Background: Gummy smile (GS) is an aesthetic disorder for some patients, which can be corrected by injection of botulinum toxin. In this study was to collect information about the responses of the muscles to the same dose Botulinum Toxin-A (Botox; Allergan Inc, Westport, Ireland) and to assess whether there is a correlation between the amount of the upper lip drop and the amount of gum displayed during smiling.
Methods: This study was performed on 8 female patients with GS due to different etiologies. All of the patient injections were made in the middle of the triangle formed by LLS, LLSAN, and Zmi bilaterally with a dose of BTX-A of 2.5 U. 8 patients (8 women) underwent pretreatment photographs and measurements, followed by bilateral injection of 2.5 U BTX-A into their lip elevator muscles. BTX-A injections to reduce excessive gingival display. Gingival display was described as the difference between the lower margin of the upper lip and the superior margin of the left or right incisor. Before injections patients when full smile, the average GD ranged from 3 to 7 mm. Injections of BTX-A into the associated muscles of the upper lip reduce the upward movement of the lip and cause the lip to drop, thus, resulting in a less gummy smile. The lip drop amount was calculated the apparent length of the central crown height was extracted from the total height by using after photos.
Results: There was a decrease in the degree of gum display in all patients. The general average of gingival display before treatment was measured 4.62 ± 1.17 mm. The mean of lip drope was measured 5.17 ± 0.88 mm after two weeks from injection. A statistically significant correlation was found between the amount of the pre-treatment gingival display during maximum smiling and the amount of lip drop.
Conclusion: The use of botulinum toxin is much less invasive, and the development of complications is less frequent with quite satisfactory results for patients compared to the other methods used in the treatment of GS. The authors conclude that in the cosmetic correction of GS, the amount of the mean lip-drop is 5-6 mm and there is a positive correlation between the lip-drop and pretreatment gingival display.
Devrim Deniz-Üner and Bozan Serhat-├â┬â├ó┬Ç┬×├â┬é├é┬░zol