Tooth relapse following orthodontic treatment remains difficult to predict and prevent. This study compared the effectiveness of an upper Hawley retainer and a fixed maxillary lingual retainer in maintaining anterior tooth alignment and evaluated associated periodontal outcomes. A retrospective chart review identified 50 subjects with comparable initial irregularity and retention duration. Post‑treatment models, photographs, and periodontal measurements were analyzed. Fixed retainers demonstrated significantly less relapse than Hawley retainers. Although greater bleeding on probing was observed in the bonded group, no differences were found in probing depths, recession, or periodontal disease indicators. Fixed maxillary retainers appear effective for long‑term incisor alignment without compromising periodontal health.
