- Email: [email protected]
A five-canal maxillary first molar
0099-2399/84/1004-0156/$02.00/0 JOURNALOF ENDODONTICS Copyright 9 1964 by the American Association of Endodontists
Printed in U.S.A.
VOL. 10, NO. 4, APRIL1984
CASE REPORT A Five-canal Maxillary First Molar Richard G. Beatty, DDS, MS
molar. The referring dentist had removed a long-standing stainless steel crown, noted a carious exposure, and diagnosed the need for nonsurgical endodontics. A preoperative radiograph was obtained (Fig. 1). Evaluation of this radiograph suggested extensive dystrophic calcification of the canals in the mesiobuccal root. The distobuccal and palatal canals were believed to be of a size appropriate for the patients's age.
A patient with a five-canal maxillary first molar was referred for endodontic treatment due to the mesiobuccal root which radiographically appeared to be calcified. Nonsurgical endodontic therapy revealed three root canals in the mesiobuccal area.
The permanent maxillary first molar has been extensively examined in root canal morphology studies (17). These studies have documented the prevalence in this tooth of both three and four root canals. Vertucci (2) found a fourth canal occurs in 55% of teeth examined and Gray (3) found it occurs in 56%. Pomeranz and Fishelberg (7) examined 100 extracted maxillary first molars and found 69% had four canals, with two located in the mesiobuccal area. Far less frequent is the occurrence of five canals in maxillary first molars. Gray (3) reported five canals occurred in 2.4% of the teeth he studied, with the canal distribution as follows: two mesiobuccal, two distobuccal, and one palatal canal. No mention was made of the occurrence of three root canals in the mesiobuccal root. Case reports (8-11 ) have noted maxillary molars with unique root canal morphological patterns. Harris (8) reported a four-canal maxillary molar having two palatal canals. Cecic et al. (10) reported a case with five canals, two mesiobuccal, one distobuccal, and two palatal canals. Staboltz (11) reported a case in which a maxillary first molar was fused to a maxillary second bicuspid. This phenomenon also resulted in a five-canal maxillary first molar. The present report describes a case in which a permanent maxillary first molar was found to have five root canals with three of the canals located in the mesiobuccal area. Clinical and radiographic examination did not suggest fusion, concrescence, or gemination as the cause for this unique canal morphology.
FIG 1. The maxillary left first molar with the mesiobuccal canal system appearing to be calcified.
CASE REPORT
A 14-yr-old male Caucasian was referred for nonsurgical endodontic therapy for the maxillary left first
FiG 2. Trial length radiograph showing three files in the mesiobuccal area. 156
Vol. 10, No. 4, April 1984
Five-canal Maxillary Molar
The patient received local anesthesia of 2% lidocaine with 1:100,000 epinephrine. A rubber dam was placed and an endodontic access opening made. Examination of the chamber floor revealed five canal orifices, three of which were located in the mesiobuccal area. All canals were easily negotiated and a working length Xray obtained (Fig. 2). K-type files were used to initially negotiate the canals and for instrumentation. Apical preparations in the buccal canals were enlarged to the size of a 30 file and in the palatal canal to a 45 file. Backfiling of all canals in 1-mm increments for three file sizes completed instrumentation. Frequent irrigation with 5.25% sodium hypochlorite was used to maintain wet canals during instrumentation. Figure 3 shows the palatal, distobuccal, and two of the mesiobuccal canal orifices. All three mesiobuccal canal orifices are shown in Fig. 4. The canals were obturated at a second appointment
157
FIG 5. Posttreatment radiograph displaying five obturated root canals.
using a zinc oxide-eugenol sealer and laterally condensed gutta-percha. A temporary restoration was placed and a postoperative radiograph taken (Fig. 5). The calcified appearance of the mesiobuccal root on the preoperative radiograph and the occurrence of three mesiobuccal canals may have resulted from the existence and superimposition of two mesiobuccal roots. This phenomenon was suggested radiographicaUy but was not confirmed. I wish to express appreciation to Dr. Frank Vertucci and to Linda Mealiea for assistance in the preparation of this report. Dr. Beatty is assistant professor, Department of Endedontics, College of Dentistry, University of Florida, Gainesville, FL 32610.
