The fourth step is to close the articulator and evaluate the anterior and posterior occlusions. In some patients Figure 18—A view of the patient’s mounted models. There is severe wear and secondary eruption of the desired changes to the maxillary the anterior teeth with minimal wear of the posterior teeth. anterior teeth may be made without a significant alteration to the anterior or posterior occlusion. However, in other patients the changes performed on the maxillary anterior will result in a posterior open bite when the articulator is closed. The decision that must be made is whether the posterior open bite will be closed by building up the posterior teeth and therefore opening the vertical Figure 19—On the right, the desired alterations for the maxillary incisors have been made in wax. dimension, or whether the posterior The mandibular incisors were reduced in length until the posterior teeth were in occlusion. The pho- open bite will be closed by altering the tograph on the left shows how much the mandibular incisors would need to be shortened to allow for the change in the maxillary anterior teeth with no change in vertical dimension. mandibular incisors. In many patients either approach may be successful. Generally, evaluating which teeth need restoration guides the clinician as to whether the lower incisors should be modified or the posterior teeth built up. Whenever possible, using the patient’s existing vertical dimension makes it easier for the patient to phase treatment over time. The fifth step, if necessary, is to modify the mandibular incisors, Figure 20—On the left, the desired changes in the maxillary incisors have been made in wax. The shortening them until the posterior mandibular incisors have been waxed to a normal length and the articulator has not yet been closed teeth touch (if that was the ultimate down. On the right, the articulator is now closed until anterior contact occurs. At that point the decision can be made as to whether the anterior relationship is acceptable or not. If it is deemed accept- decision). In many cases of severe wear, able, then the incisors have created the new occlusal vertical dimension and the posterior teeth would lengthening them to avoid the need now be built into contact.

10 Advanced Esthetics & Interdisciplinary Dentistry Vol. 2, No. 3, 2006 V Figure 22 was increasedonly1.5mmbecausethepatientalreadyhadexcessiveoverjet. lengthening. Althoughthispatient’ dimension; however Figure 21 because ofasignificantchangeintoothdisplaywithminimalalterationverticaldimension. teeth. A andrestoration oftheiranterior ening their anteriorteethorcrown length- movementto considerorthodontic of dimensionifthey arevertical willing patients canbetreated attheirexisting all unworn andinocclusion,virtually if thepatient’s posterior teethare treatment In isnotsupported. addition, dimension asasolejustificationfor be treated, therefore, using vertical tical dimensionsatwhichpatientscan Conclusion acceptable (Figures 16through 22). only onev to treatment ratherthantobelieve that sion thatallows ustotakethisapproach patients toalterationsinv the patient.It istheadaptabilityof todowhatisinthebestinterest of ing all theprevious factorsaswell asattempt- through trialanderror, whilebalancing overjet. It isarrived atonthearticulator desired functionalneedsofoverbite and anterior andposteriorteeth,the position, therestorative needsofthe andmandibularincisorincisaledge illary combination oftheestheticsmax- dimensionshouldbea chosen vertical the posteriorteethwillbebuilt. The dimensiontowhich vertical lish thenew for cr ol. 2,No. 3, 2006 There are multipleacceptablever- own lengtheningwillnow estab- t thesametime, ifapatient —These beforeandafterphotographsappeartoshowasignificantincreaseinvertical —Before andafterphotographsillustrateasignificantchangeinappearance,primarily er tical dimen , the maxillary anteriorteethhavehad4mmto5ofperiodontalcrown , themaxillary ertical dimen- ertical sion canbe s entiremouthwasreconstructedatonce,theverticaldimension are desired. the estheticsandfunctionalresults that acceptablewayofachieving a perfectly is itated, increasing dimension vertical does needalloftheirdentitionr References 10. 8. BeckmannSH,KuitertRB,Prahl-Anderson 5. 4. BjorkA.SkiellerV. Normalandabnormal 3. .RichardsonA.Skeletalfactorsinanterior 9. BjorkA,SkiellerV. Facialdevelopmentand 2. .NandaSK.Growthpatternsinsubjectswith 7. 1. 6. Dentofacial Orthop 209-262. the face. Nanda SK.Patternsofverticalgrowthin associated withoverbite. B, etal.Alveolarandskeletaldimensions types. Sassouni V. Aclassificationofskeletalfacial 1983;5:1-46. over aperiodof25years. gitudinal cephalometricimplantstudies growth ofthemandible:asynthesislon 339-383. open anddeepbite. 1998;93:103-116. tooth eruption. of Michigan. Growth andDevelopment,TheUniversity Published in2000bytheCenterofHuman long andshortfaces. The EnigmaoftheVertical Dimension facial Orthop Dentofacial Orthop ciated withlowerfaceheight. et al.Alveolarandskeletaldimensionsasso- Beckmann SH,KuitertRB,Prahl-AndersonB, eighth yearoflife. human headfromthethirdmonthto the Brodie AG.Onthegrowthpatternof the 56:114-127 Am JOrthod Am JOrthodDentofacialOrthop . 1990;98:247-258. . 1998;113:498-506. . 1998;113:443-452. Am JOrthod . 1969;55:109-123. Am JAnat Am JOrthod Am JOrthodDento- Am JOrthod Eur JOrthod Am JOrthod . 1972;62: . 1941;68: ehabil- . 1969; Advanced Esthetics& - . . . 5 Tallgren A.Changesinadultfaceheight 25. 7 GierieWV, PatersonRL,ProffitWR.Response 27. 3 ProffitWR,FieldHW, NixonWL.Occlusal 13. 20. 1 JansonGR,MetaxasA,Woodside DG. 11. 23. 14. 18. 15. CangialosiT 9 Rivera-MoralesWC,MohlND.Relationship 29. KahnJ,Tallents RH,KatzbergRW, etal. 28. ThompsonIL,KendrickGS.Changesinthe 24. 2 BrodieAG.Onthegrowthpatternof 22. 2 ProffitWR,FieldHW, NixonWL,etal.Facial 12. 19. 7 BellWH.Correctionoftheshort-facesyndrome/ 17. 16. 1 Wessberg GA,EpkerBN.Surgicalinferior 21. 6 ProffittWK,Vig KW. failureoferup- Primary 26. lower anteriorfaceheight. old subjectswithexcessnormalandshorter and incisorverticaldimensionin12-year- prosthetic treatment. due toaging,wearandlossofteeth cation. of eruptionhumanpremolarstoforce appli- forces innormalandlong-facedchildren. options. face patient:Surgical-orthodontictreatment W V radiographic cephalometricinvestigation. cator facial morphologyandactivityofthemasti- B,ThilanderB.Relationbetween Ingervall 209-262. Dentofacial Orthop drome. 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12 Advanced Esthetics & Interdisciplinary Dentistry Vol. 2, No. 3, 2006 Continuing Education Quiz Loma Linda University School of Dentistry provides 1 hour of Continuing Education credit for this article for those who wish to document their continuing education efforts. To participate in this CE lesson, please log on to www.aegisce.net/aeid, where you may further review this lesson and test online for a fee of $14.00. To obtain mailing instructions or for more information, please call 877-4-AEGIS-1.

