Hypermobility of TMJ

TMJ

1. HYPERMOBILITY OF TMJ DR. SWATI SAHU MDS FELLOW ORAL & MAXILLOFACIAL SURGERY

2. INTRODUCTION The temporomandibular joint is a synovial joint between the mandibular fossa of squamous part of the temporal bone above and the mandibular condyle below.

3. SYNONYMS 1. DIARTHROIDIAL JOINT – D iscontinuous articulation of two bones permitting freedom of movement that is dictated by associated muscles and limited by ligaments . Its fibrous connective tissue capsule is well innervated and well vascularized and tightly attached to the bones at the edges of their articulating surfaces.

4. 2. SYNOVIAL JOINT – L ined on its inner aspect by a synovial membrane, which secretes synovial fluid, which fills both joint cavities. The fluid acts as a joint lubricant and supplies the metabolic and nutritional needs of the nonvascularized internal joint structures.

5. 3. COMPOUND JOINT – A compound joint requires the presence of at least three bones, yet the TMJ is made up of only two bones. Functionally , the articular disc serves as a nonossified bone that permits the complex movements of the joint. Because the articular disc functions as a third bone, the craniomandibular articulation is considered a compound joint.

6. 4. GINGLYMOARTHRODIAL JOINT - The lower compartment permits hinge motion or rotation and hence is termed ginglymoid . The superior compartment permits sliding (or translatory ) movements and is therefore called arthrodial . Hence the temporomandibular joint as a whole can be termed ginglymoarthrodial .

7. ARTICULAR DISC Oval "dumbbell-shaped" plate Disc superior surface: Concavoconvex to fit articular eminence & mandibular fossa Disc inferior surface: Concave to conform to condylar head Intermediate zone  of disc found between anterior & posterior bands Anterior band Anteriorly attaches to joint capsule Portion is integrated into superior aspect of lateral pterygoid muscle Posterior band : Posterior disc margin is bilaminar =  bilaminar zone Superior portion composed of loose  fibroelastic tissue; attached to posterior mandibular fossa Inferior portion composed of taut fibrous material; attached to posterior margin of mandibular condyle Medially & laterally disc attaches to joint capsule as well as medial & lateral mandibular condyle

8. COMPARTMENTS OF TMJ Disc creates superior & inferior compartments Superior joint compartment Between disc & mandibular fossa of T-bone Inferior joint compartment Between disc & condyle; two distinct recesses Anterior recess: Anterior to condylar head Posterior recess: Posterior to condylar head, deep to posterior insertion of articular disc onto posterior condylar neck

9. A, Lateral view. B, Diagram showing the anatomic components. ACL , Anterior capsular ligament (collagenous); AS , articular surface; IC , inferior joint cavity; ILP , inferior lateral pterygoid muscles; IRL , inferior retrodiscal lamina (collagenous); RT , retrodiscal tissues; SC , superior joint cavity; SLP , superior lateral pterygoid muscles; SRL , superior retrodiscal lamina (elastic). The discal (collateral) ligament has not been drawn.

10. EXTRACAPSUAR LIGAMENTS Three functional ligaments support the TMJ: ( 1) the collateral ligaments ( 2) the capsular ligament, and ( 3) the temporomandibular (TM) ligament . Two accessory ligaments also exist: ( 4) the sphenomandibular and (5 ) the stylomandibular

11. To restrict movement Of disc away from condyle

12. CAPSULAR LIGAMENT Encompasses the joint thus Retaining the synovial fluid TEMPOROMANDIBULAR JOINT LIGAMENT

13. ACCESSORY LIGAMENTS

14. MUSCLES OF TMJ

15. INNERVATION OF TMJ Branches of the mandibular nerve provide the afferent innervation. Most innervation is provided by the auriculotemporal nerve Additional innervation is provided by the deep temporal and masseteric nerves.

