2 Palatal Canals

Endodontology, Vol. 15, 2003

Endodontic Miscellany : Maxillary first molar with two canals in the palatal root *Krishnaprasad P **Goel BR ***Tyagi S

During pre-clinical endodontics on extracted teeth, a maxillary first molar was found to have a palatal root with two canals. While locating the canals, because of eccentric location of the instrument in the palatal canal, a second canal was suspected. Placement of another instrument easily verified the presence of the second canal. The palatal root canal system was characterized by two canal orifices and two canals that appeared to unite in the apical third of the root (Photograph 1a and 1b) which constitute type II canal configuration according to Vertucci's classification8 (Fig. 1).

Table 1: Canal Configurations of Maxillary First Molar

Most of the clinical literature on the fourth canal in maxillary molars reports an additional mesiobuccal canal (MB2) 3,4,5 . But an anomalous root morphology that occurs infrequently, such as two palatal roots and canals, in the teeth is infrequently reported6. Unusual root canal system in maxillary first molar reported so far is presented in Table-1.

Year

Author

1979

Canal configuration P

MB

DB

Slowey

2P

1 MB

1 DB

1979

Thews

2 PS/J

1 MB

1 DB

1982

Cecic

2 PS

2 MBS

1 DB

1983

MartinezBerna

1P

3 MBS

2 DBS/J

1984

Beatty

1P

3 MBS

1 DB

1988

Bond

2 PJ

2 MBS

2 DBJ

1991

Wong

3 PS

1 MB

1 DB

1994

Jacobsen

2 PS

1 MB

1 DB

1997

Hulsmann

1P

1 MB

2 DBS

S: Separate canals with separate foramina. J: Canals joining in the apical one-third. Two canals in a single palatal root may present in one of the following types7; a. Two separate orifices, two separate canals and two separate foramina. b.

Two separate palatal roots, each with one orifice, one canal and one foramen.

c.

One palatal root, one orifice, a bifurcated canal and two foramina.

Discussion Having the information observed from the radiographs and knowing what combinations of internal anatomy are possible, the dentist should be able to determine what type of canal configuration is present. An examination of the floor of the pulp chamber offers clues to the type of canal configuration present.

Fig. 1(b). Files placed in MB, DB, MP and DP canals of maxillary first molar (Mesial view). * ** ***

P.G. Student Professor and Head Assistant Professor Department of Conservative Dentistry & Endodontics, P.M.N.M. Dental College and Hospital, Bagalkot-587 101. Karnataka.

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Krishnaprasad et al.

Two-canaled palatal root...

Fig. 1. Vertucci's classification

The most frequent cause of endodontic failure is the apical percolation and subsequent diffusion stasis into the canal2. The main reasons for this failure are incomplete canal obturation or an untreated canal. A canal is often left untreated because the dentist fails to recognize its presence. When there is only one canal, it is usually located rather easily in the centre of the access preparation. If only one orifice is found and it is not in the centre of the tooth, it is probable that another canal is present and the operator should search for it on the opposite side. The relationship of the two canal orifices to each other is also significant. The closer the orifices are to each other, the greater are the chances that the two canals join at some point within the body of the root.

Fig. 1(c). Picture taken on Radiovisiography shows files placed in MP and DP canals of palatal root of maxillary first molar which join in apical 1/3rd of the root (Type II configuration).

the size of the first file to be used, and it contributes to a rational approach to solve the problems that arise during therapy.

Among the root canal anomalies of maxillary molars, the least frequent appears to be that of the palatal root. Slowey9 stated that root canal anatomy of each tooth has certain commonly occurring characteristics as well as numerous atypical ones that can be road maps to successful endodontics. The expected root canal anatomy dictates the location of the initial entry of access, it dictates

Literature is reviewed regarding the presence of extra canals in palatal root of maxillary molars. The incidence of two root canals in the palatal root of maxillary molars has been reported to be 2- 5.1%7,10, Christie et al11 speculated that maxillary molars with 31

Endodontology, Vol. 15, 2003

two palatal roots may be encountered once every 3 years in a busy endodontic practice.

5. Vertucci FJ. The endodontic significance of the mesiobuccal root of the maxillary first molar. Navy Med.1974; 63: 29.

Although the incidence of a second palatal canal is not high, it is important to take this variation into consideration during root canal therapy of maxillary molars in order to ensure long term treatment success.

6. Maggiore F, Jou YT and Kim S. A six canal maxillary first molar: Case report. Int. Endod. J. 2002; 35: 386-491. 7. Stone HL and Stroner FW. Maxillary molars demonstrating more than one palatal root canal. Oral Surg. 1981; 51(6) : 649-652. 8. Vertucci FJ, Seelig A and Gillis R. Root canal morphology of the human maxillary second premolar. Oral Surg. 1976; 38 : 456.

References 1. Cohen S and Burns C. Pathways of the pulp 6th Ed., Harcourt Brace and Company, Asia PTE Ltd, 1997.

9. Slowey RR. Root canal anatomy, road map to successful endodontics. Dent. Clin. North Am. 1979; 23: 555.

2. Ingle JI. Endodontics. 2nd Ed., Philadelphia, Lea and Febiger, 1976 : 66-75.

10. Saler and Goel BR. Frequency of fourth root canal in the maxillary first molar, an in-vitro study. Thesis submitted to Karnataka University. 1995.

3. Pomeranz HH and Fishelberg G. The secondary mesiobuccal canal of maxillary molars. J. Am. Dent. Assoc. 1974; 88: 119-124.

11. Christie WH, Peikoff MD and Fogel HM. Maxillary molars with two palatal roots: A retrospective clinical study. J. Endod. 199117(2): 80-84.

4. Seidberg BH, Altman M, Guttuso J and Suson M. Frequency of two mesiobuccal root canals in maxillary permanent first molar. J. Am. Dent. Assoc. 1973; 87: 852856.

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