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VARIATION OF MAXILLARY FIRST PREMOLARWITH THREE ROOT CANALS

Janet Kirilova1, Snezhanka Topalova-Pirinska1, Dimiter Kirov2

1) Department of Conservative Dentistry2) Department of Prosthetic DentistryFaculty of Dental Medicine,Medical University Sofia, Bulgaria

Journal of IMAB - Annual Proceeding (Scientific Papers) 2014, vol. 20, issue 3Journal of IMABISSN: 1312-773Xhttp://www.journal-imab-bg.org

ABSTRACTBackground: Successful endodontic treatment re-

quires effective biomechanical preparation of the root canalsand three-dimensional obturation of the root canal system.This can be achieved only by knowing and identifying thevariations in the root canal system of the endodonticallytreated teeth.

The Aim: The aim of this article is to present casesof endodontic treatment of maxillary first premolar with threeroot canals – different types.

Material and Methods: Five clinical cases of success-ful endodontic treatment of patients with maxillary firstpremolar and three root canals are described.

Result and Discussion: It is noted that good endodon-tic practice requires good knowledge of dental anatomy andpossible variations, accurate X-ray images, as well as use ofmagnifying equipment.

Conclusion: Knowledge of dental anatomy is funda-mental for good endodontic practice.

Key words: Root canal anatomy, three roots, threecanals, maxillary first premolar,

Successful endodontic treatment requires effectivebiomechanical preparation of the root canals and three-di-mensional obturation of the root canal system. This can beachieved only by knowing and identifying the variations inthe root canal system of the endodontically treated teeth. Asone of the main reasons for unsuccessful endodontic treat-ment is identified the failure to find additional root canals dueto anatomical variations [1, 2, 3].

The maxillary first premolars are described as havingtwo roots and two root canals (56%) and one root and tworoot canals (40%) [4]. Although rarely, these teeth can alsohave three roots and three root canals and are identified inthe literature as small molars, as the tooth structure and thepositioning of the roots in these cases resemble those in mo-lar teeth [4, 5]. The term “ridiculous” is also used.

Maxillary first premolars were first studied by Vertucciet al. in 1979 [4]. According to this study, 5% of 400 maxil-lary first premolars have three canals: 0.5 % of them are teethwith three canals in a single root, 0.5 % have three canals intwo roots and 4 % have three canals in three roots. Carns etal. discovered three separate canals in 6 % of the upper fourthteeth. [6]

The visualization of three root canals of the maxillaryfirst molars with preoperative radiography is not always pos-sible. This makes the cases requiring endodontic treatmentof maxillary first premolars with three canals particularly dif-ficult for successful treatment.

The aim of this article is to present cases of endodontic

treatment of maxillary first premolar with three root canals– different types.

MATERIAL AND METHODSMaxillary first premolar with three roots and three

independent root canals and independent orificesAccording to Vertucci et al. a maxillary first premo-

lar with three separate roots can be observed in 4 % of thecases. When the root canals are three and the orifices are in-dependent at the level under the pulp chamber, the treatmentdoes not present a problem. Two of the root canals are al-ways vestibular. A close view of the pulp chamber and thefinding of two vestibular orifices is a prerequisite for success-ful treatment (Figure 1).

Fig. 1. Pulp chamber of the maxillary first premolarwith three separate orifices: a –intraoral; b– with magnifi-cation.

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Clinical Case 1:The right maxillary first premolar with a large radicu-

lar carious lesion and diagnosis – chronic granulomatousdiffuse periodontitis has three roots with three canals. Twoof the root canals are buccal (mediobuccal and distobuccal)and one canal is palatal. The tooth’s buccal radicular de-fect made it possible to demonstrate the buccal root canalsby placing markers in them (Figure 2a and 2b).

Fig. 2. Buccal canals of maxillary first premolar: a– definition of working lengths; b – drying.

Passages are created in the canals by means of handinstruments. They are prepared using the crown-downmethod and mechanical nickel-titanium canal instruments.After drug treatment, ozone treatment and intracanal medi-cation with calcium-hydroxide paste, they are filled withThermafil obturators and sealer.

Clinical Case 2:Following irreversible pulpitis of the left maxillary

first premolar with three root canals, endodontic treatmentwas performed (Figure 4). Under a microscope were seentwo vestibular orifices and a palatal orifice (Figure 1 a, b).

Fig. 4. Left maxillary first premolar with three rootcanals: a-pulp chamber; b- X-ray after filling.

The mesiobuccal root has a very curved root canalwith an angle of 50º, as the curve starts from the middle andcontinues up to the tip of the root (Fig. 3 a, b).

Fig. 3. Maxillary first premolar with three canals: a– X-ray before treatment; b – X-ray after obturation of ca-nals.

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The root canals are prepared using the step-backtechnique and are obturated through the cold lateral con-densation method.

Maxillary first premolar with three roots, threeroot canals and a separate orifice and a common orifice.

A possible variation of maxillary first premolar withthree roots and three independent root canals is the pres-ence of a common buccal orifice, which subsequently splitsinto two separate canals (see Figure 5 a, b).

