The radiographic image depicts a supernumerary root of the left mandibular second molar tooth of a dog. This dog is also missing the left mandibular third molar tooth. In a normal dentition, there should be no three-rooted teeth observed in the mandible. While a supernumerary root can be present, diagnostic imaging of the tooth is frequently the only way to identify whether additional or fused roots are present. Frequently, supernumerary roots are found associated with the furcation area of a tooth.