DOI: 10.

15386/cjmed-778 Case Report

ENDODONTIC MANAGEMENT OF MAXILLARY THIRD

MOLAR WITH MB2 (VERTUCCI TYPE IV) CANAL
CONFIGURATION DIAGNOSED WITH CONE BEAM
COMPUTED TOMOGRAPHY – A CASE REPORT

PRADEEP JAIN, PALLAV PATNI, PANT YOGESH, VYAS ANUP

Department of Conservative Dentistry and Endodontics, Sri Aurobindo College

of Dentistry, Indore, M.P, India

Abstract

The endodontic treatment of maxillary third molar often poses a challenge even
to an experienced endodontist because of their most posterior location in the dental
arch, aberrant occlusal anatomy, abnormal root canal configuration and eruption
patterns. Owing to these anatomical limitations, their extraction remains the treatment
of choice for many clinicians. As we know, retaining every functional component of the
dental arch is of prime importance in contemporary dental practice. This clinical case
report aims to discuss the endodontic treatment of maxillary third molar with MB2
root canal separated throughout the length and exit at two separate apical foramina
(Vertucci type IV) diagnosed with Cone Beam Computed Tomography (CBCT)..

Keywords: endodontic treatment, maxillary third molar, Cone Beam Computed

Tomography, Dental Operating Microscopes

Introduction one to five and number of encased root canal has been
Despite the increased awareness amongst the reported from one to six. However, the single, double and
patients, maxillary third molars always are prone to develop three rooted variants, either separate or fused, encasing one
tooth decay owing to their most inaccessible location in the to four root canals are considered most common.
arch and wrinkled occlusal anatomy which would favor The internal anatomy of the mesiobuccal (MB)
the accumulation of the plaque and interfere with optimum root in maxillary third molars has been investigated more
cleaning. Besides, they usually have the abnormal eruption than any other root. However, few studies examined the
patterns, which also make them susceptible to dental decay. occurrence of second mesiobuccal canal (MB2) in third
Owing to these complications, the extraction of the third molar teeth. Green found that the prevalence of MB2 in
molar is the usual choice for all practitioners unless the MB root of maxillary third molars was 37% in which 25%
tooth is strategically important. of the MB2 were type II and 12% were type IV [1]. In an
Retaining every functional component of the dental in vitro investigation of 50 maxillary third molars, Pecora
arch, including the third molars, is the principal goal of et al. found that 68% of MB2 canals have root canal type
contemporary dental practice. In certain clinical situations I, while root canals types IV and V were only presented in
retaining such teeth is even more important if they are to 14% and 18%, respectively [2]. In 1999, Stropko evaluated
serve as the convenient abutment for fixed prosthesis. the endodontic treatment of 20 maxillary third molar teeth,
The root and root canal morphology of maxillary and found only 20% of the study subjects having a MB2
third molars show an increased likelihood for aberrations in which all of them where joined and ended in a single
either in number of roots or the canal configuration. The foramen [3].
number of roots in maxillary third molar teeth ranges from The internal anatomy of the MB root in maxillary
third molars has also been examined in some population
Manuscript received: 07.02.2017 groups. In a Burmese population, Ng et al. reported 22.2%,
Accepted: 17.03.2017
Address for correspondence: pradeep.endodon18@gmail.com 11.15 and 5.6% of the MB root in maxillary third molars
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 Case Report

having root canals types IV, II, VII, respectively [4]. In deep distoproximal and occlusal caries with an exposed
a Thai population, Alavi et al. demonstrated single canal pulp. The tooth was severely tender on percussion and had
type I in the MB root in only 54.5%, and seven different moderate pain on palpation. Pulp testing with electric pulp
root canal configurations were identified in 45.5% of tester (Parkell Inc. Edgewood, NY, USA) and thermal test
the specimens [5]. In a recent morphological study on a using hot gutta- percha (GP) elicited non-responsiveness
Turkish population by Sert et al. 22.22% of the root canal from the suspect tooth. Conventional intraoral periapical
configurations in the MB root were types II, IV and V [6]. radiograph failed to provide adequate information regarding
This case report aims to discuss the endodontic the canal configuration and all the roots looked fused and
management of maxillary third molar with MB2 root canal their outline were not clear (Figure 1a). CBCT provides
configuration (Vertucci type IV) diagnosed with CBCT. three dimensional imaging and reasonably high resolutions
that would aid in better understanding in identifying the
Case report root and root canal morphological features. Hence, CBCT
A 40-year-old male reported to the department was advised to the patient. After careful evaluation of axial
of conservative dentistry, with a chief complaint of food sections at coronal, middle and apical third and sagittal
impaction and pain in the last right upper molar region. The section, it was confirmed that MB root had an additional
pain started a month ago and was dull, gnawing in nature MB2 canal which was separated throughout the length
with moderate intensity. He reported to the clinic only from MB1 and exited as two separate apical foramina, thus
when the pain became severe. On clinical examination, confirming the Vertucci type IV root canal configuration
it was observed that the maxillary right third molar had a (Figures 1 b,c.d,e).

