Lip repositioning surgeries are performed to treat patients with excessive GD (EGD). This study aimed to explore and compare the long-term clinical results and stability following the modified lip repositioning surgical technique (MLRS) with the addition of periosteal sutures compared to the conventional lip repositioning surgery (LipStaT®) in order to address EGD. A controlled clinical trial with female participants (n = 200) intended to improve their gummy smile were divided into control (n = 100) and test (n = 100) groups. The gingival display (GD), maxillary lip length at rest (MLLR), and maxillary lip length at maximum smile (MLLS) were measured at four time intervals (Baseline; 1 Month; 6 Months, and 1 Year) in millimeters (mm). Data were analyzed by t-tests, Bonferroni-test, and regression analysis using SPSS software. At the one-year follow-up, GD for the control and test groups were 3.77 + 1.76 mm and 2.48 + 0.86 mm, respectively, and their comparisons showed that GD was considerably lower (p = 0.000) in the test group compared to the control group. The MLLS measurements taken at baseline, one-month, six-month, and one-year follow-up showed no significant differences (p > 0.05) between the control and test groups. At baseline, one-month, and six-month follow-up, the mean and standard deviation for the MLLR were almost similar, with no statistically significant difference (p = 0.675). The MLRS is a successful and viable treatment option for the treatment of patients with EGD. The current study showed stable results and no recurrence with MLRS until the one-year follow-up compared to LipStaT®. With the MLRS, a 2 to 3 mm decline in EGD is usually to be expected.