Endodontics: Anatomical consideration (pulp canal) of all teeth

The root canal usually starts as a funnel-shaped at canal orifice and terminates at the apical foramen.
Normal anatomical features of the pulp space include:
•pulp chamber and root canal
•pulp horns
•root canal orifices
•apical foramina
It is important to understand the anatomical complexity of the spaces in which root canal infection could reside.
Nearly all of the root canals are curved, especially in facio-lingual direction. As a result, these curvatures could affect cleaning and shaping of the canals such as in S-shaped canals.
Variations in the root canal anatomy:
Canal systems are, however, almost infinitely variable and can have:
•lateral canals
•additional canals
•multiple foramina
•accessory canals
•accessory foramina
•fins
•deltas
•loops
•web or internal connections (isthmuses between 2 canals)
•anastomoses
•root canal furcation (such as bi-furcation or tri-furcation, could be formed in multirooted teeth during the formation of pulp chamber floor by the entrapment of periodontal vessels)
•C-shaped canals or configurations. Irregularities and aberrations in the root canals, such as hills and valleys in canal walls, internal communications (isthmuses between 2 canals), cul-de-sacs and fins, particularly in posterior teeth could be not accessible to instruments and/or irrigants.