0:18 This is Dr. Adel Bundek, Professor of Anatomy and Neuroscience, Mansour University, Egypt. I will talk about the temporal fossa and the infratemporal fossa. This is the temporal fossa. The infratemporal fossa is the space deep to the rimus of the mandible. Okay? So I will start by the temporal fossa. This is the temporal fossa. Regarding the boundaries, okay, superior boundary the two temporal lines. These are the temporal lines. Inferior boundary is the zygomatic arch. This is the zygomatic arch. Anteriorly, these two processes, zygomatic process of the frontal bone and the frontal process of the zygomatic bone.
1:04 These two processes. And then The contents, it contains the temporalis muscle and the temporal fascia. Temporal fascia and the temporalis muscle. So the boundaries, superiorly the temporal lines, inferiorly the zygomatic arch, anteriorly two processes, zygomatic process of the frontal bone and frontal process of the zygomatic bone. It is filled by the temporalis muscle and the temporal fascia. Regarding the infratemporal fossa, the infratemporal fossa is the space deep to the ramus of the mandible. This is space. Okay? Space deep to the ramus of the mandible. This is space. Okay? What are the boundaries of the infratemporal fossa? Okay,
1:53 lateral boundary, of course, if it is the space deep to the ramus of the mandible, then laterally, it is the ramus of the mandible. Medially, this plate. Medially, it is the lateral trigoid plate and the trigomaxillary fissure, this fissure. And then anteriorly, this anteriorly, it is the maxilla. And posteriorly, posteriorly, these two processes, zygomatic mastoid process and the styloid process. And this is the roof, the greater wing of the sphenoid. containing foramen ovale and foramen spinosa. Again, boundaries of the infratemporal fossa. Laterally, it is the ramus of the mandible. Medially, it is the lateral trigoid plate, this plate. Anteriorly, it is the maxilla. Posteriorly,
2:44 styloid porosis and mastoid porosis. And then, superiorly, it is the greater wing of the sphenoid containing foramen ovale and foramen spinosa. Regarding the contents of the infratemporal fossa, it contains one, two, and three insertion of temporalis. So three muscles of mastication. It contains ligament, this ligament. It contains the nerves and blood vessels. Regarding the three muscles, actually muscles of mastication are four. Three of them are located in the infratemporal fossa. The one outside the infratemporal fossa, which is the masseter. So the three muscles in the infratemporal fossa, three
3:34 lateral trigoid, medial trigoid, and the insertion of temporalis in the coronoid process. Ligament, it is only one ligament. This ligament, it is the sphenomandibular ligament. Regarding the nerves, the mandibular nerve and its branches. Okay, this is the mandibular nerve and its branches. Okay, there is a nerve joining the mandibular nerve, which is the chorda tympani, this one, and a ganglion attached to the mandibular nerve, otic ganglion. So chorda tympani, this small nerve, chorda tympani, and okay, this one, chorda tympani, joining the lingo nerve and otic ganglion. and a very small part of the maxillary
4:21 nerve here. Maxillary nerve, very small part of the maxillary nerve. Regarding the vessels, this artery, maxillary artery, and venous pelixus around the trigoid muscles, which is the pterygoid venous pelixus. So the contents of the infratemporal fossa, three muscles of mastication, lateral trigoid, medial trigoid, and the insertion of temporalis ligament, sphenomandibular ligament, nerves, mandibular nerve and its branches, corda tempuli, branch from the facial nerve, joining the lingual nerve, and otic ganglion attached, this is parasympathetic ganglion attached to the mandibular nerve, and the maxillary nerve, a very small part of the maxillary nerve, blood vessels, maxillary artery, and
5:08 the trigoid venous glexus. Again, this is the remus of the mandule, It is cut. Okay. It is cut. So this is the infratemporal fossa. Okay. This muscle is the lateral trigoid muscle. This is the upper head of the lateral trigoid. And this is the lower head of the lateral trigoid. This muscle is the medial trigoid. It has superficial head and deep head. And this ligament is a sphenomandibular ligament. So this is the infratemporal fossa. Okay. Regarding the muscles of mastication, there are four muscles. This is the first one, masseter. This is the second one, temporalis.
