TMD Flashcards
other names for TMD
Temporomandibular dysfunction
Myofascial pain dysfunction
Pain dysfunction syndrome
Facial arthromyalgia
Costen’s syndrome
‘TMJ’
masseter
orgin and insertion
Origin
* Zygomatic buttress and underside of zygomatic process
Insertion
* Angle of mandible
temporalis
origin and insertion
Origin
* Temporal fossa (lateral)
Insert
* Coronoid process mandible (standard – can extend onto ramus)
medial pterygoid
origin and insertion
origin
* medial surface of lateral pterygoid plate
insertion
* angle of mandible – medial side
lingual pterygoid
origin and insertions
origin
* base of skull and lateral surface of lateral pterygoid plate
insertion
* pterygoid fovi (just below mandible condyle), some fibres extend into capsule and disc
blood supply for TMJ
deep auricular artery
branch of 1st part of maxillary artery
nerve supply for TMJ
Auriculotemporal, masseteric, posterior (deep) temporal nerve
Supply muscles that move joint
Auriculotemporal – also sensation to parts of external auditory meatus – discomfort there too
2 accessory muscle groups for MOM
infrahyoid and suprahyoid muscles
suprahyoid muscles
4
digastric
mylohyoid
geniohyoid
stylohyoid
My Gut Seems Damaged
My Gravy Spoon Darling
digastric - blue
mylohyoid - orange
geniohyoid - red
stylohyoid - green
infrahyoid muscles
4
thyrohyoid
sternohyoid
omohyoid
sternothryoid
TOSS
thyrohyoid - yellow
sternohyoid - purple
omohyoid - brown
sternothryoid - black, dashed
anatomy of articular disc in TMJ
anterior band in not innervated
posterior band and bilaminar zone (mainly) is = pain from this part
basic movement of TMJ
condyle moves forward and disc goes with it (disc slides with condyle)
causes of TMD
8
- Myofascial pain
- Disc displacement
- degnerative disease
- Chronic recurrent dislocationRoutinely, regularly – pt often able to get back themselves when used to it
- Ankylosis
- Hyperplasia
- Neoplasia (osteochondroma, osteoma, or sarcoma)
- Infection
disc displacement in TMJ
2
Anterior with reduction (slips in front of condyle and able to move back)
Anterior without reduction (slips in front and not able to move back)
degenerative disease of TMJ
2
Localised – osteoarthritis (wear and tear)
Generalized (Systemic) – rheumatoid arthritis
how to relocate dislocated TMJ
Pt low, hands in on buccal side (external ridge) and push down and slowly relocate
hyperplasia of TMJ
Grow more
One condyle larger than other – asymmetry
cause TMD
neoplasia of TMJ
tumour in joint is rare
usually associated with structures in the area (osteochondroma, osteoma, osteosarcoma)
pathogenesis of TMD
4 main
- 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 (single or multiple episodes)
- Stress
- Psychogenic
- Occlusal abnormalities - no evidence to support this, although a restoration that is significantly “high” may cause muscle pain due to posturing
assessment for pt with TMD
history
history
* C/O
* HPC - Pain history - location, nature, duration, exacerbating / relieving factors, severity, frequency, time of occurrence (in the morning – bruxism; during the day – habits), Associated pain elsewhere – neck, shoulders
* PMH
* PDH
* SH - Important - occupation, stress, home circumstances, sleeping pattern, recent bereavement, relationships, habits and hobbies
examination for pt with TMD
extra oral
Muscles of mastication
Joints
* Clicks – early/late
* Crepitus – indicates arthritic change, crunching
Jaw movements
Facial asymmetry
examination for pt with TMD
intra oral
Interincisal mouth opening
* Max mouth opening between teeth
* Willis bite gauge - spokes facing same way
Signs of parafunctional habits
* Cheek biting (morsicatio buccarum)
* Linea alba (white line on check along occlusal plane)
* Tongue scalloping
* Occlusal non-carious tooth surface loss
Muscles of mastication – more grinding than clenching
special investigations for TMD
Not usually required, but if there is suspicion of pathology then:
Radiographic evaluation
* OPT (excl dental pathology – not just for TMD)
* CT / Cone-beam CT
* MRI
* Transcranial view (TMJ view)
* Nuclear imaging (Technetium-99) – hyperplasia, taken up more in areas of inc cellular activity – these hotspots picked up on imaging
* Arthrography – injecting something into joint and taking image
