Radiographic study of the root canal system of mandibular incisors in Palestinian population

doi:10.4236/ojst.2013.38075

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Open Journal of Stomatology, 2013, 3, 452-456 OJST

http://dx.doi.org/10.4236/ojst.2013.38075 Published Online November 2013 (http://www.scirp.org/journal/ojst/)

Radiographic study of the root canal system of mandibular

incisors in Palestinian population

Raed Mukhaimer, Maher Jarbawi

Department of Conservative Dentistry, Arab American University, Jenin, Palestine

Email: [email protected]

Received 9 October 2013; revised 10 November 2013; accepted 20 November 2013

tion License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly

cited.

ABSTRACT

Aim: The aim of this study was to survey the root

canal morphology of mandibular incisor teeth in a

Palestinian population using radiographic approach.

Materials and Methods: Five hundred and twenty

two extracted mandibular incisor teeth were randomly

collected from Palestinian population. The teeth were

radiographed from a mesiodistal direction and ex-

amined for the presence of a second canal and for the

type of canal configuration. Results: All teeth had sin-

gle root. Three hundred and sixty nine teeth (70.7%)

had one canal (type I Vertucci classification). The rest

(29.3%) had a second canal (type II and III). Conclu-

sion: Mandibular central and lateral teeth were most-

ly found to have one root and Type I canal system.

Keywords: Mandibular Incisors; Radiography; Root

Canal System

1. INTRODUCTION

Successful outcomes of endodontic treatment depend on

the identification of all root canals which in turn guaran-

tee complete extirpation of pulp tissue, proper chemo-

mechanical cleaning and shaping and three dimensional

obturation of the root canal system with an inert filling

material. Undetected extra roots or root canals had been

considered as a major reason for failure of root canal

treatment [1].

Many of the challenges faced during root canal treat-

ment may be directly attributed to an inadequate under-

standing of the canal morphology of teeth. Studies had

shown that anatomical variations can occur in all groups

of teeth with different incidences with respect to number

of roots and root canals and with respect to root/canal

system configuration [2-4].

Different techniques had been used to study the root

canal anatomy of the mandibular incisors. Vertucci [2]

used the clearing technique to study the root canal mor-

phology of 300 extracted mandibular incisors and found

that two canals were present in 30% of mandibular cen-

tral incisors and in 25% of mandibular lateral incisors.

Using the same technique, Miyashita et al. reported that

more than 85% of root canals possessed a single canal

[5]. Mauger et al. [6] used root sectioning to assess the

canal anatomy at different root levels in 100 lower inci-

sors and reported that 98% - 100% of the teeth had one

canal in the area situated 1 - 3 mm above the apex.

In a study conducted in Iranian population using

Cone-Beam Computed Tomography, 632 central incisors

and 614 lateral incisors were examined. A second canal

was found in 27.3% of central incisors and 29.4% of

lateral incisors [7]. De Oliveira et al. [8] used digital ra-

diography to analyze the presence of an extra canal in

lower incisors. The in vitro study was conducted on 200

mandibular incisors positioned on a model, simulating

the mandibular dental arch. Digital radiographs were

taken from the mandibular incisors in both buccolingual

and mesiodistal directions. The digital radiography

showed presence of bifurcation in 20% of teeth evaluated

in the mesiodistal direction. In the buccolingual direction,

15% presented bifurcation or characteristics indicating

bifurcation.

It had been reported that root canal systems of man-

dibular incisors may vary according to race. In his study,

in Southern Chinese population, Walker had found that

28% of mandibular incisors possess two separate canals

[9]. Boruah and Bhuyan [10] reported an incidence of

36.25% of the roots possessed two canals in a population

of North East India. Sert et al. investigated the root canal

configurations of mandibular permanent teeth in Turkish

population and r epo r ted th e presence of a second canal in

68% of mandibular central incisors and 63% of lateral

incisors [11].

No data are available on the root canal morphology of

OPEN ACCESS

R. Mukhaimer, M. Jarbawi / Open Journal of Stomatology 3 (2013) 452-456 453

mandibular incisors in Palestine. The aim of the present

investigation was to find out the incidence of second root

canal and the type of root canal configuration of man-

dibular incisors amongst Palestinian population.

2. MATERIALS AND METHODS

Five hundred and twenty two extracted mandibular inci-

sors were randomly collected from several private dental

clinics. The Ministry of Health Ethics Committee ap-

proved the study. All individuals agreed to participate by

signing an informed consent form. No attempt was made

to differentiate between central and lateral incisors. All

teeth included in the study had intact clinical crowns and

fully-formed roots. The teeth were cleaned from any re-

maining calculus and soft tissue by scaling and washed

with tap water and then placed in 10% formalin solution.

Teeth were arranged in a group of three over one

X-ray film (Ektaspeed Plus, Eastman Kodak, Rochester,

NY,USA) and radiographed in a mesiodistal direction

using paralleling technique. Time was set to 0.1 second.

To minimize variations, target film distance was kept to 5

cm. The X-rays were developed according to the manu-

facturer instructions.

The resultant images were examined by the author for

the presence of a single root canal or bifurcated root ca-

nal. All radiographs were examined systematically in a

darkened room using an illuminated viewer box with

magnification (2.5×).The configuration of each canal

was also categorized into the first four types of Vertucci’s

classification 2 as follows:

Type I: single canal is present from the pulp chamber

to the apex

Type II: two separate canals leave the pulp chamber

but join short of the apex to form one canal

Type III: one canal leaves the pulp chamber but di-

vides into two within the body of the root canals then

merge again to exit as one canal

Type IV: two separate canals are present from the pulp

chamber to the apex

The four canal configurations are shown in Figure 1.

