developmental dental disorders may be due to abnormalities in the differentiation of dental lamina and the hard tissues . the presence of two roots , two root canals and two crowns in maxillary anterior dentition have been documented in the literature . this results in a structure with two completely or incompletely separated crowns with a single root and root canal . the etiology is unknown , but trauma has been suggested as a possible cause , though a familial tendency has also been suggested . gemination is observed in deciduous as well as permanent dentition . in the primary dentition , a survey of the literature has revealed prevalence estimates for bilateral double teeth ranging from 0.01% to 0.04% in the primary and 0.05% in the permanent dentition . in the anterior region several treatment methods have been described in the literature with respect to different types and morphological variations of geminated teeth , including endodontic restoration , surgical , periodontal and orthodontic treatment . in the clinical situation , cases of fusion have the appearance of congenitally missing tooth while in gemination , the number of teeth in the dentition is normal , provided the double teeth is counted as one unit . isolated large or double teeth may be the result of union of two adjacent tooth buds or partial splitting of one into two . gemination has a bifid crown and usually a common root and root canal , on the other hand fusion is a union of two teeth , normally with separated tooth buds leading to the formation of a joined tooth with the confluence of dentine . it has been stated by few authors that fusion results when two tooth germ develops so close together that , as they grow , they come into contact and fuse before calcification . other researchers believe that physical pressure of force generated during growth causes contact between adjacent tooth germs . this paper reports a case of gemination of lateral incisor which was endodontically treated and esthetically rehabilitated with all ceramic crowns . cone beam computed tomography ( cbct ) was used to enhance the radiographic details of the root canal . the present case report is about a 15-year - old male patient who reported to the post graduate clinic of the department of conservative dentistry and endodontics with the chief complaint of esthetic problem in the upper front teeth . clinically , there were two crowns in the right lateral incisor with one crown in buccal relation to the other . thermal testing ( heated gutta - percha and dry ice ) and electric pulp testing ( parkel electronics division , farmingdale , ny ) showed a vital response . pre - operative radiographs revealed two separate roots and root canals with joining of the canals in the apical level [ figure 1 ] . counting the number of teeth a diagnosis of gemination intra oral periapical showing two root and root canals with joining of the canals in the apical level local anesthesia was induced using 1.8 ml 2% lidocaine with 1:200,000 epinephrines ( xylocaine ; astrazeneca pharma . bangalore , india ) . a rubber dam was placed and a conventional endodontic access opening was established with an endo access bur and an endo z bur ( dentsply tulsa , tulsa , ok ) . coronal enlargement was performed with a nickel - titanium protaper sx rotary file ( dentsply maillefer , ballaigues , switzerland ) to improve the straight - line access . root canals were explored with international organization for standardization # 15 k - files into both the canal orifices . hence we planned for a cbct after temporizing the tooth with calcium hydroxide and temporary endodontic restorative material . informed consent was obtained from the patient and a cbct scan was performed with a cbct scanner ( kodak 9500 cone beam 3d system , carestream health inc . , rochester , ny , usa ) at a tube voltage of 60 kvp , tube current of 5 ma , 0.076 mm voxel resolution and the field of view of diameter 50 ( limited cbct ) . all protective measures were taken to protect the patient from radiation according to as low as reasonably achievable guidelines . axial images were transmitted to a commercially available dental program ( kodak dental imaging software 3d module v 2.4 ) to reformat panoramic and cross - sectional images in all three planes . axial slices of the maxilla of 200-mm thickness were obtained at different levels to determine the root canal morphology . the cross sectional cbct images showed two canals fusing into one at the apical region [ figure 3 ] . this was further confirmed with axial view images [ figures 4 and 5 ] . at the next appointment after 1 week , after administering 1.8 ml 2% lidocaine with 1:200,000 epinephrine , the working lengths were determined with the help of an apex locator ( root zx ; morita , tokyo , japan ) under rubber dam isolation . cleaning and shaping were performed using protaper nickel - titanium rotary instruments ( dentsply maillefer ) with a crown - down technique . during root canal preparation , irrigation was performed using normal saline , 2.5% sodium hypochlorite solution and 17% ethylenediaminetetraacetic acid . the