zygoma

Definitions

  • WordNet 3.6
    • n zygoma the slender arch formed by the temporal process of the cheekbone that bridges to the zygomatic process of the temporal bone
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Webster's Revised Unabridged Dictionary
    • n Zygoma (Anat) The jugal, malar, or cheek bone.
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Century Dictionary and Cyclopedia
    • n zygoma The bony arch or arcade of the cheek, formed by the malar or jugal bone and its connections: socalled because it serves to connect bones of the face with those of the skull about the ear. In mammals, including man, the zygoma consists of a malar bone connected behind with the squamosal bone, usually by a zygomatic process of the latter, and abutting in front against a protuberance of the superior maxillary bone, or of the frontal or the lacrymal bone, or any of these. It is usually a stout bony arch, sometimes with a strong descending process, giving principal origin to a masseter muscle, and bridging over the temporal muscle. It is sometimes a slender rod, and may be imperfect, as in shrews. The part taken in its for mation by the malar bone is very variable in extent. (See cut under skull.) Below mammals the construction of the zygoma posteriorly is entirely altered. In birds the arch is articulated there with the quadrate bone, or suspensorium of the lower jaw, representing the malleus of a mammal, aud an additional bone, the quadratojugal, intervenes between the quadrate and the malar proper. In such cases the anterior connection is more particularly with the maxillary bone, or with this and the lacrymal, and the zygoma is generally a slender rod-like structure. (See cut under Gallinæ.) In reptiles further modifications occur, such as the completion of the arch behind by union of the jugal bone with the postfrontal and squamosal; or there may be no trace of a structure to which the term zygoma is properly applicable, as in the Ophidia, in which there is no jugal or quadratojugal bone. Among batrachians, as the frog, a zygomatic arch is represented by the connection of the maxillary bone, by means of a quadratojugal bone, with a bone called temporomastoid (see cuts there and under Anura). In any case a zygoma consists of a suborbital or postorbital series of ossifications in membrane, or membrane-bones, developed on the outer side of the maxillary arch of the embryo (the same that gives rise to the pterygopalatine bar), and when best differentiated is represented by lacrymal, maxillary, jugal, and quadratojugal bones; and its connection with the sphenoid, as occurs in man, is quite exceptional.
    • n zygoma The malar or jugal bone itself, without its connections.
    • n zygoma The cavity under the zygomatic process of the temporal bone; the zygomatic fossa.
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Chambers's Twentieth Century Dictionary
    • n Zygoma zī-gō′ma the arch formed by the malar bone and the zygomatic process of the temporal bone of the skull
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Etymology

Webster's Revised Unabridged Dictionary
NL., fr. Gr. , fr. to yoke, zygo`n a yoke
Chambers's Twentieth Century Dictionary
Gr. zygōmazygon, a yoke.

Usage

In literature:

Associated Words: zygoma, zygomatic, buccate, buccal, malar, buccinator, meloncus, meloplasty, melitis, dimple, jugal.
"Putnam's Word Book" by Louis A. Flemming
His eyes are gray, small, and deeply set; the zygomae are normal.
"Studies in the Psychology of Sex, Volume 2 (of 6)" by Havelock Ellis
Length of skull about 1-5/12 inches; width at the zygoma, 1-1/4.
"Natural History of the Mammalia of India and Ceylon" by Robert A. Sterndale
In another patient a bullet entered above the right zygoma and traversed the orbits, without wounding the globes.
"Surgical Experiences in South Africa, 1899-1900" by George Henry Makins
The contracted temporal muscle forms a prominence above the zygoma.
"Manual of Surgery Volume Second: Extremities--Head--Neck. Sixth Edition." by Alexander Miles
The series extends posteriorly some distance behind the anterior root of the zygoma, almost level with the hind edge of the palate.
"Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 10" by Various
The maxillary part of the zygoma varies from broad to slender in dorsoventral width in both species.
"Speciation and Evolution of the Pygmy Mice, Genus Baiomys" by Robert L. Packard
The maxillary bones are broad and projecting, and the zygoma has a rather bold curve.
"Narrative of the Circumnavigation of the Globe by the Austrian Frigate Novara, Volume II" by Karl Ritter von Scherzer
In the skull there is a complete though slender zygoma; the premaxillaries, though small, are not so rudimentary as in the American Edentates.
"The Cambridge Natural History, Vol X., Mammalia" by Frank Evers Beddard
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In news:

Primary intraosseous cavernous hemangioma of the zygoma: A case report and literature review.
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