* Ultrasound
common clinical features for TMD
8
- 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
- ‘Clicking/popping’ joint noises
- Headaches
- Crepitus indicates late degenerative changes
11 differential diagnosis for TMD to rule out
- Dental pain
- Sinusitis
- Ear pathology
- Salivary gland pathology
- Referred neck pain
- Headache
- Atypical facial pain
- Trigeminal neuralgia
- Angina – small area of skin on boder of mandible has same innervation
- Condylar fracture
- Temporal arteritis – worrying/serious, doctor sees, severe pain in temporal region
reversible tx options for TMD
8
pt education
* counselling - no quick fix, takes time and understanding
electromyographic recording
jaw exercises - physical therapy, massage/heat, acupuncture,
relaxation/mindfulness
TENS
CBT and hypnotherapy
Splints
* bite raising appliances
* anterior repositioning splint
medications
medications for TMD
5
NSAIDs
Muscle relaxants
Tricyclic antidepressants
* Has muscle relaxant in
Botox
* Paralysis muscle, help reduce clenching habit – reset chance to break habit
* Not standard approach – last resort
Steroids
irreversible tx options for TMD
2
Occlusal adjustment
* Rarely done – no evidence of benefit1
TMJ surgery rare
* Arthrocentesis
* Arthroscopy
* Disc-repositioning surgery
* Disc repair/removal
* High condylar shave
* Total joint replacement
key thought when tx TMD
need to tx underlying cause of TMD
or problem with recur
counselling for TMD
points to cover
- Reassurance
- Soft diet
- Masticate bilaterally
- No wide opening
- No chewing gum
- Don’t incise foods
- Cut food into small pieces
- Hobbies – reduce clenching e.g. wind instrument
- Stop parafunctional habits e.g. nail biting, grinding
- Support mouth on opening e.g. yawning
bite raising appliance options for TMD
Wenvac – soft rubbery, 1-2mm
Michigan splint – upper jaw, made by lab, hard heat cure acrylic
Essex retainer - too thin for TMD pts
Full lower – better as less aesthetic so can wear day and night
Need to cover all the biting surfaces for all of one of the arches
* Otherwise DAHL effect – intrusion/extrusion of some teeth and disrupt occlusion – not Lucia jig
The exact mechanism behind the success of bite raising appliances (BRAs) is unknown and there is little scientific evidence to support their use
* Theoretically, BRAs stabilize the occlusion and improve the function of the masticatory muscles, thereby decreasing abnormal activity.
* They also protect the teeth in cases of tooth grinding
Patients may need to wear their splint for several weeks before a benefit is felt. The splint should be worn at the time of parafunction
disc displacement (internal derangement)
pt presentation and mechanism
Patients with internal derangement of the TMJ may present with a painful clicking TMJ
Joint clicking is due to lack of coordinated movement between the condyle and the articular disc
The condyle has to overcome the mechanical obstruction before full joint movement can be achieved. Clicks may occur on opening or closing and can be classified as early, middle or late
most common cause of TMJ clicking
anterior disc displacement with reduction
anterior disc displacement with reduction
disc is intially displaced anteriorly by the condyle during opening until disc reduction occurs
signs/symptoms of anteiror disc displacment with reduction
jaw tightness/locking i.e. jaw movement is impaired for a short period of time until the disc reduces
The mandible may initially deviate to the affected side before returning to the midline.
If left untreated, may eventually progress to osteoarthritis
tx anterior disc displacement with reduction
Counselling
Limit mouth opening
Bite raising appliance
Surgery occasionally may be required
If painless, no treatment required
Reassure
trismus from trauma
Can occur after even minor ‘traumatic’ events, will usually resolve spontaneously:
* IDB
* Prolonged dental treatment
* Infection
If no resolution after acute phase:
* Physiotherapy
* Therabite® Jaw Motion Rehabilitation System
* Jaw screw - incisors at narrow end and screw turn will widen gap between incisors
* tongue depressors – inc each day number
Haematoma in medial pterygoid muscle (likely) causing restricted opening