Fig. 5. Maxillary first premolar with three canals: a–pulp chamber; b- pulp chamber with magnification.

Right maxillary first premolar with diagnosis: Peri-odontitis chronica granulomatosa exacerbatà sum fistulae.The patient comes for treatment following a trepanation andsubsiding of the swelling. Besides periapical lesions PAI 5[7], the original X-ray shows tooth 14 with root anatomythat does not suggest the presence of three separate root ca-nals. The X-ray could possibly lead to assuming apical sepa-ration of root canals from the floor of the pulp chamber andunusual root morphology (Figure 6a).

The clinical investigation performed under a micro-scope showed that the vestibular orifice is significantlylarger and almost immediately after the common beginningtwo separate orifices are formed (Figure 5b). The canal in-struments placed in the open vestibular root canals are di-rected medially and distally (Figure 6b). The control X-ray,through gutta-percha points, shows two roots of the tooth– one vestibular and one palatal (Figure 6c). Similarly tothe initial X-ray, the one with the points also leads to theconclusion that the centering of the x-ray is not in relationto tooth 14, but more probably in relation to 15 or even 16.Only after changing the radiography laboratory for the pur-pose of controlling the filling, three independent roots withtwo vestibular and one palatal root canal (Figure 6c) are dis-played. Both vestibular root canals have a very narrow lu-men (K file 008), which combined with their large lengthof 22 mm and the great curvature of the curve (45º) of themesio-vestibular root makes this endodontic treatment oneof the most difficult clinical cases (Figure 6c).

Fig. 6. Maxillary first premolar with three canals: a – pre-operative X-ray; b – definition of working lengths; c –X-ray after obturation.

Passage is made in the canals by means of handtools; after that the canals are shaped with mechanicalnickel-titan canal instruments using the crown-down tech-nique. After antibacterial treatment of the endodontic space(irrigation with sodium hypochlorite and chelator, ozonetreatment and intracanal application of calcium hydroxidepaste), the three main canals are filled with Termafil(Maillefer) obturators and Seal Apex (Kerr) sealer [5, 8].

Maxillary first premolar with two roots and threeroot canals

According to Vertucci in 0.5 % of the cases, the max-illary first premolar has two roots and three root canals.

Clinical Case 1Irreversible pulpitis is the diagnosis of a 21-year-old

patient with spontaneous pain in the left maxillary firstpremolar and a carious lesion covering the medial surfaceand part of the central fissure of the tooth. The X-ray in-spection shows two roots, but due to the overlapping of

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shades, their apical configuration is not clear enough andthe presence of a third root canal has not been assumed.

Treatment follows the vital extirpation method. Af-ter the excochleation of the contents of the pulp chambertwo orifices are discovered – a vestibular one and a palatalone. The drilling of the canals reveals that the vestibular ori-fice is an entrance to two independent root canals with re-spective lengths – mediobuccal 19.5 mm and distobuccal 19mm with the buccal cusp as a reference point. The separa-tion of the two independent canals is about halfway of theroot length or at reference point 12-13 mm. The palatal ca-nal is 20 mm long with the palatal cusp as a reference point.The preparation of the root canals is performed by step-backtechnique, while the obturation is performed using the coldlateral condensation method, with master gutta-perchapoints for mediobuccal 02.35, for the distobuccal 02.35 andfor the palatal canal 02:30 and sealer of VDW, Germany.Radiography of the filled canals is performed with a slightdisplacement of the X-rays from the distal side (Figure 7).

Fig. 7. Maxillary first premolar with two roots andthree root canals after obturation of canals

Fig. 8. Maxillary first premolar with one merged rootand three root canals a – preoperative X-ray; b –preoperative X-ray; c – definition of working lengths; d –X-ray after obturation.

The treatment in this case is particularly difficult,because one canal in the vestibular root leaves the pulpchamber and about 7 mm from the apex separates into twocanals, which end with separate foramen – type V accord-ing to Vertucci. As a favorable circumstance, the canals arenot very curved, but nevertheless are difficult to beinstrumentally processed and filled.

The preparation of the root canals is performed bystep-back technique, while the obturation is performed us-ing the cold lateral condensation method.

Clinical Case 2Tooth 24, diagnosed with irreversible pulpitis, has one

merged root and three root canals. The preoperative X-rayshows root canals that are not clearly defined (Figure 8a).This necessitates the use of an endodontic microscope whenshaping the pulp chamber. The microscope revealed three rootcanal orifices, but of special interest is their positioning in astraight line (Figure 8b). The X-ray picture performed withgutta-percha points (Figure 8c) shows vestibular root canalsthat cross each other but remain independent.

From the respective center-point, the control X-rayafter filling shows three canals, but does not take into ac-count their autonomy. The filling is performed throughTermafil (Maillefer) obturators and Seal Apex (Kerr) sealer[5, 7].

