Jeff Morley- macroesthetic elements of smile design

COSMETIC & RESTORATIVE CAREFigure 1. Restoration of anterior dentition in whichrestoration design lacks apparent harmony with surroundingsoft tissue.Figure 2. Re-treatment of dentition in Figure 1 usingmacroesthetic design principles to better blend in withand complement surrounding soft tissue.and incisal haloing all are components of themicroesthetics of each tooth. Dentists and techniciansalike endeavor to replicate the microestheticsof teeth in restorations.dMacroesthetics, the fourth of these aspects andthe focus of this article, represents the principlesthat apply when groupings of individual teeth areconsidered. 4 The relationship between those teethand the surrounding soft tissue andthe patient’s facial characteristicscreates a dynamic and threedimensionalcanvas. The artisticwork of the dentist and the techniciancan combine to create a naturaland pleasing overall appearance—ornot—depending on how well the relativeshapes, sizes and arrangementof the individual teeth harmonizewith the features of any givenpatient (Figures 1 and 2).Macroesthetics attempts to identify and analyzethe relationships and ratios between anteriorteeth and surrounding tissue landmarks. In thisarticle, we discuss the principles of macroestheticsand how to apply them.MACROESTHETIC DESIGN ELEMENTS:FACIAL MIDLINEIn smile design, the starting point of the esthetictreatment plan is the facial midline. 5 Whenviewing dentitions, many clinicians use the maxillarycentral incisors as their esthetic baselineand then move laterally in a progression from thelateral incisors to the canines to the premolarsand beyond. However, considering the importanceof the facial midline, there remains confusionCareful photographicanalysis of patients’faces shows thatprominent facialanatomy can bedeceptive in locatingthe facial midline.regarding techniques for reliably locating it. 6Careful photographic analysis of patients’ facesshows that prominent facial anatomy—includingthe eyes, nose and chin—can be deceptive inlocating the midline. Most people’s eyes are atslightly different levels or at different depthswithin the sockets. Many patients have noses orchins that deviate from the center, which underminesthese landmarks as indicatorsof the facial midline. 7A practical approach to locatingthe facial midline references twoanatomical landmarks. The first is apoint between the brows known asthe nasion. The second is the base ofthe philtrum, also referred to as thecupid’s bow in the center of the upperlip. A line drawn between these landmarksnot only locates the position ofthe facial midline but also determines the directionof the midline (Figure 3).Whenever possible, the midline between themaxillary central incisors should be coincidentalwith the facial midline. In cases in which this isnot possible, the midline between the centralincisors should be parallel to the facial midline. 8-10If the visual junction of maxillary central incisorsis at an angle to the facial midline, it is referredto as a canted midline. Canting is a major designflaw in any natural or restored dentition. Whilealignment of the maxillary and mandibulardental midlines is desirable in orthodontics, themandibular midline becomes a lesser issue inesthetics. 11 The narrowness and uniform sizes ofmandibular incisors make visualization of theirmiddle point more difficult, particularly when40 JADA, Vol. 132, January 2001Copyright ©1998-2001 American Dental Association. All rights reserved.

