Century Dictionary and Cyclopedia
- supramaxillary Of or pertaining to the upper jaw, in part or as a whole; related to or connected with the superior maxillary bone.
- supramaxillary One of several small motor branches of the facial nerve, distributed to muscles of the superior maxillary region.
- n supramaxillary The superior maxillary, or upper jaw-bone, forming a part, in man nearly the whole, of the bony framework of the upper jaw, and representing more or less of the expanse of the cheek: correlated with inframaxillary. The part which the supramaxillary takes in the formation of the upper jaw mostly depends upon the relative size of the premaxillary (intermaxillary) bone. In man the latter is very small, occupying only a little space at the anterior-inferior corner of the supramaxillary, and is observable only in infancy, as it speedily ankyloses with the supramaxillary. The supramaxillary is in inverse ratio extensive, and also expansive or inflated, being entirely hollowed out by the maxillary sinus, or antrum of Highmore. It presents to the cheek an external or facial surface, with several elevations and depressions marking the attachments of muscles, and just below the eye the large infra-orbital foramen. The posterior or zygomatic surface shows the openings of the posterior dental canals, and a rough surface for articulation with the palate bone. The superior or orbital surface forms most of the floor of the orbit of the eye. The internal or nasal surface forms much of the outer wall of the nasal meatus, and shows the opening of the antrum. Besides these surfaces, the bone has several well-marked processes, as the nasal, running up to the frontal bone, the malar, articulating with the bone of that name, the alveolar, bearing teeth, and the palatal, roofing part of the mouth. The two supramaxillary bones when together show in front a somewhat heart-shaped opening, the anterior nares, at the middle of the base of which is the prominent nasal spine, a landmark in craniometry. Each articulates with nine bones (sometimes ten), and to each twelve muscles are attached. (See cuts under skull, orbit, and palate.) In other mammals the supramaxillary has various shapes, and is comparatively smaller; it may always be recognized as the bone which bears the upper molar, premolar, and canine teeth—all the upper teeth excepting the incisors. In birds the supramaxillary is very greatly reduced, and often not distinctly defined: the palatal part of it is represented by a well-developed maxillopalatine; but nearly the whole of the upper beak of a bird, beyond the feathers, has for its bony basis the highly developed premaxillary. In the lower vertebrates the superior maxillary is presented under the most diverse conditions of size and shape, and is generally identified with the second bone from the front of those constituting the upper maxillary arch.
Chambers's Twentieth Century Dictionary
- adj Supramaxillary sū-pra-mak′si-lā-ri pertaining to the upper jaw
- n Supramaxillary the superior maxillary or upper jaw-bone