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Cosmetic Tribune United Kingdom Edition No. 4, 2015

Cosmetic Tribune United Kingdom Edition | 4/201522 Evaluating oralaesthetics The dentolabial gingival re- lationship, which is considered oral aesthetics,hastraditionallybeenthe starting point for treatment plan- ning. This process begins by deter- mining the ideal maxillary incisal edge placement (Fig. 4). This is ac- complished by understanding the incisal edge position relative to sev- eraldifferentlandmarks.Thefollow- ing questions can be used to deter- minetheidealincisaledgeposition: •Whereinthefaceshouldthemaxil- laryincisaledgesbeplaced? •What is the proper tooth display, bothstaticallyanddynamically? •Whatistheproperintra-andinter- tooth relationship (e.g., length and sizeofteeth,archform)? •Can the ideal position be achieved with restorative dentistry alone, or isorthodonticsneeded? In order to facilitate smile evalua- tion based on these landmarks, the rule of 4.2.2—which refers to the amountofmaxillarycentraldisplay whenthelipsareatrest,theamount of gingival tissue revealed, and the proximity of the incisal line to the lowerlip—ishelpful(Fig.5).Atatime when patients perceive fuller and brighter smiles as most aesthetic, 4mm of maxillary central incisor displaywhilethelipsareatrestmay be ideal.2, 5 In an aesthetic smile, see- ing no more than 2mm of gingiva when the patient is fully smiling is ideal.6 Finally, the incisal line should comeveryclosetoandalmosttouch the lower lip, being no more than 2mm away.2 These guidelines are somewhat subjective and should be usedasastartingpointfordetermin- ingproperincisaledgeposition. Dentogingival aesthetics Gingival margin placement and the scalloped shape, in particular, are well discussed in the literature. As gingival heights are measured, heightsrelativetothecentralincisor, lateral incisor, and canine in an up/down/up relationship are con- sidered aesthetic (Fig. 6). However, this may create a false perception thatthelateralgingivallineisincisal tothecentralincisor.Rather,inmost aesthetic tooth relationships, the gingival line of the four incisors is approximatelythesameline(Fig.6), withthelateralincisorperhapsbeing slightly incisal.7 The gingival line should be relatively parallel to the horizon for the central incisors and the lateral incisors and symmetric oneachsideofthemidline.2,8 Thegin- gival contours (i.e., gingival scallop) should follow a radiating arch simi- lar to the incisal line. The gingival scallop shapes the teeth and should bebetween4mmand5mm(Fig.7).9 Relatedtonormalgingivalformis midline placement. Although usu- allythefirstissueaddressedinsmile design,itisnotassignificantastooth form, gingival form, tooth shape, or smileline. Several rules can be applied when considering modifying the midline tocreateanaestheticsmiledesign: •Themidlineonlyshouldbemoved to establish an aesthetic intra- and inter-tooth relationship, with the twocentralincisorsbeingmostim- portant. •Themidlineonlyshouldbemoved restoratively up to the root of the adjacent tooth. If the midline is within 4mm of the centre of the face,itwillbeaestheticallypleasing. •The midline should be vertical whentheheadisintheposturalrest position. Evaluatingdental aesthetics Partofevaluatingdentalaesthetics for smile design is choosing tooth shapes for patients based on their facial characteristics (e.g., long and dolichocephalic, or squarish and brachycephalic).Whenpatientspres- entwithalongerface,amorerectan- gulartoothwithintheaestheticrange is appropriate. For someone with a square face, a tooth with an 80% width-to-length ratio would be more appropriate. The width-to-length ra- tio most often discussed in the liter- ature is between 75% and 80%, but aesthetic smiles could demonstrate ratios between 70% and 75% or be- tween80%and85%(Figs.8–10).1 Thelengthofteethalsoaffectsaes- thetics.Maxillarycentralincisorsav- erage between 10mm and 11mm in length.AccordingtoMagne,theaver- age length of an unworn maxillary central to the cementoenamel junc- tionisslightlyover11mm.10 Theaes- theticzoneforcentralincisorlength, according to the authors, is between 10.5mm and 12mm, with 11mm be- ingagoodstartingpoint.Lateralinci- sors are between 1mm and a maxi- mum of 2mm shorter than the cen- tralincisors,withthecaninesslightly shorter than the central incisors by between0.5mmand1mm(Fig.11). The