Hi there this is dr. Mohammed Khan Today we are going to dive in the anatomy world we're going to talk about one of the most important nerves in the human body The most important nerve for us as dentists which is the trigeminal nerve cranial nerve number 5 We're going to see where it starts and what it nourishes Without further ado let's begin the lesson translated by dr. Anhar . S. Al-Ahdal As I said, our lesson is about trigeminal nerve we're going to talk about basic information in less than 30 seconds then we will be back to clinical part the first question will be asked is weither the trigminal nerve is sensor part or motor part the answer briefly is both or you can say mixed, it contains sensory and motor nerves As we call it trigeminal nerve tri which means three what does that mean?it means that its divided into three parts thr first part is called Ophthalmic v1 Ophthalmic division of trigeminal nerve and its also called v1 which is the the first part of the fifth nerve this part is considerd only sensory I will explain about it in the clinical part its only sensory, It gives a sensation toward scalp and eys the second part is called maxillary or v2 which is also a sensory nerve it doesn't contain any motor nerves the second part is called the maxillary v2 the third part is called mandibular the third part is called mandibular division of the trigeminal nerve, its called v3 this is the only mixed part,which contains both sensory and motor nerves its not only motor , sometimes you will be asked if its just motor no, it contains both sensory and motor nerves, its mixed thats why this part of trigeminal nerve is mixed Ok, another question you will be asked in the clinical part is where is the insertion the cranial nerve is araised from the brain stem in this marked place Ok the brain stem is divided into parts It starts with thalamus, then midbrain pons , and medulla the trigeminal nerve is breifely araises from the pons it can be a question in the clinical part, or paper part where does the trigiminal nerve originate ,It originates from the pons In addition to other fibers, but it mainly originates from the pons So , this is the answer for the question We're going to take this in a few seconds at the Clinical part Look at this picture ุthis is the cranial base This is the foramen magnum as we said here is the place of the brain stem the brainstem over here will give us a tube which is the trigeminal nerve the main trunk then the trigeminal nerve basses a little and form a ganglion A ganglion means a collection of neurons which form a mass like It's rounded shape ,a mass after the ganglion , the trigeminal nerve will divide into three parts we already talked about The ophthalmic nerve, the maxillary ,and the mandibular nerve I wanted to show you this picture before we start with the clinical part clearer and more ,but you know my drawings are very bad ,so i wanted to show you this photo to make it easy to explain later As I said, this view is what we will explain What do we call this ? This is the cranial base. Let me take you to a small trip here We already said this is the foramen magnum and this bone is the sphenoid bone this is the greater wing of sphenoid and this is the lesser wing of sphenoid , and this is the body of sphenoid the body of sphenoid its a chair like What can sit there ? The pituitary gland this is the place of the pituitary gland let's see this place where the trigeminal nerve will be let's start drawing , but first let me tell you an info you might face at the clinical part In this area, in the blue area there is the cavernous sinus which is a paired dural venous ,that found inside the cranium Ok its called cavernous sinus this might be an important question ,which branch that passes through the cavernous sinus and from which wall it passes now, we will see as I said , the trigeminal nerve comes out of the brain stem then , it form a ganglion as I mentioned before, its a collection of neurons then , it divides into three parts the first division is the ophthalmic division ,notice that it pass on the lateral wall of the cavernous sinus then ,it gets in this fissure ,do you see this , fissure means a split this fissure is called superior orbital fissure which is related to the eye ,up here this is superior orbital fissure Superb we said that ,what is this this is the v1 ,ok the v1 it passes lateral to this blue color which is the cavernous sinus it comes out of the middle cranial fossa ,that is called middle cranial fossa it comes out through superior orbital fissure Excellent what comes after ? what comes after is the maxillary branch lateral to the cavernous sinus lateral to the cavernous sinus then it gets inside this foramen what is the foramen called ? this foramen is called foramen rotundum. great what's left? the third part is not related to the