TMJ Disorder

Question 1

What is blood supply and nerve supply to tmj?

Answer 1

Deep auricular artery - 1st part of maxillary artery

Auriculotemporal nerve, masseteric and posterior deep temporal nerve

Question 2

Briefly describe the anatomy of the TMJ

Answer 2

Upper and lower synovial cavity separated by an articular disc

Condyle sits in the mandibular fossa with the articular tubercle anterior to the fossa

Question 3

Give some possible causes of tmj disorder

Answer 3

Localised osteoarthritis or even rheumatoid arthritis

Disc displacement with / without reduction

Myofascial pain - muscle / fascia issue

Parafunction

Chronic recurrent dislocation

Ankylosis

Hyperplasia - facial asymmetry due to condyle hyperplasia

Neoplasia - tumour

Infection

Question 4

Pathogenesis of myofascial pain with the TMJ?

Answer 4

Inflammation of MOM or TMJ due to parafunctional habits

Trauma directly or indirectly

Stress and clenching

Psychogenic

Occlusal abnormalities??? - no evidence however significantly high restoration / overeruption can cause pain

Question 5

What E/O and I/O features may present in someone with TMJD

Answer 5

Hypertrophy of MOM

Clicks or crepitus in TMJ

Facial asymmetry

Cheek biting / linea alba

Tongue scalloping

NCTSL

Question 6

Typical clinical features for TMJD?

Answer 6

More common in females

18-30 yo usually

Intermittent pain of several months / years

Muscle, joint, ear pain particularly on wakening

Trismus

Clicking or popping TMJ

Headaches

Question 7

What are some possible differential diagnoses that can be confused with TMJD?

Answer 7

Dental pain

Ear pathology

Salivary gland pathology

Referred neck pain

Headache

Trigeminal neuralgia

Angina

Condylar fracture

Temporal arteritis

Question 8

What are some treatments for TMJD

Answer 8

Patient education and counselling
- jaw exercises and physiotherapy
- mouth guard / soft splint - bite raising appliance
- occlusal adjustment if very pronounced
- relaxation techniques
- massage or heat
- TENS
- ultrasound therapy
- hypnotherapy/CBT

Medication
- masseter Botox
- nsaids
- muscle relaxants
- steriods

Question 9

What is anterior disc displacement with reduction? Typical presentation?

Answer 9

Articular disc does not move coordinated with the condyle

Condyle moves forward but disc stuck anterior preventing opening

Jaw manipulation allows jaw to fully open accompanied by a pronounced popping or clicking sound

Question 10

How treat anterior disc displacement with reduction?

Answer 10

If painless, no treatment required and just reassure

If pain

• counselling and patient education
• limit mouth opening
• bite raising appliances
• possibly surgery

Question 11

What are TMDs?

Answer 11

Group of related MSK conditions affecting masticatory muscles, the TMJ and associated structures

Question 12

What are the categories of TMDs?

Answer 12

Myalgia / myofascial pain

Arthralgia

Intra-articular disorders

Headache - typically confined to temporal region

Chronic - longer than 3 months

Acute - short duration, self-limiting and may be related to prolonged jaw opening

Question 13

When should a TMD be suspected?

Answer 13

Patient presents with one or more of clinical features:

• pain in and around TMJ / MOM which may radiate to other structures. Pain may be provoked by palpation of TMJ or muscles, jaw movement, function or parafunction
• reproducible joint nose of the TMJ, clicking, popping or crepitus
• headache limited to temporal region
• otalgia / tinnitus in the absence of ear disease

Question 14

When should TMD be referred to OMFS / OM?

Answer 14

• history of trauma / fracture to tmj
• marked limited mouth opening
• pain in jaw in patients with known rheumatic disease
• recurrent dislocation
• persistent or worsening chronic (3 month) symptoms despite primary care tx
• inability to manage normal diet
• severe pain / dysfunction
• uncertain aetiology / diagnosis

Question 15

What approach should be taken to manage TMD?

Answer 15

Psychosocial approach

• disease education
• reassurance it should improve and is non-progressive
• info on self management such as:
• soft diet, resting the jaw if acute pain, avoiding parafunctional habits, applying ice or heat to the area
• giving paracetamol or ibuprofen for acute onset
• consider short course of diazepam for myofascial pain or amitriptyline / gabapentin for chronic TMD if appropriate

Consider referral to physiotherapist / CBT

Question 16

Give some possible causes of TMDs

Answer 16

Internal derangement of TMJ

Macrotrauma - fall and hit chin

Micro trauma - parafunction such as bruxism, leading to overloading and cartilage breakdown in TMJ

Psychosocial - stress /anxiety predisposing parafunction

Systemic / pathological - associated with migraine, fatigue, IBS or other chronic pain. RA / SLE or arthritis too

Question 17

Prognosis of TMD?

Answer 17

5-10% require tx

Spontaneous resolution in 40%

50-90% improve with conservative tx

Question 18

Factors associated with poorer prognosis TMD?

Answer 18

Females

Later age onset

More severe pain = poorer prognosis

Having an associated psychosocial disorder e.g. anxiety or depression

Poor coping skills

Question 19

What is the anatomy of the TMJ joint

Answer 19

Synovial joint with two caverns

Split in the centre by a fibrocartilaginous disc

The superior cavity allows for protrusive and lateral movements, the inferior cavity, rotational, elevation and depression movements of the mandible

Condyle of the mandible inserts into the temporal fossa of the temporal bone, just posterior to the articular eminence - a section of the zygomatic arch

Question 20

What is myalgia / myofascial pain

Answer 20

Pain caused by masticatory muscle disorders

Question 21

What is arthralgia?

Answer 21

Localised degeneration of the TMJ

Pain from within the joint

Question 22

What is an intra-articular disorder/derangement?

Answer 22

Disorder of articular disc in TMJ, often caused by abnormal relationship or misalignment of the disc relative to condyle

Question 23

What ligaments support the TMJ?

Answer 23

Lateral TMJ ligament

• joined to the inferior border of the zygomatic arch and the posterior neck of the condyle of the mandible - limits posterior movement

Medial ligaments - limit lateral movement

• stylomandibular ligament - styloid process to medial surface of the ramus
• Sphenomandibular ligament - wing of sphenoid to surrounding the mandibular foramen

Question 24

What is the normal range for opening of the mouth

Incisal edge to incisal edge?

Answer 24

35-45mm

Question 25

DD with reduction vs without reduction

Answer 25

Disk displacement with reduction typically manifests with clicking/popping and pain with jaw use (such as chewing).

Disk displacement without reduction does not manifest with clicking/popping, but maximum jaw opening is limited to ≤ 30 mm. Surrounding tissues may become painfully inflamed (capsulitis).