a quick, non-surgical cosmetic procedure that uses a few units of botulinum toxin (such as Botox or Dysport) injected into the upper lip muscle to relax it. This causes the lip to "flip" slightly upward and outward, creating a fuller, more defined, and youthful appearance without adding volume. It is often used to treat "gummy smiles" or to make thin lips appear larger, with results lasting about 3 to 4 months.