Anatomy MB2 second molar

Anatomy of the second molar has a lot of variability in the research. I cover why I think some of that is in my first molar blog. However, here is one example where it gets tricky on what someone is calling an MB2 or MB3. This root could be said to have 3 canals! However, the MB1 and MB2 join very qquickly and became one canal through the process of filing. The MB3 joins the other two at some point as well, so are these canals or fins? The canal anatomy was likely one large oval at one point in life.

 

Palazzolo Endodontic Practice 2015  40% MB2, more in men (bigger?), more in younger=less calcified (70% drop to 39% both first and second though), more in those without crown=less calcified and maybe better access, and more in older endo residents

Silva JOE 2014 – Brazil CBCT  306 teeth – 3 roots 3 canals 45% – 3 roots 2 MB 34% – fusion of roots with 1, 2, or 3 canals were 2%, 4%, and 2% respectively – 2 roots 2 canals 4% – 2 roots 3 canals 9%
4 canals – 34%
3 canals – 56%
2 canals – 8%
1 canal – 2%

24% of these have MB2 July 2012 Versaini 2012 (sample of 25)  consistent with 3 rooted molar.  They also created a classification system based on root divergence for these, which is kind of stupid

3 roots 3 canals – 57%

3 roots 4 canals with MB2 – 23%

3 roots and 3 canals that the buccal canals join – 9%

2 roots 2 canals – 7%

1 root 1 canal – 3%

Korean population study CBCT 660 teeth 2012 JOE Single root 5% and 11% fused 34% MB2 .3% MidBuccal root .3% DB2 and 2% P2

Corcoran 2007 JOE 46% to 63% from beginning to end of endo residency.  Initial experience helps

Wolcott 2005 JOE 2038 teeth but includes retreats so little lower.  34% found in untreated teeth  40% in retreats

al Shalabi IEJ 2000 MB2 58% the occurrence of two canals and transverse anastomoses decreased significantly with increasing age

Stropko JOE 1999 Clinical 611 second molars.  MB2 51% as separate canal 47%. However, as the operator became more experienced, scheduled sufficient clinical time, routinely employed the dental operating microscope, and used specific instruments adapted for microendodontics, MB2 canals were located in 93.0% of first molars and 60.4% in second molars.

Peikoff 1996 IEJ 520 completed RCT  23% MB2

Kulild 1990 JOE 54% by hand, 86% with bur, and 94% with scope.

4 roots (2 palatal) – 1200 radiographic result .4% have 4 Libfeld JOE 89

CBCT studies of second molar root canal anatomy MB2

42% one canal and 11% have 2 POE. 68% have 2 at some point. Small number are single rooted Ghobashy JOE 2017

C Shaped canal

Martins JOE 2016 4% have c shaped canal somewhere

 

Palatal canal studies

Variation in palatal canals is very low, 2%, but can be much higher in certain Asian ethnic groups reaching 14% in first molars. Nosrat JOE 2017

DB root studies

Fogel lit review JOE 2017 shows 1.7% have 2 canals, unsure how first and second molars differ.