|Year : 2015 | Volume
| Issue : 2 | Page : 74-78
Mandibular Incisors with Type II Anatomy in a Single Patient: Report of Two Cases
Vinaya Kashid1, Hemant Baonerkar2
1 Department of Conservative Dentistry and Endodontics, YMT Dental College and Hospital, Navi Mumbai, Maharashtra, India
2 Department of Oral and Maxillofacial Surgery, YMT Dental College and Hospital, Navi Mumbai, Maharashtra, India
|Date of Web Publication||17-Dec-2015|
B-7, Plot No. 7, Nav Parag CHS Ltd., Sector 16, Vashi, Navi Mumbai - 400 703, Maharashtra
Source of Support: None, Conflict of Interest: None
Mandibular incisors are smallest teeth in the dentition. It is assumed that mandibular incisor is the most easy tooth to treat but sometimes these teeth are difficult to treat because of presence of extra canal which is present more lingually and often misdiagnosed and leads to treatment failure. Success of root canal treatment depends on careful diagnosis of additional canal and thorough debridement of root canal space and obtaining a fluid-tight seal. Thus, this article emphasis on careful management of mandibular incisors with the second canal (type II anatomy) in a single patient.
Keywords: Access opening, endodontic management, lower incisors, type II canal anatomy
|How to cite this article:|
Kashid V, Baonerkar H. Mandibular Incisors with Type II Anatomy in a Single Patient: Report of Two Cases. Indian J Oral Health Res 2015;1:74-8
|How to cite this URL:|
Kashid V, Baonerkar H. Mandibular Incisors with Type II Anatomy in a Single Patient: Report of Two Cases. Indian J Oral Health Res [serial online] 2015 [cited 2019 Mar 25];1:74-8. Available from: http://www.ijohr.org/text.asp?2015/1/2/74/172040
| Introduction|| |
Successful endodontic therapy of a tooth demands that the dentist should have a thorough knowledge of the root canal morphology, making it mandatory toward thorough radiographic evaluation and diagnosis of the status of the pulp canals as well as the periapical areas. The improper diagnostic protocol may lead to the failure of endodontic treatment. 
Knowledge of the normal anatomy of pulp space of every tooth is necessary so as to diagnose the tooth with variation.
The endodontic triangle consists of the access opening, shaping and cleaning and obturation of root canal space.
Access preparation can be considered one of the most important technical phases of endodontic treatment.  An ideal access cavity preparation is the foundation of successful endodontic treatment. Sometimes this vital phase like access preparation can be overlooked which may lead to treatment failure as canal being missed. 
Vertucci classified the canal configuration of mandibular incisors into eight types [Figure 1].
Type I: Single canal is present in the pulp chamber from crown to the apex.
Type II: The pulp separates in two near the crown and joins at the apex to form one root canal.
Type III: Starts as one root canal in the pupal chamber and divided into two as it nears the apical foramen and then fuses again to form a single root near the apical foramen.
Type IV: The root separates into two distinct canals and extends till the root apex separately.
Type V: The root canal is single is a single entity extending till the apex of the root but dividing into two separate canals right before the apical foramen.
Type VI: Root canals start as two canals from the pulp chamber and join at the middle of the root to form one and extend till the apex and again divide into two canals just short of the apical foramen.
Type VII: Root canal starts as a single pulp canal till the middle third of the root and then divides into two separate canals and then re-joins after some distance and then near the apex divided into two canals again just near the apex.
Type VIII: The pulp chamber near the coronal portion divides into three separate root canals extending till the apex of the root.
The incidence of two canals at the tooth apex was reported to be as low as 11% to as high as 43%.  The literature is reviewed regarding the presence of the second canal in mandibular incisors. ,,, It is generally accepted that many mandibular incisors have two canals, which may merge into 1canal before reaching the apex. In rare cases, separate foramina may form. In a radiographic study of 364 specimens, Benjamin and Dowson reported that 41.4% of the mandibular incisors they studied had two separate canals; of these, only 1.3% had two separate foramina. In a study of 1,085 specimens by Miyashita et al.  reported that only 3.1% of the samples had separate canals and foramina. The study perform by Mauger et al.  of mandibular incisors in which, a surgical resection method was used to study canal anatomy demonstrated that, at the apical 1, 2, and 3 mm levels in the mandibular incisor, the canal is only rarely separated by hard tooth structure and that only 2% of the teeth had two canals at the 1 mm resection level.
