Dr Wajiha Qamar

Joint of Jaw

2 TMJ’s working in union

Formed byMandibular fossa and articular

Tubercle of temporal boneCondyl of mandible

GinglymoArthroidal joint

Condyl articulates with temporal bone in the mandibular fossa

Synovial joint enclosing synovial fluid

Develops in 12th week of intra uterine life

Mandibular condyls

Articular surfaces of Temporal bone

Capsule

Articular disc

Ligaments

Fibrous membrane that surrounds the joint

Covers the joint from all around

Thin above the disc and thick below it

Fibro cartilaginous tissues

Disc divides the compartment into 2

Upper formed by Temporal bone and articular disc (Menisco temporal)

Lower formed by mandible and articular disc(Menisco mandibular)

Major Ligament Temporomandibular ligament Capsular ligament

Minor Ligaments Stylo mandibular ligament Spheno mandibular ligament

Other LigamentsOto mandibular ligamentDisco malleolar ligamentMallelo mandibular ligament

Messeter

Temporalis

Medial pterygoid

Lateral pterygoid

SENSORYAuriculo temporal nerveMesseteric nerve

MOTORMandibular division of trigeminal

nerve

Branches of External Carotid ArterySuperficial temporal arteryDeep auricular arteryAnterior tympanic arteryAscending pharyngeal arteryMaxillary artery

The Blood supply to TMJ is only Superficial, i.e there is no blood supply inside the capsule

TMJ takes its nourishment from Synovial fluid

4 RECEPTORSRuffini receptorsPacinion receptorsGolgi tendon organsFree nerve endings

Ruffini EndingsPosition the mandible

Pacinion ReceptorsAccelerate movement during

Reflexes Golgi tendon Organs

Protection of ligaments Around TMJ Free Nerve Endings

Pain receptors

AnteriorlyMandibular notch

Messeteric nerve and artery Posteriorly

Tympanic plateGlenoid process of parotid gland

LaterallyParotid gland

Skin and fascia Medially

Maxillary artery and vein

Rotational movement in first 20-25mm of mouth opening

Translational movement after that when the mouth is excessively opened

1. Depression Of MandibleLateral pterygoidDigrastricGeniohyoid2. Elevation of Mandible Temporalis Masseter Medial Pterygoids

3. Protrusion of MandibleLateral PterygoidsMedial Pterygoids

4. Retraction of Mandible Posterior fibres of Temporalis