|Henry Gray (18251861). Anatomy of the Human Body. 1918.|
|part is generally seen; this forms the anterior boundary of the inferior orbital fissure: occasionally, this non-articular part is absent, the fissure then being completed by the junction of the maxilla and sphenoid, or by the interposition of a small sutural bone in the angular interval between them. The maxillary process presents a rough, triangular surface which articulates with the maxilla. The temporal process, long, narrow, and serrated, articulates with the zygomatic process of the temporal.|
FIG. 164 Left zygomatic bone in situ. (See enlarged image)
FIG. 165 Left zygomatic bone. Malar surface. (See enlarged image)
FIG. 166 Left zygomatic bone. Temporal surface. (See enlarged image)
Borders.The antero-superior or orbital border is smooth, concave, and forms a considerable part of the circumference of the orbit. The antero-inferior or maxillary border is rough, and bevelled at the expense of its inner table, to articulate with the maxilla; near the orbital margin it gives origin to the Quadratus labii superioris. The postero-superior or temporal border, curved like an italic letter f, is continuous above with the commencement of the temporal line, and below with the upper border of the zygomatic arch; the temporal fascia is attached to it. The postero-inferior or zygomatic border affords attachment by its rough edge to the Masseter.
Ossification.The zygomatic bone is generally described as ossifying from three centersone for the malar and two for the orbital portion; these appear about the eighth week and fuse about the fifth month of fetal life. Mall describes it as being ossified from one center which appears just beneath and to the lateral side of the orbit. After birth, the bone is sometimes divided by a horizontal suture into an upper larger, and a lower smaller division. In some quadrumana the zygomatic bone consists of two parts, an orbital and a malar.
Articulations.The zygomatic articulates with four bones: the frontal, sphenoidal, temporal, and maxilla.
FIG. 167 Articulation of left palatine bone with maxilla. (See enlarged image)
|5b. 5. The Palatine Bone|
(Os Palatinum; Palate Bone)
The palatine bone is situated at the back part of the nasal cavity between the maxilla and the pterygoid process of the sphenoid (Fig. 167). It contributes to the walls of three cavities: the floor and lateral wall of the nasal cavity, the roof of the mouth, and the floor of the orbit; it enters into the formation of two fossæ, the pterygopalatine and pterygoid fossæ; and one fissure, the inferior orbital fissure. The palatine bone somewhat resembles the letter L, and consists of a horizontal and a vertical part and three outstanding processesviz., the pyramidal