Received date : June 26, 2012; Accepted date : August 16, 2012; Published date : August 18, 2012
Citation: Karale R, Hegde J, Srirekha A, Sravanthi Y (2012) Multirooted- Bilateral Maxillary and Mandibular First and Second Premolars- A Rare Anatomical Variation. Dentistry 2:140. doi: 10.4172/2161-1122.1000140
Copyright: © 2012 Karale R, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Introduction: A thorough understanding of root canal anatomy and morphology is required for achieving high levels of success in endodontic treatment .The possible anatomic configurations of premolars are well documented in the literature, except for the small incidence of bilateral multi-rooted maxillary and mandibular premolars with three canals.
Case report: A 36 yrs old female patient was evaluated for painful maxillary left Ist and IInd premolars. Physical examination revealed no alteration or apparent mental retardation. Panoramic and periapical X-rays revealed multiple roots and canals in maxillary and mandibular Ist and IInd premolars. This article reports and discusses the treatment recommendations for an unusual occurrence of three canals in both the first and second maxillary premolars in the same patient drawing particular attention to radiographic interpretation and access management.
Conclusion: Findings emphasize the importance of radiographic assessment for diagnosing multiple roots which might present unusual characteristics such as multiple and bilateral appearance. The absence of a syndrome should not be used to rule out the possible manifestation of this morphologic variation.
Maxillary premolars; Mandibular premolars; Multirooted; Bilateral; Root aberrations; Endodontic treatment
To achieve endodontic success, the entire root canal system must be debrided, disinfected and obturated. Clinically, precise 3-dimensional determination of the internal structure of teeth, their form and no. of root canals is a challenge. The clinician must have a thorough understanding of normal anatomy, and of common variations from the normal anatomy. The clinician must also be able to identify those teeth that tend to vary greatly from the norm, e.g. premolars. There seems to be a racial predisposition for the presence of two or more canals in maxillary and mandibular premolars [1,2] as well as their bilateral occurrence .
In endodontic literature very few studies have shown the reasons for endodontic failures. Hoen and Pink found a 42% incidence of missed roots or canals in the teeth requiring retreatment in their investigations .
The reported frequency of maxillary first premolar varies from 0.5% to 6% . Three rooted maxillary second premolars are very rare and frequency varies from 0% to 1% . Zilich and Dawson  reported 11.7% occurrence of 2 canals and 0.4% of three canals. Ingle reported mandibular second premolars have only 12% chance of a second canal and 0.4% of a third canal and Wong has reported 11% possibility of second [7,8]. Vertucci  and Zilich  reported the occurrence of three canals in mandibular first premolar at 0.5% and 0.4% respectively and in second premolar at 0.0% and 0.4% respectively. A study at the University of Washington assessing the results of endodontic therapy, the mandibular premolar showed the highest failure rate of all types of teeth [2,3].
Clinicians have often noted that aberrant root morphology in a given tooth is also observed with varying degrees of frequency in the corresponding contra lateral tooth. Bifurcation of the canal in mandibular first premolar was the most common finding 22.8%, with 60% of there being bilateral. It was observed that unusual root morphology is bilateral approximately 60% of the time. Therefore, the incidence of root or root canal abnormalities reported by the percentage of patients involved will always exceed the incidence of abnormalities reported by the type of tooth (e.g. mandibular canine) involved except for abnormalities which are found bilateral in 100% of patients studied. Radiographic interpretation appears to result in a lower incidence of anatomical aberrations than direct identification. The more rare the aberrations, the more likely it is to be bilateral in occurrence . There are very few reported cases of such bilateral multi rooted presence of mandibular and maxillary premolars in the same patient.
So the purpose of this article is to report, as well as discusses, treatment recommendations for an unusual occurrence of multi rooted bilateral maxillary and mandibular premolars in the same patient.
A 36 yrs old female patient with a non-contributory medical history referred to the department of conservative dentistryand endodontics of the Oxford dental college, Bangalore with a history of spontaneous, dull aching pain in left maxillary back region. Left maxillary first and second premolars showed temporary restoration with positive pain on percussion. Right maxillary first and second premolars, root stumps were seen. Right mandibular first molar showed mesial deeply carious lesion where as II premolar showed distal carious lesion.
