A RARE CASE OF UNILATERAL MANDIBULAR SECOND MOLAR WITH THREE DISTAL ROOTS DIAGNOSED WITH SPIRAL COMPUTED TOMOGRAPHY - DENTAL BOOKS

A RARE CASE OF UNILATERAL MANDIBULAR SECOND MOLAR WITH THREE DISTAL ROOTS DIAGNOSED WITH SPIRAL COMPUTED TOMOGRAPHY

Case Report

A RARE CASE OF UNILATERAL MANDIBULAR SECOND MOLAR WITH THREE DISTAL ROOTS DIAGNOSED WITH SPIRAL COMPUTED TOMOGRAPHY
The variations in root canal morphology, especially in multi-rooted teeth, are a constant challenge for diagnosis and successful endodontic therapy. Complete knowledge of the root canal anatomy is mandatory because the non–treatment of one canal can lead to endodontic failure. Most endodontic textbooks and dental anatomy books describe the mandibular second molar as having two roots; one mesial and one distal with two, three or four root canals. However, mandibular second molars with a conical root and wide single root canal have also been reported.

Every attempt should be made to find and treat all root canals to ensure successful endodontic treatment. The clinician must have a thorough understanding of normal anatomy and of common variations. The clinician must also be prepared to identify those teeth that exhibit unusual anatomical configurations.

This case report describes a mandibular second molar with four roots – three distal roots (distobuccal, middle distal, distolingual – DB, MD and DL, respectively) and one mesial root and five root canals (mesiobuccal, mesiolingual, distobuccal, middle distal,  istolingual – MB, ML, DB, MD, DL) diagnosed with spiral computed tomography.
A 33-year-old male reported with pain in the mandibular left molar for 4–5 days. On clinical examination, the left mandibular second molar was found to be tender on percussion. No periodontal pockets were present, and the medical history was non-contributory. On periapical radiographic examination, the left mandibular second molar was found to be carious with the pulp distally 

The tooth was anaesthetised using 2% lignocaine with 1:100,000 adrenalin) and isolated under rubber dam. The carious lesion was excavated, and an adequate endodontic access cavity was prepared with distolingual extension to provide proper access to the distolingual canal. The pulp chamber was flushed with 3% sodium hypochlorite to remove the debris. After finding the four canal orifices, a radiographic x-ray was taken to determine the working length of the canals. The first initial file radiograph was taken with two instruments in the mesial root canals and two instruments in the distal roots. A working length radiograph confirmed two distal roots and canals but revealed one more additional distal root. To confirm this unusual root morphology of the mandibular second molar, spiral computed tomography was planned after obtaining patient’s consent. Spiral computed tomography at three levels (cervical, middle and apical) confirmed a left mandibular second molar with four roots - three distal (distobuccal, middle distal, distolingual) and one mesial and five root canals namely mesiobuccal, mesiolingual, distobuccal, middle distal, distolingual. Spiral computed tomographic images revealed a third distal orifice, which was located very distally in comparison to other two distal orifices.

A RARE CASE OF UNILATERAL MANDIBULAR SECOND MOLAR WITH THREE DISTAL ROOTS DIAGNOSED WITH SPIRAL COMPUTED TOMOGRAPHY

After enlarging the access cavity to distal aspect, the pulp chamber was again explored using ethylenediaminetetraacetic acid (EDTA) and size 10 K-file for locating the third distal orifice, which was totally calcified. This third distal orifice between the distobuccal and distolingual orifice was located far on the distal aspect of the pulp chamber in relation to the other two distal orifices. A radiograph was again taken with an initial file in three distal roots. Instrumentation was performed in all of the canals using rotary ProTaper. The crown-down technique was used to prepare canals up to size 25, which was the master apical file. The canals were irrigated with 5.25% sodium hypochlorite during treatment and finally with normal saline. The canals were then dried with paper points and obturated with gutta-percha points.