cavernous sinus it could be a MCQ question ?which branch that pass lateral to the cavernous sinus the answer are the ophthalmic division and the maxillary division the mandible division comes from the ganglion and then gets down directly . it didn't pass near the cavernous sinus at all ?it just passes through a foramen ,what does it called this foramen is called foramen ovale , which is an oval shape what is this ? this is v 3 Excellent so , this is the simplified form ,which we're going to learn now as I mentioned before , the ophthalmic division passes through the lateral wall of the cavernous sinus then , it goes through the superior orbital fissure ,superb The maxillary division , also passes lateral to the cavernous sinus and then ,gets through the foramen rotundum the mandible has no relation to the cavernous sinus and it passes through the foramen ovale great now, lets take each part and explain it but let's take another trip this is foramen ovale , notice the oval shape , this is the foramen oval Next to it , is foramen spinosum , memorize it . Then I'll explain it in the mandible part So, what are these ? his is foramen ovale , this is foramen rotundum and superior orbital fissure notice that , its large split, which called superior orbital fissure like i said , here is the cavernouse sinus in this area, In this area the cavernouse sinus exist which comes on the edge of Sella turcica Sella turcica is the chair that the pituitary gland sit on . This area is called sella turcica. what is this? This is the lesser wing of sphenoid and this is the greater wing of sphenoid Excellent now , what we are going to do let's start to explain the ophthalmic division and let's go out with the nerve now , where are we going ? see this place , where are we ? We are at the floor of the orbit this is the way where the ophthalmic division comes out let's turn the picture around What is this ? this is the superior orbital fissure this is the superior orbital fissure and this is the optic canal , which the optic nerve comes out , the cranial nerve number 2 Ok , it's not our subject Let's take the superior orbital fissure As I mentioned , the ophthalmic division , comes out of here the nerve will come out of this corner Ok , its going to divide into three main parts , what are they ? The first , smallest and easiest part is called the lacrimal nerve it comes out from here , where its going ? look here this is mesial side this is lateral side Right this is the mesial which is near to the midline this is the lateral side it will pass with the lateral wall of the eye and nourishes a gland over here what is the gland called ? its called lacrimal gland from its name , the lacrimal nerve nourishes the lacrimal gland Ok after the nerve nourished the lacrimal gland , then it comes out and feed the upper eye lid from the lateral side Great , we finished the first part the second branch , what is it ? Look with me , this bone , what does it called ? Its the frontal bone so , this nerve will pass up to the roof which is the largest branch of the ophthalmic nerve , huge frontal nerve , which is a branch of the ophthalmic nerve and a branch of the trigiminal nerve Ok The frontal nerve also will divide into 2 parts the first division is called supra trochlear it goes up and will extend and nourish the frontal bone and reach to the scalp and the back of the head What does the second division called ? Its called supra orbital nerve It gets from here which is supra orbital foramen will extend in the same way , and nourishes the scalp and reaches the back of the head So ,this is the second division So easy As I mentioned before , this is the ophthalmic nerve , the yellow painting Divide into frontal nerve which will divide into two parts One of them is supra trochlear , the other called supra orbital Which both go up and nourish the upper eye lid, Here , in this side and nourish the scalp, and extend to the back of the head . I will show you later the extension of these two nerves Superb Still the last branch and we will finish the ophthalmic division The third branch , is the most complicated branch what is it called ? Its called Nasociliary nerve The Nasociliary nerve will divide from here Then what ? In the middle wall , in this area ,a foramen found this foramen is called, posterior ethmoidal foramen one of them will pass through this foramen What the posterior ethmoidal foramen will give us ? It will give the posterior ethmoidal nerve A very important information , about this nerve This nerve doesn't exist in 30% of people First as i said earlier ,it will pass through the foramen ( i'll mention it later) It's called the posterior ethmoidal foramen Then it will continue and face another foramen It's called anterior ethmoidal foramen Which the anterior ethmoidal nerve will pass through So easy The rest will