Comparative Analysis of Envelope and Triangular Flap Designs in Reducing Postoperative Sequelae Following Mandibular...

Surgical removal of impacted mandibular third molars often results in postoperative complications, such as pain, swelling, trismus, and periodontal changes, which can affect patient recovery. The choice of the flap design may influence these outcomes. This study compared the envelope flap and triangular flap with the modified Ward's incision to minimize postoperative sequelae, focusing on pain, facial swelling, maximum mouth opening, and probing pocket depth, and to provide evidence-based insights for optimizing surgical outcomes in third molar disimpaction.

A prospective comparative study was conducted at the Department of Oral and Maxillofacial Surgery, involving 40 systemically healthy patients (American Society of Anesthesiologists or ASA I or II) aged 18-50 years with mesioangular, distoangular, or vertically impacted mandibular third molars. Patients were assigned to two groups (n=20 each): Group 1 (triangular flap with modified Ward's incision) and Group 2 (envelope flap). Standardized surgical protocols were followed, with local anesthesia and primary closure using 3-0 silk sutures. Postoperative outcomes such as pain (visual analog scale), maximum mouth opening (interincisal distance), facial swelling (metric facial measurements), and probing pocket depth were assessed on days 1, 3, and 7 and at 3 months. Data were analyzed using independent t-tests and repeated-measures analysis of variance with a significance threshold of p≤0.05.

Both groups showed significant improvements in all parameters over time (p<0.001). The envelope flap group had less facial swelling (117.68±6.27 mm on day 1, further reduced by day 7) than the triangular flap group (119.80±5.29 mm on day 1, increased on days 3 and 7). Maximum mouth opening improved faster in the envelope group (21.50±4.47 mm on day 1, significant by day 3) than the triangular group (22.70±5.27 mm on day 1). Pain decreased similarly, from 7.90±0.85 (envelope) and 7.80±0.83 (triangular) to 1.25±0.91 and 1.80±0.83 by day 7, with no notable differences. The probing pocket depth increased temporarily (mean difference = 1.47 mm, p<0.001) but equalized by 3 months (p=0.157). The simpler design of the envelope flap likely reduced tissue trauma and inflammation, enhancing swelling and trismus outcomes.

The envelope flap outperformed the triangular flap in reducing postoperative swelling and enhancing early mouth opening recovery, making it preferable for routine mandibular third molar extractions. Both techniques ensured comparable pain control and periodontal healing, supporting their use based on case-specific requirements.