bio mechanics of temporomandibular joint

8/3/2019 Bio Mechanics of Temporomandibular Joint

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Dr. Swapnali Modak


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Unique structurally and functionally. Horse-shoe shape bone that articulates with

temporal bone at each end. Thus mandiblehas two different but connected articulations.

formed by condyle of mandible inferiorly andarticular eminence of temporal bonesuperiorly with an interposed articular disk.

synovial hinge type joint. plays role in phonation,facial

expression,mastication and swallowing.


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Stationary segment of TM Joint is temporal bone.Condyles of mandible sits in glenoid fossa oftemporal bone.

Glenoid fossa is located between posterior glenoidspine and articular eminence of temporal bone.

Mandible is distal or moving segment,it devides intobody,two ramus with coronoid process andmandibular condyles.

Mandibular condyles is having medial and lateralpole.each condyle protrudes15 to 20 mm mediallyfrom ramus.

Articulatig surfaces are covered with dense, avascularcollagenous tissue reffered to as fibrocartilage. Towithstand repeted hgh level stress.


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Articular disk is biconcave,anterior andposterior portion of disk is vascular andinnervated while middle portion is avascular.

Disk appears to be firmaly attched to medial

and lateral pole of condyle of mandible,allowsit to rotate freely on disk anteroposterior indirection.

Disk attaches to joint capsule anteriorly as

well as lat.ptregoid muscle,restrict post.translation of disk. Post.attach to bilaminar retrodiskal pad.


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Joint is supported by short capsular fibersrunning from temporal bone to disk and fromdisk to neck of condyle.

Temporomandibular ligament:2 partsouter

oblique portion And inner portion of ligament. Stylomandibular lig.:band of deep cervicle fascia

runs from styloid process to temporal bone topos.border of ramus of mandible. limitsprotrusion of jaw.

Sphenomandibular lig.:attaches to spine ofsphenoid bone to middle surface of ramus ofmandible.


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Motion of TM Joint:1.mouthopening(mandibular depression) 2.mouthclosing(elevation)3.chinforward(protrusion)4.sliding teeth to either

side(lat. Deviation)


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Mouth Opening:2 Phases: Rotation and glide.Ant. rotation of condyle on disk in lower jointand ant. and inferiorly translation of disk-condyle along articular eminence. Normal

mouth opening -40 to 50 mm.

Mandibular elevation(mouth closing):Reverseof depression.


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There have been recent advances in the rehabilitationof the muscles that control the head and neck.

These advances are based on evidence of specificneck muscle dysfunction in individuals withpersistent head and neck pain.

Traditional rehabilitation strategies have focusedpredominantly on muscle strength and enduranceunder high loads.

New evidence suggests that in people with neck painthere are underlying neuromuscular problems thatmay require more immediate attention and may notbe adequately addressed by simple strength andhigh-load endurance retraining.


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Evidence of altered coordination between thedeep and superficial neck muscles, greaterneck muscle fatigue under sustained lowloads, and deficits in kinaesthetic sense have

been identified in symptomatic individuals. There is evidence to indicate that addressing

these muscle control problems, with specificgentle exercise strategies, results in areduction in neck pain and associatedsymptoms.


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AII points of mandible moves forward at sameamount.

Protrusion: ant and inf. Mov of disk andcondyle with articular eminance.

Retrusion :all points moves posteriorly atsame amount.


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Lat. deviation to one side ,one condyle spinsaround vertical axis and other condyletranslate forward.


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Inflammatory condition: 1.capsulitis2.synovitis

Capsular fibrosis

Osseous mobility condition

Articular disk displacement

Degenerative condition


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Pain in area of jaw Increase or decrease active or passive rom

Clicking noises

Difficulties with functional activity ofmandible

Locking of jaw

Forward head posture


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Active exercise, manual mobilisation, posturaltraining is effective

Mid laser is the best than any other modality.

Combination of above + relaxation is moreeffective.

Biofeedback, emg training, proprioceptivereeducation,relaxation>placebo effect

orocclusal splint.

bio mechanics of temporomandibular joint

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