DYNAMIC SMILE EVALUATION IN ALL THREE SKELETAL PATTERNS

OBJECTIVES: To compare the different smile variables amongst patients with varying vertical skeletal patterns, and to find whether there is a correlation between the dynamic contributing factors and the vertical smile parameters. METHODS: This cross-sectional study was conducted at department of Orthodontics, Nishtar Institute of Dentistry, Multan, Pakistan from 01-10-2020 to 01-04-2021. The posed smiles of 120 participants, aging 15-25 years, having well-aligned dental arches were videotaped for objective measurements and comparisons with their underlying vertical skeletal growth patterns. RESULTS: The evaluation of smile parameters showed a significantly decreased inter-labial gap in patients with skeletal low angle in males (8.92±3.6mm) and females (9.44±2.58 mm) [p<0.004]. Upper lip length was significantly decreased in low angle (16.23±1.59 mm) cases for males as compared to vertically high (18.57±1.47 mm) and normal angle (18.24±2.08 mm) cases. Inter commissural width was increased significantly in the low angle cases (63.39±8.14 mm) when compared with the high angle cases (58.24±5.44 mm) in females. Maximal Incisal Display was significantly increased in high angle cases (9.03±1.31 mm) p<0.001 as compared to the low angle cases (7.64±1.98 mm). A 65.8% (n=79) of the sample showed a flat smile arc with 26.7% (n=32) having consonant smiles while 7.5% (n=9) showed a reverse smile arc. CONCLUSION: Smile dynamics are influenced by underlying skeletal patterns. Individuals with skeletally high angles showed an increased incisal display and an increased upper lip elevation upon smiling. While the low angle patterns displayed a decreased inter-labial gap and majority showed a flat smile arc.