pass anteriorly , and comes out of the eye , from this area and will nourish the nose side and a little of the upper eyelid What is this nerve? the last one it's the infra trochlear Lets see here , this is supra trochlear and this is infra trochlear. which means that the infra trochlear is a part of the nasociliary branch of the ophthalmic nerve The supra trochlear is a branch of the frontal nerve of the ophthalmic nerve Sometimes it's confusing , I know , you can replay the video over and over again You 'll get it easily Ok we have only one branch of the nasociliary nerve We know that the eye lies here , and the cornea found in the eye So, the nerve will comes out from here and will extend in the eye floor ,and nourishes the cornea What is this nerve ? it called long ciliary nerve Why ? It's long ,which comes from here and pass all along the eye then gets inside the cornea and nourishes it as a sensation what does it called ? Its called long ciliary nerve We have finishid the ophthalmic branches Let's do a quick revision the blue part is called the lacrimal nerve which is the smallest The nerve comes out laterally and nourish the lacrimal gland here then it will pass out and nourish the upper eye lid laterally Finished The second branch ,the largest branch which is the frontal This thick one It divides into two parts the first one is called supra trochlear Will go up from the eye and will nourish the forehead and the scalp the second part is called supra orbital nerve which will pass through the orbital foramen that nourish the upper eye lid and the scalp OK The third part is called the nasociliary nerve The nasociliary nerve will be drawn better than this The nasociliary nerve will pass through the posterior ethmoidal foramen and cross anteriorly and pass through another foramen called anterior ethmoidal foramen and the rest will pass out and nourish the side of the nose and the upper eye lid And what do we call this ? its called Infra trochlear nerve the last branch is the long ciliary nerve, which comes from here We said its called nasociliary nerve the nasal part gets in the ethmoide the ciliary part goes to the cornea of the eye with long ciliary nerve and nourish the cornea Excellent After we draw this , let's see this we said the nerve comes out from here see with me , this is posterior ethmoidal foramen this is posterior ethmoidal foramen the nasociliary nerve gets within ,right here then it passes forward to the anterior ethmoidal foramen and gets inside and continue to pass and form infra trochlear nerve So , the nerve passes through these two foramen the last part , will get down from the inside and will nourish the cornea of the eye what does it called ? Its calld long ciliary nerve . Ok I diden't ask , what these two nourish when they pass through the ethmoidal bone What are they nourish? They nourish the sinuses of this area Which are the ethmoidal sinus and the sphenoid sinus which are found here ,inside the posterior nerve will nourish the posterior part the anterior nerve will nourish the anterior part The third branch , which is the infra trochlear, will nourish this area which is the side of the nose, superiorly this is the upper eye lid , it will nourish small part of it . which is the infra trochlear Suberp Now , we have finished the ophthalmic division But honestly , it's not the difficult part Let's go back Now , we have finished the ophthalmic division As I mentioned earlier , the ophthalmic division pass through the superior orbital fissure This is superior orbital fissure Which comes from the greater wing of sphenoid , and the lesser wing of sphenoid Great ! The second part is the maxillary branch Now I'll speak about the maxillary branch The maxillary branch passes through a foramen called foramen rotundum this is the foramen rotundum Where is it located ? Its located inferior to the superior orbital fissure and lies on the greater wing of sphenoid bone Look at the sphenoid bone , its a butterfly shape I'll try to draw it This is a general anatomy Look, this is the sphenoid bone Sphenoid bone , looks like butterfly and contains , greater wing of sphenoid and lesser wing of sphenoid this is the lesser wing , look how small is it this is one wing and this is the other wing Great What's in it? there are the optic canals , which the optic nerves pass through This is foramen rotundum Ok , this is the greater wing of sphenoid The sphenoid bone is a very important bone which has alot in it . Ok , what is this ? This is the sphenoid bone . Since we took the anatomy , I said let me show you OK As I said before , the second branch is the maxillary division It passes through the foramen rotundum this is foramen rotundum OK when it passes the foramen rotundum it will extend to this area It can not be shown ,because its a difficult area to reach but it extends