GEN ANA [Lab] - Temporomandibular Joint

Temporal bone

Sphenoid bone

Zygomatic bone

Maxilla

Mandible

Bones to Consider

Condyloid process

Coronoid process

2 SUPERIOR PROCESSES OF THE MANDIBLE

Neck

Ramus

Angle

INFERIOR STRUCTURES OF THE MANDIBLE

Body

Mental foramen

• Mental Nerve

ANTERIOR STRUCTURES OF THE MANDIBLE

Body

lateral to mental foramina / below the premolars

Mental foramen

The mental nerves exit here and provide sensory innervations to the chin and some of the mandibular teeth

Mental nerves

branches of the inferior alveolar nerve, part of the mandibular division of the trigeminal nerve

Mandibular foramina

Submandibular fossa

Inferior alveolar nerve

INTERNAL STRUCTURES OF THE MANDIBLE

Submandibular fossa

(housing the submandibular gland)

Inferior alveolar nerve

(entry via mandibular foramen)

Mandibular fossa

articulates with condyloid process of the mandible

Articular tubercle (articular eminence)

limits jaw movement

External auditory meatus

posterior landmark of the temporal bone

Mastoid process

posterior-inferior to mandibular fossa

Synovial

TMJ
Type: __ joint

Condyloid process of mandible

Mandibular fossa of temporal bone “region, infratemporal fossa”

Components of the TMJ

ARTICULAR DISC

Splits joint into upper and lower compartments

• gliding movements 

  • protrusion

  • retraction

  • side-to-side

Upper compartment of the articular disc allows?

• rotational movements

  • elevation 

  • depression

Lower compartment of the articular disc allows?

anterior movement

Articular tubercle limits?

articular tubercle

The TMJ will be dislocated if the condyloid process moved beyond the?

Lateral temporomandibular ligament

limits posterior displacement / movement

Medial ligaments

limits lateral movement

Sphenomandibular ligament

Stylomandibular ligament

2 Medial Ligaments

Sphenomandibular ligament

(ramus of the mandible to sphenoid process)

Stylomandibular ligament

(ramus of the mandible to styloid process)

Deep head

attached to medial aspect of lateral pterygoid plate

Superficial head

attached to maxilla & palatine bones

• Closes jaw, 

• Assists in protrusion; 

• Unilateral contraction moves jaw contralaterally

3 Functions of Medial Pterygoid Muscle

Superior head

(attaches to the roof of infratemporal fossa & lateral pterygoid plate)

Inferior head

(attaches to lateral portion of lateral pterygoid plate)

Condyloid process of mandible

Insertion of Lateral Pterygoid Muscle

• Bilateral contraction: Jaw protrusion (essential for mouth opening)

• Unilateral contraction: Jaw moves contralaterally

2 Functions of the Lateral Pterygoid Muscle

Temporal Fossa

Origin of Temporalis Muscle

Coronoid process of mandible

Insertion of Temporalis Muscle

• Anterior fibers: Elevate jaw (vertical)

• Posterior fibers: Retract mandible (horizontal)
  

2 Functions of Temporalis Muscle

• Zygomatic bone

• Zygomatic arch

Origin of Masseter Muscle

• Ramus

• Angle of mandible

Insertion of Masseter Muscle

Elevates jaw (closes mouth)

Function of Masseter Muscle

mandibular division of the trigeminal nerve

All muscles of mastication are innervated by the?

Closed, teeth in occlusion

Most stable jaw position:

Anterior dislocation

Most common dislocation:

• Articular tubercle

• Lateral ligament

• Medial pterygoid, masseter, and temporalis muscle contraction

OPPOSING FACTORS TO DISLOCATION

• Condyloid process moves anterior to articular tubercle

• Muscles of mastication spasm, preventing retraction

MECHANISM OF ANTERIOR DISLOCATION

• Apply downward pressure on inferior molars

• Guide the mandible back into mandibular fossa

RESOLUTION TECHNIQUE

Ginglymus Arthrodial Joint

Temporomandibular Joint aka?

Crepitus
Clicking

2 common sound na maririnig pag may TMJ disorder