Evaluation of smile esthetics by photographic assessment of the dento-labio-gingival complex

Context: The esthetics of a smile is determined by various factors including symmetry, anatomy and position of teeth, periodontal visibility, and musculoskeletal relationships. Aim: This study analyzed the dento-labio-gingival esthetic components of the smile, evaluating: (a) Amount of gingiva visible during natural smile and forced smile, (b) relationship between incisal edges of maxillary anterior teeth and upper border of lower lip, (c) deviation of dental midline from facial midline to right or left side. Materials and Methods: Photographs of 127 subjects were taken by standardizing by placing patients head in Frankfurt horizontal plane and photos were cropped uniformly. Analysis of the dento-labial-gingival esthetic components of the smile, evaluating the relationship between the curve formed by the incisal edges of anterior teeth that is, incisal line and the curve of the lower lip, whether the incisal line touches the lower lip, presence of overlap of the lower lip over the incisal edges or absence of touch and also the amount of periodontal visibility during natural smile and the forced smile was done using Microsoft PowerPoint. Result: During natural smile the most frequent smile line was class 4 that is, low smile line seen in 67% of participants and class 3 for forced smile that is, average smile line seen in 44% of participants. There was a highly significant prevalence for females to have more periodontal visibility during both natural and forced smile (P < 0.001).40% of participants had maxillary incisor edges slightly apart from the lower lip and 48% of participants had maxillary incisal edges in light contact with lower lip. No significant difference was seen between the two genders (P > 0.05). 78 % of subjects showed no deviation from the midline, 19.7 % of the subjects showed the deviation of midline toward the right, and 2.4% showed deviation toward the left. Conclusion: Harmony of the dento-labial-gingival complex is essential for a pleasing smile. Evaluating the smile of each patient using photographs, as well as radiographs and clinical data assures the clinician of the possibility of deciding what needs to be carried out and what can be done to treat a gummy or an assymetrical smile according to its etiology.