3. RESULTS

All examined central and lateral incisors had only a sin-

gle root. The results are summarized in Table 1 that

shows the number and percentages of each canal type in

mandibular incisors. Of the 522 teeth studied, the major-

ity (70.7%) displayed a type I root canal configuration,

type II was found in 16.3 % cases and typ e III in 13%. An

overall of one hundred and fifty three teeth (29.3%) pos-

sessed a second canal. Figures 2, 3 and 4 show samples

of the radiographs representing Vertucci’s canal configu-

ration type I, II, and III respectively.

TYPE I TYPE II TYPE III TYPE IV

Figure 1. Vertucci root canal classification.

Table 1. number and percentages of mandibular incisor

teeth with various types canal configuration based on Ver-

tucci’s classification.

Canal configuration number of teeth (%)

Type I (1 - 1) 369 (70.7% )

Type II (2 - 1) 85 (16.3%)

Type III (1 - 2 - 1) 68 (13.0%)

Type IV (2 - 2) 0 (0%)

Total 522 (100%)

Figure 2. Selected radiograph of single canal (type I) of

mandibular incisors.

R. Mukhaimer, M. Jarbawi / Open Journal of Stomatology 3 (2013) 452-456

454

Figure 3. Selected radiograph of two canals (type II) of

mandibular incisors.

Figure 4. Selected radiograph of two canals (type III) of

mandibular incisors.

4. DISCUSSION

A variety of techniques have been used to study the in-

ternal anatomy of lower incisors [5,6,8]. Although radi-

ography is unlikely to show the complexities of the root

canal system such as lateral canals and eccentrically lo-

cated apical foramina [12], it may demonstrate the main

anatomical features. Hence the present study aimed to

investigate the incidence of bifurcated canals and the

type of canal configuration, this technique was used in

this study and the examined teeth were radiographed in a

mesiodistal direction. Radiographs may be the only non-

invasive means clinically to provide clues about the

morphology of the root canal system. This technique

proved to be simple and fast and needs little equipment.

Successful root canal therapy depends on sound know-

ledge of the normal and abnormal internal anatomy of

the treated tooth. Investigators have shown multiple fo-

ramina, loops, fins, deltas, additional canals, accessory

canals, intercanal connections and “C-shaped” canals.

Consequently the practitioner must treat each tooth as-

suming that complex anatomy oc curs often enough to be

considered normal.

Mandibular incisors have been traditionally treated as

teeth with a single canal. Anatomical studies had shown

that a considerable percentage of mandibular incisors

ranging between 12.4% [5] and 68% [11] posses a den-

tinal bridge in the pulp chambe r that divides the roo t into

two canals. The two canals usually join and exit through

a single apical foramen, but they may persist as two

separate canals.

Vertucci [2] examined the root canal morphology of

300 mandibular anterior teeth and reported a second ca-

nal in 27.5% of mandibular incisors. Al-Qudah and Aw-

awdeh [13] examined the root canal morphology of 450

mandibular anteriors in Jordanian population and re-

ported a second canal in 26.2% of mandibular incisors. A

higher incidence (36.25%) was reported by Boruah and

Bhuyan [14] who investigated the root canal anatomy of

mandibular incisors of North East Indian population. In a

recent study conducted by Al-Fouzan et al, 30% of man-

dibular incisors of Saudi population were found to have a

second canal [15]. The differences between these mor-

phology studies may be related to variations of examina-

tion techniques, sample size, classification systems and

ethnic background of tooth sources.

In the present study, 29.3% of the mandibular incisors

possessed a second root canal. All of these canals joined

and exited in a single foramen (Type II and III). The fre-

quency of two canals in the present study was within the

range of previous reports and very close to the frequent-

cies reported in the Middle East region (26.2% in Jorda-

nian population, 30% in Saudi population and 28.3% in

Iranian population).

R. Mukhaimer, M. Jarbawi / Open Journal of Stomatology 3 (2013) 452-456 455

The results of this investigation indicate th at about one

third of lower incisors in Palestinian population has a

second canal. The clinicians should always take this

anatomical variation into consideration when treating

this group of teeth as this relatively high proportion is

not routinely found during clinical procedure. Clinicians

usually fail to recognize the presence of a second canal

either due to lake of knowledge of root canal morphol-

ogy or due to lake of experience and skills to negotiate

that canal [16] with a subsequent failure of root canal

treatment.

To overcome the challenge of locating the second ca-

nal and optimize the access preparation, the traditional

lingual access of lower anteriors had been modified by

extending the access toward the cingulum [17]. With the

invention of highly aesthetic restorative materials, some

authors had suggested labial or incisal approach for

mandibular incisors as an alternative approach of lingual

access [18,19].

For several reasons, the clinician should not feel se-

cure when treating only one canal. An important poin t is

that, the two canals in lower incisors, if present, usually

join 1-3 mm from the apex. If one canal is prepared and

filled shorter from this joining point, the second canal

will become necrotic and open directly into the periapi-

cal area through the apical foramen [20]. Another point is

that, when only one canal is treated, pulp tissue in the

second canal can ultimately release harmful substances

through a secondary canal to the interior space of the

periodontium ligament [21]. In both situations, a subse-

quent failure of root canal treatment may occur.

5. CONCLUSION

Based on the findings of this study, a high incidence of

two canals in the lower incisor teeth had been found in

Palestinian population. Th e clinician must be alert for the

possibility of a b ifurcated root canal in these teeth as th is

may complicate root canal treatment.

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