Fig. 3From: Perception of smile esthetics by laypeople of different agesAltered black triangles between the maxillary central incisors in 0.5-increments. 1 no black triangle; 2 0.5Â mm; 3 1.0Â mm; 4 1.5Â mm; 5 2.0Â mm; and 6 2.5Â mmBack to article page