Ullik's concavity
The Ullik concavity , named after Rudolf Ullik , is an atypical secondary feature in the area of the lower canines (33, 43). Usually the distal boundary line is always more curved than the mesial one. The canines of the lower jaw (33, 43) can, however, represent an exception: the distal boundary line is strongly curved, but can have a concavity in the cervical third. This concavity is called Ullik's concavity.