Mid 19th century; earliest use found in Thomas Huxley (1825–1895), biologist and science educationist. From ortho- + -gnathism, after orthognathic, orthognathous.
Definition of orthognathism in US English:
orthognathism
nounɔːˈθɒɡnəθɪz(ə)m
Anthropology
The condition of being orthognathous.
Origin
Mid 19th century; earliest use found in Thomas Huxley (1825–1895), biologist and science educationist. From ortho- + -gnathism, after orthognathic, orthognathous.