5:56 And then two pterygoid muscles, lateral pterygoid and medial pterygoid. This is the medial tergoid and this is the lateral tergoid. I will talk about the origin and the insertion in the next slide. But how about the nerve supply of the four muscles? The four muscles are supplied by the mandibular nerve. Why the muscles of mastication are supplied by the mandibular nerve? Because these muscles develop from the first pharyngeal arch. And the nerve of the first pharyngeal arch is the mandibular nerve. What is the action of these muscles? Okay. Actually, these muscles are inserted. They move the jaw. They move the mandible. All the muscles elevate the mandible except one lateral trigoit. So the lateral trigoit
6:46 is the only muscle which depress the mandible. And all muscles protrude the mandible except one temporalis. Okay. So you can remember the action of each one. Okay. All of them elevate. except the lateral tergoid. All of them protrude except temporalis. Let's talk about each one. Let's talk about the origin. Origin from the skull and the insertion into the mandible. Origin from the skull, insertion into the mandible. Start by the masseter. Masseter takes origin from the zygomatic arch and insert it into the outer surface of the rimas of the mandible. Regarding temporalis, It takes origin from the temporal fossa and the temporal fascia. It is inserted into the coronoid process
7:36 of the mandible. This one. Lateral trigoid. Okay, medial trigoid. Medial trigoid has superficial head and deep head. Superficial head takes origin from the maxilla and the deep head takes origin from the medial surface of the lateral trigoid plate. Okay, so from the lateral trigoid plate. The medial trigoid is inserted into the inner surface of the angle of the mandible. Okay, lateral trigoid. It has upper head and lower head. Upper head takes origin from the greater wing of the sphenoid. Lower head takes origin from the lateral surface of the lateral trigoid plate. The upper head is inserted into the capsule and the articular disc.
8:23 of the temporomandibular joint, the lower head is inserted into the teregoid fovea of the neck of the mandible. So here, here the insertion of the four muscles, masseter outer surface of the rimus of the mandible. Okay, masseter outer surface of the rimus of the mandible, temporalis into the coronoid process, medial teregoid inner surface of the angle of the mandible, and lateral trigoid into the front of the neck of the mandible. Again, origin and insertion of the four muscles. Masseter from the zygomatic arch to the outer surface of the remus. Temporalis from the temporal fossa and the temporal
9:08 fascia inserted into the coronoid process. Medial trigoid, superficial head and deep head. Superficial head from the maxilla. Tuberosity of the maxilla, okay, maxilla is okay, and the deep head from the medial surface of the lateral trigoid plate. It is inserted into the inner surface of the angle of the mandible. Lateral trigoid, upper head and lower head, origin. Upper head from the greater wing of the sphenoid, this is the greater wing of the sphenoid, and the lower head from the lateral surface of the lateral trigoid plate. Insertion of the lateral trigoid into three parts, okay, capsule of the TMG, Articular disc and the front of the neck of the mandible. This is the lateral trigoid muscle. This is the key
9:55 structure of the infratemporal fossa. Upper head and lower head. Okay, so this is upper head and this is the lower head. Just reminding you, upper head takes origin from the greater wing of the sphenoid. Lower head takes origin from the lateral trigoid plate. It is inserted into the capsule of the TMG, articular disc, and the front of the neck of the mandule. Regarding the relations of the lateral trigoid, because it is the key structure in the infratemporal fossa, we have structures above the lateral trigoid along the upper border. We have structures along the lower border. We have structures between the two heads. and
10:41 then superficial structures and deep structures. Upper border, okay, deep temporal nerves supplying the temporalis and the nervetomusceter supplying the masseter muscle. Along the lower border, okay, this is the lingual nerve appearing from below the lower border. This is the infra-alveolar nerve or inferior alveolar nerve. and the first part of the maxillary artery. This is the first part. This is the second part. First part of the maxillary artery. Between the two heads, a nerve coming from between the two heads, which is the buccal nerve, supplying the skin over the buccinator. This is the buccinator muscle. And the maxillary
11:30 artery passes between the two heads to become the third part. Superficial structures covering the lateral trigoid. Of course, masseter, temporalis, and the mandible. And the second part of the maxillary artery covering the lower head. And the superficial head of the medial trigoid. So superficial head of the medial trigoid, second part of the maxillary artery, superficial to the lower head, and it is covered by masseter, temporalis, and the mandible. Deep relation structures what? which you don't see. I don't see the mandibular nerve trunk. I don't see the otic ganglion. I don't see the chorda tympanae and the deep head of the medial
12:18 trigoid. Let us see these structures again. Okay, this is the lateral trigoid, upper head and lower head. Okay, this is the mandibular fossa and this is the articular tubercle. This is the head of the mandible This is the neck of the mandible. This is the condyler process of the mandible. Okay. This is the capsule of the TMG. This is the articular disc of the TMG. This is the upper head of the lateral trigoid inserted into the capsule and the articular disc. This is the lower head of the lateral trigoid inserted into the neck of the mandible, front of the neck of the mandible. Okay.
13:06 This is the superficial head of the medial trigoid, superficial to the lower head, and this is the deep head of the medial trigoid. Superficial head and deep head. Structures along the upper border, deep temporal nerves and vessels, and nerve tumes, ceter. Okay? Along the lower border, this is the lingual nerve, this is the inferior alveolar nerve, and this is the first part of the maxillary artery along the lower border of the lateral trigoid. Between the two heads, this is the pocket nerve, and this is the maxillary artery to continue as the third part. Superficial to the lateral trigoid. Superficial to the lateral trigoid. This is the
13:52 temporalis. This is the mandule. This is the masseter. And thank you very much. Best wishes and good luck.
