Effect of Surgical Removal of Impacted Third Molars on Trismus Value

Surgical extraction of impacted third molars is usually accompanied with inflammatory reactions which result in pain، swelling and trismus. The purpose of this study was to evaluate the effect of different pre-and- inter-surgical variables such as age، gender، temporomandibular disorders (TMD)، type of impaction، root morphology and experience of surgeon on the maximum mouth opening after surgical extraction of impacted third molars. In this prospective study we included seventy six patients with impacted lower or upper third molar in this study. Pre-and-per surgical variables were recorded through a questionnaire. Degree of trismus was evaluated through maximum interincisal mouth opening before and 48 hours after surgery. Data was analyzed using T-paired in SPSS. 15 software. The minimum and maximum interincisal openings before surgery were، respectively، 22 mm and 65 mm with an average of 47. 1 ± 8. 5 mm. Two days after operation، the maximum interincisal opening was 62 mm، and the minimum was 8 mm with an average of 28. 5 ± 6. 2 mm (p<0. 05). None of the variables except root morphology had any significant correlation with maximum interincisal opening. However trismus was lower in patients operated with professors (attendants) than postgraduate students (p>0. 05). In patients who were treated by postgraduate students was lower than that of undergraduate students (p>0. 05). Trismus was high in TMD patients. Trismus was significantly higher in patients who had third molars with separate and divergent roots.