The objective of this study is to enhance the importance of clinical anatomical knowledge of the structures that conform the anterior maxilla, particularly the sinuous canalis and its accessory branches, and how these structures are presented in complementary two- and three-dimensional imaging examinations such as periapical radiography and Cone Beam Computed Tomography (CBCT). A clinical case of superposition of an accessory branch of the canalis sinousus that simulates internal root resorption is presented. The meticulous analysis of each clinical case, together with the use of current imaging tools, allows us to establish accurate clinical diagnoses and avoid unnecessary treatments.