[The dimensions of the roots and root canals of human premolars and molars]

Dental roots and channels were measured in 160 premolars and molars on human upper and lower jaws. The longest roots were found in 5-th teeth and shortest in 7-th. The data suggest that dental channels can be extended up to 10 mm. Their maximal widening in upper jaw molars and premolars is 1 mm and in lower premolars 1.2 mm.