This study evaluated long-term clinical and patient satisfaction outcomes following a modified lip repositioning technique that utilized periosteal sutures in a twin population. Twin sisters diagnosed with maxillary lip hypermobility were randomly assigned to either the control group (original LipStaT technique) or test group (addition of periosteal sutures). The participants (n = 12; 6 per group) were evaluated at intervals for up to 3 years postoperative. Clinical measurements, digital images, and patient satisfaction surveys were collected. Descriptive statistics were used to assess outcome variables: average lip width at rest (ALW), vertical lip translation (VLT), and average gingival display (AGD). Student t test, one-way analysis of variance, and Spearman rank correlation tests were used to compare mean values of variables at five time points for both groups. The level of significance was α = .05. In the control group, mean VLT and AGD values showed statistically significant decreases from baseline (14.8 mm and 7.0 mm, respectively) to 2 years (5.7 mm and 2.4 mm, respectively), but a slight increase was seen at 3 years (7.5 mm and 5.0 mm, respectively; P < .0001). In the test group, mean VLT and AGD values showed statistically significant decreases from baseline (14.8 mm and 6.9 mm, respectively) to 3 years (5.5 mm and 3.5 mm, respectively; P < .0001). A higher participant satisfaction score at 3-year follow-up was observed in the test group. The modified lip repositioning technique in a population of twins resulted in more stable outcomes that lasted up to 3 years postoperatively.