Factors Associated with Postsurgical Pain and Swelling Following Endodontic Microsurgery: The Role of Radiographic Characteristics.

: Endodontic microsurgery has become an integral part of daily endodontic practice. However, research on the correlation between the lesion characteristics observed via cone beam computed tomography (CBCT) and pain and swelling after endodontic microsurgery (EMS) is still lacking in the literature. The present study aims to examine the relationship between the radiographic characteristics of preoperative periapical lesions obtained from CBCT images and post-surgical symptoms such as pain and swelling. : A total of 61 patients undergoing EMS utilizing modern techniques were asked to report their level of pain and swelling at 8, 24, 48, and 72 h after EMS using VAS. Independent variables such as age, gender, tooth location, CBCT periapical index, endodontic diagnosis, cortical bone perforation by the lesion, duration of the EMS, preoperative analgesic consumption, antibiotic prescription, and pre-/postoperative mouthwash were analyzed using the Fisher Exact test. Multivariate regression analysis was also conducted to determine the independent significant factors associated with pain and swelling. A -value of ≤0.05 was considered statistically significant. : The maximum pain score was recorded at 8 h (4.26 ± 3.13), while peak swelling was measured after 24 h (6.46 ± 2.87). The risk of swelling was more likely to decrease by 75.7% for patients with a CBCT index score of >3 than those with a CBCT index score of ≤3 (AOR = 0.243; CI = 0.071-0.831; = 0.024). The effects of all other factors on pain, including cortical bone perforation by the lesion ( = 0.290), swelling ( = 0.071), postoperative mouthwash use ( = 0.062), and swelling ( = 0.934), did not reach statistical significance. Patients with periapical lesions larger than 4 mm will likely experience less swelling after EMS, while pain is not affected by lesion size, cortical bone perforation, or mouthwash use. : This study identified a new predictor of swelling after EMS based on the size of the periapical lesion. These results will improve the management of post-surgical sequelae after EMS and support shared decision making.