Lecture 2- TMJ

Question 1

Body posture in relation to patients with TMJ disorders

Answer 1

Patients with disc displacement showed a higher incidence of pain in the TMJ but there were no differences in para function habits. In disc displacement groups postural deviations were found in the pelvis, lumbar and thoracic spine as well as well as deviation of the head to the right and deviation of the mandible to the left on mouth opening

Question 2

Biomechanics of the TMJ

Answer 2

• initial opening is a rotational or hinge movement

- full opening requires continued rotation with addition forward translation

Question 3

What occurs during TMJ opening

Answer 3

-Stretching of the discotemporal
-Forward displacement of the fibrocartilagenous disc (absolute) but the disc is posterior to the condyle
-When the TMJ reaches maximum opening the articular disc is posterior
-Contrary to the joint capsule the articular disc is not innervated

Question 4

What is the most effective way of determining a TMJ disorder?

Answer 4

• careful review of the chief complaint
• the history of present illness
• dental, medical and psychological behaviour histories
• comprehensive head and neck evaluation including cranial nerve assessment

Question 5

What are the accessory movements of the TMJ?

Answer 5

Long-axis distraction
Anterior glide
Posterior glide
Lateral glide

Question 6

What is the primary action of the masseter?

Answer 6

Elevation of the mandible (most likely to be causing severely restricted jaw movement)

Question 7

What is the primary action of medial pterygoid?

Answer 7

• Lateral deviation of the mandible to the contra lateral side (unilateral)
• elevation of the mandible (closing of the jaw) (masseter and Temporalis) bilateral
• generally causing deviation to the contralateral side and difficulty in late opening

Question 8

Action of the lateral pterygoid

Answer 8

Inferior division
-protrudes and depresses the mandible (opening)
Superior division
- provides traction to the condyle and disc complex during closing

Question 9

Action of the temporalis

Answer 9

Opening and closing of the joint in retraction

Question 10

Signs and symptoms of TMJ disorder

Answer 10

Signs
May be a history of trauma
Noise emanating from the joint (clicking, crepitus)
Myofascial pain & tenderness: masseter, temporalis
Decreased ROM in opening or lateral deviation
Symptoms
Pain in the TMJ itself, neck pain, facial pain and headaches
Auricular symptoms: otalgia, tinnitus, vertigo, hearing loss or feeling of a full ear

Question 11

Disorder of TMJ:

Intracapsular: derangement of the articular disc/ meniscus

Answer 11

• caused by trauma, prolonged muscle spasm or severe occlusion disorders
• late opening click or early closure click
• crepitus due to meniscal degeneration
• may progress to OA of the TMJ

Question 12

Disorder of TMJ:

Capsular

Answer 12

• sprain
• capsulitis
• synovitis
• almost always following trauma or as a consequence of Intracapsular pathology e.g RA

Question 13

Disorders of the TMJ

Extracapsular

Answer 13

Disorders of muscles of mastication
Often involves pterygoid spasm which causes anterior displacement of the meniscus
Presents as:
TMJ pain
Limited ROM
Exacerbated by mastication or other movements
Clicking on opening and/or closing

Question 14

Treatment of TMJ

Answer 14

Manipulation / Mobilization
-Requires evaluation of TMJ movements
-Effect on TMJ itself, capsule and myofascial structures Correct upper cervical mechanics
STT
-postural muscles
-Advice / Corrective Actions
-Learning and maintaining good posture
-Avoiding oral habits such as exhaustive chewing, clenching and grinding of teeth (bruxism)
Primarily masseter, medial & lateral pterygoid
Also evaluate temporalis, digastric, supra
Home self-stretch exercises

Question 15

Explain the joint of the TMJ

Answer 15

• bicondylar
• articular disc (Fibrocartilaginous)
• two joint cavities
• upper cavity; gliding
• lower cavity; rotary or hinge
• extracapsular ligaments