Mandibular incisor anatomy – Mandibular central and lateral anatomy

The mandibular incisor anatomy partially because the root is so small and there is a high percentage of teeth with more than one canal. This is not what many were taught in dental school.

Mandibular incisor anatomy basics

Mandibular incisors almost always have only 1 foramen which explains why even those never finding a second canal have success. However, the anatomy is complex and possibly half have 2 canals at some point.

Mandibular incisor anatomy research

Micro-CT 612 Brazilian teeth – Leoni 2014

• Accessory canal absent 60% and 74% central and lateral
• 1-2 in 38% and 26% central and lateral (all apical 1/3)
• 2% central had apical delta

•  84% and 90% 1 canal at 1mm central and lateral
• 12% and 8% 2 canal at 1mm central and lateral
• 4% and 2% 3 canals at 1mm central and lateral

• 92-94% centrals seem to have just one apical foramen
• 96% laterals seem to have just one apical foramen

Micro-CT 340 Brazilian teeth

• 75% 1
• 16% 1-2-1
• The rest account for 8% total

Shemesh has article in JOE from 2018 with CBCT of around 3000 incisors and found more than one canal in 40%.

Han 2014 JOE 3871 teeth CBCT China

non-CT dental research on mandibular incisor anatomy

Sectioning study 100 teeth Mauger 1998  2 canals 1mm from apex 2%

Kartal 1992 100 teeth dissection Very similar to Leoni results – Type 1 1 55%   Type 2 2-1 16%    Type 3 1-2-1 20%   Type 4 2 4%    Type 5 1-2 3%   Type 6 2-3-1 1% Type 7 1-2-1-3 1%

• 92% have one apical foramen

Miyashita 1997 1085 teeth – Type 1 88%   Type 2 9%   Type 3 1%   Type 4 2%

• 95% have one apical foramen
• other differences are likely just less stringent methods of categorization

Vertucci found that 70-75% have a single canal and 1 foramen in JADA 1974 and that only 2-3% have more than one foramen.

Green found that 79% have a single canal and 1 foramen in 1973.