Usually the fourth upper and first lower, and sometimes the sixth lower, tooth-rows are interrupted medially.
"A Review of the Middle American Tree Frogs of the Genus Ptychohyla"
William E. Duellman
The edge of the dentary rises above the bases of the teeth medially, thereby producing a small depression at the junction of each base with the dentary bone.
"Two New Pelycosaurs from the Lower Permian of Oklahoma"
Richard C. Fox
Gravity, acting chiefly upon the distal fragment, also plays a part in determining the displacement-for example, in fractures of the thigh or of the leg, where the lower segment of the limb rolls outwards, and in fractures of the shaft of the clavicle, where the weight of the arm carries the shoulder downwards, forwards, and medially.
"Manual of Surgery Volume Second: Extremities--Head--Neck. Sixth Edition."
Alexander Miles Alexis Thomson