The purpose of this prospective, randomized, controlled, single-blind clinical trial is to compare the efficacy of local submucosal administration of dexamethasone versus methylprednisolone on postoperative morbidity following impacted lower third molar surgery. The study evaluates postoperative pain using the Visual Analog Scale (VAS) and quantifies three-dimensional facial edema using a mobile smartphone-based scanning workflow (Qlone aligned in CloudCompare). Patients requiring unilateral extraction of fully bone-impacted mandibular third molars are randomly allocated into three parallel groups: Control (no injection), Methylprednisolone (40 mg), and Dexamethasone (8 mg).