TMJ summary Flashcards
(117 cards)
1
Q
which part of the disc is innervated?
A
bilaminar zone
2
Q
fct of ligaments
A
surround joint capsule - stability, protect against extreme movements
3
Q
ligaments
A
lateral ligament - limits AP joint movement
sphenomandibular and stylomandibular - limit lateral movements
4
Q
describe the disc
A
fibrocartilage
avascular
biconcave
5
Q
articulating surface of condyle
A
fibrocartilage
6
Q
articular eminence
A
temporal bone
dictates path of condyle during mandibular movements
7
Q
glenoid cavity/fossa
A
hollow on inferior surface of squamous temporal zone
fibrocartilage
8
Q
capsule
A
thin fibrous CT attached to rim of fossa and neck of condyle
disc attaches to it medially and laterally
lat aspects thickened by TM ligament
9
Q
blood supply
A
deep auricular artery
- branch of internal maxillary artery
10
Q
nerve supply
A
auriculotemporal, masseteric, posterior temporal nerves
11
Q
superior joint compartment
A
gliding
protrusion, retrusion, side to side
12
Q
inferior joint compartment
A
rotation
elevation and depression
13
Q
what does the disc blend with?
A
anteriorly blends with LP margins
posteriorly attached to bilaminar zone - loose CT and nerves
lined with synovial membrane
14
Q
suprahyoids
A
digastric
mylohyoid
geniohyoid
stylohyoid
15
Q
infrahyoids
A
thyrohyoid
sternohyoid
omohyoid
sternothyroid
16
Q
synovial membrane
A
lines non-articular surfaces
produces the synovial fluid that lubricates the joints and nourishes the cartilage
17
Q
when is the joint loaded?
A
eating or clenching
18
Q
superficial MofM
A
temporalis
masseter
19
Q
deep MofM
A
LP
MP
20
Q
what supplies the MofM
A
motor branches of V3
21
Q
origin and insertion of temporalis
A
temporal fossa
tendon onto coronoid process
22
Q
fct of temporalis
A
elevate (anterior vertical fibres)
retract (posterior diagonal/horizontal fibres)
23
Q
origins of masseter
A
superficial - maxillary process of zygomatic bone
deep - zygomatic arch of temporal bone
24
Q
insertion of masseter
A
lateral surface ramus and angle mandible
25
fct of masseter
elevate mandible
26
origins of MP
superficial - maxillary tuberosity and pyramidal process of palatine bone
deep - medial aspect LP plate (sphenoid)
27
insertion MP
medial surface ramus/angle
28
fct of MP
elevates (bilateral)
| swing jaw to contralateral side (unilateral)
29
origins of LP
superior head - greater wing of sphenoid, roof of infratemporal fossa
inferior head - lat surface LP plate
30
insertion of LP
tendon - joint capsule and neck of condyle. pterygoid fovea
31
fct of LP
protrudes and depresses - bilateral
| lateral excursions - unilateral
32
depressing the mandible
infra and suprahyoids act together: hyoid bone stabilised
suprahyoids contract further - pulls down on mandible
LPs contract - translates condyles down articular eminence
also assisted by gravity
= forward and downward movement of mandible
33
initial mouth opening
hinges from centric relation up to 25mm
- aided by supra/infrahyoid contraction
- LPs relaxed
34
further mouth opening
to max opening - condyle translates anteriorly (forwards and downwards) along articular eminence
- bilateral contraction of LPs and contraction of supra and infrahyoids
35
protrusion
condyle translates forwards and downwards along the articular eminence
bilateral contraction of LPs
36
mouth closing
condyle held within glenoid fossa
| aided by contraction of temporalis, masseter and MP
37
when is the jaw most stable?