COSMETIC & RESTORATIVE CAREFigure 3. Plotting the facial midline using nasion andcupid’s bow as reference points.Figure 5. Unrestored dentition exhibiting the 50-40-30relationship of interproximal connectors between thecentral incisor, the lateral incisor and the canine.seen in relationship to lips and other soft-tissuelandmarks.Incisal embrasures. The pattern of silhouettingcreated by the edges and separations betweenthe maxillary anterior teeth against thedarker background of the mouth helps define agood-looking smile. These spaces between theedges of the teeth known as embrasure spacesfollow a pattern that develops between the centralincisors and then progress laterally. Thesize and volume of the incisal embrasuresbetween teeth increase as the dentition progressesaway from the midline 12 (Figure 4). Inother words, the incisal embrasure spacebetween the lateral incisor and the centralincisor should be larger than the incisal embrasurebetween the central incisors. The embrasurebetween the canine and the lateral incisorshould be larger than the embrasure betweenFigure 4. Cosmetic restoration of dentition showing progressiveincrease of incisal embrasure size from centralincisor to lateral incisor to canine.the lateral and central incisors.Connectors. The places in which the anteriorteeth appear to touch has been referred to as theconnector space. There is a distinction between aconnector space and a contact point. The contactpoints between the anterior teeth are generallysmaller areas (about 2 × 2 millimeters) that can bemarked by passing articulating ribbon betweenthe teeth. The connector is a larger, broader areathat can be defined as the zone in which two adjacentteeth appear to touch. An esthetic relationshipexists between the anterior teeth that isreferred to as the 50-40-30 rule. 13 This rule definesthe ideal connector zone between the maxillarycentral incisors as 50 percent of the length of thecentral incisors. The ideal connector zone betweena maxillary lateral incisor and a central incisorwould be 40 percent of the length of the centralincisor. The optimum connector zone between amaxillary canine and a lateral incisor when seenin lateral view would approximate 30 percent ofthe length of the central incisor (Figure 5).Axial inclinations. Each combination of toothinclinations in a smile is unique. The long axis of,or direction of the anterior teeth in, an estheticsmile also follows a progression as the teeth moveaway from the midline. If the long axis of thetooth tips toward the midline when assessed fromthe height of the gingival margin toward theincisal edge, the tipping is medial. Conversely, ifthe long axis of the tooth seems to move awayfrom the midline, the tooth is said to tip laterallyor buccally. When the maxillary anterior teeth tipmedially, the overall esthetic impact is one of aharmonious relationship with the framing of thelower lip. 14 As in many of the macroesthetic rulesJADA, Vol. 132, January 2001 41Copyright ©1998-2001 American Dental Association. All rights reserved.

COSMETIC & RESTORATIVE CAREFigure 6. Progressive medial tipping of the axial inclinationsof the anterior teeth.of progression, the medial tipping of the axialinclinations increases as one moves further fromthe midline (Figure 6).Shade progression. Even the shade and colorpatterns of the maxillary teeth follow a progressivepattern based on the distance from the midline(Figure 7). The maxillary central incisors arethe lightest and brightest teeth inthe smile. 15 The maxillary lateralincisors have a similar hue to that ofthe central incisors but are typicallyjust slightly lower in color, or value.The canines have greater chromasaturation and also are lower invalue than any of the other anteriorteeth. First and second premolarsappear lighter and brighter than thecanines and have a value similar tothat of the lateral incisors. 15 Reproductionof shade progression in anterior restorativeand cosmetic treatment re-creates a look thatapproximates natural esthetics even whenpatients seek the very lightest shades.MACROESTHETIC DESIGN ELEMENTS:TOOTH REVEAL“Tooth reveal” is a term for the amount of toothstructure or gingiva that shows in various viewsand lip positions. Even the most beautiful anteriortooth or teeth will have little esthetic valuefor the patient if the amount of reveal is unflatteringto the face. By standardizing maximumand minimum lip parameters based on muscularand phonetic positions, the clinician can quantifyesthetic ratios and relationships of tooth reveal.These various ratios, while somewhat anecdotal,can assist the dentist when analyzing esthetics inEven the mostbeautiful anteriorteeth have littleesthetic value if theamount of toothreveal is unflatteringto the face.day-to-day practice while at the same time providingvaluable guidelines in the cosmeticrestoration of natural dentitions. In many cases,cosmetic treatment can involve a determination oftooth length and positioning of the incisal edgesof the anterior teeth. Esthetic reveal positions area strategic treatment-planning tool when takeninto consideration with occlusal and phoneticguidelines.“M” position. By having the patient say theletter “M” repetitively and then allow his or herlips to part gently, the clinician can assess minimumtooth reveal (Figure 8). The amount ofmaxillary or mandibular teeth that show in thisposition has been demonstrated to be different atdifferent stages of life. While younger patientsmay show between 2 and 4 mm of maxillaryincisal edge in this position, the maxillary incisaledge reveal shrinks and even disappears aspeople age. 17 In some elderly patients, the mandibularincisal edges begin to show. Carefullylocating the “M” position reveal and creating therestoration accordingly can have the fluid effect ofmaking a smile age-specific, beingeither younger or older in appearance.“E” position. When patients saythe letter “E” in an uninhibited andexaggerated way, the clinician canascertain the maximum extension ofthe lips (Figure 9). While patientscommonly say they do not normallysmile in this position, the revealexhibited reaches the maximum positionachievable under extreme conditions. Duringphotographic analysis of the smile, everythingthat shows can be considered to be in the estheticzone. 17 Restorative, surgical and periodontaltreatment within the esthetic zone should takeinto consideration both the cosmetic and thehealth consequences of the result. While healthnever should be sacrificed for appearance alone,neither should the patient’s appearance be sacrificedfor convenience or through the clinician’sfailure to consider all of the esthetic options. 18Intercommissure line and lower lipframing. When a patient’s mouth is in broadsmile position, the clinician can draw an imaginaryline through the corners of the mouth. Thisline is known as the intercommissure line, orICL (Figure 10). The amount of maxillary toothreveal below the ICL interacts with the viewer’sperception of the patient’s age. In a youthful42 JADA, Vol. 132, January 2001Copyright ©1998-2001 American Dental Association. All rights reserved.