Figure 1. a) Preoperative radiograph; b) The limited volume CBCT axial scan at coronal third; c) The limited volume CBCT axial scan
at middle third; d) The limited volume CBCT axial scan at apical third; e) The limited volume CBCT sagittal scan confirming Vertucci
type IV canal configuration.

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 Case Report

By evaluating the tooth clinically, radiographically the MB2 orifices, the patency of all the four root canals was
and dental imaging, a diagnosis of pulpal necrosis with checked with #10 K file (Kerr USA). The working length
an acute apical periodontitis was made and an endodontic was determined by Root ZX II (J. Morita, Kyoto, Japan)
approach was planned for this tooth. apex locator for all the four root canals and confirmed by a
Rhomboidal shape access was made to gain entry to radiograph (Figure 1g). A sterile paper point was inserted
the pulp chamber after administration of local anesthesia in to the MB2 to determine if it joined with the MB1.
(2% lignocaine with 1:1,00000 epinephrine). Placement of The fluid level in MB1 was found to be remaining same
rubber dam for isolation was not possible owing to poor in volume, therefore confirming two separate root canals
accessibility. After careful extensions of the access cavity in MB root throughout the length thus confirming Verucci
under the magnification and illumination of dental operating type IV canal configurations. The root canals were cleaned
microscope (DOM) (Global Surgical corporation St. Louis and shaped by rotary nickel-titanium ProTaper instruments
MO, USA) 8x, all the three root canal orifices were visible (Dentsply, Maillefer) using Glyde (Dentsply, Maillefer) as a
at the floor but the orifice for MB1 was hidden under the lubricant. The canals were sequentially irrigated using 5.2%
thin shelves of the dentin (Figure 1f). The mesial marginal NaOCl and 17% ethylyne diamine tetraacetic acid (EDTA)
ridge was infringed upon to achieve enough access to reveal during the cleaning and shaping procedure. Selected master
the mesially positioned and mesially inclined MB2canal. GP were placed in all the canals and a check radiograph
Slow-speed Mueller burs (Brasseler, Savannah, GA, USA) was taken to evaluate the fit (Figure 1h).The canals were
were used with a brushing motion between the MB and thoroughly dried and were coated with AH-plus resin based
the palatal canal orifice to remove the dentinal shelves that sealer (Dentsply Maillefer). Obturation was carried out
overlay the anticipated MB2 canal orifice using intermittent using the ProTaper GP points. Immediate post obturation
irrigation with 5.2% sodium hypochlorite (NaOCl) solution radiograph showed well obturated root canals (Figure 1
and were examined under the DOM at 8x. An ultrasonic i).The access cavity was restored with posterior composite
nonactive tip with active lateral part Start-XTM #2 resin (ClearfilmajestyTM posterior, Kuraray America, Inc.
(Dentsply Maillefer) was introduced with a Piezo ultrasonic NY, USA). The patient was asymptomatic during follow-
generator (EMS Minipiezon) at medium speed and with up after 3 months (Figure 1j) and six months (Figure 1k)
light force along the MB sub-pulpal groove extending and was advised to get the final post endodontic restoration
palatally from the main MB canal orifice, with continuous done for the tooth.
water irrigation. MB2 orifice was located. After locating

Figure 1. f) Access cavity preparation under DOM 8x; g) Working length radiograph; h) Radiograph with master guttapercha in place; l)
Immediate post obturation radiograph; j) Follow up radiograph after three months; k) Follow up radiograph after six months.

