cone beam international magazine of cone beam dentistry

36 I I case report _ CBCT in endodontics _Abstract The aim of this article is to report a rare anatomic case and the contribution of new technologies in bestresolvingit.Fusionisdefinedastheunionoftwo separate tooth germs at any stage of tooth develop- ment. Planning treatment for this condition can be difficult and requires all diagnostic means available. A45-year-oldfemalepatientpresentingwithafused secondandthirdmolarunderwentendodontictreat- ment and direct restoration after CBCT imaging re- vealed a direct relationship between the two germs. The treatment was successful once the correct diag- nosis had been made. _Introduction Fusion is defined as the union of two separate tooth germs at any stage of tooth development. Fused elements may be attached at the dentine or enamel. This process involves the epithelial and mes- enchymal germ layers, and results in irregular tooth morphology.1 Depending on the stage of develop- ment in which the fusion occurs, pulp chambers and canals may be linked or separated. The reason for this phenomenon is unknown, but geneticfactors,physicalforces,pressure,andtrauma may be influencing factors.2 The prevalence of dental fusion is higher in primary dentition (0.5–2.5%) than in permanent dentition (0.1%); in both cases, the anterior region has the highest prevalence.3 The inci- dence is the same between males and females. Cases of affected posterior teeth are rare in the literature. Most posterior teeth are fused with fourth molars (supernumerary). Fusion between premolars and molars or second and third molars has also been reported, but is less common. In some reported cases, teeth are bilaterally fused with supernumerary molars.4–9 In these cases, the number of teeth in the dental arch is also normal and differentiation from gemination is clinically difficult or impossible. A di- Fig. 1_Initial clinical situation. Observe the plaque in the lingual side in the fusion area and discoloration due to caries. Fig. 2_Initial X-ray situation. CBCTin endodontic treatment of fused second and third mandibular molars Authors_ Dr Andreas Krokidis, Greece, & Dr Riccardo Tonini, Italy cone beam1_2014 Fig. 3_Reconstruction. Fig. 1 Fig. 2 Fig. 3 CBE0114_36-40_Krokidis 31.01.14 15:53 Seite 1