COSMETIC & RESTORATIVE CAREFigure 7. Unrestored dentition showing shade progressionfrom central incisor to canine.Figure 8. Reveal of the incisal edges of the maxillaryincisors in the “M” position.Figure 9. Reveal of the anterior dentition in the “E”position.smile, approximately 75 percent to 100 percentof the maxillary teeth would show below thisline. 2 The position of the incisal edges of theanterior teeth as they relate to the lower lipalso may have esthetic consequences. When thevisual space created between upper and lowerlips in full smile is considered, the maxillaryanterior teeth should fill between 75 percent to100 percent of that space to create a youthfullook. 19Vestibular space. In a broad smile, theamount of reveal of the maxillary posteriorteeth also can become an esthetic consideration.In patients who have narrow arch form andwide lip extension, tooth reveal behind thecanines can be in shadow or disappear completely(Figure 11). This condition has beencalled deficient vestibular reveal, or DVR. 20DVR may have negative esthetic consequencesin certain patients.Smile line. The plane of the incisal edges ofFigure 10. The intercommissure line and reveal of themaxillary anterior teeth can be useful in developing anesthetically pleasing smile.the maxillary anterior teeth also can be related tothe two fundamental criteria of midline andreveal. Traditional orientation of the smile linecalls for it to be parallel with a line drawnbetween the pupils of the eyes. 21 Unfortunately,this guideline does not accommodate situations inwhich patients have eyes in different planes(Figure 12). Creation of an incisal plane that isperpendicular to the facial midline produces areliable and repeatable position that does notdepend on the interpupillary line. 22Once the clinician has determined the orientationof the smile line, he or she can design itscurve, or shape. When the incisal edges of themaxillary central incisors appear to be below thetips of the canines, the smile line has a convexappearance that can approximate and harmonizewith the line of the lower lip 23 (Figure 13). A socalled“reverse smile line” results when the tips ofthe canines or premolars are longer than those ofthe central incisors. This design condition doesJADA, Vol. 132, January 2001 43Copyright ©1998-2001 American Dental Association. All rights reserved.

COSMETIC & RESTORATIVE CAREFigure 11. Teeth in shadow distal to the maxillary caninecan contribute to deficient vestibular reveal.Figure 13. Convex arch of anterior teeth in which theincisal edges of central incisors are visibly lower than thetips of the canines.not harmonize well with other facial features andalso may be associated with occlusal malfunctionor loss of vertical dimension.CONCLUSIONThe cumulative visual impact of the smile cannotbe associated exclusively with the beauty of individualteeth. The microesthetics of natural andrestored dentitions must be combined withmacroesthetic considerations, of which we havepresented only a partial list. Smile design is a relativelynew discipline in the area of cosmetic dentistry,and it involves several areas of evaluationand treatment planning. As mentioned earlier,macroesthetic principles are only part of theoverall picture; gingival esthetics, facial estheticsand microesthetics are the other three essentialcomponents of effective smile design. In addition,occlusal and engineering issues also may alter theFigure 12. Asymmetrical facial features, including eyes indifferent planes, are not useful reference points in determiningthe smile line.smile design in both natural and restored dentitionsand could influence the longevity of cosmetictreatment.It should not be forgotten that each patient isunique, representing a special blend of age characteristicsand expectations, as well as sex andpersonality specificity. Macroesthetic conceptsprovide only guidelines and reference points forbeginning esthetic evaluation, treatment planningand subsequent treatment. The artistic componentof dentistry—and particularly