Endodontic Treatment of Fused Teeth with Talon Cusp

Tooth anomalies are rare phenomena that may be reported by patients as chief complaints or may be discovered by dentists in the oral examination. In a few cases, rare anomalies are found together in one mouth. Decision to treat such anomalies depends on whether or not they interfere with function and esthetics and also the patient's preference. In the present case, a 19-year-old male presented with two right maxillary fused central and lateral incisors and a geminated left maxillary central incisor. A talon-like projection was found at the junction site of the fused teeth. His chief complaint was sensitivity to cold at the site of the giant fused tooth. This report describes the process of diagnosis and treatment of the two anomalies according to patient preference and needs. 1. Introduction Clinical tooth anomalies are deviations in normal appearance that may involve color, shape, size, or number of teeth and may be found in oral examination by a dentist [1]. In your clinical examinations, rarely, you may face a giant tooth with a large mesiodistal width. Commonly, this phenomenon is referred to as “double teeth.” In definition “double teeth” may occur as either gemination or fusion. Gemination and fusion are developmental anomalies with the prevalence rate of 0.1% and 0.5% in permanent and primary dentition, respectively. Gemination happens as a result of an unsuccessful attempt of tooth germ to divide which usually leads to a single root, root canal, and a large bifid crown with a common pulp chamber. Fusion is the union of hard tissue between two developing teeth. Fused teeth may share a common pulp chamber or have separate root canals and chambers. Fusion may occur between two normal adjacent teeth or a normal and a supernumerary tooth. In the latter case, differentiation between gemination and fusion is difficult, as a strong tool of differentiation (tooth count) is missed [2]. Another tooth anomaly in shape is called “talon cusp.” Talon cusp appears as a hard tissue projection usually rising from cementoenamel junction on the lingual surface and extending at least half the way to the incisal edge of anterior teeth. This projection may contain normal enamel, dentin, and varying amounts of pulp tissue. It mostly involves permanent maxillary lateral incisor with equal prevalence in both sexes. A wide range of less than 1% to 7.7% prevalence has been reported in different populations [3, 4]. Gemination, fusion, and talon cusp are rare developmental anomalies with unknown etiologies. Both genetic and environmental, local and systemic factors are