Nerve Supply of the Face

00:00 3rd, 4th and yeah. So these are the main nerves.

00:04 What are the things, we have been discussed are V2 and V3. So that’s the second and third branches of trigeminal nerve. So V1 which is the ophthalmic branch, I said comes out of the superior orbital fissure. V2 which is called the maxillary division of trigeminal, comes out through -- Foramen rotundum. Foramen rotundum, very good. V3 is -- Ovale. Ovale, foramen ovale. What are the other important structures in foramen ovale, coming out through the foramen ovale? It has a mnemonic.

00:55 Accessory meningeal artery. Accessory meningeal artery, okay. What is “O” for? Otic ganglion.

00:59 V3, so that this is your mandibular division of trigeminal nerve, accessory meningeal artery, lesser petrosal nerve and emissary veins.

01:15 What’s the “A” again, sorry? Accessory meningeal artery. “L” is for lesser petrosal nerve. Where does the lesser petrosal nerve come from? Emissary veins? Yeah. Lesser petrosal nerve is a branch of glossopharyngeal, and lesser petrosal nerve is responsible for parasympathetic fibers to the parotid gland and clinical significance is even though you have facial nerve which lies in the substance of the parotid gland, the parasympathetic is coming from glossopharyngeal. So the secretion of the parotid gland is not from the facial nerve, it’s coming through the lesser petrosal nerve, which is a branch of the glossopharyngeal. Okay, so this is essentially your cranial nerves and the foramen they come out through. In the face you need to remember, sensory and motor. All the intersensory part of the face, this one, all these are by V1, V2, or V3. Now all muscles of facial expression are by facial nerve. Muscles of mastication, chewing are by mandibular division of trigeminal nerve. So in other words your superior orbital fissure, the ophthalmic division, that’s mostly sensory. The next one is maxillary, that is mostly sensory. And third one is mandibular. Mandibular is sensory as well as motor.

03:11 The motor component is the muscles of mastication? What are the muscles of mastication? Temporalis? Buccinator. Buccinator is not.

03:21 Masseter, pterygoid. Masseter, medial pterygoid and lateral pterygoid.

03:25 These are the four muscles of mastication. They’re all supplied by mandibular division of trigeminal. So if I go back to recreate this part again, the whole of the face, sensory is by trigeminal, lateral medial pterygoid. The muscles of facial expression is by facial, and muscles of mastication is by mandibular division of trigeminal.

03:56 The maxillary division of the trigeminal, can you think of anything, any branches? Any names? I’m only asking the big, the important ones, you know. For example, if you are saying this part of the face is supplied by maxillary division of trigeminal, fine, but then you need to know a little bit more, couple of names. Zygomaticotemporal and zygomaticofacial, they are all coming from the maxillary division. Then remember I told you that there is supraorbital nerve and the supratrochlear, likewise you have an infraorbital nerve, that’s also from the maxillary division. Zygomatic what? Sorry. Zygomaticotemporal, zygomaticofacial.

04:48 Mandibular division of trigeminal, that’s quite important for part A. Kindly name some nerves or divisions. What does the mandibular division of trigeminal nerve do? It comes through the foramen ovale and then what happens? What does it supply? Alveolar.

05:12 Yes one of it is alveolar. Anything else, it’s easy you remember if you classify.

05:21 It divides into an anterior division and a posterior division. Now clearly I haven’t gone through all the names of the other nerves because they are not that important, but this is important. That’s why I’m just going through the anterior and the posterior division.

05:50 I said V3 is a mixed nerve. It has got sensory component and motor component and supplies the muscles of mastication. So before it divides into this, a branch comes off, here, which supplies the medial pterygoid. Then there’s also something called a meningeal branch of mandibular nerve, which also is sensory going to the meninges. From your anterior division, you have the other muscles of mastication, temporalis, lateral pterygoid and masseter.

06:32 So temporalis, lateral pterygoid, masseter. These are all coming from the anterior division of mandibular division of trigeminal nerve. So this anterior division as it essentially supplies the muscles of masticatio,n along with your medial pterygoid which is coming off there. Posterior division, the mnemonic to remember is MAIL, M-A-I-L, Can you think of any names here? Lingual.

07:20 Lingual, yeah. So that’s lingual. So basically if you track it back, lingual is supplied by the posterior division of the mandibular division of trigeminal. So that’s lingual. “I” is for inferior alveolar, you said inferior alveolar. Inferior alveolar nerve is a nerve which enters the mandibular canal, here. So when the dentist is plucking your tooth, that’s inferior alveolar nerve. It comes out through the mental foramen, here, mental foramen and forms the mental nerve. So that’s the continuation of inferior alveolar.

08:00 That’s sensory, this is also sensory. "A" is for auriculotemporal nerve. That’s the one which supplies sensation to the ear, auriculotemporal. Here on this side of the face. And "M" is for nerve to mylohyoid. So that’s the mnemonic, MAIL. This is a little bit you need to remember.

08:23 This always comes up in some form in your exam, which nerve is coming out from which division. And so what the posterior branch is it then? That’s only sensory, right? Apart from nerve to mylohyoid, that’s motor.

08:40 So nerve to mylohyoid, auriculotemporal, inferior alveolar, lingual. So that’s your posterior division and anterior division. So that brings us to the parotid gland.