Temporomandibular joint anatomy

hi everyone so next important topic from your Anatomy is a temporal mandibular joint which is very important for your basics paper okay so let's discuss myself doctors IT team MDS conquer so any essay question so we usually TMJ is given as an essay so if it's an essay question then you have write the contents so either you can write the contents first and then you can write the answer or else you can leave some space right the descriptive part of the answer and then write the contents okay so based on your length of your answer you can write the contents so it exactly actually attracts the examiner if the contents are very clear okay so vice-versa you can do this way or that way it's up to you okay so these are those contents that you need to put in in on your paper so that includes the introduction the development the innovation and the blood supply the components of the joint and components of the muscle the jaw movements examination in various imaging modalities disorders followed by the conclusion and the references so these contents you have to put in for sure so introduction you can give it's a very important joint for the movement of the jaws okay so it is the joint is where the bones get connected to each other and it is constructed to allow the movement as well as to provide the mechanical support okay so next coming to the important introduction for the temporal mandibular joint so it is actually called as a England at throttle joint why so because it provides a hinging movement in one plane that's the reason it's called as ganglia Moyne and at the same time it also provides a gliding movement so which classifies it as a at throttle joint so that's the reason it is called as a king Lima at throttle joint okay so you have to write this for sure and you have to underline that so coming to the development so meckel's catalyst the catalyst of the first arch if I actually functions as a primary joint jaw joint okay later the Incas and the malice of the middle ear are derived from the dorsal and the ventral part of this cartilage which is surrounded by the developing mandible so the formation actually in the 12 weeks in the utero where the join spaces and the articular disk actually start to develop and at approximately 10 weeks the fetus future component of the joint becomes evident in the Maison Kaymer between the candela cartilage of the mandible as well as a developing temporal bone so this is how you have to ride the development related to TMJ okay so the first evidence is actually it is divided or it is given as a two distinct regions or which is related to the mesenchymal concerns condensation that includes a temporal and the condylar blastoma so little introduction of the development is enough next we have to write the blood supply of that so all the Bloods arteries which supply the TMJ include these arteries so you have to write okay so they are actually the branches of the external carotid artery predominantly the superficial temporal branch so and the other branches include these so this branch you have to mention and the other branches also you have to write if possible if you can draw this diagram okay it's good so you can you have can draw the TMJ joint along with that Eclair disk and Maya fossa do you know it for sure and you can draw these diagrams like the maxillary artery tympanic artery showing the arteries posterior auricular deep or ocular artery so you can just show arteries it's not mandatory if you can it's better you draw then coming to the nerve supply and so the mandibular nerve actually provide the efferent innervation additionally it is also provided by the deep enteral as well as a mass Ettrick okay most of the innervation is actually provided by the auricular temporal now okay so by mandibular nerve auto-close temporal nerve you have to write next coming to the main anatomy so we have given a mild description or a small description brief description of the development followed by the blood supply and the nerve supply now coming to the main anatomy of the joint of how it looks so it has actually have the hard components and the soft tissue components so the first is a kondal ahead you can write the dimensions as shown in this picture you can write you can draw and you can give the dimensions and then you can also next you have fried the fossa so it is located where is located exactly it's an infinite part of the squamous part of the temporal bone which is composed of the articular eminence at the anterior limit and the glenoid fossa so you have to write like this next coming to the soft tissue components which include the articular surfaces are two clear discs and the ligaments so first you have tried the hard tissue which includes the fossa as well as the condyle condyle ahead then you have to come to the soft tissues which include these articular surfaces the discs and the ligaments so articular surfaces the upper articular surface is actually formed by the eminence the articular eminence and the anterior part of the fossa whereas lower articular surface is formed by the head of the mandible it's very simple okay next articulate this graph to highlight short answer can also be asked on articulate this okay after draw beautiful diagram and you can color the articular disk and showing that Gladys as shown in this picture this picture is very easy to draw as you can see you can draw this showing the article a disc okay so the unique feature of the TMJ is the its its articular desk okay it is actually a vascular in the center okay whereas the peripheral portion is vascular and thicker the center area is thin and it is a vascular okay that dysfunctions at the articular dis against the temporal bone as well as the mandible and it's usually 10 mm in anterior posterior and 20 mm and medial lateral dimension those always you have to put in okay next coming to the attachments of the disc so posteriorly it is attached via retro at a skull tissue it is highly vascularized and innovated and so also called as by lamina joan because it has superior rhetorical lamina and inferior to the skull lamina as you can see in the picture so it's also called as a by lamina joan so you can write this next coming to the attachment anterior posterior attachments you have written