1. Which of the following factors does not affect 7. Problems with speech after a change in vertical occlusal vertical dimension during growth and dimension are often corrected after an adapta- development? tion period of how long? a. growth of the ramus a. 1 week b. gonial angle of the maxilla b. 10 days c. gonial angle of the mandible c. 2 to 4 weeks d. eruption of the teeth d. 6 to 8 weeks 2. Treatment of vertical dimension in patients 8. Most dental schools advise how much of with a long ramus often involves which of freeway space as normal? the following? a. 1 mm to 2 mm a. double jaw surgery b. 2 mm to 4 mm b. single jaw surgery c. 4 mm to 6 mm c. orthodontic treatment d. 6 mm to 8 mm d. none of the above 9. Which of the following is not a method of 3. Dentists commonly alter vertical dimension determining vertical dimension? in order to: a. use of freeway space a. improve esthetics b. use of trial appliances b. improve occlusal relationships c. TENS c. gain space for the restoration of short or d. method of tooth proportion worn teeth 10. In a study evaluating whether dentists were d. all of the above capable of seeing the facial differences caused by 4. When vertical dimension is increased, resting changes in vertical dimension, the differences muscle activity level does which of the following? were not seen until the change had reached a. increases until there is approximately which of the following measurements? 10 mm to 12 mm of anterior vertical opening a. 2 mm b. decreases until there is approximately b. 4 mm 10 mm to 12 mm of anterior vertical opening c. 6 mm c. decreases until there is approximately d. 8 mm 7 mm to 9 mm of anterior vertical opening d. there is no change 5. Resting muscle activity level returns to levels close to pretreatment levels when vertical change has been maintained for how long? a. 1 month to 2 months b. 3 to 4 months c. 6 to 8 months d. 10 to 12 months 6. Practitioners are sometimes concerned with how a change in vertical dimension will affect the patient’s speech, particularly sounds using which letter? a. L b. P c. S d. T

14 Advanced Esthetics & Interdisciplinary Dentistry Vol. 2, No. 3, 2006