Mandibular first molar with six root canals: a rare entity

Endodontic treatment of the mandibular first molar with six root canals: A case report and literature review

The mandibular first molars normally have three or four root canals and rarely have five or more root canals. The present study reported a rare anatomical configuration with six root canals in the mandibular right first molar diagnosed during endodontic treatment using a dental operating microscope and confirmed with the help of cone-beam computed tomography (CBCT) images. The present case report revealed that there is an increasing possibility of detecting additional canals through the magnification of the microscope and the improvement of CBCT diagnostic technology. As more abnormal morphologies in root canals are reported, dentists need to understand this diversity in anatomical structure and improve treatment techniques.

Morphology and prevalence of middle canals in the mandibular molars: A systematic review

Objectives:

The purpose of this paper is to systematically review the various studies and case reports on the morphology and prevalence of middle canals in the mandibular molars.

Methodology:

Electronic databases such as MEDLINE, PubMed, EBSCOhost, ScienceDirect and various journals were screened to identify published literature till March 2017 and earlier for articles related to middle canals in the human permanent mandibular molars. Obtained articles were categorized as original researches, case reports and review articles. Well-defined review questions were developed using the patient population, intervention, comparison and outcome framework to summarize the objectives: “Does middle canal vary in morphology and anatomic location? What is the prevalence of middle canals in mandibular molars? Does ethnicity affect the prevalence of middle canals in mandibular molars?” Morphology was studied and prevalence rates were determined from the evaluation of data extracted from the articles.

Results:

The search strategy resulted in 87 articles, of which 36 were original research papers and 51 were case reports. The prevalence of middle canals in the various populations ranged from 0.26% to 53.8%. Middle canals were reported in Europeans, Asians, Africans and South and North American populations. The prevalence of middle mesial canal and middle distal canal in various races was reported as up to 53.8% and 10%, respectively. The orifice of middle canal exists below a dentinal projection in the groove between the two main canals. They were observed in fin, confluent and independent configuration. Out of these, confluent configuration was more prevalent.

Conclusion:

Middle canal varies in morphology and anatomic location. Ethnicity affects the prevalence of middle canals in the mandibular molars.

Endodontic treatment of the mandibular first molar with six roots canals - two case reports and literature review

The most common configuration of the mandibular first molar is the presence of two roots and three root canals. The objective of this work is to present two rare anatomic configurations with six root canals on two mandibular left first molars diagnosed during endodontic therapy. Root canal therapy was performed using a dental operating microscope. Ultrasonic troughing in the grooves in between the mesial root canals and in between the distal root canals was able to show the middle root canals. Large samples population characterization researches and systematic reviews were unable to detect a single case of six root canals configuration in a mandibular first molar in their investigations. Although it is a rare configuration, a six root canal configuration is possible to be found in the mandibular first molar. Three different pulp chamber configurations are possible to be found. Two or three roots may be present and the root configuration more common in the mesial root is the Type 8 and Type 12 for the distal root. Some concepts about the required technique to approach these cases are also debated.