Paresthesia caused by damage of the inferior alveolar nerve and mental nerve as branches of the trige minal nerve is a common neurological damage in dentistry related to the extraction of mandibular third molar and implant placement. In America, the occurrence rate of paresthesia in the inferior alveolar nerve related to the extraction of mandibular third molar was 0.4~8.4%. In 2009, a domestic research reported a rate of 0.14~0.19%. For the impairment evaluation on the damage of the inferior alveolar nerve, McBride impairment evaluation is generally used. Written by Professor McBride in 1963, this standard was out of print after the 6th edition was published in 1963. Note, however, that medicine has developed drastically after the 1930s when McBride’s standard was established, yet the McBride standard does not refl ect such changes. The reasons are improvement of modern medicine, impairment evaluation and impairment treatment, development of new treatments, and absence of a revised edition for 50 years. In Korea, McBride’s standard has been used frequently to determine the rate of physical impairment. In addition to the McBride impairment J Korean Dent Sci. 2012;5(2):45-47 http://dx.doi.org/10.5856/JKDS.2012.5.2.45 ISSN 2005-4742