Thirty-eight patients were randomly divided into 2 groups; the intraosseous injection group of dexamethasone (4 mg) and the submucosal injection group. All surgeries were performed by one surgeon.

Postoperative pain was evaluated by visual analog scale score immediately after surgery and on postoperative days 1, 3, and 7.

Swelling (determined using two linear measurements) were assessed just before the surgery and on postoperative days 1, 3, and 7 by using a digital vernier caliper.

Early healing of periodontal soft tissue wound was assessed by using Early Wound Healing Score (EHS) which composed of 3 parameters: clinical signs of re-epithelization (CSR), clinical signs of hemostasis (CSH), and clinical signs of inflammation (CSI) and were assessed on postoperative days 1, 7, and 14. Mouth opening (determined by measurement of the maximum inter-incisal distance) were assessed just before the surgery and on postoperative days 1, 3, and 7 by using a digital vernier caliper.

Inclusion criteria

• Patient complaining of impacted mandibular third molar mesioangular or horizontal, according to the Pell and Gregory classification 1933)
• Healthy patient (American society of anesthesiologists class I status)
• Patient age range from 18 to 40 years old.
• Patient without any local inflammation or pathology.
• Patient who will able to understand verbal and written instructions.

Exclusion criteria

• Pregnant or breast-feeding women.
• Patient had anti-inflammatory drugs within 2 weeks before the procedure.
• Patient under radiotherapy or chemotherapy.
• Habits (heavy smoking and alcoholic).
• Allergy to drugs used in this study.
• Patient under anticoagulant or corticosteroid therapy.