16. VASCULARIZATION OF TMJ S uperficial temporal artery from the posterior M iddle meningeal artery from the anterior I nternal maxillary artery from the inferior Deep auricular A. A nterior tympanic A. A scending pharyngeal arteries

17. BIOMECHANICS OF TMJ

18. HYPERMOBILITY OF TMJ Introduction Definitions Classification Cause of Hypermobility Pathogenesis of hypermobility Clinical presentation Diagnosis Treatment options Nonsurgical Surgical conclusion References CONTENTS –

19. DEFINATIONS Subluxation (hypermobility)- An overextension of the disc–condyle complex on opening beyond the eminence & is able to return to the fossa after either self manipulation or spontaneous voluntary retention . Joint dislocation- A dislocation of the entire disc–condyle complex beyond the eminence combined with the inability to return passively into the fossa

20. SUBLUXATION OF TMJ

21. An incomplete dislocation of the condyle with maximum opening the condyle translates anterior to the articular eminence and is able to return to the fossa after either self manipulation or spontaneous voluntary retention. It usually report a momentarily / short duration of open dislocation with the jaw ‘sticking’ / temporarily inability to close the jaw completely.

22. ETIOLOGY 1. Intrinsic trauma . Yawning, vomiting. Wide biting, seizure disorder 2. Extrinsic trauma: I. Trauma Flexion, extension injury to the mandible. Intubation with general anesthesic . Endoscopy. Dental extractions. Forceful hyperextensions.

23. II. Connective tissue disorders Hypermobility syndrome. E hler’c Danlos syndrome. Marfan syndrome . III. Miscellaneous causes Internal derangement. Contralateral intraarticular obstruction. Host vertical dimensions. Occlusal discrepancies. IV. Psychogenic Tardive orofacial dyskinesia . V. Drug induced Phenothiezines

24. PREDISPOSING FACTORS Previous capsule and ligament injury. Laxity of ligaments (TMJ) Degenerative joint disease. Morphologic conditions of the condyle and eminence. Joint over extension may be caused by yawning ,wide jaw opening / vomiting.

25. CLINICAL FEATURES Subluxation is noted by the mandible sticking / catching open for a short period before it reduces itself into the fossae. When internal derangement is associated with hypermobility multiple clicks can be detected which represents the condyle snapping over the posterior and anterior edges of the disk. “Click” occurs only on wide opening and not on protrusive or lateral movement / excursions.

26. TREATMENT Limit mouth opening. Exercise to strengthen the elevator muscle. Inj of sclerosing solution to reduce the laxity of the capsule. Eminectomy .

27. DISLOCATION OF TMJ

28. “Occurs when the condyle moves into a position anterior to the articular eminence (open lock) from which it cannot be voluntarily reduced or repositioned into the glenoid fossa”. Dislocation is also called luxation of the TMJ.

29. CLASSIFICATION UNILATERAL BILATERAL

30. Acute Chronic Long standing Recurrent Habitual

31. Based on the position of the head of the condyle to the articular eminence seen on clinico -radiological evaluation Type I - the head of condyle is directly below the tip of the eminence Type II - the head of condyle is in front of the tip of the eminence Type III -the head of condyle is high up in front of the base of the eminence.

32. PATHOGENESIS Normal joint stability depends on: i . Integrity of joint ligaments Laxity of ligaments Capsular abnormality ii. Bony architecture of joint surfaces iii. Activity of muscles acting on the joint

33. ACUTE DISLOCATION Acute dislocation is common. Can be brought about by a blow on the chin while mouth is open. Injudicious use of mouth gag during G.A ., excessive pressure during dental extractions , excessive yawning, vomiting, laughing loudly, opening mouth too wide .

34. CHRONIC DISLOCATION 3 TYPES - Long standing. Recurrent Habitual.

35. RECURRENT DISLOCATION Dislocation which takes place repeatedly and which last for short/long intervals .

36. LONG STANDING A dislocation that remains locked anteriorly for several days to years

37. HABITUAL DISLOCATION This term chronic dislocation is appropriately used in those cases where the patient is able to dislocate and reduce at will ,this condition is often referred as habitual. Habitual dislocation is usually associated with psychological factor. Chronic dislocation may be an expression of a centrally mediated motor disturbance.

