Background and aim: Surgery of the third incisor molars leads to inflammatory reactions that cause pain, swelling and trismus. The aim of this study was to determine the effect of various factors before and during surgery such as age, sex and experience of the surgeon on the amount of trismus after latent third molar surgery. In this prospective study, 76 patients with different wisdom teeth occlusions in the maxilla or mandible participated. Preoperative and intraoperative factors were recorded in a checklist according to clinical examinations and radiography. The amount of trismus was assessed by maximal opening of the mouth in the area of central teeth before surgery and 48 hours after surgery. The obtained data were analyzed by SPSS software version 27 and paired t-test. The rate of mouth opening before surgery was at least 22 and at most 65 and the mean was 47.1 8 8.5 mm. 2 days after surgery, the maximum opening was at least 8 and at most 62 and the mean was 28.5 6 6.2 mm. none of the variables, except for root morphology, had a specific relationship with the rate of mouth opening. However, trismus was lower in patients who underwent surgery by specialists than in assistants. Most trismus was observed in cases performed by students. Trismus was more common in patients with joint disorders than in normal individuals. As a result, the rate of trismus was significantly higher in patients with third molars with distinct and subsequent roots.