Word Study
orthognathous
CIDE DICTIONARY
orthognathous, a. [Ortho- + Gr. gna`qos the jaw.].
Having the front of the head, or the skull, nearly perpendicular, not retreating backwards above the jaws; -- opposed to prognathous . See Gnathic index , under Gnathic. [1913 Webster]
OXFORD DICTIONARY
orthognathous, adj. (of mammals, including man) having a jaw which does not project forwards and a facial angle approaching a right angle.
Etymology
ORTHO- + Gk gnathos jaw
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