Describe the 2 separate motions involved in opening the jaw and which axis each is on?
- Rotation about a RT/LF (transverse axis)
- Anterior glide (over the articular disc)
Which 3 muscles of mastification close the jaw tightly?
- Temporalis m.
- Masseter m.
- Medial ptergoid m.
Which muscle of the mouth approximates and compresses lips?
Orbicularis oris m.
Which muscles of the mouth raise the lateral angle of the mouth (smile)?
Which muscle of the mouth approximates lips and draws lips and corners of mouth lateral (grimace)
What are some of the common signs/sx's someone with TMJ issues may complain about?
- CC of Cephalgia (HA)
- May or may not mention jaw problems
- May describe as dull ache ---> worse w/ chewing
The audible click associated with TMJ dysfunction is almost always do due?
Disc displacement after disc thin/stretched
A person with osteoarthritis is more likly to have what sound associated with the jaw?
A direct blow to a pt with a closed mouth results in what type of injury to the TMJ?
Posterior capsule injury
What are 4 types of trauma which may be etiologies for TMJ dysfunciton?
1. Direct blow
2. Whiplash injury
3. 3rd molar extraction
What is a class 1 malocclusion of the jaw?
1st molars normal, problem elsewhere
What is a class 2a vs. class 2b malocclusion of jaw?
- 2a = lower 1st molar posterior to upper mandibular retrustion (overbite)
- 2b = lower 1st molar posterior to upper to greater degree (larger overbite)
What is a class 3 malocclusion of the jaw?
Lower 1st molar anterior to upper mandibular protrusion (underbite)
What devleopmental abnormality is associated with TMJ dysfunction?
Which mood disorders may be associated with TMJ dysfunction?
What have some studies showed?
- Hx of Abuse
- Some studies show association btw chronic TMD and these mood disorders
What are 2 metabolic causes of TMJ dysfunction?
- Endocrine abnormalities
What are 6 pathologies of intracapsular TMJ dysfunction?
- Metastatic CA
- Articular disc displacements
Extracapsular cause of TMJ dysfunction?
Myofascial pain of masticatory muscles
What are some of the risk factors associated with TMJ dysfunction?
- Hyperlaxity (controversial)
- Neck trauma (i.e., whiplash)
- Femal hormones
- Bruxism and clenching
- Pyschological abnormalities
Which country has the highest prevalence of TMJ dysfunction?
Germany > Netherlands
Which age/sex is TMJ dysfunction more common in?
What should be evaluated during the OSE of someone with TMJ pain/dysfunction?
- Leg length ---> Innominate, Sacrum, SI joint
Normal functional opening (ROM) of TMJ is how many mm?
Suspect TMJ dysfunction if
- Normal = 35-55 mm
- Susepct TMJ dysfunction if <25 mm and very often associated w/ pain
What is a PE finding associated with Bruxism?
Signs of wear and tear on teeth
What are 8 differential diagnoses for TMJ dysfunction?
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)
C. tetani is associated w/ what TMJ dysfunction?
What are 2 medications which may be associated with SE's related to TMJ dyfunction?
1) Steroids --> Avascular necrosis
2) Bisphosphonates --> Osteonecrosis of jaw
What is Eagle's Syndrome?
Elongated Styloid Process
When should radiological examination be used for TMJ dysfunction?
- 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
What imaging modality is the procedure of choice for TMJ dysfunction?
MRI - allows to see position and shape of disc