from here anteriorly , ok What does this area called ? A very important question in the clinical part Where does the maxillary nerve pass through ? It will pass through this fossa Where does the fossa come from ? Look with me another anatomy lecture this is called pterygoid plate which is part of sphenoid bone remmber the sphenoid bone which has a butterfly shape This is how it looks from inside view It has a pterygoid plate, This is lateral pterygoid plate, laterally , and this is the medial pterygoid plate OK First thing you want to know about fossa , is that its related to the pterygoid plate OK Anteriorly what does this area called ? Its relatd to the palatine bone which lies posteriorly This is the maxilla and this is the palatine bone So what does the fossa called ? its called pterygopalatine fossa Let's see the maxilla , how it comes from As I mentioned before ,maxilla will pass in a straight line and comes out the fissure Ok When it passes the fissure, it will form a ganglion As i said the ganglion is a collection of neurons Now , this is the main trunk and will give us a ganglion This ganglion is called pterygopalatine ganglion excellent Its derived from the place name there Ok, i'll explain the branches of the ganglion The ganglion will give few branches that goes inside Ok Now , we want to focus on the main trunk Which goes anteriorly let's see where its going We have finished explaining that the maxillary passes through the foramen rotundum then it will go to the pterygoplatine fossa Look at this picture , this foramen is foramen rotundum notice that , this is foramen rotundum we still at the orbit of the eye what is this ? let's take a quick revision this is superior orbital fissure and what is this ? this is obtic canal Excellent Now , this is foramen rotundum first , the maxillary nerve will pass through the eye The question is , where the maxillary nerve will pass from ? let's watch the movement of the maxillary nerve to see where the nerve will pass from notice that , this is foramen rotundum this is pterygopalatine fossa Ok , It will pass through this fissure ,here then it will pass anteriorly on the floor of the orbit What is the name of this fissure ? we knew the upper fissure is called superior orbital fissure. So we call this, inferior orbital fissure It's an answer for a question that might be asked in the clinical part Where the maxillary division pass from when it gets in the eye ? it passes through inferior orbital fissure Great Now , let's see once it passes through this fissure , it will divide Ok we said it comes from here to here now what is it going to do? it will divide into two parts Two One passes here , the other passes there Great What does the 1st part called ? the first division will pass through this foramen Do you see this foramen? It will pass through this foramen and goes out what is this area ? this is zygomatic bone it will pass out through the zygomaticofacial foramen and gives zygomaticofacial nerve This is the 1st part zygomaticofacial nerve the second will pass through another foramen here what does it called ? It's called zygomaticotemporal foramen which gives us zygomaticotemporal nerve Excellent what is this called ? this is the zygomatical branch of the maxillary nerve Here it is the first part As I said , once it gets to the orbit through the inferior orbital fissure it will divide into two parts, One of them ,is zygomatic branch , this big one The zygomatic branch will divide into two parts one is called zygomaticofacial nerve , this is it gets through the zygomaticofacial foramen the other is zygomaticotemporal nerve , which will go through the zygomaticotemporal foramen Superb let's see what they nourish Let's delete this Look with me, this is the foramen it will get out from here this is zygomatico facial nerve What does it feed ? It nourishes the zygomatic area from the cheek side , the sensation, here what is this nerve ? it's zygomaticofacial nerve Ok what is the second part ? Here is a foramen membrane , which the nerve will pass through and gets out there it will gets out from here , what does it nourish ? This area is calld temporal bone And the nerve gets out from the zygomatic bone So , we call it zygomaticotemporal nerve And will nourish the temporal area This is zygomaticotemporal nerve Excellent now, we have finished the first branch of the maxillary nerve Which is the zygomatic branch Ok we have the other branch that comes from the main trunk remmber that , I mentioned before that it divides into two parts one part go to the zygomatic bone The other part will pass along , wait a second will pass along with the orbital floor and gets to this place it gets inside it , What happened when it gets in ? A part of it will get inside the bone We will see its function in a few second the other part will pass through here