of cosmeticdentistry—can be applied and perfected by dentistswho understand the rules, tools and strategiesof smile design. ■1. Dzierzak J. Restoring the aging dentition. Curr Opin Cosmet Dent1995;41-4.2. Morley J. The role of cosmetic dentistry in restoring a youthfulappearance. JADA 1999;130:1166-72.3. Golub-Evans J. Unity and variety: essentialingredients of a smile design. Curr OpinCosmet Dent 1994;2:1-5.4. Morley J.Advanced smiledesign. Course presentedat: PostgraduateAdvancedDr. Morley is the codirectorof advancedrestorative estheticspostgraduate programsat Louisiana State University,New Orleans;University of Californiaat Los Angeles; andUniversity at BuffaloSchool of DentalMedicine, New York. Hemaintains a privatepractice in cosmeticand restorative dentistryin San Francisco.Address reprintrequests to Dr. Morleyat 1648 Union St., SanFrancisco, Calif. 94123.Dr. Eubank is the codirectorof advancedrestorative estheticspostgraduate programsat Louisiana State University,New Orleans;University of Californiaat Los Angeles; andUniversity at BuffaloSchool of DentalMedicine, New York. Hemaintains a privatepractice in cosmeticand restorative dentistryin Plano, Texas.Restorative EstheticsProgram, Baylor Collegeof Dentistry,Department of ContinuingEducation;Feb. 12, 1999; Dallas.5. Spear F. Theesthetic managementof dental midlineproblems withrestorative dentistry.Compend ContinEduc Dent1999;20:912-8.6. Brown JD, MonettiL. The midlinecrisis: esthetically.Gen Dent1987;35:110-1.44 JADA, Vol. 132, January 2001Copyright ©1998-2001 American Dental Association. All rights reserved.

COSMETIC & RESTORATIVE CARE7. Barnett JW. Problems of facial asymmetry as diagnosed by thelaminagraph. Proc Found Ortho Res 1971;135-42.8. Miller EL, Bodden WR, Jamison HC. A study of the relationship ofthe dental midline to the facial median line. J Prosthet Dent1979;41:657-60.9. Beyer JW, Lindauer SJ. Evaluation of dental midline position.Semin Orthod 1998;4:146-52.10. Latta GH. The midline and its relation to anatomic landmarks inthe edentulous patient. J Prosthet Dent 1988;59:681-3.11. Johnston CD, Burden DJ, Stevenson MR. The influence of dentalmidline discrepancies on dental attractiveness ratings. Eur J Orthod1999;21:517-22.12. American Academy of Cosmetic Dentistry. Accreditation examinationcriteria, number 21: Is there a progressive increase in the size ofthe incisal embrasures? Madison, Wis.: American Academy of CosmeticDentistry; 1999.13. Morley J. A multidisciplinary approach to complex aestheticsrestoration with diagnostic planning. Prac Perio Aesth Dent2000;12:575-7.14. Lombardi RE. The principles of visual perception and their clinicalapplication to denture esthetics. J Prosthet Dent 1973;29:358-82.15. Goodkind RJ, Schwabacher WB. Use of a fiber-optic colorimeterfor in vivo measurements of 2,830 anterior teeth. J Prosthet Dent1987;58:535-42.16. McIntyre F. Restoring esthetics and anterior guidance in wornanterior teeth: a conservative multidisciplinary approach. JADA2000;131;1279-83.17. Vig R, Brundo G. The kinetics of anterior tooth display. J ProsthetDent 1978;39(5):502-4.18. O’Regan J, Dewey M, Slade P, Lovius B. Self-esteem and aesthetics.Br J Orthod 1991;18:111-8.19. Wagner I, Carlsson G, Ekstrand K, Odman P, Schneider N. Acomparative study of assessment of dental appearance by dentists,dental technicians and laymen using computer-aided image manipulation.J Esthet Dent 1996;8:199-205.20. Morley J, Eubank J. Advanced smile design. Course presented at:141st Annual Session of the American Dental Association; Oct. 17,2000; Chicago.21. Singer B. Principles of esthetics. Curr Opin Cosmet Dent 1994:6-12.22. Morley J. Smile design. Course presented at: Advanced EstheticsContinuum, Louisiana Academy of Continuing Dental Education,Louisiana State University School of Dentistry; Jan. 16, 2000; NewOrleans.23. Tjan A, Miller G, The G. Some esthetic factors in a smile. J ProsthetDent 1984;51:24-8.JADA, Vol. 132, January 2001 45Copyright ©1998-2001 American Dental Association. All rights reserved.