FIG 3. The palatal (P), distobuccal (DB), and two mesiobuccal canal orifices.
FIG 4. All three mesiobuccal canal orifices in view.
(MB)
References 1. Hess W. Anatomy of the root canals of the teeth of the permanent dentition. Part 1. New York: William Wood and Co., 1925:32-35. 2. Vertucci F. The endodontic significance of the mesiobuccel root of the maxillary first molar. US Navy Med 1974;63:29-31. 3. Gray R. The maxillary first molar. In: Bjorndal A, Skidmore E, eds. Anatomy and morphology of the human teeth. Iowa City: University of Iowa College of Dentistry, 1983;31-40. 4. Weine F, Healey H, Gerstein H, Evanson L. Canal configuration in the mesiobuccal root of the maxillary first molar and its endodontic significance. Oral Surg 1969;28:419-25. 5. Pineda F. Roentgenographic investigation of the mesiobuccal root of the maxillary first molar. Oral Surg 1973;36:253-60. 6. Green D. Double canals in single roots. Oral Surg 1973;35:689-96. 7. Pomeranz H, Fishelberg G. The secondary mesiobuccal canal of maxillary molars. J Am Dent Assoo 1974;88:119-24. 8. Harris W. Unusual root canal anatomy in a maxillary molar. J Endodon 1980;6:573-5. 9. Grossman K. Endodonticsinvolving an unusual case of fusion. J Endodon 1981 ;7:40-1. 10. Cecic P, Hartwell G, Bellizzi R. The multiple root canal system in the maxillary first molar: a case report. J Endodon 1982;8:113-5. 11. Stabholz A, Friedman S. Endodontic therapy of an unusual maxillary first molar. J Endodon 1983;9:293-5.
Printed in U.S.A.
VOL. 10, NO. 4, APRIL1984
CASE REPORT A Five-canal Maxillary First Molar Richard G. Beatty, DDS, MS
molar. The referring dentist had removed a long-standing stainless steel crown, noted a carious exposure, and diagnosed the need for nonsurgical endodontics. A preoperative radiograph was obtained (Fig. 1). Evaluation of this radiograph suggested extensive dystrophic calcification of the canals in the mesiobuccal root. The distobuccal and palatal canals were believed to be of a size appropriate for the patients's age.
A patient with a five-canal maxillary first molar was referred for endodontic treatment due to the mesiobuccal root which radiographically appeared to be calcified. Nonsurgical endodontic therapy revealed three root canals in the mesiobuccal area.
The permanent maxillary first molar has been extensively examined in root canal morphology studies (17). These studies have documented the prevalence in this tooth of both three and four root canals. Vertucci (2) found a fourth canal occurs in 55% of teeth examined and Gray (3) found it occurs in 56%. Pomeranz and Fishelberg (7) examined 100 extracted maxillary first molars and found 69% had four canals, with two located in the mesiobuccal area. Far less frequent is the occurrence of five canals in maxillary first molars. Gray (3) reported five canals occurred in 2.4% of the teeth he studied, with the canal distribution as follows: two mesiobuccal, two distobuccal, and one palatal canal. No mention was made of the occurrence of three root canals in the mesiobuccal root. Case reports (8-11 ) have noted maxillary molars with unique root canal morphological patterns. Harris (8) reported a four-canal maxillary molar having two palatal canals. Cecic et al. (10) reported a case with five canals, two mesiobuccal, one distobuccal, and two palatal canals. Staboltz (11) reported a case in which a maxillary first molar was fused to a maxillary second bicuspid. This phenomenon also resulted in a five-canal maxillary first molar. The present report describes a case in which a permanent maxillary first molar was found to have five root canals with three of the canals located in the mesiobuccal area. Clinical and radiographic examination did not suggest fusion, concrescence, or gemination as the cause for this unique canal morphology.
