Evaluation of zenith position of maxillary gingiva in the dental students in Isfahan Dental Faculty

Analysis of smile is one of the esthetic evaluations in dentistry. In the present study, GLA, LID, the long axis position and the oblique axial angle of each tooth were evaluated. In this cross-sectional analytical study, 80 subjects with properly-aligned teeth and healthy periodontium were selected. A digital camera was to take photos of lip areas in uniform conditions. The zenith (the margin tip) of the gingiva of maxillary incisors was determined in the photographs. The line connecting the zenith of canine to that of central was called the gingival line. The angle between this line and tooth midline (GLA) and the distance between the Zenith of the later and that line (LID) was calculated. Then the long axis and the oblique axial angles of maxillary anterior teeth were determined. Data was analyzed with t-test and McNemar’s test (α=0.05). No significant differences were observed in GLA and LID between the left and right sides (p value < 0.05). The overall GLA and LID averages were 90.01±6.10º and 0.55±0.52 mm. There was no significant difference in long axis position of maxillary anterior teeth between the left and right sides (p value > 0.05). There were significant differences in the overall oblique axial angles of anterior teeth between the right and left sides (p value < 0.05). The zenith of centrals and canines were mostly on the same level and LID was 0-1 mm coronal to the gingival line. The mean oblique axial angle of canine was higher than that of lateral, which in turn was higher than that of central.