Assessment of Root and Root Canal Shapes of Supernumerary Teeth in Maxillary Incisor Region Using Cone-Beam Computed Tomography

Supernumerary teeth are most commonly located in the maxillary incisor region. Recently, their directions and crown shapes were observed in detail using cone-beam computed tomography (CBCT), and their sizes were measured. Here, the root shapes and courses of the root canal of supernumerary teeth in the maxillary incisor region were assessed using CBCT. A total of 126 supernumerary teeth were assessed. The root shape, root curvature, and root canal deformity were evaluated. Also, delayed eruption of the permanent incisor and a median diastema were evaluated as complications caused by supernumerary teeth. The bifurcated-root type was noted in only 4.0%. Root curvature was observed in 27.4%, and root canal deformity was observed in 12.4%. Significant differences in root lengths were noted in root curvature and root canal deformity. Delayed eruption was observed in 12.9%, and a median diastema was observed in 25.04/0. In conclusion, the root shapes and courses of the root canal of supernumerary teeth in the maxillary incisor region could be observed in detail using CBCT. The bifurcated-root type was rare. Root curvature was frequent in the inverted and horizontal types. Root canal deformity was frequent in the inverted type.