Abstract
Statement of problem : The beauty has a little different meaning according to a time, culture, and nation. Purpose : This study was undertaken to determine the Korean perception of the altered upper anterior dental esthetics including the lack of symmetry, the midline deviation, the gingival exposure, the inclination of incisal plane, the type of incisal plane, and the type of gingival line. Material and Method : 670 subjects were participated in this survey. A questionnaire accompanied by 12 sets of computer-manipulated images using 3D MAX 4.2 software was used to record the ranking of the geometric preference related to the anterior esthetic discrepancies in three or four degrees of alteration. The statistical significance of the differences between the groups was determined by a one-way ANOVA and a t-test. Results : The results obtained were as follows: 1) The Korean perception of the anterior dental esthetics according to the subjects' occupation, sex, and age was most affected by occupation. 2) The masked image emphasizing the dentition and lips appeared stranger than the non-masked image at the same alteration. 3) The lack of symmetry, which was expressed as a unilateral discoloration of the tooth, showed incongruity in any teeth of the anterior dentition. The incongruity was more severe as the degree occurred closer to the midline. 4) The deviation of midline was showed more severe strangeness as the degree of deviation increased. However, more than half of the subjects did not perceive a deviation of 5mm. 5) During smiling, the exposure of the upper gingiva showed more severe incongruity as the degree of gingival exposure increased. 77% of the subjects perceived strangeness at the gingival exposure of 4.5mm. 6) The inclination of the incisal plane appeared stranger as the degree of inclination increased. 62% of subjects perceived strangeness at the $7.5^{\circ}$ inclination of the incisal plane. 7) The type of incisal plane showed increasing strangeness in the order of convex/downward, straight/horizontal, and concave/upward. 80% of subjects perceived strangeness at concave/upward. 8) The type of gingival line was showed increasing incongruity in the order of the same, a little above, and a little under the zenith of the lateral incisor to the line joining the zenith of the central incisor and the canine. However, less than half the subjects did not perceive strangeness at any alteration of the gingival line. Conclusion : The Korean perception of the upper anterior dental esthetics was different to the westerner's perception in the some respects.