0099-2399/91/1704-0179/$03.00/0 JOURNAL OF ENDOOONTICS Copyright 9 1991 by The American Association of Endodontists
Printed in U.S.A.
VOL. 17, NO. 4, APRIL 1991
Treatment Considerations in a Geminated Maxillary Lateral Incisor Marston Wong, DDS, MS
incisor to have an unusual clinical crown. The clinical diagnosis of gemination or fusion associated with tooth 7 was obvious. A large carious lesion involving the facial and distal aspect of the crown was present (Fig. 1). The patient had additional multiple carious lesions throughout his dentition as well as generalized type 1 periodontitis and localized type 3 periodontitis involving the mandibular incisors. Tooth 7 was symptomatic, with spontaneous, continuous pain, and was percussion sensitive. Tooth 6 responded to the percussion test within normal limits. Palpation tests revealed teeth 6, 7, and 8 to respond within normal limits. The ice test resulted in an increase in severity of symptoms only when placed on tooth 7. A radiographic examination revealed tooth 7 to have one broad root with an image of a single broad root canal. No periapical radiolucency was associated with the tooth (Fig. 2). A diagnosis was made of irreversible pulpitis secondary to caries of 7. Tooth 7 was also diagnosed as being geminated. Due to the patient's apprehension, a relaxation technique was demonstrated to the patient before any dental manipulation. The tooth was anesthetized with 1.5 ml of 2% Xylocaine with 1:100,000 epinephrine. All caries was excavated revealing a pulp exposure: a zinc oxide-eugenol temporary filling was placed over the facial and distal aspect of the crown. Access openings were made on the lingual surface revealing two apparently separate pulp chambers and root canals. The canals were initially instrumented using 5.4% sodium hypochlorite irrigation (Fig. 3), dried with paper points, and cotton pellets and temporary fillings were placed over the access openings. At the second appointment final instrumentation of both canals to a #40 file was performed. Master gutta-percha points were fitted and placed into the canals with a zinc oxideeugenol sealer. Lateral condensation with accessory points was used to obturate the canals. The lingual access openings were sealed with temporary fillings. A final radiograph was taken (Fig. 4). The patient was directed to the referring dentist for follow-up dental treatment. At the 1-yr recall visit, a clinical examination revealed that the patient had not seen a dentist since completion of the root canal treatment on tooth 7. The tooth was asymptomatic and all clinical findings were within normal limits. Consultation with the fixed prosthodontist was made and a recommendation of a post and resin restoration was advised. The patient was counseled on the over-all condition of his dentition and the need for follow-up care. The relaxation technique was reviewed with the patient and the patient appointed for a dental prophylaxis and restoration of teeth 6 and 7. The
A patient with an anomalous maxillary lateral incisor was referred for endodontic therapy. A diagnosis of irreversible pulpitis of a geminated maxillary lateral incisor was made. The preoperative radiograph revealed an image of a single root canal but in fact the tooth had two separate and distinct root canals. Treatment considerations of this anomaly are discussed.
Gemination may be defined as the attempt of a single tooth bud to divide, resulting in two identical crowns joined in a midline to align in a mirror-image effect. Radiographically the root may appear to have one canal (1). When the bifid crown is counted as one tooth, the normal number of teeth are present (2). Fusion is a condition where two separate tooth buds unite at some stage in their development to form a bifid crown (3). Radiographically, two root canals and one or two roots may be evident (1). When the bifid crown is counted as one tooth, the adjacent tooth appears to be congenitally missing (2). The clinical appearance may be of nonidentical crowns joined at the midline (1). In the case of fusion between a normal tooth and a supernumerary tooth, differentiation from the condition of gemination may be difficult or impossible (4). Radiographic studies may be of aid in the diagnosis (3). Few articles (5-8) have been written regarding the endodontic treatment of the geminated or fused tooth. The morphological variations of the root canals associated with these anomalies have required a variety of approaches to treatment. The following is a case report of an endodontically involved geminated maxillary lateral incisor which presented with a radiographic image of having one canal but in fact had two. CASE R E P O R T A 26-yr-old white male was referred for evaluation of an upper right maxillary incisor. The patient's chief complaint was that the tooth had been continuously hurting for the past 3 days. The patient stated that cold drinks made it hurt worse. The patient also stated that he was extremely apprehensive of all dental procedures and avoided the dentist if at all possible. The patient's medical history was noncontributory. Clinical examination revealed the right maxillary lateral
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FIG 1. Preoperative clinical photograph of tooth 7.
