[Effect of triangular flap design and healing procedure on the sequelae after extraction of impacted lower third molars].

Objective: To evaluate the effect of different triangular flap design and healing procedure on the sequelae after extraction of impacted lower third molars.
Methods: In this prospective, split-mouth study, 60 healthy patients with bilateral, symmetrically fully impacted lower third molars (LM3) were included, of whom 30 patients with totally bony impacted LM3 were allocated into group A, while the other patients with partially bony impacted LM3 were allocated into group B. All the teeth were extracted by the same surgeon. Triangular flap was used on one side, and the wound was primarily closed with two sutures (TF-P). On the other side, modified triangular flap was used with a triangular region of mucosa posterior to LM2 removed during operation, and a triangular soft tissue defect was left for drainage after suture (MTF-S). The patients were followed up on postoperative days 1, 3 and 7. Clinical parameters included postoperative pain, swelling, and trismus. Distal probing depth of adjacent second molar was assessed 6 months after extraction. Doctors responsible for the evaluation did not know the group and flap design. Paired sample t test was used to analyze the differences of postoperative sequelae between the two strategies.
Results: In group A, MTF-S strategy could reduce postoperative pain, ibuprofen consumption, and swelling significantly compared with TF-P strategy on the postoperative 1st and 3rd days (P<0.05). Besides, the trismus in the patients with TF-P strategy was more serious than that with MTF-S strategy on the postoperative 1st, 3rd and 7th days (P<0.05). However, statistic difference between the two strategies in pain, swelling and trismus was not detected in group B. Additionally, the VAS score in the patients with MTF-S strategy in group B increased slightly on the postoperative 4th day. The probing depth of the adjacent second molar was evaluated 6 months after extraction. Statistic difference was not detected between MTF-S strategy and TF-P strategy in the both groups.
Conclusion: Modified triangular flap with secondary healing procedure could effectively reduce the postoperative complications of totally bony impacted LM3. However, the difference between the two strategies in the probing depth of the adjacent second molar was not statically significant 6 months after extraction.