An OPG was advised for multiple carious teeth. OPG examination showed pulp involvement of maxillary left I and II premolars which was confirmed with pulp vitality test. Both teeth were sensitive to cold test and EPT with responses indicating irreversible pulp involvement. So the endodontic treatment was planned for left maxillary I and II premolar and right mandibular I molar where as restorative treatment for right mandibular II premolar. The OPG showed (Figure 1) that nearly all the premolars had multiple roots, so IOPAs of maxillary right and left premolars, mandibular right and left premolars were taken at different angles which confirmed the presence of three roots in all premolars (Figures 2 and 3).
So the maxillary left I and II premolars were isolated under local anaesthesia and access cavity was modified with a cut at the buccoproximo angle from the entrance of the buccal canals to the cavosurface angle resulting in a cavity with a T-shaped outline as described by Balleri et al. .
After removing the coronal pulp, the buccal canals were explored with sizes no. 8 and 10 files and the palatal with a size 15 K file, resulting in clinical and radiographic confirmation of three canals (Figure 4). The root canal preparation of buccal canals was completed to size F1 ProTaper (Dentsply, Maillefer) & palatal canal to size F2 ProTaper with copious irrigation using 17% EDTA and 5.25% sodium hypochlorite. After drying, the canals were obturated with AH plus sealer and gutta percha using lateral condensation (Figure 5). The access cavity was sealed with GIC (Ketac fil, 3M ESPE, Seefeld, Germany) and the patient was appointed for permanent restoration. Recall visit after 2 yrs showed healing of periapical lesion (Figure 6).
The precise three-dimensional determination of the internal structure of teeth, their form and number of root canals is a challenge clinically. Because of the complex, varied morphology of the premolars, endodontic treatment in the premolar is a challenging task. The anatomy of maxillary premolars with three root canals, mesio-buccal, disto-buccal and palatal, is similar to that of adjacent maxillary molars, and they are therefore sometimes called molars or ‘radiculous’ [12,13]. Accurate preoperative radiographs, straight and angled, using parallel technique is essential in providing clues as to the number of roots that exist . Abrupt straightening or loss of a radiolucent canal in the pulp cavity, an extra canal should be suspected that could be in the same root or independent root. Sieraski et al.  found that whenever the mesio-distal width of the mid-root image was equal to or greater than the mesio-distal width of the crown, the tooth most likely had three roots. Sabala et al.  studied 501 patient records for aberrant root and root canal morphology. In the study, occurrence of the same aberration on the contralateral tooth varied according to the type of anomaly. Out of 501 patients, four patients found to have threerooted maxillary first premolars, all were bilateral. Their study found that the rarer the anomaly, the greater the incidence of the anomaly occurring bilaterally. Those anomalies occurring less than 1% found to occur bilaterally up to 90% of the time. The bilateral symmetry of the three-rooted premolars expected in many patients, as this anomaly is quite rare. Keeping this fact in mind, we could successfully detect the multiple roots in nearly all premolars of the patient.
Diagnostic measures such as multiple pre-operative radiographs, examination of pulp chamber floor with a sharp explorer, troughing of grooves with ultrasonic tips, staining the chamber floor with 1% methylene blue dye, performing the NaOCl ‘champagne bubble’ test and visualizing canal bleeding points are important aids in locating root canal orifices. Yoshioka et al.  have indicated that sudden narrowing of canal system (fast break rule) on a parallel radiograph suggests canal system multiplicity. Martinez–Lozano et al. have suggested a 40 degree mesial angulation of X-ray beam to identify additional canals . Clinicians should be aware of anatomical variations in maxillary and mandibular premolars and be able to apply this knowledge in radiographic and clinical interpretation. Findings emphasize the importance of radiographic assessment for diagnosing multiple roots which might present unusual characteristics such as multiple and bilateral appearance. The absence of a syndrome should not be used to rule out the possible manifestation of this morphologic variation.