(3.11)
Now that we’ve looked at the shape of the facial skeleton, and the parts of the cranium that it’s attached to, let’s look at the individual facial bones, and see how each of them contributes to the features that we’ve seen. We’ll look at the five largest facial bones first. They're the frontal and zygomatic bones, the maxilla, the sphenoid bone, and the ethmoid bone.
The frontal bone is a very large bone. The lower part of the frontal bone forms the beginning of the root of the nose, the upper part of the orbital margin, a small part of the temporal fossa, and a large part of the roof of the orbit.
The frontal bone also forms most of the floor of the anterior cranial fossa. The part of the frontal bone near the midline is hollow. The hollow space is the frontal sinus, one of the paranasal sinuses, which we’ll look at shortly. Next we’ll look at the zygomatic bone.
The zygomatic bone forms the bony prominence of the cheek. It also forms the lower lateral part of the orbital margin, and this part of the lateral orbital wall. The zygomatic bone extends backward to meet the zygomatic process of the temporal bone, forming the zygomatic arch. Now we’ll move forward and look at the maxilla.
Here’s the maxilla. The right and left maxillae are joined together in the midline. On each side the maxilla forms the lower medial part of the orbital margin, and almost all of the floor of the orbit. The maxilla bears the upper teeth. On the underside it forms much of the hard palate.
The maxilla is hollow. It contains the largest of the paranasal sinuses, the maxillary sinus. To see the posterior part of the maxilla, we’ll remove the zygomatic arch. ...
(3.11)
Now that we’ve looked at the shape of the facial skeleton, and the parts of the cranium that it’s attached to, let’s look at the individual facial bones, and see how each of them contributes to the features that we’ve seen. We’ll look at the five largest facial bones first. They're the frontal and zygomatic bones, the maxilla, the sphenoid bone, and the ethmoid bone.
The frontal bone is a very large bone. The lower part of the frontal bone forms the beginning of the root of the nose, the upper part of the orbital margin, a small part of the temporal fossa, and a large part of the roof of the orbit.
The frontal bone also forms most of the floor of the anterior cranial fossa. The part of the frontal bone near the midline is hollow. The hollow space is the frontal sinus, one of the paranasal sinuses, which we’ll look at shortly. Next we’ll look at the zygomatic bone.
The zygomatic bone forms the bony prominence of the cheek. It also forms the lower lateral part of the orbital margin, and this part of the lateral orbital wall. The zygomatic bone extends backward to meet the zygomatic process of the temporal bone, forming the zygomatic arch. Now we’ll move forward and look at the maxilla.
Here’s the maxilla. The right and left maxillae are joined together in the midline. On each side the maxilla forms the lower medial part of the orbital margin, and almost all of the floor of the orbit. The maxilla bears the upper teeth. On the underside it forms much of the hard palate.
The maxilla is hollow. It contains the largest of the paranasal sinuses, the maxillary sinus. To see the posterior part of the maxilla, we’ll remove the zygomatic arch. Here’s the back of the hollow part of the maxilla. Down here the maxilla is joined to the bone behind it, the sphenoid bone.
Apart from this attachment the maxilla is separated from the sphenoid by this impressive cleft, which has a vertical part and a horizontal part. The vertical part of the cleft is called the pterygo-maxillary fissure. The horizontal part of the cleft is called the inferior orbital fissure.
The inferior orbital fissure - here it is from in front - separates the floor of the orbit, formed by the maxilla, from the lateral wall that’s formed by the sphenoid.