the retro driscoll tissue and next coming to the anteriorly so the superior inferior attachments of the anterior region of the disc are to the capsular ligament which surrounds the most of the joint so anteriorly it is to the capsular lignin and between this attachments the disk is also attached to the lateral pterygoid muscle okay so that you have to mention so if a question is as again on that this little description of the joint and the disk description and its attachments are very important okay the posterior as well as the anterior attachments so next coming to the capsule or the joint capsule so it is completely in a capsule the TMJ surrounded by a beautiful capsule okay superiorly that is again attached to the circumference of the mandibular fossa anteriorly to the articular eminence and again inferiorly up to the mandibular or the condylar neck as you can see so inferiorly it's to the neck and superiorly it is to the fossa anteriorly it is to the articular eminence as you can see okay so that's it so again next important concept as the synovial fluid so it actually divides the joint into two distinct cavities it's upper or the superior cavity and the lower cavity so the upper is again Phi the disc and a mandibular fossa superior surface of the disc and the mandibular fossa lower is by the condyle and the inferior surface of the disc quite simple so this is again surrounded by synovial lining so what is the important functions of this synovial fluid it acts as a lubricant okay the boundary lubricant and the whipping lubricant so boundary lubrication is to prevent the friction between the moving joint and it's a primary mechanism of the joint lubrication whereas whipping lubrication helps and eliminating the friction in the compressed but not in the moving joint so you have to write this okay next coming to the ligament so we have written the heart tissue components in the soft tissue components we have written that to clear surfaces and then we have gone to the articular disc it's attachments okay and then also then we have come to the ligaments part okay so coming to the ligaments they have mainly three functional ligaments and to access area ligaments so again you have to draw a diagram showing the ligaments as shown here okay the diagram is very important the three functional ligaments through the collateral the capsular and the temporomandibular Lichtman whereas necessary includes a Sneiderman tubular and the spin oh man tubular so the collateral ligaments attach the medial and the lateral posts of the articular dis to the poles of the condyle these are also called as a disco Lippman so medial disco ligament and the lateral disco ligament okay they're actually true ligaments which is composed of the collagenous connective tissue and they usually do not stretch okay they are responsible for the hinging moment of the TMJ next is a capsular ligaments oh it is attached about to the articular tubercle around the circumference of the fossa and the squatting panic fissure and below to the mandibular neck or the neck of the mandible as you can see in the picture so this diagram if you draw it will be really fetching so as I said this diagram showing the ligaments you can draw it is taken from the occasion textbook which is especially given for the TMJ joint so this is articular disease is a condyle and this is your glenoid fossa ah the Manjula for serve okay so here you can see the middle and the lateral fiscal ligaments or the collateral ligaments and these two are the capsular ligaments okay so you can show like this okay so this is the so the medial and the lateral ligaments you can see the lines which are there okay so these are the middle and the lateral discs are ligaments whereas this one is the collateral sorry capsular ligaments okay so you have to draw accordingly as per the label given do draw this diagram the diagrams are very much fetching to answer and to for the marks to score okay next coming to the temporal mandibular ligament so it has a inner horizontal portion and outer oblah portion so the outer oblique portion actually this is the excessive drooping of the condyle therefore limiting the extent of the mouth opening whereas the inner horizontal portion actually limits the lateral pterygoid muscle from over lengthening so you can draw this diagram as well especially the ligaments question if it disaster you have to draw individual diagrams or else for the twenty marks were for the essay question if they ask if you draw the diagrams for all the ligaments then it's really fetching for you then coming to the assessor documents at a style of manwë and the spine or mandibular you can draw this diagram and you can just mention them that's enough coming to the various muscles so the muscles you know the temporal temporal is masseter lateral pterygoid and medial pterygoid so again a separate presentation will be made on muscles of mastication so here if it is si question is being as we have to mention the muscles of mastication along with the origin and the insertion and the functions if you can mention it will be really useful so that separate presentation is being made will discuss therefore the muscles of mastication okay next coming to the jaw movements so he tell now we have given the clear-cut idea of the anatomy of the TMJ along with the muscles of mastication okay it includes the heart and soft tissues okay the articular surface articular discs and the important ligaments along with the diagrams and also the muscles of mastication the origin the insertion and the function so here with we have completed the main answer the main core of the answer next necessary things you have can give the jaw moments okay so first there is a hinge movement or the rotational movement by which the condyle actually rotates around the glenoid fossa then followed by the gleaning gliding moment or the translation moment so if a person wants to open the mouth from a rest or from occlusion position to the rest position then first the condyle rotates okay within the fossa it rotates later if he wants to open the mouth widely it glides over the articular eminence so that the person can open the vault open the mouth widely this is important moments related to the TMJ so the normal mouth opening is around 40 to 50 mm okay