These two case reports illustrating mandibular incisors having two canals in all four incisors in a single patient.
| Case reports|| |
A 47-year-old male reported to the Department of Conservative Dentistry and Endodontics, YMT Dental College, Navi Mumbai, with slight sensitivity and discomfort of lower anterior teeth and difficulty in mastication. Medical history revealed the history of chronic acid regurgitation. Clinically, there was a severe erosion of lower anterior teeth and collapse of anterior bite [Figure 2].
|Figure 2: Clinical view showing severe erosion and attrition of lower anterior|
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Radiographic examination showed loss of crown structure in the lower anterior region with periodontal ligament widening [Figure 3]. Cold test and electric pulp test (EPT) were negative. The diagnosis was made as chronic apical periodontitis. Endodontic treatment was initiated and at the same time raising the vertical height of anterior teeth was accomplished. This would further facilitate oral rehabilitation procedure.
Teeth were anesthetized and isolated under rubber dam. The radiograph showed an abrupt change in root canal space. Access cavities were made in all four mandibular incisors. During pulp extirpation change in direction of instrument in the canal suggested the possible presence of the second canal in the incisors.
Access cavities of incisors were slightly modified in labiolingual direction to gain straight-line access into the second canal. Canals revealed Vertucci type II morphology of root canals [Figure 4]. The working length was estimated using an apex locator (Propex, Dentsply) and also confirmed radiographically to determine the anatomic relationship between the root canals of each tooth [Figure 5] after the canals were prepared using a step back instrumentation technique. A 2.5% of sodium hypochlorite and normal saline (sodium chloride injection I.P 0.9% w/v) were alternatively used as irrigants at every change of instruments. The access cavities were then temporarily sealed with MD-Temp (Meta Biomed, Korea). At 2 weeks follow-up as the teeth were asymptomatic, obturation of the root canals was done by vertical compaction technique and AH Plus sealer [Figure 6] and [Figure 7]. Postobturation radiograph showed well-obturated two canals in all lower incisors, and the access cavities were sealed with MD-Temp [Figure 5].
A 36-year-old male presented to the Department of Conservative Dentistry and Endodontics, YMT Dental College, Navi Mumbai with the discomfort of lower anterior teeth. Medical history was noncontributory. Clinically, there was severe attrition of lower anterior teeth and collapse of anterior bite.
Radiographic examination showed loss of crown structure in the lower anterior region with periodontal ligament widening [Figure 8]. Cold test and EPT tests were negative. The diagnosis was made as chronic apical periodontitis. Endodontic treatment was planned and at the same time raising the vertical height of anterior teeth was accomplished. This would further facilitate oral rehabilitation procedure.
After anesthetizing, all mandibular incisors and rubber dam placement. Access cavities were made in all four mandibular incisors. During pulp extirpation change in direction of the instrument in the canal suggested the possible presence of the second canal in the incisors [Figure 9]. Access cavities were modified in labiolingual direction. Shaping and cleaning and obturation were carried out same as that of above case [Figure 10] and [Figure 11].
| Discussion|| |
A good preoperative radiograph is mandatory for initiation of any treatment. To see any variation from normal or an abrupt change in root canal space radiograph with different angulation is also equally important. Prognosis and success of tooth depend on correct diagnosis as well as adequate access opening, debridement of root canal space and achieving a three-dimensional seal with an inert filling material is also needed.
Extra root or root canals if not detected are a major reason for the failure of this treatment  Incomplete removal of all the irritants from the pulp space may increase the possibility of treatment failure. , The main reason for failure in the endodontic treatment of mandibular incisors can be due to inability to detect the presence of a second root canal, which can then not be prepared and obturated during treatment. 
Careful interpretation of the radiographic features is essential to ensure that additional root canals are not overlooked. This may necessitate imaging the tooth from different angles so that the root canals may be distinguished in the resulting films. In addition, if an obvious canal ends abruptly, the clinician should be suspicious that there are in fact two canals.  According to various authors, percentage of canal system types in mandibular incisors are tabulated [Table 1].
