[0:17]Hello everyone. This is Dr. Adel Bondok, Professor of Anatomy and Neuroscience. Mansura University, Egypt. I will talk about the temporal fossa and infratemporal fossa. This is the temporal fossa. The infratemporal fossa is the space deep to the ramus 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 frontal bone and frontal process of zygomatic bone. 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 the frontal process of the zygomatic bone. It is filled by the temporalis muscle and temporal fascia. Regarding the infratemporal fossa. The infratemporal fossa is the space deep to the ramus of the mandible. This space. Okay, space to the deep to the ramus of the mandible. This space. What are the boundaries of the infratemporal fossa? Okay, 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 pterygoid plate and pterygo max fissure, this fissure. And then anteriorly, this anteriorly, it is the maxilla. And posteriorly, posteriorly, these two processes, zygomatic, uh, mastoid process and styloid process. And this is the roof, the greater wing of the sphenoid containing foramen ovale and foramen spinosum. Again, boundaries of the infratemporal fossa laterally, it is the ramus of the mandible. Medially, it is the lateral pterygoid plate, this plate. Anteriorly, it is the maxilla, posteriorly, styloid process and mastoid process. And then superiorly, it is the greater wing of the sphenoid containing foramen ovale and foramen spinosum. 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 nerves and blood vessels. Regarding the three muscle, 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 lateral pterygoid, medial pterygoid, and 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, joining the lingual nerve. And otic ganglion, and a very small part of the maxillary nerve here. Maxillary nerve, very small part of the maxillary nerve. Regarding the vessels, this artery, maxillary artery and venous plexus around the pterygoid muscles, which is the pterygoid venous plexus. So, the contents of the infratemporal fossa, three muscles of mastication, lateral pterygoid, medial pterygoid, and insertion of temporalis. Ligament, sphenomandibular ligament, nerves, mandibular nerve and its branches. Chorda tympani, branch from the facial nerve, joining the lingual nerve, and otic ganglion, attached, this is parasympathetic ganglion, attached to the mandibular nerve. And maxillary nerve, very small part of the maxillary nerve. Blood vessels, maxillary artery and pterygoid venous plexus. Again, this is the ramus of the mandible. It is cut, okay? It is cut. So, this is the infratemporal fossa. Okay? This muscle is the lateral pterygoid muscle. This is the upper head of the lateral pterygoid, and this is the lower head of the lateral pterygoid. This muscle is the medial pterygoid. It has superficial head and deep head. And this ligament is sphenomandibular ligament. So, this is the infratemporal fossa. Okay? Regarding muscles of mastication are four muscles. This is the first one, masseter. This is the second one, temporalis. And then two pterygoid muscles, lateral pterygoid and medial pterygoid. Okay? This is the medial pterygoid, and this is the lateral pterygoid. I will talk about the origin and 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, 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 pterygoid. So, the lateral pterygoid is the only muscle which depresses 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 lateral pterygoid. All of them protrude except temporalis. Let us talk about each one. Let us talk about the origin from the skull and insertion into the mandible. Origin from the skull, insertion into the mandible. Start by the masseter. Masseter takes origin from the zygomatic arch and inserted into the outer surface of the ramus of the mandible. Regarding temporalis. It takes origin from the temporal fossa and temporal fascia. It is inserted into the coronoid process of the mandible. This one. Lateral pterygoid. Okay, medial pterygoid. Medial pterygoid 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 pterygoid plate. Okay? So, from the lateral pterygoid plate. The medial pterygoid is inserted into the inner surface of angle of the mandible. Okay? Lateral pterygoid. 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 pterygoid plate. The upper head is inserted into the capsule and articular disc. of the temporomandibular joint, the lower head is inserted into the pterygoid fovea of the neck of the mandible. So, here, here, the insertion of the four muscles. Masseter, outer surface of the ramus of the mandible. Okay? Masseter, outer surface of the ramus of the mandible. Temporalis from the temporal fossa and temporal fascia.
[9:09]Inserted into the coronoid process. Medial pterygoid, superficial head and deep head. Superficial head from the maxilla, the tuberosity of the maxilla. Okay, maxilla is okay. And the deep head from the medial surface of the lateral pterygoid plate. It is inserted into the inner surface of the angle of the mandible. Lateral pterygoid, 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 pterygoid plate. Insertion of the lateral pterygoid into three parts. Okay, capsule of the TMJ, articular disc, and front of the neck of the mandible. This is the lateral pterygoid muscle. This is the key structure of the infratemporal fossa. Upper head and lower head. Okay, so, this is the upper head and this is the lower head.
[10:09]Just reminding you, upper head takes origin from the greater wing of the sphenoid. Lower head takes origin from the lateral pterygoid plate. It is inserted into the capsule of the TMJ, articular disc, and the front of the neck of the mandible. Regarding the relations of the lateral pterygoid, because it is the key structure in the infratemporal fossa. We have structures above the lateral pterygoid along the upper border. We have structures along the lower border. We have structures between the two heads, and then superficial structures and deep structures. Upper border. Okay? Deep temporal nerves supplying the temporalis and nerve to masseter 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. Okay? Supplying the skin over the buccinator. This is the buccinator muscle. And the maxillary artery passes between the two heads to become the third part. Superficial structures covering the lateral pterygoid. Of course, masseter, temporalis, and the mandible, and the second part of the maxillary artery covering the lower head, and it is covered by masseter, temporalis, and the mandible. And the superficial head of the medial pterygoid. Deep relation. Structures, what which you don't see.
[12:10]I don't see the mandibular nerve trunk. I don't see the otic ganglion. I don't see the chorda tympani. And the deep head of the medial pterygoid. Let us see these structures again. Okay? This is the lateral pterygoid. 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 condylar process of the mandible. Okay? This is the capsule of the TMJ. This is the articular disc of the TMJ. This is the upper head of the lateral pterygoid, inserted into the capsule and the articular disc. This is the lower head of the lateral pterygoid, inserted into the neck of the mandible, front of the neck of the mandible. Okay? This is the superficial head of the medial pterygoid, superficial to the lower head. And this is the deep head of the medial pterygoid, superficial head and deep head. Structures along the upper border, deep temporal nerves and vessels, and nerve to masseter. 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 pterygoid. Between the two heads. This is the buccal nerve, and this is the maxillary artery to continue as the third part. Superficial to the lateral pterygoid. Superficial to the lateral pterygoid. This is the temporalis. This is the mandible. This is the masseter. And thank you very much, best wishes and good luck.
