TMJ And MOM

Question 1

Label the mandible

Answer 1

Pterygoid fovea
Mandibular notch
Condyle
Ramus
Angle
Oblique line
Inferior border
Mental foramen
Mental symphysis
Mylohyoid ridge
Anterior border
Mandibular foramen
Coronoid process

Question 2

What bones make up the TMJ?

Answer 2

Mandibular fossa of temporal bone and condylar process of mandible

Question 3

Describe the TMJ joint

Answer 3

Atypical modified hinge joint (synovial)

Bones covered with fibrocartilage not hyaline

Fibrocartilaginous disc separates the joint into superior and inferior articular cavities

Question 4

What ligaments support the TMJ joint?

Answer 4

Lateral ligament

Stylomandibular ligament

Sphenomandibular ligament

Question 5

What movements can the TMJ make and which muscles facilitate this?

Answer 5

Protrusion - lateral and medial pterygoid

Retraction - posterior temporalis and deep masseter

Elevation - masseter and temporalis and medial pterygoid

Depression - suprahyoid muscles but mainly gravity

Lateral movements - temporalis of same side and pterygoid spine of opposite sides

Question 6

What is the most common TMJ injury?

Answer 6

Anterior dislocation

• tmj most unstable during depression
• jaw locked open

Question 7

What is the location, insertion, origin and innervation of the masseter?

Answer 7

Origin = superficial and deep = inferior zygomatic arch

Insertion = lateral of ramus and angle of mandible

Innervation = CNV V3 massenteric nerve

Question 8

What is the location, insertion, origin and innervation of the temporalis

Answer 8

Origin = temporal fossa

Insertion = coronoid process

Innervation = deep temporal nerves of V3

Question 9

What is the location, insertion, origin and innervation of the lateral pterygoid?

Answer 9

Superior head

Origin = greater wing of sphenoid

Insertion = neck of mandible

Innervation = CNV V3

Inferior head

Origin = lateral pterygoid plate

Insertion = neck of mandible

Innervation = CNV V3

Question 10

What is the location, insertion, origin and innervation of the medial pterygoid?

Answer 10

Deep head

Origin = lateral pterygoid plate
Insertion = medial surface of angle and ramus of mandible
Innervation = CNV V3

Superficial head

Origin = maxillary tuberosity
Insertion = medial surface of angle of ramus and mandible
Innervation = CNV V3