There are approximately 30,000 new cases of oral and pharyngeal carcinoma treated in the United States each year. A large number of these patients go on to receive segmental resection of the mandible, and have natural teeth remaining on the surgical side. To the best of our knowledge, there has not been a thorough discussion of the blood supply to these remaining teeth. Radiographic evidence of periapical pathology in these teeth is unusual, despite the compromised vascular supply. The purpose of this article is to report a case and review the literature on blood supply to teeth after segmental mandibulectomy. Microscopic examination was conducted on the pulpal tissue of a premolar retained on the side of, and anterior to, a segmental mandibular resection. Although abnormal, the pulp tissue showed evidence of a vascular supply 4 yr after mandibular surgery. A literature review was performed, and a discussion is given to explain the continued vascularity of the dentition through collateral and retrograde circulation. Despite the compromised dental circulation on the surgical side, unless radiographic evidence of periapical pathology occurs, endodontic therapy or extraction is not necessary. Due to the compromised nature of the circulation however, these teeth may be more susceptible to caries or restorative dental procedures that may lead to pulpal necrosis.