The inferior alveolar nerve (IAN) is one of the branches of the mandibular division of the trigeminal nerve and innervates the mandible, mandibular teeth, gingiva of inferior alveolus, and lower lip. IAN dysfunction can occur during many dental surgical procedures and is associated with pathologic findings such as mandibular fractures, benign and malignant tumors, and osteomyelitis. We treated two patients with IAN injuries, caused by periapical and pericoronal lesions, by decompression via extraction and medication, and confirmed quantitative improvement. The aim of this article report was to review rare cases of successful treatment of IAN dysfunction following periapical and pericoronal lesions.