The carotid canal runs superiorly and anteriorly through the petrous portion and provides an entrance for the internal carotid artery into the cranial cavity ( Figure 8-3). The petrous portion articulates with the occipital bone in the floor of the skull. The mastoid process and styloid process project from the inferior aspect, and between these two processes is the stylomastoid foramen, through which the facial nerve exits the skull. The petrous portion extends within the cranium and houses the middle and inner ear structures. An anterior projection, the zygomatic process, articulates with the zygomatic bone (see Figure 8-1). The squamous portion forms the side of the cranium and articulates with the parietal bone and the sphenoid bone. That portion of the maxillary bone forming the cheek contains the maxillary sinus.Įach of the temporal bones is composed of two portions: a large, flat plate, the squamous portion and a thickened, wedge-shaped area, the petrous portion. Each maxillary bone articulates with the frontal, nasal, lacrimal, ethmoid, sphenoid, palatine, and zygomatic bones. The two maxillae, or maxillary bones, form the upper jaw, the hard palate, the lateral walls of the nasal cavity, and the floor of both orbits (see Figure 8-4). The sutures joining adjacent bones of the face generally are named according to the names of the two bones that are connected (e.g., the suture between the frontal bone and the zygomatic bone is the frontozygomatic suture). The single frontal bone forms the forehead and articulates with the nasal bones, maxillae, and zygomatic bones in formation of the face (see Figure 8-4). The reader is advised to have a skull available for reference while reading this chapter, particularly for distinguishing the relationships and articulations between bones and identifying foramina and fissures. Air-filled cavities called sinuses are contained within several of the bones.Īfter a brief description of the bones of the skull, this chapter presents a more detailed presentation of the orbital bones. The exception is the movable temporomandibular joint, which attaches the mandible to the temporal bones. Generally, the bones of the skull unite at sutures that form immovable joints. The single frontal bone is a part of both the cranium and the face. The face is made up of two maxillary bones, two nasal bones, the vomer, two inferior conchae, two lacrimal bones, two palatine bones, two zygomatic bones, and the mandible. The cranium consists of two parietal bones, the occipital bone, two temporal bones, the sphenoid bone, and the ethmoid bone. The skull can be divided into two parts: the cranium and the face.
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