What will give us ? it will give the infra orbital nerve The Infra orbital nerve , good let's see the infra orbital nerve what will give when it gets out of here , its called the infra orbital nerve Which will divide into three parts the first part what will nourish Look it will nourish the lower eye lid what does the lower eye lid called ? It's called Palpebra and what is this ? this is inferior not superior so, what do we call the nerve ? It's called inferior palpebral nerve Which feeds the lower eye lid Great It will give another branch which will nourish the side of the nose What does it called ? It's called , lateral nasal nerve ,which feed the lateral side of the nose Good One place is left to nourish What is this place ? its the upper lip this is the upper lip the nerve will get down to the lip , the lip is called Lipia and it lies superiorly So, its called superior lipia nerve Excellent By the place that feeds we knew the branches of the infra orbital nerve This yellow is infra orbital nerve ?OK What did I say earlier ? I said that , a part of the nerve will pass through the bone when it gets in What is the way of this part? A part of it will divide and gets inside the bone Right ? We said that it comes from here and a part of it will get inside the bone The inside bone part will get down within the bone and divides into two parts the first part will nourish the central incisor , lateral incisor and the canine the second part will nourish the 1st premolar , 2nd premolar and the mesiobuccal root of the upper 1st molar just the mesiobuccal root of the upper 1st molar What do the nerves called ? the first one is called anterior superior alveolar nerve and this is the middle superior alveolar nerve the anterior superior alveolar nerve comes anterior to the teeth and the middle superior alveolar nerve comes in the middle of the teeth Excellent Now , we have finished the main trunk of the maxillary Let's take a quick revision We said that , when the nerve passes through the floor of the orbit and gets out to the bone It will divide into two parts one will pass out on the surface , which is this yellow line The other part will pass inside the bone the part that pass outside will divide into inferior palpebral nerve , lateral nasal nerve and superior labial nerve Ok The blue lines are the inside parts which lies inside the bone What the inside bone part will give us ? It will give , anterior superior alveolar nerve which will nourish the teeth from central to canine and will give middle superior alveolar nerve which will nourish the teeth from the 1st premolar to the mesiobuccal root of the 1st molar and will nourish also the maxillary sinus because it lies here so these nerves will nourish the maxillary sinuse Great we still have a few simple branches of the maxillary nerve let's go back here, do you still remmber the maxillary nerve ? It passes anteriorly toward the eye Ok What did I say ? I said that it will form a ganglion , a small neurons these neurons will feed some places but before , the main trunk will give a lonly branch that passes next to the ganglion this is the nerve This nerve will get down anteriorly and will enter in the back of the tuberocity of the maxilla through a foramen Ok What does this nerve called ? its called posterior superior alveolar nerve What did I mentioned before ? I mentioned that , there is anterior superior alveolar nerve and middle superior alveolar nerve Ok , so what feeds the posterior teeth ? The posterior superior alveolar nerve will nourish them What is the difference between the P.S.A.N and the other nerves? The P.S.A.N comes alone from above , from here this is fossa ,pterygoid palatine fossa the nerve will pass through a specific foramen , here It will pass through the bone and feeds the posterior teeth What does it called ? Its called posterior superior aveolar nerve What this nerve will do ? it will combine the other nerves which is M.S.A.N and A.S.A.N But focus in the clinical part that it's not the same way that anterior and middle S.A.N pass through No, it passes alone posteriorly He has a strong personality ๐ Ok So , what is this ? This is posterior superior alveolar nerve Now , let's see the last thing which is very simple , I'm not going to focus on it alot What is here ? there is a gangelion where does it found ? this is the pterygoid plate , the gangelion considered existing here behind this plate Great there is a nerve passing down to this foramen Ok let's see , from the gangelion existing behind the plate a nerve will pass out to this foramen when it gets out this foramen it will nourish the roof of the mouth What does this nerve called ? It's called greater palatine nerve Ok Where does this come from ? It comes from the greater palatine foramen and pass to nourish the hard palate area untill the premolar area Focus