Esthetics and Smile Characteristics from the Patient's Perspective, Part 1

INTRODUCTION: The paradigm shift from occlusion to esthetics emphasizes the interplay between dental structures and the surrounding soft tissue envelope. OBJECTIVES: To quantify the ideal and maximum acceptable deviation for nine smile characteristics by using digital manipulation of hard and soft tissue smile components. METHODS: Intraoral photographs were manipulated using Adobe® Photoshop® CS2 to alter buccal corridor, smile arc, gingival display, crown torque, and occlusal cant. Smiles were placed in a gender neutral face showing nasal tip to mentolabial fold. Quask™ Form Artist was used to generate the survey, which was administered in Columbus, OH (n=43); Seattle, WA (n=41) and Boston, MA (n=40). An interactive interface allowed raters to move a slider to answer questions. Rater reliability was assessed for each variable. RESULTS: Raters were reliable (K = 0.5-0.8). Gender and survey location were not significant. SMILE ARC MOST IDEAL: Cusp tips of the posterior teeth were 7.2mm above the incisal edges of the maxillary central incisors. SMILE ARC UNACCEPTABLE: >7.9mm and <2.6mm above the incisal edges. BUCCAL CORRIDOR IDEAL: 5.8 mm each side (16%) BUCCAL CORRIDOR UNACCEPTABLE: >9.4 mm (26%) and <2.9 mm (8%) of dark space. GINGIVAL DISPLAY IDEAL: 2.1mm (-2.1mm gingival display) central incisor coverage by upper lip GINGIVAL DISPLAY UNACCEPTABLE: >3.6mm of gingival display and 4mm of incisal coverage. CANINE TORQUE, IDEAL CORRIDOR: -1 degree considered ideal with acceptable range of +10 to -7 degrees. CANINE TORQUE, LARGE CORRIDOR: -4 degrees considered ideal with acceptable range of +8 to -10 degrees. POSTERIOR TORQUE, IDEAL CORRIDOR: +4 degrees considered ideal with acceptable range of +5 to -7 degrees. POSTERIOR TORQUE, LARGE CORRIDOR: +6 degrees considered ideal with acceptable range of +5 to -8 degrees.

CONCLUSIONS: Smile arc and buccal corridor data are near previous results, while other variables demonstrate large ranges of acceptability.