Background: Altered passive eruption (APE) is a clinical condition characterized by insufficient apical migration of the gingival margin, resulting in a gummy smile and short clinical crowns without pathological findings. The condition can be treated using various surgical approaches, including gingivectomy, apically repositioned flap, osseous recontouring, or a combination of these. The surgical procedure of choice depends on the APE type and subtype, as described by Coslet et al. The aim of this study was to compare two commonly used esthetic crown lengthening techniques—non-staged (submarginal incision) and staged (flap reposition)—in patients with APE, focusing on long-term gingival margin stability. Materials and Methods: A retrospective data review was conducted on six APE patients, divided into two groups: submarginal incisions (non-staged) and flap reposition (staged), with three patients in each group. Preoperative assessments included cone beam computed tomography (CBCT), intra-oral scanning, and photographs. A mock-up procedure was performed using CBCT and intra-oral scans to simulate the expected outcome. After surgery, intra-oral scans were taken at 3 and 6 months, and gingival margin positions were compared with baseline measurements. Descriptive statistics, t-tests, and Wilcoxon signed-rank tests were used for statistical analysis. Results: Analysis of the data showed that both techniques demonstrated similar gingival margin stability at the 6-month follow-up. However, the flap reposition technique exhibited more significant changes in gingival margin position during the first 3 months and required fewer corrective procedures, alongside a wider band of keratinized tissue relative to the one-stage approach. These findings were statistically significant at the 3-month follow-up, but no significant difference was found at the 6-month mark. Conclusions: Advanced imaging, such as CBCT, played a critical role in pre-surgical planning, particularly in identifying the cementoenamel junction (CEJ) and guiding the surgical approach. Both techniques are viable for esthetic crown lengthening in APE patients, but the flap reposition approach may offer better gingival stability and fewer post-operative complications. Further studies with larger sample sizes and long-term follow-ups are necessary to confirm these findings and refine clinical decision-making for APE management.