here, it's a very important question in the clinical part until the premolar area and it passes to the midline of the mouth from the other side , there is another nerve which also nourish the area until the premolar, this area, it nourishes this area Excellent what is this nerve ? It's greater palatine nerve Where does it come from ? It comes from the ptrygopalatine ganglion Excellent What's remaining ? This area remains it's v shape there is no nerve to nourish , right ? because we said that this nerve comes until the premolars only and stops I mean the greater palatine nerve Ok , the ganglion will give a branch A nerve that pass through the nose and cross the paranasal floor and will come out from here What this is called? It's called the incisive foramen The nerve will come out of this foramen and nourish this whole area What this is callled?This nerve is called nasopalatine nerve Why it has this name ? Because ,it passes through the nose ,then it nourish the nasal floor then it will get out from here and nourish this area What does it called? It's called nasopalatine nerve Where does it come from? It comes from pterygopalatine ganglion Great Now, let's see there position Look with me , this is the nasal cavity from posterior view the nerve comes from here this is nasal cavity from posterior view the nerve comes from here and gets down and pass through the floor of the nose then , it gets down from here Through this what does it called ? it's called incisive foramen the nasopalatine nerves gets down from here and nourish this area ,the anterior palatal area The triangle shape area , from central to canine the posterior area feeds from the greater palatine nerve Ok We still have one side there is another foramen here , its not painted Let's make it more clear one is here, and one is there It lies behind the greater palatine foramen What does it called ? it's called lesser palatine foramen Which nerve comes out of this foramen ? it's the lesser palatine nerve It's a small nerve that nourish the soft palate area which is the back of the mouth , the soft area that doesn't contain bone its a small nerve that called lesser palatine nerve Where does it come from? It comes from the pterygopalatine ganglion All what I mentioned lately comes from pterygopalatine ganglion Which are lesser palatine nerve ,the greater palatine nerve and nasopalatine nerve These three , this is nasopalatine nerve , this is greater palatine nerve and this is lesser palatine nerve These three comes from pterygopalatine ganglion Which is a collection of neurons that comes out of the maxillary branch the maxillary branch comes out from the trigeminal nerve Superb Now we have finished the most difficult part which is the maxillary nerve If you think the amount of information is alot , You can take a break , pause the video and take a break We still have one branch Which is the mandibular division It will be a little easier for me the maxillary nerves are the most difficult Now , after the break for few seconds Let's take the last branch , which is the mandibular branch Ok Where does this branch come from? It comes from foramen ovale This is foramen ovale which is an oval shap Notice the oval shape And there is a foramen next to it What does it called ? Its called foramen spinousum This is a very important information you should focus on foramen spinousum Now , I 'll tell you why Ok Like I mentioned earlier , it comes out of foramen ovale Let's go through this foramen ovale and see where does it go Now , we are out Let's see above Before I explain about the mandibular nerve , let's take a small lesson about mastication muscles Ok We know that , the motor part of the mandibuler nerve goes to mastication muscles Which are the muscles that make us move the jaw ,chew the food and make us speak Great ! But , what are these mastication muscles ? ? what does the first muscle called It is the masseter muscle Do you see this ? What is this ? This is zygomatic arch The lower border of the zygomatic arch is the origin of the masseter muscle It comes from here , then it gets down to the angle of the mandible and the lateral surface of the ramus This is the first muscle which called the masseter muscle Ok, let's take the second muscle Let's see the origin of the second muscle It's two part , it originates from the tuberocity and insert to the medial surface of ramus and the angle of the mandible We know that , this is the medial wall of the ramus The ramus from outside ,this is it's medial surface It comes from here and insert to the angle of the mandible Ok There is a second part in the medial wall of the lateral pterygoid plate This is lateral pterygoid plate It originate from the medial wall of pterygoid plate ,like this and it insert in the same place here What does this muscle called? Its called medial pterygoid muscle It