Temporomandibular Joint By RABIA INAM GANDAPORE.pptx

Gross Anatomy

1. TEMPOROMANDIBULAR JOINT DR.RABIA INAM GANDAPORE Assistant Professor & Head of Department ( Dentistry-BKCD ) B.D.S (SBDC), M.Phil. Anatomy (KMU), Dip. Implant (Sharjah, Bangkok, ACHERS) , CHPE (KMU), CHR (KMU), Dip. Arts (Florence, Italy)

2. CONTENTS DEFINITION RELATIONS OF THE TMJ COMPONENTS OF TMJ LIGAMENTS OF TMJ SYNOVIAL MEMBRANE BLOOD SUPPLY NERVES SUPPLY PROPERIOCEPTION OF TMJ JAW MOVEMENTS CLINICAL ASPECT CLINICAL EXAMINATION REVIEW QUESTIONS (MCQ) REFERENCES

3. Temporomandibular Joint T wo joints connecting the jawbone to skull . Ball & socket joint B ilateral  synovial articulation  between: ABOVE: Temporal bone  of skull. BELOW: Mandible. Formation of TMJ occurs at around 12 week of embryonic life. TEMPORAL BONE MANDIBLE

4. Relation Of Tmj S.No ANTERIORLY POSTERIORLY LATERALLY MEDIALLY 1. Mandibular notch Tympanic plate of the external auditory meatus Parotid gland Maxillary artery & vein 2. Messeteric nerve & artery Glenoid process of the parotid gland. Temporal branches of the facial nerve Auriculo -temporal nerve. 3. Lateral Pterygoid muscle Fascia and skin

5. Relation Of Tmj ANTERIORLY 1. Massenteric nerve & vessels 2. Mandibular notch 3. Lateral pterygoid muscle POSTERIORLY 1. Glenoid process of parotid gland 2. Tympanic plate of external auditory meatus LATERALLY 1. Parotid gland 2. Temporal branches of facial nerve 3. Fasica 4. Skin MEDIALLY 1. Maxillary vessels 2. Auriculotemporal nerve

6. Structure A).COMPONENTS: a). Joint capsule b). Articular disc c). Mandibular condyles d). Articular surface of temporal bone e). Lateral Pterygoid muscle B). LIGAMENTS: a ). Temporo -mandibular ligament b ). Stylo -mandibular ligament c). Spheno -mandibular ligament

7. A) Components 1. CAPSULE D ense fibrous membrane that surrounds the joint . It attaches to the: ABOVE: Articular tubercle, articular disc & margins of mandibular fossa BELOW: Neck of mandibular condyle 2. ARTICULAR SURFACE Covered with fibrocartilage.

8. 3. Articular Disc O val plate of fibro-cartilage that is attached circumferentially to capsule. CENTERAL AREA OF DISC : Avascular Thinner Denser consistency PERIPHERAL AREA OF DISC: Vascular T hicker C ushioned consistency. PERIPHERAL AREA OF DISC CENTRAL AREA OF DISC

9. Disc Surfaces Upper Surface: Concavo-convex from before backward to fit the shape of articular tubercle & mandibular fossa Lower Surface: Concave to fit the head of mandible D i sc is composed of: a). Anterior extension b). Anterior thick band c). Intermediate zone d). Posterior thick band e). Bilaminar region (containing venous plexus) ANTERIOR BAND ANTERIOR EXTENSION INTERMEDIATE ZONE BILAMINAR REGION POSTERIOR BAND

10. Cavities A rticular disc divides the joint into 2 cavities (compartments): A . MENISCO-TEMPORAL CAVITY (UPPER) Between upper articular surface & articular disc Permits gliding movements. B . MENISCO- MANDIBULAR CAVITY (LOWER) Between disc & head of mandible Permits rotatory & gliding movements

11. Function Of Articular Disc a ). P revents friction. b). Cushioning effect. c). H elps in shock absorption. d). Stabilize the condyle. e). Proprioceptive fibers helps to regulate movements of joints. f). Helps in distribution of weight across TMJ by increasing the area of contact. DISC

12. Synovial Membrane Lines the joint capsule Produces synovial fluid that fills these cavities. P rovide nutrition for avascular central area of disc.

