The aim of this study was to evaluate the efficacy of dexamethasone, as a single 4-mg dose, which was injected into the masseter muscle upon completion of extraction of impacted lower third molars . this study is A prospective, randomized controlled study . This study involves 40 healthy patients of both sexes with impacted mandibular third molars in this study . The difficulty of extraction was similar in all cases. The test side received 4 mg of dexamethasone This dose was injected into the masseter muscle via the intrabuccal approach, immediately after suturing of the surgical wound. The control side received 4 mg of dexamethasone injected into the gluteal area.