Assessment of mini-aesthetics in Class I malocclusion subjects who underwent orthodontic treatment with or without extraction of four premolars – A prospective study

Smile and facial attractiveness are strongly correlatedThis study aimed to assess the effect of extraction or non-extraction orthodontic treatment on mini-aesthetics in patients with Class I malocclusion by measurement of the smile variables. A total of 56 subjects were selected and grouped as Group 1- treated non-extraction, Group 2A-treated with extraction of first premolars and groups 2B- treated with extraction of second premolar teeth. Each subject was photographed with a posed smile and NHP using DSLR camera. The images were then imported into a computer software and the following smile parameters were assessed: gingival display, smile index, maxillary incisor display on smile and buccal corridor ratio. The mean measured maxillary incisor display was 1.39±0.34, 2.31±0.50 and 0.90±0.19mm in Group 1, Group 2A and Group 2B. The mean measured gingival display on smiling was 0.07±0.07, 0.38±0.65 and 0.07±0.15mm in Group 1, Group 2A and Group 2B. The mean measured smile index was 0.15±0.68, 1.20±0.22 and 0.95±0.41 in Group 1, Group 2A and Group 2B. The mean measured buccal corridor ratio was 0.83±0.39, 1.59±0.26 and 1.26±0.31 in Group 1, Group 2A and Group 2B. There was an increase in maxillary incisor display after fixed Orthodontic treatment in the non-extraction group and a decrease in first premolar extraction group while second premolar extraction group showed no changes. Smile index was increased post-treatment in first premolar and second premolar extraction group while non-extraction group showed no significant difference. Buccal corridor ratio decreased in first premolar and second premolar extraction groups while non-extraction group showed no changes.