RESULTS AND DISCUSSIONOne of the major challenges in endodontic therapy

is to treat teeth with variable anatomic configurations.The careful examination of pre-operative radiographs

is essential. In case of a doubt regarding possible variationsin dental anatomy, two diagnostic X-ray images are recom-mended [1, 2, 3, 5]. If suddenly the X-ray image of a wideand well-shaped root canal narrows or disappears, it is as-sumed that there is a special root anatomy and probably asplit of the root canal [5, 8, 9].

Of primary importance in such cases is the clinicalstudy of the root canals with a surgical microscope or amagnifying glass. The careful inspection of the shape of thepulp chamber might be a signal for a greater number of rootcanals [3, 5, 10, 11]. The buccal pulp horn is larger thanthe palatal pulp horn. The mean distance between the mostcervical region of the pulp chamber roof and the canal bi-furcation and trifurcation is 3.13 and 5.08 mm [12].

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1. Arizu HD, Alacam T. Diagnosisand treatment of three-rooted maxillarypremolars. Eur J Dent. 2009 Jan;3(1):62-6. [PMC]

2. Karumaran CS, Gunaseelan R,Krithikadatta J.Microscope-aided endo-dontic treatment of maxillary firstpremolars with three roots: A case se-ries. Ind J Dent Res. 2011; 22(5):706-8. [PubMed] [CrossRef]

3. Nica L, Ianes C, Florita Z. Rootcanal treatment of a three-rooted max-illary first premolar –a case report. En-dodontic Practice Today. 2011; 5(1):63-6.

4. Vertucci FJ. Root canal anatomyof the human permanent teeth. OralSurg Oral Med Oral Pathol. 1984 Nov;58(5):589-99. [PubMed]

5. Topalova-Pirinska Sn, Kirilova J,Pirinska Ð. Radiographic investigationof root canal morphology of permanentpremolars. Stomatologia. 2008: 90(2):98-103. [in Bulgarian]

Address for correspondence:Dr Janet Kirilova, PhDDepartment of Conservative Dentistry, Faculty of Dental Medicine,1, St. George Sofiiski Str., 1431 Sofia, BulgariaE-mail: janetkirilova@gmail.com

REFERENCES:6. Carns EJ, Skidmore AE. Configu-

ration and deviation of root canals ofmaxillary first premolars. Oral SurgOral Med Oral Pathol. 1973; 36(6):880-6. [CrossRef]

7. Ørstavik D, Kerekes K, EriksenHM. The periapical index: a scoringsystem for radiographic assessment ofapical periodontitis. Endod DentTraumatol. 1986 Feb; 2(1): 20-34.[PubMed]

8. Kirilova J, Chaucheva B,Razsipyiska ÌG. The case with three ca-nals of first maxillary premolar. Prob-lems of Dental Medicine. 2009;35(2):80- 2. [in Bulgarian]

9. Kuzmanova Y. Prospective appli-cation of the clinical and X-ray analy-sis in endodontics. Stomatology 1998;80(1):63-68. [in Bulgarian]

10. Kumar A, Iftekhar H, AndrabiSM. Endodontic management of a threerooted maxillary first premolar.Guindent. 2012; 5(2):32-33.

11. Victorio FR, Men-Martins M.Maxillary first premolar with threeroots. Case report. Dental Press Endod.2013 Jan-Apr; 3(1):73-7.

12. Vier-Pelisser FV, Dummer PM,Bryant S, Marca C, Só MV, FigueiredoJA. The anatomy of the root canal sys-tem of three-rooted maxillary premolarsanalysed using high-resolution com-puted tomogaphy. Inter Endod J. 2010Dec:43(12):1122-31. [PubMed][CrossRef]

13. Aggarwal V, Singla M, MiglaniS. Evaluation of root canal anatomy ofmaxillary premolars in an Indiansubpopulation using spiral computedtomograthy. ENDO (Long Engl). 2011;5(2):119-24.

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Establishing the presence of three root canals in thepresented endodontic treatments of maxillary first premolarsis a prerequisite for successful endodontic practice.

The study of the anatomy of the maxillary firstpremolar reveals significant anatomical variations. The es-tablishment of three canals in maxillary first premolarsranges from 1.2 % to 6 % according to various authors [2,6, 10. Definitely much rarely three canals of maxillary firstpremolar can be observed in Asian population [3, 10,13, ].

An interesting anatomical feature has been reportedby Sieraski et al. When the mesio-distal width of the mid-

dle part of the root in the X-ray is equal to or greater thanthe width of the tooth’s crown, it is possible that we havethree roots in the maxillary first premolar [14].

CONCLUSIONKnowledge of dental anatomy is fundamental for

good endododntic practice. Although the frequency of max-illary second premolars with three root canals is rare, eachcase should be investigated carefully and radiographically,to detect the anatomical anatomy.

Please cite this article as: Kirilova J, Topalova-Pirinska S, Kirov D. Variation of Maxillary First Premolar withthree root canals. J of IMAB. 2014 Jul-Sep;20(3):584-588. DOI: http://dx.doi.org/10.5272/jimab.2014203.584

Received: 07/07/2014; Published online: 19/09/2014