Adequate exploration of canal chamber with an endodontic file or endodontic explorer (DG 16) facilitates to navigate extra canal. The practice of endodontic should involve the buccolingual extension of access for the mandibular anterior teeth.
Numerous antimicrobial agents have been recommended as inter-appointment dressings. , Calcium hydroxide paste being one of the simplest and remarkably effective antimicrobial medicament was used in this case. Warm vertical compaction can increase the GP mass density and homogeneity on previous cold lateral condensation obturations , hence warm vertical technique was used to obturate the canals in both the cases.
This case reports demonstrated the root canal treatment of all mandibular incisors, each with two separate canals merging as single foramina.
| Conclusion|| |
Not knowing the root canal anatomy of the tooth you are treating, is like setting out on an unknown journey without a road map. Therefore, judicious interpretation of radiographs, radiographs with different angulations, modification of access cavity in labiolingual direction, through shaping and cleaning and obturation are keys for successful therapy of mandibular anteriors.
| References|| |
Hedge V, Kokate S. An unusual presentation of all the 4 mandibular incisors having 2 root canals in a single patient - A case report. Endodontology 2010;22:70-4.
Walton RE, Torabinejad M. Principles and Practice of Endodontics. 3 rd
ed. Philadelphia: WB Saunders Co.; 2002.
Cantatore G, Beruti E, Castellucci A. Missed anatomy: Frequency and clinical impact. Endod Topics 2009;15:3-31.
Vertucci FJ. Root canal anatomy of the mandibular anterior teeth. J Am Dent Assoc 1974;89:369-71.
Rankine-Wilson RW, Henry P. The bifurcated root canal in lower anterior teeth. J Am Dent Assoc 1965;70:1162-5.
Madeira MC, Hetem S. Incidence of bifurcation in mandibular incisors. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1973;36:589-91.
Benjamin KA, Dowson J. Incidence of two root canals in human mandibular incisor teeth. Oral Surg Oral Med Oral Pathol Oral Radiol Oral Endod 1974;38:122-6.
Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1984;58:589-99.
Miyashita M, Kasahara E, Yasuda E, Yamamoto A, Sekizawa T. Root canal system of the mandibular incisor. J Endod 1997;23:479-84.
Mauger MJ, Schindler WG, Walker WA 3 rd
. An evaluation of canal morphology at different levels of root resection in mandibular incisors. J Endod 1998;24:607-9.
Slowey RR. Radiographic aids in the detection of extra root canals. Oral Surg Oral Med Oral Pathol 1974;37:762-72.
Nair R, Sjogren U, Kreg G, Khanberg KE, Sandquist G. Intraradicular bacteria and fungi in root filled asymptomatic human teeth with therapy resistant periapical lesion - A long term light and electron microscope follow up study. J Endod 1990;16:580-8.
Sjogren U, Hagglund B, Sundqvist G, Wing K. Factors affecting the long-term results of endodontic treatment. J Endod 1990;16:498-504.
Kartal N, Yanikoglu FC. Root canal morphology of mandibular incisors. J Endod 1992;18:562-4.
Cohen S, Burns RC. Pathways of the Pulp. 8 th
ed. St. Louis: Mosby Year Book Inc.; 2002. p. 202.
Bystrom A, Claesson R, Sundqvist G. The antibacterial effect of camphorated paramonochlorophenol, camphorated phenol and calcium hydroxide in the treatment of infected root canals. Endod Dent Traumatol 1985;1:170-5.
Hasselgren G, Olsson B, Cvek M. Effects of calcium hydroxide and sodium hypochlorite on the dissolution of necrotic porcine muscle tissue. J Endod 1988;14:125-7.
Nelson EA, Liewehr FR, West LA. Increased density of gutta-percha using a controlled heat instrument with lateral condensation. J Endod 2000;26:748-50.
Lea CS, Apicella MJ, Mines P, Yancich PP, Parker MH. Comparison of the obturation density of cold lateral compaction versus warm vertical compaction using the continuous wave of condensation technique. J Endod 2005;31:37-9.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11]