Orbital

(or'-bit-al). I. Pertaining to the orbit. 2. The orbital portion of the orbicularis palpebra rum. O. Arch, the upper margin of the orbit. O. Breadth, in craniometry, the distance between the middle points of the inner borders of the orbits. O. Fascia, the capsule of Tenon. O. Fi ure. See Fi ures, Table of. O. Fo a, the cavity of the orbit. O. Height, in craniometry, the greatest vertical width of the opening of the orbit. O. Index. See Index . Plane. See Plane. O.Plate: I. That part of!e frontal bone helping to form the roof of the orbit. 2. That part of the ethmoid bone helping to form the inner wall of the orbit O. Point, the lowest point on the inferior margin of the orbit. O. Proce : 1. The orbital portion of the malar bone. 2. The orbital portion of the palate bone. O. Ridge, the free edge of the nasal proce of the superior maxilla. O. Surface, that portion of the superior maxilla that helps to form the floor of the orbit. O. Vault, the roof of the orbit. Drbito- (or'-bit-o-). A prefix denoting relation to the orbit. O. -basilar, both orbital and basilar. O.-b. Angle, the angle formed between the line continuing the axis of the orbit and one tangent to the lower border of the inferior maxilla. O. -malar, pertaining to both the orbit and the malar bone. O.-m. Index, in craniometry, the ratio existing between the bizygomatic diameter of the face, and the superior facial diameter, the latter being taken as 100. O. -nasal, pertaining to both orbit and nose. O. -occipital, pertaining to both orbit and occipital bone. O.-o. Angle, in craniometry, the angle formed between the optic axis and the plane of the foramen magnum. O. -ocular, pertaining to both orbit and eye. O. -palpebral, pertaining both to the orbit and the eyelids. O. - sphenoid: 1. Pertaining both to the orbit and to the sphenoid bone. 2. The le er wing of the sphenoid bone; in some animals, and in early human life, it is a separate bone.