Independent and Confluent Middle Mesial Root Canals in Mandibular First Molars: A Report of Four Cases

Abstract

Mandibular molars demonstrate considerable variations with respect to number of roots and root canals. The possibility of additional root canals should be considered even in teeth with a low frequency of abnormal root canal anatomy. This paper discusses the endodontic management of the rare anatomical complexity middle mesial canals in mandibular first molar and also serves to remind the clinicians that such anatomical variations should be taken into account during the endodontic treatment of the mandibular molars.

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

“…Deepalakshmi et al . [ 70 ] reported four cases of MMC in mandibular first molars in which the middle canal was present at equidistance between the two mesial canals. De Moor RJ et al .,[ 60 ] presented two cases of MMC, one located almost equidistant from the two main canals of a left mandibular first molar and the other located very close to the MB canal of a right mandibular first molar.…”

“… Mandibular first molar with MMC[ 3 42 43 44 45 46 48 49 52 53 54 55 56 59 60 61 67 70 71 72 73 74 80 ] Mandibular second molar with MMC[ 43 72 ] Mandibular first molar with MDC[ 51 57 64 65 68 ] Mandibular first molar with MMC and MDC[ 3 53 55 56 71 73 80 ] Mandibular first and second molar with double middle mesial[ 47 50 66 75 78 ] Mandibular first molar with double distal canal[ 63 76 77 79 ] Mandibular first molar with DMMC and MDC[ 47 ] Mandibular second molar with DMMC and MDC[ 78 ] Mandibular first molar with DMMC and double MDC[ 77 ] Mandibular first molar with one distal root with three canals at orifice exiting as two canals[ 64 ] Mandibular first molar with two distal roots, with one canal at the orifice and apex in one root and two canals at the orifice exiting as one canal at the apex in the other root[ 40 41 ] Mandibular first molar with two distal roots with two independent canals in each root[ 63 ] Mandibular first molar with three distal roots with one canal in each root[ …”

Endodontic retreatment of a mandibular first molar with five root canal systems: an important clinical lesson

“…However, the presence of internal anatomic variances and anomalies is not uncommon. Among these internal deviations, the incidence of middle mesial canals ranges from 0.5% to 15% based on several case reports which make them difficult to locate 6 8–15 17. Moreover, these canals are known to have a high frequency of intercanal isthmuses which pose an additional barrier to shaping and cleaning procedures 21…”

“…There is a general consensus on the presence of multiple foramina in the mesial root of the mandibular first molars, however, the presence of three separate canals is still considered a very rare finding 17. With regard to the root canals, teeth demonstrate several anatomical variations and aberrations which pose a significant challenge to the clinician 18.…”

Management of middle mesial canal under dental operating microscope

“…3 In addition, literature also describes occurrence of an extra canal in the mesial root of the mandibular molars referred to as "intermediary mesial canal" or the "middle mesial canal". 4 The percentage of this clinical phenomenon is low and usually cited subsequent to careful exploration of the isthmus connecting the main mesiobuccal (MB) and mesiolingual (ML) canal. This paper describes successful non-surgical management of two cases of mandibular first molar with middle mesial (MM) canal under DOM.…”