Radiographic evaluation of the classification of the extent of tooth resorption in dogs

Objective-To determine applicability of the 2007 American Veterinary Dental College (AVDC) classification method for determining extent of tooth resorption in dogs. Animals-224 dogs > 1 year old admitted for periodontal treatment or other dental procedures in 2007. Procedures Full-mouth radiographs of all dogs were reviewed for evidence of tooth resorption. Tooth resorption in dogs was classified in accordance with the radiographic criteria described for use in human teeth and, when applicable, the guidelines described in the 2007 AVDC classification method. Results-851 of 943 (90.2%) affected teeth met the radiographic characteristics of 1 of the 5 stages of tooth resorption described by the AVDC classification method. Among tooth resorption types described for human teeth, the AVDC classification method was totally applicable (100%) in 17 teeth with external surface resorption, 21 teeth with external replacement resorption, and 736 teeth with external cervical root surface resorption, but it was applicable in only 56 of 121 (46.3%) teeth with external inflammatory resorption and none of the teeth with internal resorption. Conclusions and Clinical Relevance-The AVDC classification method was useful to describe the extent of tooth resorption in dogs, but it did not reflect the radiographic patterns and location of lesions. The AVDC classification method was applicable in some, but not all, of the teeth with various resorption types in dogs. The AVDC classification method could be adapted best to lesions that have radiographic patterns of external replacement resorption and external cervical root surface resorption. (Am J Vet Res 2010;71:794-798)