38. CLINICAL PRESENTATION Bilateral dislocation Pain Inability to close mouth Tense masticatory muscles Difficulty with speech Excessive salivation A protruding chin Open bite A distinct hollow in front of the tragus The lateral pole of the condyle produces a characteristic protuberance anterior to and below the articular eminence Coronoid process may create a prominence below the zygoma . Pain is usually experienced in the temporal fossa rather than in the joint.

39. Unilateral dislocation The mandible swung away from the side of dislocation. The deviation produces a open bite on the contralateral side. Occlusion is protrusive The hollow just in front of the tragus is present on the ipsilateral side. 

40. DIAGNOSIS History Determine cause & onset. A prior h/o local joint laxity, ID, & other TMJD use of antipsychotic drugs physical examination Neurological and musculoskeletal disorders Radiological examination

41. RADIOGRAPHIC EXAMINATION

42. GOALS OF TREATMENT The goals of treatment are- To restrict mandibular translation Remove obstacles Thus preventing mandibular dislocation and locking anterior to the articular eminence.

43. MANAGEMENT SURGICAL NON-SURGICAL

44. NON-SURGICAL MANAGEMENT

45. ACUTE DISLOCATION Requires immediate treatment Manual reduction can be done with or without the use of LA immediately or within 72 hours. Beyond that duration, reduction may be done under sedation/LA or GA

46. 1. DINGNAN & NATWIG Recommended use of LA based on theory that dislocation is maintained by muscle spasm secondary to painful stimuli arising from the capsule On injection of lignocaine into the glenoid fossa or muscle of mastication Sensory muscle spasm is blocked Muscle spasm overcomed

47. 2. REDUCTION Manipulation under G.A. with the muscle relaxants. Manipulation under either oral / IV sedation.. Bimanual mandibular manipulation Dingman & Natwig

48. YURINO’ S METHOD – Yurino’s method places the patient is a supine position without a pillow. The patient is encouraged to relax completely while the operator stands near the patient’s head and holds the body of the mandible from the opposite side. The patient is asked to open and close the mouth and the operator moves the mandible up and down in phase with the patients opening and closing movements. The operator then locates the dislocated condyle with his thumb and simultaneously with the patients closing motion pushes it completely downward while moving the body of the mandible upward by this procedure the condyle moves over the articular eminence and ships into the fossa. In case of bilateral dislocation one side is reduced first.

49. 3. INTERMAXILLARY FIXATION Limiting the oral opening by giving elastics total immobilization of the jaw for the period of 3 to 4 weeks gives rest to the joint. Keep the patient on soft diet.

50. CHRONIC / LONG-STANDING DISLOCATION Develops fibrous adhesion between the disc, condyle & articular eminence Jaw muscles & ligaments also undergo fibrous change, preventing non-surgical reduction

51. Manual reduction – under GA & muscle relaxant IF fails – Open reduction Wire is passed through inferior border of ramus or a hook placed in the sigmoid notch to aid in distracting the condyle inferiorly & repositioning the condyle into fossa. Condylectomy Bilateral ramus osteotomy – to restore occlusion

52. RECURRENT DISLOCATION IMF for prolonged period of 4-6 weeks B. CHEMICAL CAPSULORRAPHY - The injection of sclerosing agents into the supporting ligaments into the joint. Objective: is to produce fibrosis and tightening of the capsular ligaments thus limiting motion of the mandible and preventing subluxation and dislocations. Ex: Sodium psylliate emulsion in oil. Sodium morrhurate Sodium tetraderyl sulfate Alcohol, homogenous blood.