originates from the pterygoid that's why it took this name And it passes medially to the jaw That's why its called pterygoid medial muscle Ok, this is the second muscle The function of this muscle is the occlusion of the teeth when biting and helps in chewing food Very good Ok ,let's take the next muscle It originate from here , what is this area ? Its the infratemporal surface of the sphenoid bone This is the sphenoid bone This is the infratemporal surface , this area It will originate from this area and insert to the neck of the condyle Ok , it's two parts This is the first one The second part originates from the lateral pterygoid plate This is lateral pterygoid plate , it originates from here and it insert to the condyle It's fan-like muscle Ok What does it called ? It's called lateral pterygoid muscle Because it originates from the lateral pterygoid plate Let's see it from another view See that it originates from here and inserts here Ok What is the function of this muscle ? This muscle will protrude the lower jaw forward It's like two lines here When the muscle contract , it will pull the condyle And then it will protrude forward It will make a jaw protrusion Excellent We have the last mastication muscle So easy and so clear The last muscle lies here , notice with me It originates from the temporal bone It inserts into an area called coronoid process of the mandible We took this lecture in the previous video The coronoid process Let's see it , it lies behined the zygomatic arch This is it . What is this ? this is the coronoid process The muscle inserts from here and originates from here What does this muscle called ? It's called temporalis Because it's in the temporal area , so easy It took the name from the place of the origin It's clear that , when the muscle contract this area will pull the lower jaw and make it close This is temporalis So these are the muscles of mastication Why did I mentioned the muscles of mastication? I mentioned them because that , the mandibular division (V3) nourish the motor part of the mastication muscles It make these muscles move Ok , let's talk about the mandibular branch I mentioned earlier that the mandibular branch will pass through the foramen ovale Ok Once it gets down the foramen ovale , its not divided yet ,this is the main trunk Focuse here , its a practical question The main trunk A small nerve will get out of it Remmber the small foramen , foramen spinosum From the main trunk , a small nerve will divide and goes up to the cranium again It will nourish the dura mater This could be a question From the main trunk , once it gets out of the foramen ovale ,a small nerve ,spinousum nerve will go up through the foramen spinousum and nourish the dura mater inside the cranium This is the first thing , good From the main trunk a nerve will come out and nourish the medial pterygoid muscle that I mentioned earlier That's found here It nourishes the medial pterygoid muscle The same nerve ,will give two small branches for two muscles One is tensor tympani and the other is called tensor palati Tensor Tympani and , Tensor Palati Memorize it . Memorize that, the main trunk will give two small nerves The first one is called spinousum nerve which will pass through the spinousum foramen that nourish the dura matter You spouse to know this The second nerve , a branch gets down from the main trunk That nourish the medial pterygoid muscle The medial pterygoid muscle has a strong personality, that's why it has a branch before it divides It nourish the medial pterygoid muscle with two small followers Which are tensor tympani and tensor palati Good! After all of this , the mandibular nerve will divide into two parts A posterior division and an anterior division Great , It's difficult to draw everything So , I will try to explain in an easy way . Let's talk about the anterior division what will give It will give a nerve to masseter muscle The outside muscle And a nerve to the temporalis muscle The outside muscle And it will give a nerve to the last muscle Which is medial pterygoid muscle Superb ! So now , we cover the whole muscles of mastication Which are four One comes from the main trunk , this blue drawing And the rest , all three comes from the anterior division ุ focus with me Ok The anterior division has three motor nerves Ok Still one ,the fourth nerve , what does it called ? It's long buccal nerve It comes from here , pass like this , and will nourish the buccal soft tissue of the posterior teeth 6th , 7th , and 8th I will show you clearly A clinical question , you should know that ,the anterior division has three motor branches Lateral pterygoid nerve , masseter nerve and the temporalis nerve And one sensory nerve which is the long buccal nerve Where does it go ? It goes to the buccal side and nourish the posterior teeth Very good Ok , we will