The trigeminal nerve, one of the cranial nerves, innervates the maxillofacial area and has three branches: the ophthalmic, maxillary, and mandibular nerves. Paresthesia, due to damages to the inferior alveolar nerve and mental nerve (branches of the mandibular nerve), is quite frequent in dental implants and third molar extractions. As medical disputes are increasing, it is necessary to formulate an objective and reasonable disability evaluation. When evaluating the frequent rate of impairment for inferior alveolar nerve damage, it may be reasonable to follow the criteria for the rate of maxillofacial impairment of the American Association of Oral and Maxillofacial Surgeons (AAOMS) - the most scientific and reputable criteria based on the American Medical Association (AMA). Therefore, the Committee of Guides for Maxillofacial Impairment Ratings, in the Korean Association of Oral and Maxillofacial Surgeons (KAOMS), is trying to suggest more reasonable and realistic guidelines for evaluating impairments by reviewing the current evaluation criteria and those of AMA and AAOMS.