13. 4. Lateral Pterygoid Muscle A rticular disc is attached in front to the tendon of lateral pterygoid muscle & by fibrous capsule to head of condyle. These bands ensure that the disc moves forward & backward with the head of mandible during protraction & retraction of mandible .

14. B. Ligaments 3 ligaments associated with TMJ: 1. MAJOR LIGAMENT Lateral Temporomandibular ligament 2. MINOR LIGAMENT Stylomandibular ligament Sphenomandibular ligament These ligaments define border movements i.e. the farthest extents of movements of mandible. 

15. Oto Mandibular Ligaments Connects middle ear (malleus) with TMJ 1. Disco- malleolar ligament: Malleus to medial retrodiscal tissue of TMJ 2. Mandibular- malleolar ligament: Malleus to lingual of mandible via spenomandibular ligament

16. Lateral Temporo -mandibular Ligament Strengthens the lateral aspect of capsule. Its fibers run downward & backward from the tubercle on root of zygoma to the lateral surface of neck of the mandible . This ligament limits the movement of the mandible in a posterior direction . Thus, p rotects the external auditory meatus.

17. Spheno -mandibular Ligament Lies on the medial side of joint. A thin band that is attached: ABOVE: S pine of sphenoid bone BELOW: L ingula of mandibular foramen . I t represents the remains of the first pharyngeal arch in this region ( i.e . dorsal part of meckel's cartilage)

18. Stylo -mandibular Ligament Lies behind & medial to the joint & some distance from it . It is merely a band of thickened deep cervical fascia (which separates the parotid & submandibular salivary glands) Extends from apex of styloid process to angle of mandible .

19. Blood Supply Branches of external carotid artery , i.e   superficial temporal branch . Other branches of external carotid artery also contribute i.e. 1. D eep auricular artery 2. A nterior tympanic artery 3. A scending pharyngeal artery 4. M axillary artery V eins follow the arteries.

20. Nerve Supply SENSORY INNERVATION Auriculo -temporal nerve. M assenteric branches of mandibular nerve (V3 ). MOTOR INNERVATION: From muscles

21. Proprioception In Tmj Involves 4 receptors: 1. RUFFINI ENDINGS S tatic mechano -receptors. Position the mandible. 2. PACINIAN CORPUSCLES: Dynamic mechano -receptors Accelerates movement during reflexes 3. GOLGI TENDON ORGAN Static mechano -receptor Protects ligaments around TMJ. 4. FREE NERVE ENDINGS Pain receptor for protection of TMJ DISC

22. Jaw Movements In position of rest , teeth of upper & lower jaws are slightly apart . On closure of jaws, teeth come into contact . Mandible movements can be : a). Depression of mandible b ). Elevation of mandible c ). Protrusion of Mandible d). Retraction of Mandible c). Rotation of mandible (lateral chewing movement) DEPRESSION & ELEVATION

23. Depression Of Mandible M outh is opened: head of mandible rotates on the undersurface of articular disc around a horizontal axis . Depression causes contraction of: a. Digastric b. Geniohyoid c. Mylohyoids d. Lateral pterygoids LATERAL PTERYGOID DEPRESSION

24. Elevation Of Mandible Head of mandible & disc move backward, & then head rotates on the lower surface of disc Elevation causes contraction of: a.Temporalis b. Masseter c. medial pterygoids . TEMPORALIS MASSETER

25. Protrusion Of Mandible Articular disc is pulled forward onto the anterior tubercle , carrying the head of mandible with it . All movement takes place in upper cavity of joint. P rotusion,is brought by contraction of: a. Lateral pterygoid muscles b. A ssisted by both M edial pterygoids .

