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ePaper created 2015-05-14, 11:05:01 | version 1.38.0
special _ smile analysis and smile design I _Initiating smile analysis: Evaluating facial and orofacial aesthetics The smile analysis/design process begins at the macro level, examining the patient’s face first, pro- gressing to an evaluation of the individual teeth, and finally moving to material selection considerations. Multiple photographic views (e.g., facial and sagittal) facilitate this analysis. At the macro level, facial elements are evaluated forformandbalance,withanemphasisonhowthey may be affected by dental treatment.3,4 During the macro-analysis, the balance of the facial thirds is examined (Fig. 1). If something appears unbalanced in any one of those zones, the face and/or smile will appear unaesthetic. Such evaluations help determine the extent and type of treatment necessary to affect the aesthetic changes desired. Depending on the complexity and uniqueness of a given case, orthodontics could be considered when restorative treatment alone would not produce the desired results (Fig. 2), such as when facial height is an issue and the lower third is af- fected. In other cases—but not all—restorative treat- ment could alter the vertical dimension of occlusion to open the bite and enhance aesthetics when a pa- tientpresentswithrelativelyevenfacialthirds(Fig.3). _Evaluating oral aesthetics The dentolabial gingival relationship, which is consideredoralaesthetics,hastraditionallybeenthe starting point for treatment planning. This process beginsbydeterminingtheidealmaxillaryincisaledge placement(Fig.4).Thisisaccomplishedbyunderstand- ingtheincisaledgepositionrelativetoseveraldiffer- ent landmarks. The following questions can be used to determine the ideal incisal edge position: _Where in the face should the maxillary incisal edges be placed? _What is the proper tooth display, both statically and dynamically? _Whatistheproperintra-andinter-toothrelationship (e.g., length and size of teeth, arch form)? _Can the ideal position be achieved with restorative dentistry alone, or is orthodontics needed? In order to facilitate smile evaluation based on theselandmarks,theruleof4.2.2—whichreferstothe amount of maxillary central display when the lips are atrest,theamountofgingivaltissuerevealed,andthe proximity of the incisal line to the lower lip—is help- ful(Fig.5).Atatimewhenpatientsperceivefullerand brighter smiles as most aesthetic, 4mm of maxillary central incisor display while the lips are at rest may be ideal.2,5 In an aesthetic smile, seeing no more than 2mm of gingiva when the patient is fully smiling is ideal.6 Finally, the incisal line should come very close toandalmosttouchthelowerlip,beingnomorethan 2mm away.2 These guidelines are somewhat subjec- tive and should be used as a starting point for deter- mining proper incisal edge position. Fig. 2_Sagittal views best demonstrate which specialists should be involved in treatment, whether orthodontists or maxillo- facial surgeons, to best aesthetically alter the facial aesthetics. Fig. 3_Drawing a line along the glabella, subnasale, and pogonion enables a quick evaluation of aesthetics without the need for radiographs to determine alignment of ideal facial elements. I 11CAD/CAM 2_2015 Fig. 2 Fig. 3