 Good day everybody. I'm Sanjay Sanyal, Professor, Department Chair. We shall demonstrate the bit of the perotid in the skeleton in front of us. The perotid gland has got two parts, a deep portion and a superficial portion. Therefore, it is wedge shaped. The deep portion is related to the stalate process of the temporal bone. The superficial portion is related to these following structures. This is the ramus of the mandible. The meseter muscle is on the outside. The medial teregoid muscle is in the inside. So these are the anterior relations of the perotid. The posterior relation of the perotid is this structure here. This is the mastoid process of the temporal bone. The posterior of the digastric and the muscle attached here, which is the sternocleidomastoid. The muscles which are attached to the stalate process are the stylo glosses, stylo pharyngeas, and the stylo hyoid. Pustero superiorly, we have the external rematers and the tip panic plate of the temporal bone. And superiorly, the perotid is related to the zygomatic arch, which is composed of the zygomatic process of the temporal bone and the temporal process of the zygomatic bone. So these are the bed of the perotid gland. This structure that you see in front of us, this is the perotid, the superficial part of the perotid gland. The deep portion, we cannot see because it is in relation to the styloid process of the temporal bone. So let's take a quick look at the relations of the superficial part of the perotid gland. Anteriorly, it is related to the ramus of the mandible, which is covered by the meseter muscle here. Pustero, it is related to this bone, which we can feel here, this is the mastoid process. And the sternocleomastoid. Pustero superiorly, it is related to the external or rematers and the tip panic part of temporal bone. And superiorly, it is related to the zygomatic arch. This perotid gland was covered by a tough sheath, which is known as the perotid sheath or the perotid fascia, which is a derivative of the investing layer of deep cervical fascia. And this perotid sheath is continuous with yet another sheath which is covering the meseter muscle, and the two of them are together known as the perotidomethetric fascia. And they give an extension inside, which is called the stylo-mandibular ligament, which extends from the styloid process to the angle of the mandible, but we cannot see it here. So all those facial sheath have been removed and it took quite a bit of dissection. At this point, we can mention one important clinical correlation. Whenever we have any inflammation or any swelling, no matter how minor of the perotid gland, it produces intense pain, and that is because of stretching of the perotid sheath. The perotid gland is closely related to the lobule of the ear, so therefore any enlargement or any sum of the perotid gland will always be associated with elevation of the lobule of the ear. So if we see a patient with a swelling on the cheek with elevation of the lobule of the ear, we can safely say that it is a perotid enlargement. Now let's see the structures which are passing through the perotid. The first structure that passes through the perotid is the external perotid artery with its synthetic periartereal plexus. Here inside the perotid gland, it divides into a larger terminal division that is the maxillary artery and the smaller terminal division, the superficial temporal artery. So this is the first structure which is going through the perotid gland. The next structure going through the perotid gland is this, the superficial temporal vein. The superficial temporal vein, inside the perotid gland, it meets up with this vein which is coming from the intratemporal fossa. This is the maxillary vein. And once it meets with the maxillary vein, it forms the retromandibular vein. This is called the retromandibular vein because it is running behind the ramus of the mandible. And the retromandibular vein then meets with the posterioricular vein and it forms the external jugular vein. So this is the second structure which is passing through the perotid. The third structure which is passing through the perotid is this structure which I'm holding up with my foresip. This is the facial nerve. The facial nerve emerges through the stylomastoid foramen. It winds around the neck of the mandible and it enters the perotid gland. And inside the perotid gland, it splits into a plexus. And we can see part of the plexus here. If you are to trace the facial nerve inside the perotid, I'm holding up the facial nerve as it is emerging from the stylomastoid foramen. And then we have split the perotid gland and we can see the plexus here. And we can see the facial nerve emerging from the perotid gland. The facial nerve divides into two principal trunks. A temporal facial and a cervical facial. The temporal facial supplies the temporal branch and the zygomatic branch. The cervical facial supplies the buckle, the marginal mandibular and the cervical branch. We can see some of the fibers of the facial nerve here. Facial nerve is the most important structure which divides the perotid gland into a superficial and a deep part. And the plane between the retromandibular vein and the facial nerve is called the fasiovenous plane of PT, which is used as a plane of surgical dissection which not only safeguards the facial nerve during surgery but also allows us to do a superficial perotidectomy as and when required. The next structure which passes through the perotid and which I have lifted up with my foresip, this is the auriculotemporal nerve. The auriculotemporal nerve supplies secretome motor fibers to the perotid gland. And after that, it continues through the perotid and it supplies the skin of the temporal region and the skin in front of the tragus of the ear. Another structure which also passes through the perotid but we cannot see it here because there's two small fibers that is the great auricular nerve which supplies the sensory fibers to the perotid gland, to the perotid sheath and to the skin over the perotid gland. So therefore these are the structures that we can see passing through the perotid. And we can see all of the structures in this particular view and I will quickly enumerate them. This is the external perotid artery, dividing into the maxillary artery, the superficial temporal artery, superficial temporal vein, the facial nerve and the auricular temporal nerve. The sympathetic plexus also passes through the perotid gland with the arteries. Now let's take a look at this structure which is emerging from the anterior surface of the perotid. This is the perotid duct of the stensis duct. It arises from the superficial part of the gland, runs over the masseter muscle and it pierces the buccinator and it opens up with the crown of the upper second molar tooth and this is the perotid duct of the stensis duct. Now let's come to a few important clinical correlations. Perotid inflammation, as I already mentioned, or perotid abscess can lead to severe pain. Any tumor of the perotid gland will produce elevation of the lobule of the ear which is an indication that the swelling is arising from the perotid gland. When we do an incision for perotid, that incision is called cis-trunk incision and that is something which we have made here. Perotid duct stones lead to inflammation and structure of the perotid duct, in which case we have to investigate by doing a radiographic contrast injection into the perotid duct through the opening and that procedure is known as silo-graphy. Another important clinical correlation, though not very common, is called the gusty tree sweating. That happens when there's a penetrating injury to the perotid gland. During the process of healing, abnormal communications develop between the branches of the auricular temporal nerve, which I showed you, and the great auricular nerve. When the person eats, the impulses instead of going and supplying the perotid gland, they go through the great auricular nerve and they produce sweating of the skin and that is known as gusty tree sweating. Some tumors of the perotid gland, namely pleomorphic adenoma, is not very uncommon and that usually arises from the superficial part of the gland and in which case we have to do a superficial perotid duct. That's all for the perotid gland and its relations and its clinical correlations. Thank you very much for watching. If you have any questions or comments, please put them in the comment section below. Have a nice day. Dr. Sanjay Sanyal signing out. 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