Table 1.

A review of the case reports with the discovery of three or more canals in distal root/roots of mandibular first molars

Investigator	Year	No. of mesial roots	No. of distal roots	No. of mesial canals	No. of distal canals	Distribution of canals in distal root
Stroner et al.[9]	1984	1	2	2	3	Distobuccal 1&2and distolingual
Beatty and Interian[18]	1985	1	2	2	3	Distobuccal, mid-distal, distolingual
Friedman et al.[19]	1986	1	3	2	3	Distobuccal, distal center, distolingual
Reeh [16]	1998	1	1	4	3	Distobuccal, mid-distal, distolingual
Kimura and matsumoto[20]	2000	1	2	2	3	Distobuccal and distolingual 1&2
Lee et al.[21]	2006	1	3	2	3	Distobuccal, distal center, distolingual
Ghoddusi et al.[6]	2007	1	2	2	4	Distobuccal 1&2 , mid-distal, distolingual
Bareletta et al.[22]	2008	1	2	2	3	Distobuccal and distolingual 1&2
Chandra et al.[23]	2009	1	1	2	3	Distobuccal, mid-distal, distolingual
Kottoor et al.[14]	2010	1	1	2	3	Distobuccal, mid-distal, distolingual
Mushtag et al.[24]	2011	1	1	2	3	Distobuccal, mid-distal, distolingual