Gnath"ic (?), a. [Gr. ? the jaw.]
(Anat.) Of or pertaining to the jaw.
Gnathic index, in a skull, the ratio of the
distance from the middle of the nasofrontal suture to the basion
(taken equal to 100), to the distance from the basion to the middle
of the front edge of the upper jaw; -- called also alveolar
index.
Skulls with the gnathic index below 98 are
orthognathous, from 98 to 103 mesognathous, and above 103 are
prognathous.
Flower.