FIG 3. Length determination radiograph.
FIG 2. Preoperative radiograph of tooth 7.
patient followed through with his subsequent appointments. Figure 5 shows a radiograph of the final restoration and Fig. 6 shows a clinical photograph of tooth 7. DISCUSSION At times the diagnosis of gemination versus fusion cannot be conclusively established. In this case report, tooth 7 presented with an initial radiographic appearance of having only one root and one root canal. Only upon preparing access openings were two separate root canals observed; a radiograph of the final root canal filling suggests that the root canals were
FPG4. Radiograph of final root canal filling.
Vol. 17, No. 4, April, 1991
FIG 5. Radiograph of tooth 7: 1-yr recall.
Gemination of a Maxillary Incisor
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the final root canal fillings. In the present case report, no radiographic evidence of communication between the two root canals was observed (Fig. 4). Although two separate root canals lend more support to the diagnosis of fusion, the diagnosis of gemination was made for the following reasons: (a) the crowns appeared as two identical crowns joined at the midline resulting in a mirror-image effect; (b) the tooth had only one root; (c) there were no teeth missing in the maxilla; and (d) presupposition of the existence of a supernumerary tooth was not required for the diagnosis. In previous endodontic case reports (5-8), the teeth involved were either nonvital or had a previously inadequate root canal filling in place. Root canal treatment or retreatment was a foregone conclusion. In this case the tooth had some degree of vitality and the symptoms were indicative of an irreversibly inflamed pulp. The ice test was used merely to localize the involved tooth. The obturation techniques for geminated or fused teeth have included performing an apexification procedure before filling, using zinc oxide-eugenol as a major portion of the root canal filling, and thermomechanically and laterally condensing gutta-percha. In this case, because the root canal system was fully developed, the lateral condensation technique alone proved adequate. In spite of the patient's poor oral hygiene, peridontal probings revealed no periodontal pocketing around tooth 7. However the clinician should be aware that in geminated maxillary incisors, the groove dividing the crowns may extend apically. Such a condition can lead to a periodontal defect similar to the palatal gingival groove seen in lateral incisors (4). Patient compliance is an important consideration when determining a treatment plan. Libfeld et al. (8) chose not to perform an apexification procedure partly because of patient compliance. In this case, ideally a post and crown could have provided an esthetic final restoration (5). However, because of the patient's high level of anxiety and poor compliance, a postresin restoration was recommended instead. The opinions or assertions contained herein are the private ones of the author and are not to be construed as official or as reflecting the views of the United States Army. Dr. Wong is chief and mentor of endodontics, Advanced Educational Program in general dentistry (2 yr), Fort Hood, TX.
References
FiG 6. Clinical photograph of final restoration of tooth 7.
completely separate. The realization that this preoperative radiographic presentation can exist makes the distinction between gemination and fusion even more ambiguous. In previous case reports, a similar clinical appearance of two root canals in one root have been diagnosed as fusion (5-7) and gemination (8). In those cases, some communication between the two canals was apparent on the radiographs of
1. Itkin AB, Barr GS. Comprehensive management of the double root: report of case. J Am Dent Assoc 1975;90:1269-72. 2. Levitas TC. Gemination, fusion, twinning, and concrescence. J Dent Child 1965;32:93-100. 3. Tannenbaum KA, Ailing EE. Anomalous tooth development: case report of gemination and twinning. Oral Surg 1963;16:883-7. 4. Mader CL. Fusion of teeth. J Am Dent Assoc 1979;98:62-4. 5. Wolfe RE, Stieglitz HT. A fused permanent maxillary lateral incisor. NY State Dent J 1980;46:654-7. 6. Blaney TC, Hartwell GR, Betlizzi R. Endodontic management of a fused tooth: a case report. J Endodon 1982;8:227-30. 7. Friedman S, Mor H, Stabholz A. Endodontic therapy of a fused permanent maxillary lateral incisor. J Endodon 1984;10:449-51. 8. Libfeld H, Stabholz A, Friedman S. Endodontic therapy of bilaterally geminated permanent maxillary central incisors. J Endodon 1986;12:214-6.