inter-tooth relationship, or arch form, involves the golden pro- portion and position of tooth width. Although it is a good beginning, it doesnotreflectnaturaltoothpropor- tions. Natural portions demonstrate a lateral incisor between 60% and 70% of the width of the central inci- sor,andthisislargerthanthegolden proportion.11 However,aruleguiding proportionsisthatthecanineandall teeth distal should be perceived to occupy less visual space (Fig. 12). An- other rule to help maintain propor- tionsthroughoutthearchis1-2-3-4-5; thelateralincisoristwo-thirdsofthe centralincisorandthecanineisfour- fifthsofthelateralincisor,withsome latitude within those spaces (Fig. 13). Finally, contact areas can be moved restorativelyuptotherootofthead- jacenttooth.Beyondthat,orthodon- ticsisrequired(Fig.14). Creatingadigitalsmile designedinPhotoshop Although there are digital smile design services available to dentists for a fee, it is possible to use Photo- shop CS5 software (Adobe Systems) to create and demonstrate for pa- tients the proposed smile design treatments. It starts by creating tooth grids—predesigned tooth templates in different width-to- length ratios (e.g., 75% central, 80% central)thatcanbeincorporatedinto a custom smile design based on pa- tient characteristics. You can create asmanydifferenttoothgridsasyou likewithdifferenttoothproportions in the aesthetic zone. Once com- pleted, you will not have to do this step again, since you will save the created tooth grids and use them to create a new desired outline form forthedesiredteeth. Followtheserecommendedsteps: •Tobegincreatingatoothgrid,usea cheek-retractedimageofanattrac- tive smile as a basis (e.g., one with a 75% width-to-length ratio). Open theimageinPhotoshopandcreate anewcleartransparentlayerontop of the teeth (Fig. 15). This transpar- entlayerwillenabletheimagetobe outlined without the work being embeddedintotheimage. •Name the layer appropriately and, when prompted to identify your choice of fill, choose “no fill,” since thelayerwillbetransparent,except forthetracingofthetoothgrid. •To begin tracing the tooth grid, ac- tivate a selection tool, move to the tool palette, and select either the polygonal lasso tool or the mag- netic lasso tool. In the authors’ opinion, the polygonal works best. TRENDS&APPLICATIONS Fig.18: Image of the central incisor with a two-pixel black stroke (tracing).—Fig.19: Image of the teeth traced up to the second premolar to create a tooth grid.—Fig.20: Size the image in Photoshop.—Fig.21: Save the grid as a .png or .psd file type and name it appropriately. Create other dimension grids using the same technique.—Fig. 22: To determine the digital tooth size,a conversion factor is created by dividing the proposed length by the existing length of the tooth.—Fig.23: Select the ruler tool in Photoshop.—Fig.24: Measure the digital length of the central incisor using the ruler tool.—Fig.25: Measure the new digital length using the conversion factor created earlier.—Fig.26: Create a new transparent layer and mark the new proposed length with the pencil tool.—Fig.27: Open the image of the chosen tooth grid in Photoshop and drag the grid on to the image of teeth to be smile designed.This will create a new layer in the image to be smile designed. 18 19 20 21 22 23 24 25 26 27 Fig.28: Adjust the grid as required while maintaining proper proportions by using the free transform tool from the edit menu.—Fig.29: Modify the grid shape as necessary using the liquify tool.—Fig.30: Select all of the teeth in the grid by activating the magic wand selection tool and then clicking on each tooth with the grid layer activated (highlighted) in the layers palette.—Fig.31: Use the selection modify tool to expand the selectiontobetterfit thegridshape.—Fig.32:Activatethelayeroftheteethbyclickingonit.Blue-colouredlayersareactive.—Fig.33:Withthelayeroftheteethhighlighted,choose“liquify”;anewwindowwillappear with a red background called a“mask”.—Fig.34: Shape one tooth at a time as needed by selecting“wand”.—Fig.35: Once all of the teeth have been shaped,use the liquify tool.—Fig.36:Tooth brightness is adjusted using commands from the dodge tool menu or image adjustments menu.—Fig.37: Image of all the teeth whitened with the dodge tool. 28 29 30 31 32 33 34 35 36 37 1819202122 2324252627 2829303132 3334353637

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