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 Case Report

Discussion has a remarkable mesial incline just apical to its orifice in

The maxillary third molar has one of the most the coronal 1 to 3 mm. When the instrumentation is done
complex root and canal anatomy. The presence of a MB2 for MB2, the tip of the file tends to catch against the mesial
canal in the MB root of the maxillary third molars has been wall of the canal, preventing its apical progress. Since the
the subject of many discussions and studies. MB2 canal is smaller and usually more calcified than MBI,
An inability to detect and treat MB2 canal is a reason the problem is accentuated [3]. To facilitate its location and
for endodontic failure in maxillary molars. Endodontically instrumentation, the access has to be rhomboidal in shape
retreated teeth were found to contain more undetected MB2 to allow the necessary mesially directed shaping. Since
canals than first-time treated teeth, suggesting that failure CBCT has confirmed the presence of an additional MB2
to treat existing MB2 canals leads to a poorer prognosis [7]. root canal, to explore this, a rhomboidal access cavity was
John J. Stropko 1999 studied the incidence of MB2 prepared. In the presented case since the MB2 was hidden
in the MB root of maxillary molars. There was a higher and finer as compared to MB1, proper care has been taken
frequency of MB2 canals 73.2% in the maxillary first to negotiate it with fine 10# K file using glyde as a lubricant.
molars (U1M), 50.7% in maxillary second molars (U2M) Yoshioka et al. found that both magnification and
and a smaller percentage 20.0% in the maxillary third dentin removal under magnification were effective in
molars (U3M). A higher incidence of separate MB2 canals detecting the presence of MB2 canals. Particularly the
54.9% was recorded in U1M than in U2M and joined in authors could detect the MB2 canal in 7% of cases without
all U3M [3]. The presented case report also showed an the microscope, in 18% of cases using magnification and
additional MB2 root canal which was separated throughout in 42% of cases using ultrasonic tips under the operating
the course and exit as two separate apical foramina therefore microscope [9]. Furthermore, the use of ultrasonic
confirming Vertucci type IV canal configuration. instruments under magnification enhances precision
With the advent of newer imaging technology and reduces the risk of complications like ledges and
like CBCT, a better understanding of root and root canal perforations. In the presented case the illumination and
configuration is possible. However, it should be prescribed magnification was achieved with the use of DOM with 8x.
only after weighing the cost of radiation exposure with
the benefit of the diagnostic information that can be Conclusion
obtained from the scan [8]. In the presented case report The maxillary third molar has one of the most
since the conventional radiograph did not give the relevant complex root and canal anatomy.
information, hence CBCT was advised to the patient, which The presence of a MB2 canal in the MB root of
clearly indicated the presence of an MB2 root canal with the maxillary third molars has been the subject of many
Vertucci type IV canal configuration. discussions and studies.
With the routine use of the DOM, specific It is important that the clinician should have a strong
instruments were required to enhance the effectiveness conviction for the presence of an additional MB2 canal in
of the clinical procedure. In the presented case report a 100% cases until it is proven otherwise. In conjunction
troughing process was utilized as MB2 orifice was hidden with the DOM, use of current diagnostic aid likes CBCT,
under the thin shelves of the dentin. It was essential to locate a rhomboidal access preparation, specific burs and newer
most MB2canals, and this can be accomplished either with set of ultrasonic instruments is highly recommended to
burs or ultrasonic instruments. With the advent of newer enhance the visualization of MB2 systems. The use of
sets of ultrasonic, the troughing process has become faster ultrasonic tips under the magnification of DOM may be
and cleaner. In the presented case report specific Mueller more conservative and it allows us for clear visualization
burs were used followed by the ultrasonic Start X tip # 2, an of the pulpal floor as well as the missed root canal orifice.
MB2canal scouter for locating the orifice of hidden MB2
canal. Acknowledgement
In most teeth, the locations of MB2 canal orifices The authors are grateful to Dr. Vinod Bhandari,
agree with the findings of several authors. The MB2 orifice Chairman, Sri Aurobindo College of Dentistry (SAIMS),
were usually found mesial to an imaginary line between Indore, Dr. Mahak Bhandari, Director, Mohak super
the MB1 and palatal orifices and about 2 to 3 mm palatal to specialty centre, Indore, for providing all necessary
the MB 1 orifice. This imaginary line is more appropriately facilities and infrastructure for the research work.
described as an arc with an apogee toward the mesial,
following the contours of the mesial surface of the root. References
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