The study never started.

This is a two part study to measure and observe the efficacy of botulinum toxin A for the treatment of gummy smiles.

Part A will randomly compare three different doses of botulinum toxin type A (abobotulinumtoxin A) for the treatment of upper anterior gummy smile with larger gingival exposure (> 4 mm).

Part B will assign one of two doses of botulinum toxin type A for participants with smaller gingival exposure (< 4 mm).

Follow-up visits with photography will occur 4 and 12 weeks after their treatment. Subjects currently living in the Chicago metropolitan area and meet inclusion/exclusion criteria will be considered for enrollment.

This study is a pilot study designed to determine feasibility of this procedure.

Inclusion Criteria:

1. Written informed consent
2. Males or females ≥ 18 years old
3. Anterior gingival exposure during smiling larger than 4 mm measured from the central incisor tooth (part A), or 2-4 mm (part B).
4. Subjects of childbearing potential who present a negative urine pregnancy test at baseline and use an effective contraceptive method.
5. Subjects are in good health as judged by the investigator.
6. Subjects who are willing and have the ability to understand and provide informed consent for participation in the study and are able to communicate with the investigator.

Exclusion Criteria:

1. Pregnant women or women intending to become pregnant in the next 8 months after the screening for eligibility
2. Subjects participating in other clinical trials
3. Any prior surgery affecting the area of study
4. Subjects with neoplastic, muscular or neurological disease
5. Subjects who have received botulinum toxin treatment for gummy smile in the previous 12 months before the inclusion date
6. Subjects who have received Botulinum toxin treatment for any other cosmetic indication in the previous 6 months before the inclusion date
7. Subjects using aminoglycosides and penicillamine antibiotics, quinine or calcium channel blockers
8. Subjects with inflammation or active infection in the area to be injected
9. Subjects with history of sensitivity to the components of the formulation.
10. Uncooperative patients or patients with neurological disorders who are incapable of following directions or who are predictably unwilling to return for follow-up examinations.
11. Subjects who are unable to understand the protocol or give informed consent.