BACKGROUND: The purposes of this study were to quantify some clinical parameters that are useful as esthetic guidelines when the gingival contour is modified and to compare the left and right sides of the six maxillary anterior teeth. METHODS: Maxillary casts mounted on an articulator according to the axis orbital plane were photographed from 103 young adults. The angle formed between the gingival line and the maxillary midline (GLA) and the distance between the gingival zenith of the lateral incisor and the gingival line (LID) were measured. The asymmetry was evaluated using a paired t test for the left versus right measurements of GLA and LID. The descriptive statistics for GLA and LID were calculated. RESULTS: The GLA measurements of the left side (86.5 degrees +/- 5.1 degrees ) were significantly greater than those of the right side (85.2 degrees +/- 4.9 degrees ), and the mean absolute asymmetry for GLA was 4.1 degrees +/- 3.0 degrees . The mean LID measurement was 0.68 +/- 0.52 mm. CONCLUSIONS: The gingival zenith of the canine is apical to the gingival zenith of the incisors (GLA <90 degrees ), and the gingival zenith of the lateral incisor is below (81.1%) or on (15%) the gingival line when the head is oriented in the axis orbital plane. A directional asymmetry was shown, with the right side higher than the left side. Along with other parameters related to dental esthetics, these clinical parameters applied to the gingival contours may serve as esthetic guidelines and may enable us to obtain a more predictable esthetic outcome.
BACKGROUND: The purposes of this study were to quantify some clinical parameters that are useful as esthetic guidelines when the gingival contour is modified and to compare the left and right sides of the six maxillary anterior teeth. METHODS: Maxillary casts mounted on an articulator according to the axis orbital plane were photographed from 103 young adults. The angle formed between the gingival line and the maxillary midline (GLA) and the distance between the gingival zenith of the lateral incisor and the gingival line (LID) were measured. The asymmetry was evaluated using a paired t test for the left versus right measurements of GLA and LID. The descriptive statistics for GLA and LID were calculated. RESULTS: The GLA measurements of the left side (86.5 degrees +/- 5.1 degrees ) were significantly greater than those of the right side (85.2 degrees +/- 4.9 degrees ), and the mean absolute asymmetry for GLA was 4.1 degrees +/- 3.0 degrees . The mean LID measurement was 0.68 +/- 0.52 mm. CONCLUSIONS: The gingival zenith of the canine is apical to the gingival zenith of the incisors (GLA <90 degrees ), and the gingival zenith of the lateral incisor is below (81.1%) or on (15%) the gingival line when the head is oriented in the axis orbital plane. A directional asymmetry was shown, with the right side higher than the left side. Along with other parameters related to dental esthetics, these clinical parameters applied to the gingival contours may serve as esthetic guidelines and may enable us to obtain a more predictable esthetic outcome.