Lim S S
Dent J Malays. 1985 Jan;8(1):13-6.
The mandibular first molar usually has only two mesial canals, a mesiolingual and a mesiobuccal. Cases of a third canal described as the middle mesial canal has been reported and is found to be uncommon. In this case report, three canals in the mesial root of a mandibular first molar were located, prepared and filled. The third canal presented as a fin when during instrumentation the instrument could pass freely between the mesiolingual canal and the middle mesial canal.
下颌第一磨牙通常只有两条近中根管，即近中舌根管和近中颊根管。有报道称存在第三条根管，即中间近中根管，但这种情况并不常见。在本病例报告中，在下颌第一磨牙的近中根发现了三条根管，并进行了预备和充填。在根管预备过程中，当器械能够在近中舌根管和中间近中根管之间自由通过时，第三条根管呈鳍状。