when mouth closed and teeth in occlusion
38
lateral excursion
mandible moves to left
left condyle pulled backwards slightly by the temporalis and rotates but sits within the glenoid fossa
R condyle moves forwards, downwards and inwards along articular eminence - R LP contracts
posterior fibres of L temporalis contract
39
TMD definition
collective term "a group of conditions that cause pain and dysfct in the jaw joint and muscles that control jaw movement'
- masticatory muscles
- TMJ and associated structures
- both
40
basic classification
disorder of the MofM
disorder of the TMJ
headache attributable to TMD
= often they co-exist
41
basic classification - disorder of the MofM
usually caused by parafct habits
42
basic classification - disorder of TMJ
```
disc displacement +/- reduction
osteoarthritis
osteoarthrosis
hypermobility
subluxation
adhesions
```
43
Groups of TMD
Group 1 - muscle disorders
Group 2 - disc displacement
Group 3
44
Group 1 - muscle disorders
1a - myofascial pain
| 1b - myofascial pain with limitations in aperture
45
Group 2 - disc displacement
2a - disc displacement with reduction
2b - disc displacement without reduction and no limitations in aperture
2c - disc displacement without reduction and with limitations in aperture
46
soft end feel
pt guarding against opening due to pain
47
hard end feel
can't open any further
48
Group 3
3a - arthralgia (pain)
3b - osteoarthritis of TMJ
3c - osteoarthrosis of TMJ
49
masticatory muscle disorders
```
local myalgia (pain felt locally within muscle)
myofascial pain (pain felt within and referred outside of the muscle)
```
50
common cause of masticatory muscle disorders
parafct activity
- clenching, grinding, biting nails, chewing gum
can be thought of as overworking the muscles almost causing a sprain-like injury
51
S+S of MM disorders
tender muscles on palpation
pain with jaw activity i.e. speaking, chewing
pulling, tight or achey sensation
52
disc displacement with reduction tx
```
no pain = no tx
tx
- advice
- limit opening
- BRA
- occ surgery
```
53
disc displacement with reduction pathogenesis
ideal disc position no longer maintained in relation to the condyle throughout range of motion
disc initially displaced anteriorly by the condyle during opening until disc reduction (relocation) - click
54
S+S of disc displacement with reduction
click on opening and closing
deviation of jaw to affected side (same side) on opening
if left untxed may eventually progress to OA
55
disc displacement without reduction pathogenesis
disc anteriorly displaced and no longer reduces (relocates)
56
S+S of disc displacement without reduction
"closed lock" - limited opening 25mm - disc displacement without reduction with reduced mouth opening
deviation of jaw to same side on opening
limited contralateral excursion i.e. if left joint is affected there is limited jaw movement to right
if chronic the joint can become stretched and allow a nearly full range of movement
- history of limited opening but not anymore and MRI showing remodelling
- disc displacement without reduction without limited mouth opening
get pain as bilaminar zone innervated
57
osteoarthritis
deterioration of joint, often relating to condyle
58
S+S of osteoarthritis
pain and crepitus (grating/grinding)
radiographic features
- joint space narrowing
- osteophytes
59
osteoarthrosis
same signs and changes as osteoarthritis but no pain, just crepitus
moth eaten condyles
60
hypermobility
excessive range of movement which may lead to subluxation
61
subluxation
dislocation of joint - condylar process beyond articular tubercle
62
subluxation causes
excessive mouth opening
yawning
trauma
prolonged dental tx/intubation
63
presentation of subluxation
malocclusion
open bite
empty articular sockets - palpate as pre-tracheal hollowing
if unilateral - chin shifted to contralateral side
click palpated at max opening
open lock may result - jaw is 'stuck open'
- MofM spasm and hold mandible in this position
64
subluxation preventive aftercare
support chin
limit opening
can use circular fixation bandage for 24hrs
65
subluxation - when should you not relocate?
if you suspect any facial fractures
66
subluxation relocation
ASAP as may avoid need for additional measures i.e. muscle relaxants/sedation/GA
chair with head support
one side at a time
put downward pressure on L molars with thumb and grip mandible with rest of hand (fingers buccal sulcus)
increasing force until you feel condyle move
then hold in position with non-dominant hand by one finger in front of condyle
relocate other side
verify normal occlusion
67
complications of subluxation
unable to reduce
subcondylar fracture
early repeat redislocation
68
adhesions
limit extensibility of joint capsule
- chronic inflammation
- history of trauma/surgery
- immobilisation
- chronic disc displacement without reduction
69
S+S of adhesions
limited opening
deviation to same side on opening
limited contralateral excursion
70
multifactorial aetiology - biopsychosocial model
biological: inflammation
- local factors: secondary to parafct, trauma, infection, tooth loss, prolonged dental procedures
- systemic factors: arthritis, fibromyalgia, hypermobility (EDS)
psychological: anxiety, depression, thoughts, beliefs
social: work, finances, family, relationship
71
HPC key points
```
pain
- associated pain elsewhere e.g. neck, shoulders
clicking
other noises e.g. grating
limitation of opening
locking
altered occlusion
sensory disturbance
history of trauma
parafct activity
what have they prev tried and did it help?
