Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 2 1-2 2015 10 13 91 94 EN Farnoosh Mohammadi Craniomaxillofacial Research Center, Shariati Hospital and Department of Oral and Maxillofacial Surgery, Dental School, Tehran University of Medical Sciences, Tehran, Iran Mahboube Hasheminasab Craniomaxillofacial Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Asadollah Asgarian Oral and Maxillofacial Surgeon, Private Practice Alireza Zahedanaraki Dentist, Private Practice 2015 10 12 2015 10 12 Introduction: Our study was designed to assess the effect of the submucosal injection of dexamethasone on postoperative discomfort after surgical removal of impacted mandibular third molars. Materials and methods: Twenty six patients with bilaterally bony impacted mandibular third molars were recruited to this split mouth study. On the study side, prior to surgery, 8 mg of dexamethasone was injected in buccal vestibule submucosally, while the control side received no steroid. Complications such as swelling, trismus and infection were evaluated postoperatively. Results: The results showed that the patients experienced significantly less swelling  (p=  0.001)  on  study  side  on  the  3rd   and  7th   postoperative  days compared to the control side. The amount of trismus was significantly less (p=0.001) after submucosal injection of dexamethasone on both time intervals. Conclusion: Perioperative submucosal injection of dexamethasone can significantly reduce postoperative swelling and trismus after surgical removal of the impacted teeth. https://jcr.tums.ac.ir/index.php/jcr/article/view/24 https://jcr.tums.ac.ir/index.php/jcr/article/download/24/69