FIG 1. The maxillary left first molar with the mesiobuccal canal system appearing to be calcified.
CASE REPORT
A 14-yr-old male Caucasian was referred for nonsurgical endodontic therapy for the maxillary left first
FiG 2. Trial length radiograph showing three files in the mesiobuccal area. 156
Vol. 10, No. 4, April 1984
Five-canal Maxillary Molar
The patient received local anesthesia of 2% lidocaine with 1:100,000 epinephrine. A rubber dam was placed and an endodontic access opening made. Examination of the chamber floor revealed five canal orifices, three of which were located in the mesiobuccal area. All canals were easily negotiated and a working length Xray obtained (Fig. 2). K-type files were used to initially negotiate the canals and for instrumentation. Apical preparations in the buccal canals were enlarged to the size of a 30 file and in the palatal canal to a 45 file. Backfiling of all canals in 1-mm increments for three file sizes completed instrumentation. Frequent irrigation with 5.25% sodium hypochlorite was used to maintain wet canals during instrumentation. Figure 3 shows the palatal, distobuccal, and two of the mesiobuccal canal orifices. All three mesiobuccal canal orifices are shown in Fig. 4. The canals were obturated at a second appointment
157
FIG 5. Posttreatment radiograph displaying five obturated root canals.
using a zinc oxide-eugenol sealer and laterally condensed gutta-percha. A temporary restoration was placed and a postoperative radiograph taken (Fig. 5). The calcified appearance of the mesiobuccal root on the preoperative radiograph and the occurrence of three mesiobuccal canals may have resulted from the existence and superimposition of two mesiobuccal roots. This phenomenon was suggested radiographicaUy but was not confirmed. I wish to express appreciation to Dr. Frank Vertucci and to Linda Mealiea for assistance in the preparation of this report. Dr. Beatty is assistant professor, Department of Endedontics, College of Dentistry, University of Florida, Gainesville, FL 32610.
FIG 3. The palatal (P), distobuccal (DB), and two mesiobuccal canal orifices.
FIG 4. All three mesiobuccal canal orifices in view.
(MB)
References 1. Hess W. Anatomy of the root canals of the teeth of the permanent dentition. Part 1. New York: William Wood and Co., 1925:32-35. 2. Vertucci F. The endodontic significance of the mesiobuccel root of the maxillary first molar. US Navy Med 1974;63:29-31. 3. Gray R. The maxillary first molar. In: Bjorndal A, Skidmore E, eds. Anatomy and morphology of the human teeth. Iowa City: University of Iowa College of Dentistry, 1983;31-40. 4. Weine F, Healey H, Gerstein H, Evanson L. Canal configuration in the mesiobuccal root of the maxillary first molar and its endodontic significance. Oral Surg 1969;28:419-25. 5. Pineda F. Roentgenographic investigation of the mesiobuccal root of the maxillary first molar. Oral Surg 1973;36:253-60. 6. Green D. Double canals in single roots. Oral Surg 1973;35:689-96. 7. Pomeranz H, Fishelberg G. The secondary mesiobuccal canal of maxillary molars. J Am Dent Assoo 1974;88:119-24. 8. Harris W. Unusual root canal anatomy in a maxillary molar. J Endodon 1980;6:573-5. 9. Grossman K. Endodonticsinvolving an unusual case of fusion. J Endodon 1981 ;7:40-1. 10. Cecic P, Hartwell G, Bellizzi R. The multiple root canal system in the maxillary first molar: a case report. J Endodon 1982;8:113-5. 11. Stabholz A, Friedman S. Endodontic therapy of an unusual maxillary first molar. J Endodon 1983;9:293-5.