TEMPOROMANDIBULAR JOINT

Temporomandibular joint

Type ( प्रकार )
- Synovial
- Condylar type ( स्थूलक )
Articular surfaces
- Upper articular surfaces : ( ऊपरी संधायक स्तर/मुख )
  - Articular tubercle ( संधायक गण्डिका )
  - Anterior part of mandibular fossa ( अधःहनु का अग्र खात )
  - Posterior non articular part formed by tympanic plate ( कर्णपटह पत्ताल का विसंधायक पश्चभाग )
- Inferior articular surface is formed by head of mandible ( निम्न मुख हनु का मुंड )
Coverings ( छादन )
- Covered with fibrocartilage ( तन्तुउपास्थि )
Cavity ( गुहाा )
- Joint cavity divided by intraarticular disc ( दो भाग में बाँटता है , अंतरा संधायक चाप )
  - Upper and ( ऊपर )
  - Lower part ( नीचे )
Ligaments ( स्नायूबंधन )
- Fibrous capsule ( तन्तु परिच्छद )
  - Attached ( जुड़ता हैं )
  - Above to ( ऊपर में )
    - articular tubercle , circumference of mandibular fossa in front and squamotympanic fissure behind
  - Below
    - Neck of mandible ( अधःहनु के गर्दन से )
  - Capsule ( परिच्छद )
    - Loose above intra articular disc ( ऊपर का ढीला ) and tight below it ( नीचे का सख्त )
    - Synovial membrane lines the fibrous capsule and neck of mandible
- Lateral temporomandibular ligament ( पार्श्व शंखहनु स्नायुबंधन )
  - Reinforces and strengthens lateral part of capsular ligament
  - Fibers directed downwards and backwards ( तन्तु नीचे और पीछे की ओर )
  - Attached ( जुड़ता है )
    - above to articular tubercle ( ऊपर )
    - Below to posterolateral aspect of neck of mandible ( नीचे
- Sphenomandibular ligament ( पक्षहनु स्नायूबंधन )
  - Accessory ligament
  - Lies in a deep plane away from fibrous capsule ( तंतुमय परिच्छद से दूर रहता है )
  - Attached superiorly to spine of sphenoid ( पक्षाभ के कंटक से जुड़ता हैं )
  - Inferiorly to lingula of mandibular foramen ( नीचे में अधःहनु छिद्र से जुड़ता है )
  - Remnant of meckels cartilage
  - Relations. ( संबंध )
    - Medial ( मध्यवर्ती )
      - Chorda tympani nerve
      - Wall of pharynx ( ग्रसनी की दीवार )
    - Lateral ( पार्श्व )
      - Lateral pterygoid muscle ( पार्श्व )
      - Auriculotemporal nerve
      - Maxillary artery ( ऊर्ध्वहनु धमनी )
- Stylomandibular ligament ( शरहनु स्नायूबंधन )
  - Accesory ligament of the joint
  - Thickened part of deep cervical fascia
    - Separates parotid and submandibular salivary glands
  - Attached above to lateral surface of styloid process
  - Below to angle and adjacent part of posterior border of ramus of mandible
ARTICULAR DISC ( संधायक चाप )
- oval fibrous plate ( तंतुमय पत्तल )
- Upper compartment ( ऊपरी भाग )
  - Gliding ( फिसलन )
- Lower compartment ( निचला भाग )
  - Rotatory and gliding ( घूर्णन और फिसलन )
- Surface ( स्तर )
  - Concavo convex superior surface
  - Concave inferior surface
- Attachment( जुड़ाव )
  - Periphery attached to fibrous capsule
Disc ( चाप )
- Anterior extension ( अग्र विस्तार )
- Anterior thick band ( अग्र गाढ़ा पट्टी )
- Intermediate zone ( मध्य क्षेत्र )
- Posterior thick band ( पश्च गाढ़ पट्टी )
- Bilaminar region
- Represents degenerated primitive insertion of lateral pterygoid
Function
- Prevents friction between articulating surface
- Acts as a cushion , helps in shock absorption
- Stabilises condyle by filling up space between articulating surface
RELATIONS OF TMJ ( संबंध )
- Lateral ( पार्श्वीक )
  - Skin and fascia ( त्वचा और प्रावरणी )
  - Parotid gland ( कर्णपूर्व ग्रन्थि )
  - Temporal branches of facial nerve ( शंखिय शाखा आनन तंत्रिका के )
- Medial ( मध्यवर्ती )
  - Tympanic plate separates the joint from internal carotid artery (
  - Spine of sphenoid with upper end of sphenomandibular ligament
  - Auriculotemporal and chorda tympani nerves
  - Middle meningeal artery ( मध्य तानिक धमनी )
- Anterior ( अग्र )
  - Lateral pterygoid
  - Masseteric nerve and artery
- Posterior
  - Parotid gland separates joint from external auditory meatus
  - Superficial temporal vessels
  - Auriculotemporal nerve
- Superior ( अधि )
  - Middle cranial fossa ( मध्य कपाल खात )
  - Middle meningeal vessels
- Inferior ( अधः )
  - Maxillary artery ( अधःहनु धमनी )
  - Maxillary vein ( अधःहनु शिरा )
BLOOD SUPPLY
NERVE SUPPLY
MOVEMENTS
- depression ( open mouth )
- Elevation ( closed mouth )
- Protrusion ( protraction of chin )
- Retrusion ( retraction of chin )
- Lateral or side to side movements ( chewing or grinding )