canals were dried with absorbent points ( dentsply maillefer ) and obturation was performed using cold lateral compaction of gutta - percha ( dentsply maillefer ) and ah plus resin sealer ( maillefer dentsply , konstanz , germany ) . a final radiograph was taken to establish the quality of the obturation [ figure 6 ] . after completion of root canal treatment , the tooth was restored with a posterior composite filling ( z100 ; 3 m espe dental products , st paul , mn ) . crown preparation was done in the same appointment and an all ceramic crown was placed . root canals were explored with international organization for standardization # 15 k - files into both the canal orifices the cross sectional cone beam computed tomography images showed two canals fusing into one at the apical region axial cone beam computed tomography image at the cement enamel junction showing two coronal openings axial cone beam computed tomography image 5 mm from apical region showing single apical opening post obturation photograph the terminology dental fusion and gemination are used to define two different morphological dental anomalies , characterized by the formation of a clinically wide tooth . the main periodontal complication in gemination cases occurs due to the presence of fissures or grooves in the union between the teeth involved . if these defects are very deep and extend sub gingivally , the possibility of plaque accumulation in these area is quite high . furthermore , gemination , may have an adverse effect on occlusion , causing deviation and sometimes delaying the eruption of other teeth with esthetic problems . in this case , despite the buccal groove in the maxillary lateral incisor , no serious periodontal breakdown was evident . clinically , it may be difficult to differentiate between fusion and gemination when a supernumerary tooth is fused with a permanent tooth . a full complement of teeth indicates gemination , whilst one tooth less than normal indicates fusion . generally geminated teeth have a single large pulp chamber and a root canal , as in the present case , tomazinho et al . in their study have reported a geminated tooth with a single large pulp chamber and a mesial and distal root canals that were joined at the apical third . a prerequisite for endodontic treatment of anomalous teeth is a careful examination of radiographs from various angles . the amount of information gained from conventional film is limited by the fact that the 3d anatomy of the area being radiographed is compressed into a two dimensional image . as a result of superimposition , in addition , there may also be geometrical distortion of the anatomic structures being imaged . in this case , the root canal morphology was confirmed with the help of cbct . complex internal anatomy has stressed the importance of root canal morphology before starting endodontic treatment . cbct images provide a better understanding of root canal anatomy , enabling the clinician to investigate the root canal system and to clean , shape and to obturate more efficiently . recent imaging tools like spiral computed tomography and cbct have emerged as valuable tools in the field of endodontics due to its accuracy , reliability and 3d imaging capabilities . in cbct , a cone shaped beam rotates 360 around the patient to obtain a volume and capture the image in the form of three - dimensional isotropic voxels . these multiple voxels are further combined with the help of viewing software and a 3d image is reconstructed . its use in endodontics include identifying dental anatomic variations such as additional roots or canals , fused roots , identification of horizontal / vertical fracture line in the tooth root , management of internal and external resorptive defects and identification of the configuration of inferior alveolar canal . detailed analysis of the 3d reconstruction image at the cervical , middle and apical regions of the root helped to know internal anatomy precisely . in this case , intraoral periapical intra oral - radiograph showed two separate canals , but after biomechanical preparation the canals seemed to join at the apical third of the root . primary complaint of gemination is esthetics , so such cases should be treated with high patient satisfaction . this paper demonstrates a predictable and successful solution toward the endodontic management of a geminated maxillary lateral incisor . although cbct is a valuable adjunct which aids in diagnosis and treatment planning , conventional intraoral periapical radiographs still continue to be used in routine clinical practice due to accessibility , financial and dose considerations .
geminated teeth are consequences of developmental anomalies leading to joined elements , due to incomplete attempt of one tooth germ to divide into two . 
 this case report describes successful endodontic treatment of an unaesthetic geminated permanent maxillary lateral incisor tooth and its esthetic rehabilitation using all ceramic crowns . 
 newer imaging technique like cone beam computed tomography was taken for the better understanding of the complicated root canal morphology .