Opisthoglyphous is a coordinate term of proteroglyphous.

In of a snake terms the difference between proteroglyphous and opisthoglyphous

is that proteroglyphous is having shortened maxillae bearing few teeth except for a substantially enlarged fang that forms a hollow needle for injecting venom while opisthoglyphous is whose teeth include an enlarged pair at the back of the maxillae which normally angle backwards and are grooved to channel venom into the puncture.