Printed in U.S.A.
VOL. 17, NO. 4, APRIL 1991
Treatment Considerations in a Geminated Maxillary Lateral Incisor Marston Wong, DDS, MS
incisor to have an unusual clinical crown. The clinical diagnosis of gemination or fusion associated with tooth 7 was obvious. A large carious lesion involving the facial and distal aspect of the crown was present (Fig. 1). The patient had additional multiple carious lesions throughout his dentition as well as generalized type 1 periodontitis and localized type 3 periodontitis involving the mandibular incisors. Tooth 7 was symptomatic, with spontaneous, continuous pain, and was percussion sensitive. Tooth 6 responded to the percussion test within normal limits. Palpation tests revealed teeth 6, 7, and 8 to respond within normal limits. The ice test resulted in an increase in severity of symptoms only when placed on tooth 7. A radiographic examination revealed tooth 7 to have one broad root with an image of a single broad root canal. No periapical radiolucency was associated with the tooth (Fig. 2). A diagnosis was made of irreversible pulpitis secondary to caries of 7. Tooth 7 was also diagnosed as being geminated. Due to the patient's apprehension, a relaxation technique was demonstrated to the patient before any dental manipulation. The tooth was anesthetized with 1.5 ml of 2% Xylocaine with 1:100,000 epinephrine. All caries was excavated revealing a pulp exposure: a zinc oxide-eugenol temporary filling was placed over the facial and distal aspect of the crown. Access openings were made on the lingual surface revealing two apparently separate pulp chambers and root canals. The canals were initially instrumented using 5.4% sodium hypochlorite irrigation (Fig. 3), dried with paper points, and cotton pellets and temporary fillings were placed over the access openings. At the second appointment final instrumentation of both canals to a #40 file was performed. Master gutta-percha points were fitted and placed into the canals with a zinc oxideeugenol sealer. Lateral condensation with accessory points was used to obturate the canals. The lingual access openings were sealed with temporary fillings. A final radiograph was taken (Fig. 4). The patient was directed to the referring dentist for follow-up dental treatment. At the 1-yr recall visit, a clinical examination revealed that the patient had not seen a dentist since completion of the root canal treatment on tooth 7. The tooth was asymptomatic and all clinical findings were within normal limits. Consultation with the fixed prosthodontist was made and a recommendation of a post and resin restoration was advised. The patient was counseled on the over-all condition of his dentition and the need for follow-up care. The relaxation technique was reviewed with the patient and the patient appointed for a dental prophylaxis and restoration of teeth 6 and 7. The
A patient with an anomalous maxillary lateral incisor was referred for endodontic therapy. A diagnosis of irreversible pulpitis of a geminated maxillary lateral incisor was made. The preoperative radiograph revealed an image of a single root canal but in fact the tooth had two separate and distinct root canals. Treatment considerations of this anomaly are discussed.
Gemination may be defined as the attempt of a single tooth bud to divide, resulting in two identical crowns joined in a midline to align in a mirror-image effect. Radiographically the root may appear to have one canal (1). When the bifid crown is counted as one tooth, the normal number of teeth are present (2). Fusion is a condition where two separate tooth buds unite at some stage in their development to form a bifid crown (3). Radiographically, two root canals and one or two roots may be evident (1). When the bifid crown is counted as one tooth, the adjacent tooth appears to be congenitally missing (2). The clinical appearance may be of nonidentical crowns joined at the midline (1). In the case of fusion between a normal tooth and a supernumerary tooth, differentiation from the condition of gemination may be difficult or impossible (4). Radiographic studies may be of aid in the diagnosis (3). Few articles (5-8) have been written regarding the endodontic treatment of the geminated or fused tooth. The morphological variations of the root canals associated with these anomalies have required a variety of approaches to treatment. The following is a case report of an endodontically involved geminated maxillary lateral incisor which presented with a radiographic image of having one canal but in fact had two. CASE R E P O R T A 26-yr-old white male was referred for evaluation of an upper right maxillary incisor. The patient's chief complaint was that the tooth had been continuously hurting for the past 3 days. The patient stated that cold drinks made it hurt worse. The patient also stated that he was extremely apprehensive of all dental procedures and avoided the dentist if at all possible. The patient's medical history was noncontributory. Clinical examination revealed the right maxillary lateral
179
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Journal of Endodontics
FIG 1. Preoperative clinical photograph of tooth 7.
