Effect of extraction of first four premolars on smile aesthetics.

The objective of the present study was to assess smile aesthetics after orthodontic treatment in subjects with and without the extraction of four first premolars. Post-treatment coloured frontal photographs (4 × 6 inches) of 60 Pakistani subjects, 21 males and 39 females, aged between 15 and 30 years were assessed by one examiner. For 50 per cent (n = 30) of the patients, treatment included the extraction of four first premolars, whereas the other half were treated without extractions. Smile aesthetics were evaluated by a panel of 10 laypersons, five males and five females, aged between 20 and 30 years. Smile aesthetic parameters were measured using seven variables, and the ratios were calculated. An independent sample t-test was used to assess smile aesthetics. All seven variables namely smile width, smile height, visible dentition width, maxillary intercanine width, visible maxillary first molars, visible mandibular teeth, visible maxillary gingival margin, and the ratios between the above mentioned variables showed no detrimental effects following extraction of four first premolars on smile aesthetics.