finish The posterior side divides into few parts the first part it's easy and will not focus on it A nerve will come out and will go back to the skull and will go to the auriculotemporal area It will go to the ear area and temporal area which is in the back of the head This is the auriculotemporal nerve , I'm not foccusing on it Excellent The largest ,strongest and the most common part is the inferior alveolar nerve Inferior alveolar nerve starts from here And gets down to this foramen What does it called ? It's called mandibular foramen Great Once it passes through, it will nourish the whole lower teeth Then it will go to mental foramen and form a mental nerve a part of it will get within the bone and form the incisive nerve I'll explain it later clearly I want to say an important thing Before the inferior alveolar nerve gets in the mandibular foramen , a nerve is formed This nerve is a motor one Focus with me , motor nerve Where is it heading ? To the mylohyoid muscle As we know, the mylohyoid is the floor of the mouth How does the mouth take the tongue and the other things ? Through the mylohyoid muscles The mylohyoid muscle is considered the floor of the mouth So , the motor nerve is going there , is called nerve to mylohyoid What else ? The same nerve to mylohyoid will give another motor nerve To the anterior belly of digastric muscle Excellent , we have finished ! Still the last branch and we will finish the whole trigiminal nerve thing What is it ? It's the lingual nerve The lingual nerve passes near to the inferior alveolar nerve It will not go through the foramen , it continues forward to the lingual side of the teeth , like this What does it nourish ? It nourishes the lingual side of the lower jaw from the third molar to the central and the anterior two third of the tongue Superb ! With the lingual nerve , a branch of cranial nerve number 7 , a nerve is called corda tympani will compain together and make the special sensation Which is the food sensation It comes from the corda tympani , a branch of the facial nerve the cranial nerve number 7 But the general sensation ,like when you feel that your tongue is exist Is through the lingual nerve Which is a branch of posterior division ,of the mandibular division , of trigiminal nerve I know that it's confusing , but there is no other easiest way to understand it like this Now , let's delete this And see how each nerve will pass through As I said before , This is the mandibular foramen , which the inferior alveolar nerve passes through Then it passes through the bone And nourishes the pulp and the bone of these teeth Untill it reaches here , what does it calld ? It's called mental foramen Then the nerve comes out of the mental foramen A clinical question ! The mental part doesn't nourish any bone or teeth It just nourish the soft tissue of this area and the side of the lower lip This is soft tissue nerve A clinical question , the mental nerve is a nerve for the soft tissue Excellent ! Like I said, it will come from here and will go out , a part of it will continue like this This part will nourish the bone and the pulp tissue of the teeth What does it called ? It's called incisive nerve which nourishes this area Great ! Let's see the lingual nerve I said that , the lingual nerve passes next to the inferior alveolar nerve And continue forward in this area , like this And nourishes the tongue , the tongue will be here It nourishes the tongue , and this whole area , the lingual area of the gingiva And the anterior two third of the tongue 2/3 Great I said also , that , the inferior alveolar nerve , before it gets inside the foramen , it will give a nerve to mylohyoid This is the mylohyoid ridge , that mylohyoid muscle lies on Imagine with me the mylohyoid muscle is here It will give a motor nerve And another nerve is called anterior belly of digastric nerve Now , I will draw the mandibular nerve It comes from foramen ovale Ok Then , a small part of it will go to the back through a small foramen called foramen spinousum Then another branch comes from here and go to the medial pterygoid muscle And other muscle called tensor palati and tensor tempani Good Then it will divide into two parts the anterior part and the posterior part Ok The posterior part will give , auriculotemporal nerve ,lingual nerve and the inferior alveolar nerve Ok The anterior part will give , nerve to masseter Nerve to temporalis And nerve to lateral pterygoid And also give , but I will change the color because its the only sensory nerve Which is the buccal nerve You know that my drawing is so bad , And I hope you understand from my drawing That was our lecture today If you get benifited , don't forget to subscribe to the channel By clicking the subscribe button If you like to see the rest of my contents You can press watch next Untill I meet you again , be save .