TMD Flashcards
What are the different names for TMJ dysfunction?
Temporomandibular dysfunction (TMD)
Myofascial pain dysfunction
Pain dysfunction syndrome
Facial arthromyalgia
Costen’s syndrome
What is the origin and insertion of masseter muscle?
Origin- zygomatic arch/zygomatic
Insertion- lateral angle of mandible
What is the origin an insertion of temporalis?
Origin- temporal fossa/fascia
Insertion- Coronoid process/ramus
What is the origin an insertion of medial pterygoid?
Origin- medial surface of lateral pterygoid plate
Insertion- medial angle of mandible
What is the origin an insertion of lateral pterygoid?
Origin- base of skull/lateral surface of lateral pterygoid plate
Insertion-pterygoid fovea/capsule of TMJ (and disc)
What are the suprahyoid muscles? (accessory MoM- slightly involved in opening)
Digastric
Mylohyoid
Geniohyoid
Stylohyoid
What are the infrahyoid muscle? (acc. MoM)
Thyrohyoid
Sternohyoid
Omohyoid
Sternothyroid
What nerve supplies the EAM, how does this relate to TMJ?
Auriculotemporal nerve- some times TMD can present as ear pain
What are the anatomical features of the TMJ?
Mastoid process/EAM behind
2 joint cavities- upper and lower
Anterior band of disc is not innervated (posterior part and bilaminar zone is- pain on compression)
What are the causes of TMD?
Degenerative diseases- OA (localised)/RA (generalised)
Myofascial pain
Disc displacement- slips out of place
Chronic recurrent dislocation- tends to lock open (joint is stuck in front of articular eminence)
Ankylosis- condyle is fused to base of skull (mostly pseudo- genetics)
Hyperplasia- one condyle grows more (facial asymmetry- require surgery)
Neoplasia- tumours (related to bone and cartilage- RARE)
Infection of joint- incredible rare can result in ankylosis
What are the types of disc displacement?
Anterior with reduction (goes back into place)
Anterior without reduction (gets stuck in front of condyle)
How is chronic recurrent dislocation of TMJ treated?
Thumbs in buccal sulcus, push down and backwards slowly
-> Muscle relaxants may be required
Which elements can be involved in the pathogenesis of TMD?
Inflammation of muscles of mastication or TMJ secondary to parafunctional habits
Trauma, either directly to the joint or indirectly e.g. sustained opening during dental treatment
Stress
Psychogenic
Occlusal abnormalities - no evidence to support this, although a restoration that is significantly “high” may cause muscle pain due to posturing
What would you want to find out when determining HPC when assessing for TMD?
Location, nature, duration, exacerbating / relieving factors, severity, frequency, time of occurrence
(in the morning – bruxism; during the day – habits)
->Associated pain elsewhere – neck, shoulders
What EO checks should be completed when examining for TMD?
Muscles of mastication
Joints
-> Clicks – early/late
-> Crepitus- crunching noise indicating arthritis/degeneration
Jaw movements- measure max opening with willis bite gauge
Facial asymmetry
How are lateral/medial pterygoids checked in EO exam?
Medial pterygoid exam- check in lingual surface, pressing medial angle of mandible
Lateral pterygoid- not a useful examination
-> Would need to palpate behind tuborosity
Which IO checks should be carried out when examining for TMD?
Signs of parafunctional habits
-> Cheek biting (morsicatio buccarum)
-> Linea alba- white lines on cheek
-> Tongue scalloping- wavy appearance due to imprint of lingual surfaces of teeth
Occlusal non-carious tooth surface loss- attrition (seen in grinding- not clenching)
Which special investigations may be utilised in TMD examination? (not required unless pathology is expected)
OPT- excludes dental pathology
CT / Cone-beam CT- if pathology of jaw joint
MRI- if disc is out of place
Transcranial view (TMJ view)
Nuclear imaging (Technetium-99)
Arthrography (dye into capsule)
Ultrasound- good for checking if displacement but not reduction
What us nuclear imaging useful for checking?
Hyperplasia (radioactive element is taken up in areas with increased cellular activity- appears blacker in image)
What are the clinical features of TMD?
Females > males
Age: most common between 18-30 years
Intermittent pain of several months or years duration
Muscle / joint / ear pain- particularly on wakening
Trismus / locking- if disc cannot reduce
‘Clicking/popping’ joint noises
Headaches- overuse of temporals
Crepitus indicates late degenerative changes
Which other conditions can mimic TMD? (to be considers as differential diagnoses)
Dental pain
Sinusitis
Ear pathology
Salivary gland pathology
Referred neck pain
Headache
Atypical facial pain
Trigeminal neuralgia
Angina
Condylar fracture
Temporal arteritis
Why may angina mimic TMD?
