Lecture 6: Temporomandibular Dysfunction

Question 1

Describe the 2 separate motions involved in opening the jaw and which axis each is on?

Answer 1

• Rotation about a RT/LF (transverse axis)
• Anterior glide (over the articular disc)

Question 2

Which 3 muscles of mastification close the jaw tightly?

Answer 2

• Temporalis m.
• Masseter m.
• Medial ptergoid m.

Question 3

Which muscle of the mouth approximates and compresses lips?

Answer 3

Orbicularis oris m.

Question 4

Which muscles of the mouth raise the lateral angle of the mouth (smile)?

Answer 4

Zygomaticus major

Question 5

Which muscle of the mouth approximates lips and draws lips and corners of mouth lateral (grimace)

Answer 5

Risorius

Question 6

What are some of the common signs/sx’s someone with TMJ issues may complain about?

Answer 6

• CC of Cephalgia (HA)
• May or may not mention jaw problems
• May describe as dull ache —> worse w/ chewing
• Tinnitus

Question 7

The audible click associated with TMJ dysfunction is almost always do due?

Answer 7

Disc displacement after disc thin/stretched

Question 8

A person with osteoarthritis is more likly to have what sound associated with the jaw?

Answer 8

Crepitus

Question 9

A direct blow to a pt with a closed mouth results in what type of injury to the TMJ?

Answer 9

Posterior capsule injury

Question 10

What are 4 types of trauma which may be etiologies for TMJ dysfunciton?

Answer 10

1. Direct blow
2. Whiplash injury
3. 3rd molar extraction
4. Intubation

Question 11

What is a class 1 malocclusion of the jaw?

Answer 11

1st molars normal, problem elsewhere

Question 12

What is a class 2a vs. class 2b malocclusion of jaw?

Answer 12

• 2a = lower 1st molar posterior to upper mandibular retrustion (overbite)
• 2b = lower 1st molar posterior to upper to greater degree (larger overbite)

Question 13

What is a class 3 malocclusion of the jaw?

Answer 13

Lower 1st molar anterior to upper mandibular protrusion (underbite)

Question 14

What devleopmental abnormality is associated with TMJ dysfunction?

Answer 14

Condylar hypoplasia/agenesis

Question 15

Which mood disorders may be associated with TMJ dysfunction?

What have some studies showed?

Answer 15

• Anxiety
• Depression
• PTSD
• Hx of Abuse
• Some studies show association btw chronic TMD and these mood disorders

Question 16

What are 2 metabolic causes of TMJ dysfunction?

Answer 16

• Endocrine abnormalities
• Hypocalcemia

Question 17

What are 6 pathologies of intracapsular TMJ dysfunction?

Answer 17

• Infection
• RA
• Ostoarthritis
• Gout
• Metastatic CA
• Articular disc displacements

Question 18

Extracapsular cause of TMJ dysfunction?

Answer 18

Myofascial pain of masticatory muscles

Question 19

What are some of the risk factors associated with TMJ dysfunction?

Answer 19

• Hyperlaxity (controversial)
• Neck trauma (i.e., whiplash)
• Femal hormones
• Bruxism and clenching
• Pyschological abnormalities

Question 20

Which country has the highest prevalence of TMJ dysfunction?

Answer 20

Germany > Netherlands

Question 21

Which age/sex is TMJ dysfunction more common in?

Answer 21

Young women

Question 22

What should be evaluated during the OSE of someone with TMJ pain/dysfunction?

Answer 22

• Cranial
• C-spine
• Scoliosis
• Leg length —> Innominate, Sacrum, SI joint

Question 23

Normal functional opening (ROM) of TMJ is how many mm?

Suspect TMJ dysfunction if

Answer 23

• Normal = 35-55 mm
• Susepct TMJ dysfunction if <25 mm and very often associated w/ pain

Question 24

What is a PE finding associated with Bruxism?

Answer 24

Signs of wear and tear on teeth

Question 25

What are 8 differential diagnoses for TMJ dysfunction?

Answer 25

1. **Migraine related disorder** --\> Carotodynia 2. **Inflammatory Dz** --\> local infection, RA, giant cell arteritis 3. **Dental problems** --\> posterior teeth support loss 4. **Neuralgias** --\> Trigeminal or Glossopharyngeal 5. **Parotid gland disorders** 6. **Lymphoproliferative disorders** 7. **Medication SE's** 8. **Eagle's Syndrome (stylohyoid syndrome)**

Question 26

*C. tetani* is associated w/ what TMJ dysfunction?

Answer 26

Lockjaw

Question 27

What are 2 medications which may be associated with SE's related to TMJ dyfunction?

Answer 27

1) **Steroids** --\> Avascular necrosis 2) **Bisphosphonates** --\> Osteonecrosis of jaw

Question 28

What is Eagle's Syndrome?

Answer 28

Elongated **Styloid Process**

Question 29

When should radiological examination be used for TMJ dysfunction?

Answer 29

- Usually **NOT** helpful - Use when you **suspect dental problems** or concern for alternative cause - Pt with **severe sx's** that **don't improve** w/ conservative tx tactics - Recent, severe trauma

Question 30

What imaging modality is the procedure of choice for TMJ dysfunction? Why?

Answer 30

MRI - allows to see position and shape of disc

Question 31

What is the level 1 intervention for TMJ dysfunction?

Answer 31

**Cognitive behavioral therapy** for chronic TMJ reduces activity interference, pain an drepression

Question 32

What are level 2 interventions for TMJ dysfunction?

Answer 32

- Meds --\> Amitriptyline, glucosamine (for OA of TMJ), Benzo, Botox - Accupuncture - Oral habit reversal Tx - OMT - Therapeutic exercises

Question 33

What are the level 3 intervention for TMJ dysfunction?

Answer 33

- OMT: biofeedback alone - Surgery - Occlusal splints: including athletic mouthguards - Occlusal adjustment - Intra-articular corticosteroid inj. - Physical therapy + counseling

Question 34

What is the minimum goal of treatment of TMJ dysf. for opening the jaw?

Answer 34

Able to **fit knuckles** of the **index and middle finger** btw the teeth

Question 35

Using the holistic approach to the plan for TMJ dysfunction the goal is to eliminate?

Answer 35

Jaw stress

Question 36

Oral devices/occlusal splints for TMJ dysfunction should be avoided in patients with what?

Answer 36

Sleep apnea