The stephanion is the point on the skull where the temporal line converges with the coronal suture, which is a serrated juncture that unites the frontal and parietal bones. As an anatomical reference, the stephanion can be used to take craniometric measurements, or measurements of the skull, which will yield age, sex, race, and other postmortem information. The stephanion is located above the ear canal, which is located in the tympanic region of the temporal bone.
There is a slight depression on both sides of the human skull called the temporal fossa. Several of the bones of the skull come together in this area at connection points called sutures. The entire area of the temporal fossa is encompassed by the temporal lines, which are bony ridges emanating from the skull's surface. The temporal line is singular in the lower boundary of the temporal fossa, along the zygomatic arch, or cheekbone, and up to the outer ridge of the eye socket.
In the back of the skull, the temporal line splits into two lines behind the ear just prior to the point where the mastoid process of the temporal bone meets the mastoid angle of the parietal bone along the squamosal suture. In the front part of the skull, the singular temporal line divides into two lines on the cranial frontal bone above the bony outer ridge of the eye socket near the temple region. The upper of the two lines is called the superior temporal line and the lower is called the inferior temporal line.
As the superior and inferior temporal lines arch up and backward from the frontal bone toward the parietal bone, they cross the coronal suture. The point of intersection with the inferior temporal line and the coronal suture is called the stephanion, and it marks the upper region of the temporal fossa. Following the coronal suture below the stephanion is another anatomical marker called the pterion, which is the meeting point of the frontal, parietal, sphenoid, and temporal bones.
Laying over the stephanion is the temporalis muscle, which arises from the temporal fossa and attaches to the entire expanse of the inferior temporal line. It's one of the four muscles of mastication, which are responsible chewing. The superior temporal line provides the upper attachment for the temporal fascia, which is a layer of fibrous tissue that covers the temporalis muscle. The zygomatic arch provides the two lower attachment points for the temporal fascia.