opening/closing
aggravating/relieving factors
temp/persistent
timing and duration
- morn bruxism
- day habits
```
72
MH key points
```
arthritis
prev malignancy
immunosuppression
mental health
fibromyalgia
hypermobility syndromes
```
73
SH key points
```
occupation
stress
home circumstances
sleeping pattern
recent family difficulty or bereavement
relationships
```
74
DH key points
```
recent tx (in particular lengthy or difficult appts)
surgical procedures (recent 3rd molar removal)
denture wearers
```
75
why should you palpate the neck?
some pts can present with tenderness of SCM
76
how to palpate masseter
bimanual palpation
- one finger inside cheek and one EO over masseter
- clench then slightly part teeth
- palpate inferior, mid and superior aspects
- presence/absence of tenderness/pain
77
TMJ examination
palpation
listening on opening and closing
observe lateral excursions and protrusion (10mm)
mouth opening - interincisal distance 35-50mm
mandibular position - posturing habits
78
ideal lateral excursion and protrusion
should be smooth unobstructed movement
| observe for deviation, restrictions and abnormal sounds
79
what should you do if the pt is guarding due to discomfort/trismus?
ask if they can open any further - sometimes use gentle finger pressure
80
ST exam
buccal mucosa - linea alba
cheek biting - morsicatio buccarum
bony prominences - tori - associated with overload on teeth
tongue - scalloping
81
examining teeth
```
wear facets
attrition
occlusion
high spots
teeth present/absent
interfering contacts
occ NCTSL
```
82
palpating MP
one finger inside mouth - slide it posteriorly along your lower teeth past the last standing molar
push finger into the tissues and gently close - you will feel MP contract
83
differential diagnoses
```
odontogenic pain
sinusitis
temporal (giant cell) arteritis
ear pathology
salivary gland (parotid) pathology
referred neck pain
headache
atypical facial pain
trigeminal neuralgia
angina/MI
burning mouth syndrome
condylar fracture
```
84
should you routinely image?
no - only in special circumstances, not routine investigations
85
plain film
```
mouth open (allows better visualisation of condyle - can show arthritic changes)/closed OPT
only if joint pathology suspected e.g. arthritic changes
```
86
CBCT
more accurately demonstrates bony anatomy and changes
87
arthrography
radiopaque dye injected into joint space using videofluoroscopy
used when meniscal tears suspected
88
MRI
ST anatomy inc disc
| can detect anterior disc displacement
89
US
muscle/ST pathology overlying joint
90
nuclear imaging - technetium 99
use for suspected hyperplasia
| isotope picked up in areas of increased cell turnover
91
exclude any red flags
history of malignancy
lymphadenopathy (persistent/unexplained)
neurological symptoms (headache/CN abnormalities)
facial asymmetry (mass/swelling/profound trismus)
severe unilateral TMJ pain can indicate malignancy
recurrent epistaxis, nasal discharge, anosmia or reduction in hearing (ipsilateral) - nasopharyngeal carcinoma
unexplained weight loss/fever - malignancy, infective, immunosuppression
change in occlusion (neoplasia, RA, trauma etc)
new onset unilateral headache/scalp tenderness, jaw claudication, general malaise, esp if >50yrs - may indicate temporal arteritis (systemic inflammatory vasculitis)
92
broad management categories
```
reassurance and education
conservative advice
reversible therapies - BRA, physio, acupuncture, hypnosis, clinical psychology, pain clinic, TENS, replacement of missing teeth (esp if lacking posterior support)
meds
surgery
```
93
meds
simple analgesics
BZDs - if seen early during acute exacerbation as muscle relaxant
amitriptyline/nortriptyline (muscle relaxants)
intra-articular steroid injection
94
surgery
```
botox
high condylar shave
arthrocentesis
arthroscopy
joint replacement
disc repositioning/repair/removal
```
95
arthrocentesis
flushing out joint, often in combination with steroids to break down adhesions
96
arthroscopy
visualises joint, can simultaneously remove adhesions/flush joint
97
joint replacement
last resort
v rarely used
if no other option and gross pathology present i.e. tumours
98
management of trismus
usually resolves spontaneously
identify and tx underlying cause e.g. infection/trauma
improve mouth opening gradually by stretching the muscles and ligaments over weeks/months
physio
- esp H+N radio pts
- therabite, trismus screw, tongue spatulas
a few pts with severe trismus refractory to conventional measures may undergo surgical intervention e.g. coronoidectomy
99
why should a splint always be full coverage?
to prevent overeruption
100
when is split therapy offered?
