ENDODONTIC INVOLVEMENT OF A GEMINATED TOOTH WITH TALON CUSP: A RARE OCCURRENCE CLINICAL CASE STUDY TANU TEWARI, BDS, MDS AMBER ATHER, BDS, MDS HUNAIZA ATHER, BDS Introduction E nvironmental factors, along with genetics, play a substantial role in determining the morphology of the tooth. 1 Disturbances during the formative stage of the developing tooth can lead to malformed tooth structure. Gemination and talon cusp are two such anomalies taking origin during the morpho- differentiation stage of odontogenesis. Gemination, a developmental aberration of both ectoderm and mesoderm, is a partial cleavage of a single-tooth germ result- ing in one root with two partially or totally separated crowns. 2 It affects primary dentition more frequently than permanent denti- tion, with a prevalence of 1 percent and 0.1 percent, respectively, in the Caucasian population. 3 A multifactorial model comprising polygenic and environmental influences has been linked to the etiology of gemination. 3 The talon cusp is characterized by the presence of an acces- sory cusp-like structure projecting from the cingulum area of the anterior teeth in both the primary and permanent dentition. This aberrant structure is composed of normal enamel and dentin, and may contain varying extensions of pulp tissue. 3 The reported prevalence of talon cusp has a considerable variation, ranging from less than 1 percent to approximately 8 percent. 4 It is pro- posed that the talon cusp originates as a result of outward folding of inner enamel epithelial cells and transient focal hyperplasia of the peripheral cells of mesenchymal dental papilla. 5 The aim of this case report is to present an extremely rare finding of occurrence of talon cusp in a geminated maxillary cen- tral incisor with an inverted “Y”–shaped root canal system and its endodontic management. Case Report An 18-year-old female patient reported with a chief complaint of lingering pain in the upper front tooth for three days. Clinical ex- amination revealed a discolored groove on the labial surface (see Figure 1) and decay on the lingual aspect of the permanent max- illary right-central incisor. The decay was surrounded by a well- defined elevated ridge suggestive of talon cusp (see Figure 2). The tooth exhibited no tenderness on percussion, and a pulp vitality test elicited an exaggerated response. Radiographic examination of the tooth in question revealed a coronal radiolucency approxi- mating the pulp space. The coronal radiolucency was surrounded by a distinct radiopacity suggestive of remnant talon cusp. The intraoral periapical radiograph depicted an inverted Y–shaped root canal space with two separate canals joining to form a single canal at the junction of the middle and cervical third of the root (see Figure 3). Based on the clinical, radiographic, and pulp vi- tality findings, a diagnosis of irreversible pulpitis was made and endodontic treatment was carried out (see Figures 4a and 4b). Figure 1. Discolored groove on labial surface of right maxillary central incisor. Figure 2. Caries on the lingual surface of right maxillary central incisor surrounded by well-defined elevated ridge suggestive of remnant of talon cusp (indicated by arrow). 46 Journal of the Massachusetts Dental Society