Frequency of Two Canals in Maxillary Premolars at a Dental Teaching Institution

Frequency of Two Canals in Maxillary Premolars at a Dental Teaching Institution
Talha M Siddiqui1, Aisha Wali2, Noman Qamar3

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Siddiqui TM, WaliA, Qamar N. Frequency of two canals in maxillary premolars at a dental teaching Institution. J Pak Dent Assoc. 2012;21(03): 173 – 176


The aim of the present study was to estimate the frequency of two canals in maxillary second premolars in patients from Gadap area attending Out Patient Department at Baqai dental College.


The study included 100 patients requiring root canal therapy, out of which 32 were females and 68 weremales. Two periapical radiographs were taken at different angulations, numbers of canals were visible on the X-ray were recorded and then verified clinically upon access opening. Frequency and percentages was analyzed by using SPSS 19.0


We observed type-I canal configuration in16%, type II in 49%, type III in 12%and type IVin 23%.


It is concluded that the occurrence of two canals in maxillary premolars was high in our study population.Type II canal configuration is themost prevalent among our sample followed by type IVand type I


maxillary second premolar, root canal morphology, Vertucci’s classification, frequency of two canals inmaxillary second premolar


Success of endodontic therapy depends on clear understanding of canal configuration . The mostpossible reason for failure of endodontic therapy is a lack of knowledge of morphology of the root canal . Researches done on the internal and external anatomy of teeth have shown that anatomic variations can occur in all groups of teeth and can be extremely complex . Factors that contribute to the variations found in the root canal studies includes ethnicity , age , gender and study design . The maxillary second premolars are among the most difficult teeth to be treated endodontically .

Vertucci , De Grood and Cunnighan and Maniglia- Ferrana et al reported that number of failures could be attributed due to anatomical variations, such as presence of canals not usually found. Radiographic examination requires angled exposure and is of great importance for the endodontist for distinguishing the correct configuration of roots and root canals, assisting in correct diagnosis . Vertucci classified canal configurations into the following types.
Type I: one canal fromthe pulp chamber to apex.
Type II: Two canals with two orifices leaving the pulp chamber but joining short of the apex to formone canal.
Type III: One orifice leaving the pulp chamber and splits into two canals then joins into one apical for a men.
Type IV: Two orifices with two distinct canals from the pulp chamber to the apex.
Type V: One orifice leaving the pulp chamber and splitting into two separate and distinct canals with separate apical for a men.
Type VI: Two orifices with two canals canals leaving the pulp chamber, merging in the body of the root and redividing into two distinct canals.
Type VII: One orifice with one canal then splits into two, joins into one then splits into two distinct canals short of the apex.
Type VIII: One orifice with three separate and distinct canals from the pulp chamber to the apex.

Prevalence of single canal in maxillary second premolars was detected in 48% of cases, two canals may be found in 58% of cases . Vertuccietal found type II canal in 22%, type III canal in 5%, type IV in 11%, type V in 6%, type VI in5%, type VII in2%and type VIII in1%.

These studies previously were performed on Indian , Chinese , Turkish and North American population .

However uptil now there is only one study reported on estimation of two canals inmaxillary premolars in relation to gender and age in Pakistani population 20

The aim of the present study was to estimate the frequency of two canal configuration in maxillary second premolars in patients from Gadap area attending Operative Dentistry Department at Baqai Dental College.


This, in vivo descriptive cross sectional study was carried out on patients attending Operative Dentistry Department at Baqai Dental College, Karachi from June 2011- December 2011. All patients requiring root canal therapy inmaxillary second premolarwere included in the study. Teeth with resorbed roots, sclerosed , calcified canals ,roots not fully formed were excluded from the study. Ethical approval of the studywas obtained from the ethical committee, Baqai Medical University and each patient signed informed consent. After administering local anesthesia using 2% lignocaine 1:80,000 epinephrine, Straight line access was made into pulp chamber through buccopalatal outline form for easy access to root canal. Canal was explored with DG-16 endodontic explorer. K-hand files were inserted into the canal and two periapical radiographs at different angulations were taken. The number of canals were explored and recorded in a data sheet. The data were statistically analyzed for frequencies and percentages using SPSS 19.


The results of our study showed that out of 100 patients treated, 32 were females and 68 were males (Table I). According to Vertucci root canal configuration the frequency came outwith type 1 in16%, type II in 49%, type III in 12%, type IV in 23% as shown in ( Table 2). Type II was the most prevalent canal configuration found followed by type IV, type I, type III. (Table 3) shows the frequency of root canal according to Vertucci among males and females.


Root canal morphology is considered to be utmost important factor when performing endodontic therapy. Maxillary second premolar showswide variations in canal configuration. The present study was conducted on a small population attending OutPatient Department at Baqai Dental College. During the six month study period, June 2011- December 2011, the total number of included patientswere 100. Using angled radiographs, Sardar et al identified a higher number of premolars with two canals . Sieraski et al found that mesiodistal width of the crown, the premolar likely to have three roots. Jesus et al found that 67.3% had one canal, 32.4% two canals and 0.3% three canals. Previous studies in literature reported frequency of two canals by Hess was 42%, Pineda and Kuttler was 45%,Green was 28%,Vertucci and Gregauff was 24%, Bellizzi and Hartwell was 58.6%, De Deus was 46.3%, Sardar KP was 78%. Researches by various authors on types of canals were also reported , Caliskan etal type I 44%, type II 22%, type III 6%, type IV 12%. Kartal etal reported type I 48.6%, type II 6.3%, type IV37.99%. Sert and Bayirili found type I 32%, type II 20%, type III 10%, type IV 25.5%. Udayakumar reported type I in 29.2%, type II in 33.6%, type III in 1.3%, type IVin 31.1%.Weng etal found type I in 27.7%, type II in 36.9%, type IV in 33.8%. Our study results differ from some studies (Table 4).The most common canal configuration found in this study was Vertucci type II followed by type IV, type I, type III.

It ismandatory to clean, shape and obturate root canal.In Vertucci type III configuration there is one opening which divides into two isthmus and rejoins at apex again forming one exit, Isthmus is an narrow, ribbon shaped communication found in teeth with multiple canals , In this case we cleaned, shaped and obturated the canals separately. . It means that these 12% of type III Vertucci cases requires special attention during endodontic treatment. Vertucci type 1, II and IV were prepared straight forwardly and obturated. Endodontists when treating Maxillary second premolars should be cautious of the anatomical configuration in order to avoid any mishap of leaving a missed canal. To avoid this, careful examination of the root canals should be done . Furthermore, two diagnostic radiographs should be taken with parallel and shift cone angle techniques


Type II vertucci was the most frequent canal configuration found in our study sample


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