Comparison of Botulinum Toxin and Orthognathic Surgery for Gummy Smile Correction

This study aimed to compare the changes in the gummy smile in cases treated with botulinum toxin (BTX) application or orthognathic surgery.

The retrospective sample comprised 61 subjects with gummy smile divided into 2 groups according to treatment received for gummy smile correction: 1-38 patients (6 male; 32 female), at a mean age of 28.60 years (s.d.=6.09), treated with BTX application; 2- 23 patients (7 males and 16 females) at a mean age of 29.59 years (s.d.=5.72) treated with orthognathic surgery. Patients from the BTX group refused to undergo orthognathic surgery. The measurement of the gingival exposure was performed in extraoral photographs of the posed smile, before and after treatment, and it was defined as the difference between the stomion of the upper lip and the incisal edge of the maxillary central incisor minus the height of maxillary central incisor obtained in the patient's dental casts. The data were obtained before (T1) and after treatment (T2) and change of gingival exposure with treatment (T2-T1). Intergroup comparison of gummy smile was performed with independent t-tests.

The surgical group presented significantly greater correction of the gummy smile with treatment than the BTX group.

Gummy smile presented a greater improvement in patients treated with orthognathic surgery than with botulinum toxin application.