FIG 3. Length determination radiograph.
FIG 2. Preoperative radiograph of tooth 7.
patient followed through with his subsequent appointments. Figure 5 shows a radiograph of the final restoration and Fig. 6 shows a clinical photograph of tooth 7. DISCUSSION At times the diagnosis of gemination versus fusion cannot be conclusively established. In this case report, tooth 7 presented with an initial radiographic appearance of having only one root and one root canal. Only upon preparing access openings were two separate root canals observed; a radiograph of the final root canal filling suggests that the root canals were
FPG4. Radiograph of final root canal filling.
Vol. 17, No. 4, April, 1991
FIG 5. Radiograph of tooth 7: 1-yr recall.
Gemination of a Maxillary Incisor
181
the final root canal fillings. In the present case report, no radiographic evidence of communication between the two root canals was observed (Fig. 4). Although two separate root canals lend more support to the diagnosis of fusion, the diagnosis of gemination was made for the following reasons: (a) the crowns appeared as two identical crowns joined at the midline resulting in a mirror-image effect; (b) the tooth had only one root; (c) there were no teeth missing in the maxilla; and (d) presupposition of the existence of a supernumerary tooth was not required for the diagnosis. In previous endodontic case reports (5-8), the teeth involved were either nonvital or had a previously inadequate root canal filling in place. Root canal treatment or retreatment was a foregone conclusion. In this case the tooth had some degree of vitality and the symptoms were indicative of an irreversibly inflamed pulp. The ice test was used merely to localize the involved tooth. The obturation techniques for geminated or fused teeth have included performing an apexification procedure before filling, using zinc oxide-eugenol as a major portion of the root canal filling, and thermomechanically and laterally condensing gutta-percha. In this case, because the root canal system was fully developed, the lateral condensation technique alone proved adequate. In spite of the patient's poor oral hygiene, peridontal probings revealed no periodontal pocketing around tooth 7. However the clinician should be aware that in geminated maxillary incisors, the groove dividing the crowns may extend apically. Such a condition can lead to a periodontal defect similar to the palatal gingival groove seen in lateral incisors (4). Patient compliance is an important consideration when determining a treatment plan. Libfeld et al. (8) chose not to perform an apexification procedure partly because of patient compliance. In this case, ideally a post and crown could have provided an esthetic final restoration (5). However, because of the patient's high level of anxiety and poor compliance, a postresin restoration was recommended instead. The opinions or assertions contained herein are the private ones of the author and are not to be construed as official or as reflecting the views of the United States Army. Dr. Wong is chief and mentor of endodontics, Advanced Educational Program in general dentistry (2 yr), Fort Hood, TX.
References
FiG 6. Clinical photograph of final restoration of tooth 7.
completely separate. The realization that this preoperative radiographic presentation can exist makes the distinction between gemination and fusion even more ambiguous. In previous case reports, a similar clinical appearance of two root canals in one root have been diagnosed as fusion (5-7) and gemination (8). In those cases, some communication between the two canals was apparent on the radiographs of
1. Itkin AB, Barr GS. Comprehensive management of the double root: report of case. J Am Dent Assoc 1975;90:1269-72. 2. Levitas TC. Gemination, fusion, twinning, and concrescence. J Dent Child 1965;32:93-100. 3. Tannenbaum KA, Ailing EE. Anomalous tooth development: case report of gemination and twinning. Oral Surg 1963;16:883-7. 4. Mader CL. Fusion of teeth. J Am Dent Assoc 1979;98:62-4. 5. Wolfe RE, Stieglitz HT. A fused permanent maxillary lateral incisor. NY State Dent J 1980;46:654-7. 6. Blaney TC, Hartwell GR, Betlizzi R. Endodontic management of a fused tooth: a case report. J Endodon 1982;8:227-30. 7. Friedman S, Mor H, Stabholz A. Endodontic therapy of a fused permanent maxillary lateral incisor. J Endodon 1984;10:449-51. 8. Libfeld H, Stabholz A, Friedman S. Endodontic therapy of bilaterally geminated permanent maxillary central incisors. J Endodon 1986;12:214-6.