53. SURGICAL MANAGEMENT

54. SURGICAL PROCEDURE ALTERATION OF LIGAMENTS ALTERATION OF MUSCULATURE ALTERATION OF BONY STRUCTURES Use of sclerosing agents Strengthing of ligaments Capsular plication Ligamentorraphy Active physiotherapy Injection of Botulinum Toxin Lateral pterygoid myotomy Closed Condylotomy Ligation of coronoid process to the zygomatic arch Scarification of temporalis tendon Condylectomy Eminectomy Creation of mechanical obstacle

55. ALTERATION OF LIGAMENTS

56. USE OF SCLEROSING AGENTS Injection of sclerosing agents into capsular space of the TMJ AIM – Cause fibrosis with resultant tightening of the capsule, prevents / limits exaggerated condylar movement Sclerosing Agents – Alcohol 5% sodium psylliate Sodium morruhate 3% sodium tetradecyl sulphate Autologous blood

57. STRENGTHING OF LIGAMENTS Surgical exposing the temporalis fascia & suturing a flap of fascia onto the capsular ligaments

58. CAPSULAR PLICATION Exposure of the capsule, followed by an incision vertically through the body of ligaments Incision margins are then overlapped and sutured

59. LIGAMENTORRAPHY Involves anchoring the lateral ligaments of the capsule to the periosteum of the zygomatic arch, followed by IMF for a week

60. ALTERATION OF MUSCULATURE

61. ACTIVE PHYSIOTHERAPY To strengthen the suprahyoid muscles thereby counterbalancing the action of lateral pterygoid muscle

62. INJECTION OF TYPE A BOTULINUM TOXIN 1 cm anterior to condyle in a slight mouth opening position So as to inject into the lateral pterygoid AIM – to weaken the lateral perygoid muscle sufficiently to prevent dislocation Contraindication – patient with impaired n euromuscular function

63. LATERAL PTERYGOID MYOTOMY Attachment of the muscle to condylar neck & anterior aspect of disc is exposed & divided Followed by IMF for 7-10 days DISADVANTAGE – loss of translatory movement in the condyle

64. CLOSED CONDYLOTOMY To affect the lateral pterygoid muscle indirectly Gigli saw is used to bisect the condylar neck thus eliminating the effect of spasticity of lateral pterygoid Disadvantage – potential bleeding from internal maxillary artery

65. LIGATION OF CORONOID PROCESS TO ZYGOMATIC ARCH 2 holes are drilled, one into the condylar neck & other into zygomatic arch A dacron mesh is passed through the 2 holes & tightened, thereby restraing the condyle

66. SCARIFICATION OF TEMPORALIS TENDON AT ITS AREA OF INSERTION An intraoral incision is made in the posterior regions along the external oblique ridge Tendinous fibres are dissected off from the ascending ramus& sutured to the reflected periosteum & oral mucosa Incision is then sutured This creates a horizontal scar which may tighten the tendon & limit the range of motion

67. ALTERATION OF BONY STRUCTURES

68. CONDYLECTOMY Intracapsular procedure Involves removal of entire articular surface of the condyle, above the attachment of lateral pterygoid Resulting pseudoarthrosis may limit the range of mandibular motion Occlusion returns to normal after 4 weeks of surgery

69. EMINECTOMY Reduction of height of eminence to allow free forward & backward movements of the condyle Success rate – 100% COMPLICATIONS – Pneumatisation of eminence Dural tear Recurrent subluxation Formation of postoperative osteophytes Crepitus & pain

70. CREATION OF MECHANICAL OBSTACLE LINDEMANN – performed an osteotomy on the eminence and turned it down in front of condylar head to prevent its forward movement. MAYOR – advocated a placement of a graft over the eminence to increase size & height Placement of silastic block or vitallium mesh implants to add the height of eminence MAYORS PROCEDURE

71. DAUTRY advocated osteotomy on the zygomatic arch & depressing it in front of the condylar head to serve as an obstacle to abnormal forward translation FINDLAY – used L-shaped pins anchored in the zygomatic process of the temporal bone& projecting it anterior to the condyle DAUTRY PROCEDURE

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