 Good day, everybody. This is Dr. Sanjay Sanyal, Professor of Department Chair. So this is going to be a demonstration of the temporal region. This is the supine cadaver. We are standing on the right side. Before I go to the temporal region itself, first I will give you an overview of the complete dissected area that we have exposed here. So this is the galea aponeurotica, which we are reflecting. That is the aponeurosis of the epicranial or the occipital frontalis muscle that we have reflected. The next structure that we see here, this is the lateral extension of the galea aponeurotica. This is the superficial temporal fascia. So we have reflected that also. Okay. Under that is the temporal region that we are going to describe shortly. But before I go to the temporal region, let me give you a quick overview of the other areas so that we get the orientation. This is the zygomatic arch where my hand is moving right now. And under that we can see the structure here. This is the parotid gland. This is the superficial part of the parotid gland. And this is the parotid duct, which we have cut here just to show the muscle, which is right underneath. This is the meseter muscle. While lifting up the parotid gland, we can see the various neuromascular structures here. And finally, this is the sternocleidomastoid muscle. And we can see this nerve crossing in front of it. This is the great auricular nerve, which is heading towards the parotid gland. Having mentioned these structures, now let's come back again to the temporal region, because that is the main focus of the present section. So this is the superficial temporal fascia, as I mentioned earlier. It's the lateral extension of the galea aponeurotica. And if you look carefully, we can see running of the superficial temporal fascia is this blood vessel here. This is the branch of the superficial temporal artery. And we can see these venous channels. These are the tributaries of the superficial temporal vein. And also running will be the auricular temporal nerve. These all come through the parotid gland here. So this is the superficial temporal fascia. In surgical parlance, we also call it the temporal parietal fascia. We are going to now reflect this. This temporal parietal fascia or the superficial temporal fascia was attached to the zygomatic arch. And we have cut it out from there. Now having reflected this, now let's come to the temporal region proper. First, let's start with the clinical correlation. A person comes to you with a bloody jury to the temporal region. He becomes unconscious. He recovers. And after some time, again, he becomes unconscious and he doesn't recover. That is what is known as the lucid interval. When you take an emergency CT scan, you find a football shaped opacity on the right temporal region. What exactly is the problem? The problem is he has got a rupture of the middle meningeal artery from a fracture of the tereon. And that is produced, what is known as an extradural hematoma. So let's take a look at the temporal region and understand exactly what has happened and how we should deal with it. This structure which we have cut open, this is the deep temporal fascia or the temporal fascia proper. This is attached to the superior temporal line all the way around like this. It is located under the temporal parietal fascia of the superficial temporal fascia. This is the true temporal fascia and we can see it is tough structure and it is leathery membranous. If you were to take a look at this deep temporal fascia or the temporal fascia proper, we see that on the top it is quite thin though it is tough. But lower down at its attachment to the psychometric arch it becomes very thick. Why does it become thick? That is because it splits it into two layers, an outer layer and an inner layer. The outer layer gets attached to the outer margin of the psychometric arch and the inner layer gets attached to the inner surface of the psychometric arch. There is another important function of this deep temporal fascia. If you take a look downstairs you will find that there is this tough muscle here. This is the besieter muscle which takes origin from the psychometric arch and the fibers they go down and they get started onto the besieter tuberosity on the lateral aspect of the angle of the mandible. This is a very strong muscle of mastication. When this besieter muscle contracts forcefully it exerts a very powerful pull, downward pull on the psychometric arch and really it can even lead to fracture of the psychometric arch. So therefore the function of this deep temporal fascia is to give a counter traction to the downward pull of the besieter muscle on the psychometric arch. So this is an important clinical functional aspect about this deep temporal fascia. Taking partial origin from the under surface of this temporal fascia was this muscle here. What is this muscle? This is the temporalis muscle. The temporalis muscle takes origin from inferior temporal line and the fibers they converge inframedially like this and my finger is going down inside and the fibers they go under the psychometric arch. My finger has gone under the psychometric arch and they get inserted onto a narrow insertion at the coronoid process of the mandible which you cannot see here and to the temporal crest of the mandible. So that is the full temporalis muscle. This is a muscle of mastication and it's a very powerful muscle of mastication. When we clench our jaw we can feel the temporalis muscle contracting. Now if you take a look at the fibers we can see that there are two sets of fibers. The posterior set of fibers are almost horizontal and the anterior set of fibers are almost vertical and of course the fibers in between are in between the two. The anterior set of fibers, the vertical set of fibers are responsible for closing the jaw powerfully, that is elevation of the mandible. While the posterior set of fibers which are almost horizontal, they are responsible for retrusion of the mandible which is one of the steps which happens when we do side to side chewing movements or open the jaw and close the jaw. This is for retrusion of the mandible. I will draw your attention to this blood vessel here. This is a temporal vessel which is a branch of the maxillary artery second part. In most sections we have seen that deep temporal arteries and the deep temporal nerves they all run deep to the temporalis major muscle sometimes they can run superficial also and in this case it is running superficial. Now we have lifted a temporalis muscle and we can see this depression here. This is the temporal fossa that I was eluding to earlier. What are the boundaries of this temporal fossa? The floor of the temporal fossa is formed by four bones. The frontal bone here the bridal bone, the squamous part of temporal bone and a little bit here which is the greater ring of sphenoid and at the meeting point of these four bones there is an edge shaped suture here which is referred to as the tereon and running right under the tereon is located the anterior division of the middle meningeal artery which is a branch from the first part of the maxillary artery. It enters through the foremen spinosome and it runs under the tereon. So if there is a fracture of this tereon here it can rupture the middle meningeal artery anterior division and that's what produces extra dural hematoma which compresses on the motor cortex of the brain and can lead to even death of the person. So therefore when we are faced with a person who has got a suspected extra dural hematoma which is obvious from a CT scan what are we supposed to do? What we do is we make what is known as a burr hole a temporal burr hole we slit open temporalis muscle we split the fibers in the direction of the fibers and we reach the tereon how do we locate the tereon in a living person? There are several ways of doing it one is to feel the zygomatic arch and go from the midpoint of the zygomatic arch go one and a half inches above that that is the easiest method. The second method is one thumb width behind this ridge of bone here this is the frontal bone and two finger width above the zygomatic arch where the two meet this is the location of the tereon that is the second method of locating it and there is a third method of locating it using the triggers of the year as a landmark by any one of these methods once we have located the approximate location of the tereon we are supposed to cut this open and once we reach inside we are supposed to make an opening in the floor of the temporal region and we have to evacuate the extra dural hematoma and ligate the bleeding middle menager artery and that is a life saving procedure so that is exactly the procedure that is done here having mentioned that there are other procedures also which are possibly done in the temporal region like for example if you want to remove an astrocytoma or a tumor from the temporal lobe of the brain what we do is called an osteoplasty craniotomy where we make an incision like this based on the superficial temporal artery this was a superficial temporal artery which I had mentioned earlier and lift up the whole thing the superficial fascia deep fascia the temporalis muscle and we cut open a slab of bone here and lift up the whole thing that is known as osteoplasty craniotomy and after we have removed the tumor or whatever we can put the bone flap back the bone regenerates by means of the vascularity provided by the superficial temporal artery and the muscles that is osteoplasty craniotomy so these are some procedures which are performed in the temporal region and some clinical correlations pertaining to the temporal region thank you very much for watching this is Dr. Sanjoy Sanyal signing out SEP is the camera person if you have any questions or comments please put them in the comment section below have a nice day please like and subscribe