26. Retraction Of Mandible B y contraction of posterior fibers of temporalis .

27. Lateral Chewing Movements A lternately protruding & retracting the mandible on each side. A ll muscles of mastication responsible on both sides work alternately & not in unison. TEMPORALIS MASSETER LATERAL PTERYGOID MEDIAL PTERYGOID

28. Clinical Relevance

29. Disorder & Causative Factors MYO-FACIAL PAIN DYSFUNCTION SYNDROME CONGINITAL DISORDERS OSTEO-ARTHER ITIS TEMPORAL ARTERITIS TMD PATHOLOGICAL CONDITIONS Involves muscle of mastication Aplasia Hypoplasia Hyperplasia Dysplasia Degenerative joint disease of articular surface Inflammatory disease of large blood vessels Problems related to: Muscles Tendons Ligaments Blood vessels Associated tissues. Causes Pain & swelling Chondrosarcoma Osteosarcoma Giant cell tumor Aneurysmal bone cyst TMD

30. Disorders & Causative Factors TRAUMATIC DISORDERS INFLAMMATORY DISORDERS DEGENERATIVE DISORDERS IDOPATHETIC DISORDERS Mandibular dislocation Fracture Sub laxation Synovitis Capsulitis Myositis Osteo -arthritis Rheumatoid arthritis TMD Fibromyalgia TMD

31. Disc Displacement Articular disc attached: ANTERIORLY: To superior head of lateral pterygoid muscle POSTERIORLY: To retrodiscal tissue, moves out of condyle & fossa, so that mandible & temporal bone contact is made & doesnot involve the articular disc. Very painful condition. Opening mouth: ‘Pop’ or click heard or felt & Trismus . Upon clenching: condyle compresses the bilaminar area, nerves & blood vessels against temporal fossa,causing pain & inflammation. DISC DISPLACEMENT

32. Temporomandibular Joint Syndrome ( Tmd ) When TMJ is dislocated or injured it causes localized pain called TMD . Causative factors: Injury to teeth or jaw. Misalignment of teeth or jaw. Teeth grinding or clenching Poor posture Stress Arthritis Gum chewing

33. Sign & Symptoms

34. Treatment 1. HOME REMEDIES Ice packs NSAIDs Avoiding chewing gum Jaw excerises Stress management Women (18-44) have increased risk 2. MEDICAL TREATMENT Dental splints Botox injections Physical therapy Prescribed medications TMJ athroscopy

35. Clinical Examination Medical History Physical examination TMJ can be palpated anterior to or within the external acoustic meatus during movements of mandible.  Auscultation  of joint can be done. No specific test diagnosis. MRI (Rule out: Damage to cartilage & t rigeminal neuralgia). Refer to Oral maxillofacial surgeon .

36. Fixative Method For Tmj Dislocation REDUCTION OF MANDIBLE: Pressing the premolar area with thumb & holding the chin underneath. METHOD: Downward,backward & upward fixative movement.

37. Test?

38. REVIEW QUESTIONS 1. When the disc of the TMJ is deranged it is usually: Immobile Displaced posteriorly Displaced anteriorly Displaced laterally 2. Which structure prevents condyle from moving too far anteriorly? Articular eminence TMJ capsule Lower collagenous lamina Temporomandibular ligament Both b and c Both b and d

39. REVIEW QUESTIONS 3. The posterior collagenous lamina function to: Pull the disc back. Pull the disc forward Keep the disc from being pulled too far back Keep the disc from being pulled too far forward 4. The posterior elastic lamina function to Pull the disc forward Pull the disc backward Keep the disc from being pulled too far backward Keep the disc from being pulled too far forward

40. REFERENCES Snell’s Clinical Anatomy 9 th Edition by Richard S. Snell. Human Anatomy B.D Chaurasia .

41. THANK YOU