As heart is supplied by C2 and so is corner of jaw and left arm (typical radiating spots)
How does temporal arteritis present? Why is it concerning? How is it differentiated from TMD?
Very severe pain anterior to temporalis (can be uni/bilateral) caused by inflammation of temporal artery- can cause blindness
Patient given high dose steroid
Area is biopsied
Which reversible treatment for TMD are available?
Patient education
Medication
Splints
Physical therapy
What are the elements of patient education in treatment of TMD?
Counselling- fully explain condition and how it can be helped (chronic condition- no quick fix)
Electromyographic recording
Jaw exercises- physiotherapy
What advice can be given to a patient suffering TMD via counselling?
Soft diet
Masticate bilaterally
No wide opening
No chewing gum
Don’t incise foods
Cut food into small pieces
Stop parafunctional habits e.g. nail biting, grinding
Support mouth on opening e.g. yawning
What medications can be used in treatment of TMD?
Paracetamol
NSAIDs- diclofenac
Muscle relaxants- addictive
Tricyclic antidepressants- for muscle relaxant effect
-> nortryptiline, gabapentin
Botox- injected into masseter to stop clenching
Steroids- reduce inflammation
Which physical therapies can be utilised to treat TMD?
Physiotherapy
Massage/heat- reduces inflammation
Acupuncture
Relaxation
Ultrasound therapy- produces heat
TENS (Transcutaneous Electronic Nerve
Stimulation)
Hypnotherapy
What types of splints can be used?
Bite raising appliances
Anterior repositioning splint
What are the types of bite raising appliances for TMD treatment?
Essix retainer- may be too thin (placebo? More awareness?)
Michigan splint (acrylic)/ wenvac (rubber)- preferred
Why must bite raising appliances cover every tooth in arch?
To prevent over eruption
How do BRAs work?
Unknown- little scientific evidence to support (despite anecdotal success)
Theoretically- BRAs stabilise the occlusion and improve the function of the masticatory muscles, thereby decreasing abnormal activity. They also protect the teeth in cases of tooth grinding
When should BRA be used?
During time that parafunction takes place (may take a few weeks to see benefit)
What are the irreversible treatment options for TMD?
Occlusal adjustment- rarely done (no evidence of benefit)
TMJ surgery:
Arthrocentesis
Arthroscopy
Disc-repositioning surgery
Disc repair/removal
High condylar shave
Total joint replacement
Why is surgery for TMD so rare?
Irreversible- need to deal with underlying cause or else surgery will only fix it temporarily
What causes clicking of TMJ? (disc displacement- internal derangement)
Joint clicking is due to lack of coordinated movement between the condyle and the articular disc
-> Condyle has to overcome obstruction to achieve full movement
How are TMJ clicks classified?
Either on opening OR closing
-> early, middle, late
How is disc displacement with reduction (clicking) treated?
Treatment:
Counselling
Limit mouth opening
Bite raising appliance
Surgery occasionally may be required
If painless, no treatment required
Reassure
What are the causes of traumatic trismus?
IDB
Prolonged dental treatment
Infection
-> Haematoma formed in medial pterygoid causing spasm- most resolve spontaneously
What are the treatments for traumatic truisms if acute phase of treatment is unsuccessful?
Therabite- available on NHS (gradual reopening)
Sequentially increase amount of wooden tongue compressors
Jaw screws (wax or acrylic)- between incisors, run up the spiral to cause opening
Physio
What are the signs and symptoms of TMD?
- Limited opening
- Clicking
- Crepitus
- Headache
- Earache
- Locking of jaw- fixed or patient may be able to manipulate back in (subluxation)
- Wear facets/micro-cracks
- Lost fillings
- Linea Alba on buccal surface- keratin layer (protective)
- Radiographically Flattening of bones in joint, Widened PDLs (also seen in high fillings)
What are other causes of limited opening?
- Infection
- Recent dental treatment
- Restorations that have affected occlusion
- Tumour (space occupying lesion)
- Haemophilia A- bleeding into jaw joint
What patient factors can trigger TMD?
- Clenching when stressed
- Trauma to jaw joint
- Woodwind instrument playing
- Singers- joint at maximum opening a lot
- Chewing gum
- Builders/carpenters- holding nails in mouth
What should you include when referring a patient who has TMD?
- Full History
- Noises or losses in function
- Duration
- What treatments they have already tried
How does botox injections for TMD work?
- Comes in vial and is mixed with saline
- Given into masseter- reduces muscle tone without reducing function
*Consent patient for temporary paralysis (could last about 3 months), allergy, damage to facial nerve (palsy), doesn’t always work