being measured from the edge of the lower front teeth and the edge of the upper front teeth okay these are the various functions it uses for elevation depression of the jaws and also protrusion and rotation are also further exertion moments and the lateral moments so these are the important movements and functions given by the TMJ so next coming to the clinical examination just brief description of the functions of the TMJ is enough what is the hinge movement and what is a guide moment and a little description that's enough next coming to the history we have to as a patient whether is having pain with his having tenderness in the muscles whether he's able to open the mouth frequently or sorry widely or not any frequent headaches and tooth aches and any injuries or any history of trauma and any changes in his bite so all this detailed history you need to take followed by which you can do inspection by measuring the opening with comfort and without comfort or like with pain or without pain okay and also the maximum lateral and protrusion movements should also be inspected later you have to make a diagnosis based on the alaskans diagnostic criteria this you have to mention students it's very useful for scoring point of view so Alaskan has given a diagnostic criteria so it has two four four sorry four cardinal signs and two negative characteristics so the four cardinal signs which denote there's a TMJ disorder is a unilateral pain the muscle tenderness the clicking or the popping noise in the TMJ and limitation in the jaw movement whereas negative characteristics include there is no radiographic evidence and there is no tenderness in the T J on palpation via external auditory meatus so this alaskans criteria diagnostic criteria irrespective of your department if you're right it's really fetching for you so next coming to the earth deviation and deflection you have to write so deviation so on wide opening again the mouth before you come back to its normal position whereas in deflection it stays back in the deviated or a deflected position so it deviates from the midline and it stays like that that's a major difference so you know how to palpate an auscultate the boast intraocular and the extraordinary you have to mention them and the provocation tests like the examiner is asked to apply pressure against resistance so the patient is asked to open the mouth widely against resistance so how far you can open with pain and without pain or with comfort and is without discomfort is being measured that is called as a static pain test okay so here the manual forces actually applied lateral upward and downward direction okay so this if you right it's okay or else you can leave it next intraocular examination you have to see for all these you have to see for any history of cheap chick cheek or lip biting s any weighted Linea Alba any scalloped tongue or borders occlusion where tooth mobility and all these so you have to look further internal examination as well next of various TMJ imaging modalities we can write just the names you can write if it is an oral medicine student if you can give little bit description of the imaging modalities it will be useful for you so these are the various imaging modalities but for the articular disk to observe MRI is more useful okay because MRA is especially it gives a detailed of the articular disk or the soft tissue part so MRA is more useful so you can mention there so for observing the articular disk MRI is more useful so next the diagnostic Elena blocks also you can give and the various disorders the classification you can give like intra or claw or intrinsic and extrinsic disorders again you can give this in disorders and you can give this classification as an applied aspect okay I can give a heading as applied aspects and you can give related disorders due to intrinsic as well as extrinsic so these are the various intrinsic factors as you can see okay so can just note it down and these are the other factors intrinsic factors which are broadly classified as all these then extrinsic you include them masticatory muscle disorders also from the trauma like Myositis tendonitis internal dis rearrangement and all this okay next inflammatory join disorders include the inflammation of the synovial membrane or the synovial lining or the capsulitis or even the that is an inflammation of the capsule or the retro disc itis which is the inflammation of the retro difficult issue okay so again you can give a brief introduction of the ankylosis where is an abnormal a mobility of the joint okay that again you can if you know you can give a mild description of the causes and the main signs and symptoms of ankylosis that's it and the relation between the teeth and the joints at the end you can give so which includes like the any habits like the clenching of the teeth or bruxism so that's again related to any TMJ disorder that you can end like that so you can finally conclude so this is how you have to write the answer student so first we have to give a Maggie's introduction or this simple brief introduction of the joint and the ding limb of a throttle join later you have to give the blood and nerve supply followed by and also the development of TMJ followed by the hard and soft tissue components of the TMJ you have to give detailed description of that followed by the muscles of mastication and the various TMJ movements the hinge movement the gliding movement and the functions of the TMJ followed by the clinical examination that is inspection and palpation and the static provocation test again followed by the disorders and the applied aspects so for if it's oral medicine student you can give a detailed description of the imaging aspects as well okay this is how you have to write the exam more answer in your exam for the anatomy part of point of view for the TMJ okay and these are the various reference that you can put in so the must and the if a TMJ question comes do write this reference that's occasion occasion is a specific texture book for the management of the TMJ disorders so case and you do write that apart from that your chowder shared your development book for in the basing and the bucket okay you can write that and any articles if you can you can write so as shown here you can put forward any articles if you