opisthiobasial

o·pis·thi·o·ba·si·al

(ō-pis'thē-ō-bā'sē-ăl),
Relating to both opisthion and basion; denoting a line connecting the two or the distance between them.

opisthiobasial

(ō-pĭs″thē-ō-bā′sē-ăl)
Pert. to the opisthion and basion of the skull.