This study aimed to evaluate volumetric lip changes with hyaluronic acid (HA) by comparing pixel values between pre- and post-filling lip photographs. Thirty-two female patients, aged 35 to 66 years, were selected and received 1 mL of HA, which was applied to both the lower and upper lips. In the before-and-after photographs, the changes in pixel count resulting from the HA injection were quantified using GIMP, a reliable, widely used image analysis tool. Paired t-tests and ANOVA were applied. Our study revealed significant increases in the left upper lip (p = 2.73 × 10⁻⁷), right upper lip (p = 6.04 × 10⁻⁶), lower lip (p = 9.65 × 10⁻⁵), and total lip area (p = 0.0019). Younger patients showed greater volumetric gain. Our findings demonstrate that lip filling with 1 mL of HA is effective and measurable, as evidenced by photographs of patients' lips. Additionally, pixel analysis is a reliable clinical tool that provides valuable insights into the effectiveness of lip augmentation, supporting the validity of our results.
