gnathic index 名詞
頜指數,頜突度
Me·sog·na·thous a. Anat. Having the jaws slightly projecting; between prognathous and orthognathous. See Gnathic index, under Gnathic.
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Or·thog·na·thous a. Anat. 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.
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Prog·na·thous a. Anat. Having the jaws projecting beyond the upper part of the face; -- opposed to orthognathous. See Gnathic index, under Gnathic.
Their countenances had the true prognathous character. --Kane.
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Fa·cial a. Of or pertaining to the face; as, the facial artery, vein, or nerve. -- Fa*cial*ly, adv.
Facial angle Anat., the angle, in a skull, included between a straight line (ab, in the illustrations), from the most prominent part of the forehead to the front efge of the upper jaw bone, and another (cd) from this point to the center of the external auditory opening. See Gnathic index, under Gnathic.
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Gnath·ic a. 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.
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