This study aims to determine whether giving a single dose of dexamethasone before surgery can reduce pain and difficulty in opening the mouth after removal of an impacted lower wisdom tooth. Pain and limited mouth opening are common problems after this procedure and can affect eating, speaking, and daily activities.

A total of 268 patients aged 18 to 55 years who require surgical removal of an impacted mandibular third molar will be included. Participants will be randomly assigned to one of two groups. One group will receive a 4 mg dexamethasone injection under the gum before surgery, while the other group will not receive this medication. All patients will undergo the same surgical procedure and receive standard postoperative care.

Pain will be measured using a visual analogue scale, and mouth opening will be assessed using a standard measuring method. These outcomes will be recorded on the second and seventh days after surgery.

The results of this study will help determine whether preoperative dexamethasone is an effective and simple method to reduce postoperative discomfort and improve recovery after third molar surgery.

This randomized controlled trial is designed to evaluate the efficacy of a single preoperative 4 mg submucosal dexamethasone injection in reducing postoperative discomfort following surgical removal of impacted mandibular third molars. Postoperative discomfort is defined by two primary components: pain intensity and degree of trismus.

The study will be conducted at the Department of Oral and Maxillofacial Surgery, MTI-Hayatabad Medical Complex, Peshawar, Pakistan. A total of 268 participants aged 18-55 years requiring surgical extraction of impacted mandibular third molars will be enrolled using non-probability consecutive sampling. Participants with systemic disease, pregnancy, lactation, recent use of antibiotics or anti-inflammatory drugs, or periodontal disease will be excluded.

Eligible participants will be randomly allocated into two equal groups (n=134 each) using a computer-generated randomization method. The intervention group will receive a single 4 mg submucosal injection of dexamethasone at the surgical site following administration of local anesthesia. The control group will undergo the same surgical procedure without administration of dexamethasone.

All procedures will be standardized, including surgical technique (Ward's incision, bone removal, and suturing) and postoperative analgesia (diclofenac 50 mg). No blinding will be performed due to the nature of the intervention.

Pain intensity will be assessed using a 10-cm visual analogue scale (VAS), while trismus will be evaluated by measuring maximum inter-incisal distance (in millimeters) using a vernier caliper. Measurements will be recorded preoperatively and on postoperative days 2 and 7.

Data will be analyzed using SPSS. Continuous variables will be assessed for normality using the Shapiro-Wilk test and expressed as mean ± standard deviation. Between-group comparisons will be performed using independent samples t-test or Mann-Whitney U test, as appropriate. Categorical variables will be expressed as frequencies and percentages and analyzed using chi-square or Fisher's exact test. A p-value ≤0.05 will be considered statistically significant.

This study is expected to provide evidence on the effectiveness of submucosal dexamethasone as a simple, cost-effective intervention to reduce postoperative morbidity following third molar surgery.

Inclusion Criteria:

• Adults aged 18 to 55 years
• Patients requiring surgical extraction of impacted mandibular third molars
• Patients willing to provide informed consent

Exclusion Criteria:

• Patients with systemic diseases
• Patients with periodontal disease
• Pregnant or lactating women
• Patients who have used antibiotics or anti-inflammatory drugs within the past 7 days
• Patients with known hypersensitivity to dexamethasone

The plan to share individual participant data has not been finalized at this stage. Data sharing will be considered following study completion and publication, subject to institutional policies, ethical considerations, and participant confidentiality safeguards.

This study is conducted as an open-label trial. No blinding is applied to participants, care providers, investigators, or outcome assessors due to the nature of the intervention (submucosal injection versus no intervention).