as second line tx - if advice is not enough
101
education and reassurance
condition usually non-progressive, symptoms may fluctuate but should improve
often self-limiting
can often be managed with simple conservative management
address biopsychosocial aspects
all pts unique so need to find strategies which work for them
- will be trial and error to find right strategies
- can take a couple of weeks to see any benefit
102
conservative advice
soft diet
reduce caffeine
avoid parafct activities that may exacerbate symptoms - wide yawning, teeth grinding, clenching, chewing gum or pencils, nail biting
avoid using incisors to slice food
ensure chewing on both sides
keep teeth at least 2mm apart when at rest
limit mouth opening to 2 fingers width
consider simple analgesia for short-term use e.g. paracetamol/NSAID
consider local measures for pain relief - covered ice/warm flannel/heat pad, massaging affected muscles
try to identify sources of stress
- give advice on relaxation techniques, setting realistic targets, pacing activities, getting social support, counselling
support mouth on opening
jaw exercises - physio helps some pts
103
BRAs theory
exact mechanism unknown, little scientific evidence to support use
can make better/worse/no effect
theoretically
- stabilise occlusion
- improve fct of MofM
- therefore reduce abnormal activity and protect teeth in cases of grinding
despite lack of evidence, may feel that due to their relative inexpense, non-invasive nature and historical benefit to a significant number of pts, their use is justified
104
soft splint advantages
quick, easy, cheap
preferable for clenchers
can be used in teenagers whose occlusion may still be developing
vacuum formed (simple construction)
105
soft splint disadvantages
may need regular replacement
may exacerbate condition
difficult to adjust
106
bilaminar splints
soft inner, hard outer
slightly more £ but can be simply made by any dental lab
may be better for those who are chewing through soft splints, or where it promotes clenching
107
Wenvac
cheap, some chew through/bounce on it as soft and rubbery
108
splint instructions to pt
may need to wear splint for several weeks before benefit felt
wear every night
wear at time of parafct - usually sleep, may be driving, using computer, other times of stress
if v severe symptoms wear continuously apart from eating
use may then decrease as symptoms improve, and recommence as symptoms worsen
but many pts continue to wear long term
pt may still clench/grind with splint in situ, but hopefully splint will act as habit breaker
occ splints may worsen a pts problem in which case they should be reassessed
soft splints may occ promote clenching leading to worsening of discomfort - may consider a hard splint
109
which type of splint to use?
evidence doesn't favour any particular splint
- soft and bilaminar 'go to'
- Lucia jigs may be used, particularly in Rx dentistry
- hard splints may be favoured by those with Rx experience but are rarely constructed in primary care
110
anterior bite plane - Lucia jig
discludes posterior teeth to allow relaxation of MofM
used as a v short term measure during acute exacerbations, prior to more definitive splint
may also be used as diagnostic tool for TMD pts
simple to construct chairside - cold cure acrylic or greenstick (can also buy preformed)
airway risk, get dahl effect
111
stabilisation splint
Michigan splint U
tanner appliance L
full coverage to prevent over-eruption
creates
- uniform contact in centric relation
- canine guidance to separate posterior teeth in eccentric excursions
- anterior guidance to separate posterior teeth in protrusion
i.e. the splint creates an artificial 'ideal' occlusion
complex construction - imps, jaw reg in centric relation, facebow and adjustments at fit appt required
preferable for bruxers
112
pathogenesis
inflammation of MofM or TMJ secondary to parafct habits
trauma either directly to joint or indirectly e.g. sustained opening during tx
stress (parafct)
psychogenic
occlusal abnormalities (v rare)
- no evidence, but a Rx that is significantly 'high' may cause muscle pain due to posturing
113
common clinical features
F>M
most common 18-30yrs
intermittent pain of several months/years duration
muscle/joint/ear pain, particularly on wakening (clenching overnight)
trismus/locking
'clicking/popping' joint noises
headaches (temporalis)
crepitus indicates late degenerative changes
114
anterior repositioning splint
a maxillary appliance
often used for those with disc derangements
- promotes a more harmonious condyle-disc relationship by capturing an anteriorly displaced disc
directs mandible anterior to ICP
115
causes of TMD
myofascial pain
disc displacement (anterior +/- reduction)
degenerative disease
- localised: osteoarthritis (often asymptomatic)
- generalised/systemic: RA
chronic recurrent dislocation
ankylosis
hyperplasia - one condyle larger, asymmetry
neoplasia - osteochondroma, osteoma, sarcoma
infection - rare, usually from ear
116
reversible tx
education
meds
physical therapy
splints
117
irreversible tx
occlusal adjustment
- DON'T do, no benefit
surgery
