Exam 1: TMJ Flashcards
shape of TMJ disc
bi-concave
superior (from ant-post): slightly concave, flat, convex
inferior (from a-p): flat inferiorly, concave, concave
What is the primary ligament of the TMJ?
lateral ligament
What are the primary muscles of mastication?
masseter, temporalis, medial and lateral pterygoids
What are the secondary muscles of mastication?
digastric, hyoids
Mandible elevators
masster, temporalis, medial pterygoid
Mandible depressors
lateral pterygoid, assisted by suprahyoids
so early BRAIN BREAK
go look at the TMJ kines review
How are neck muscles and TMJ muscles related?
Cervical and cranial flexors and extensors are influenced by muscles of mastication and the hyoids; dysfunction in any group can create imbalances. C-spine influences mandibular closing, rest position, occlusal patterns and masticatory muscle activity.
How does mouth breathing facilitate FHP?
- low and forward tongue position
- abnormal swallowing
- hyperactive accessory muscles (SCM, scaleni, pectorals)
- decreased diaphragm use
Cervical flexors and TMD
reduced endurance, but no decrease in strength
What are outcome measures for TMJ?
TMJ scale
Temporomandibuar joint disability questionnaire
What factors increased confidence that a patient has TMD?
History of locking jaw and decreased ROM
What is the limitation of radiography at the TMJ?
It’s difficult to get an unobstructed view of articular surfaces
What views are used for TMJ radiography?
transcranial
submentovertex
cephalometry: lateral radiographs
transcranial view
- lateral oblique projection of TMJ
- osseous structures of TMJ-condyle, articular eminence mandibular fossa
submentovertex
alignment and shape of condyles
cephalometry: lateral radiographs
- method of measuring dimensions of head
- profile assessment, mandibular angle, height of hyoid
- craniovertebral relationship
- cervical alignment
What’s the best modality for seeing the disk?
MRI
describe the dual axis system
Axis 1 assigns dx of most commonly occurring masticatory muscle and/or TMJ disorders
Axis 2 is used to assess behavioral, psychological, and psychosocial factors relevant to TMD
Axis 1 groups
I-muscle disorders
II-TMJ disc displacements
III-arthralgia, arthritis, arthroses of TMJ
Axis 2 factors
- pain status variables
- functional mandibular limitations
- psychological distress
- graded scale of chronic pain
capsular fibrosis
- can result from hypomobility, systemic process (RA), immobilization, head and neck cancer, procedure, trauma, acute inflammation
- capsule tightens down; pain and/or decreased ROM
Hypomobility commonly accompanies…
- resoluation of acute articular inflammatory process
- chronic low-grade articular inflammatory process
- immobilization that involved capsule
What CN may refer pain with TMD?
CN V
How much should a non-reducing disk open their mouth?
limit interincisal opening to 30mm to protect retrodiscal tissues from being overstretched
What are PIRs?
- postisometric relaxation techniques
- active muscle contractions of various intensities
- control position in a specific direction against a counter-force to facilitate motion
What is the most common mechanical disorder of the TMJ?
hypermobility
What movement characterizes hypermobility?
early/excessive anterior translation
-occurs in first 11mm instead of last 15-25mm
How does hypermobility ultimately end for some people?
- arthritic changes
- loss of motion (hypomobility)
What kind of curves are associated with hypo and hyper mobility?
hypo-C curve
hyper-S curve
capsulitis
- can be due to injury, disease, or developmental abnormalities
- inflammatory response to fibrous capsule, synovial membrane, or retrodiskal tissues
- likely due to joint overloading
How can capsulitis affect mastication?
It can disrupt normal pattern and cause asymmetric muscle activity and mandibular malalignment
Signs and symptoms of capsulitis
- pain at rest or on closing
- increased pain with functional and parafunctional movements
- pain on involved side, possible CNV referral
- impairment from minor joint restrictions to total immobilization
retrodiskitis
encroachment of condyle on articular disk; causes inflammation or exacerbation of inflammatory condition
What can cause retrodiskitis?
- repetitive microtrauma
- acute external trauma to chin
How can retrodiskitis affect the lateral pterygoid?
can lead to overfatigue and disrupt disk movement with jaw movement
signs and sx of retrodiskitis
- constant pain, palpable postero-lateral TMJ tenderness
- pain increases with clenching or moving to affected side
- swelling may force condyle ant->acute malocclusion
intervention of retrodiskitis caused by microtrauma
- splint to reduce bruxism, decrease jt pressure
- ant repositioning therapy (splints)
- patient education: reduce pain, muscle guarding; stretching and muscular re-education
OA/DJD presentation
- similar to other jt dysfunction
- pain and crepitus during ROM
- movement restriction
- crepitation likely to persist
OA/DJD presentation
- surgery, meds
- AROM throughout the day
- joint protection (avoid excessive opening)
- rest position of tongue
How does malocclusion relate to disc derangement?
- overclosure of the mouth with backwards displacement of condyle
- may cause partial tearing of disk from capsular attachment
Theories on how disk derangment happens
- excessive pressure on joint-clenching, trauma
- uncoordinated bodies of lateral pterygoid
- deterioration of disk and cartilaginous surfaces
- stretching of ligaments by frequent subluxation
What does clicking during various ranges of opening probably mean?
- ruptures or tears of the disk
- early: small degree of ant displacement
- near max opening: farther ant displacement
Opening click
- anteriorly displaced disc with condyle posterior and superior
- condyle must pass over posterior band of disk adn fall into normal position on disk
closing click
- condyle slips behind posterior edge of band of disc (disc left ant & med)
- opening click as disk snaps back into position
- results in disk displacement
ADD with reduction-signs
- click on opening accompanied by jarring of the joint (disk in place)
- subtler click during closing (disk has displaced anterior)
ROM with ADDw/R
generally normal; vertical opening may be greater than normal
ADD without reduction
- no noise, series of reproducible restrictions during mandibular movement
- disc blocks translator glide: “closed lock”
- max opening to 20-25 mm
- mandible deflected to affected side at end of opening
- occasional locking
ROM with ADDw/oR
- lateral excursion to contralateral side is limited
- over time, more normal range due to stretching of posterior attachments (physiologic changes to closed lock)
What can cause trismus?
So many things!
- disk
- inflammation around teeth or muscles of mastication
- radiation therapy to head/neck
- TMJ dysfunction
- abscess
ADDw/R intervention
- repositioning appliance-dentist
- TMJ and cervical muscle relaxation exercises
- the usual
- self-monitoring
TMJ clicking interventions
- controlled joint movement under load
- isometric stabilization exercises
- ant positioning splint
- low-load exercises
ADDw/oR intervention
- joint mobes
- soft tissue mobes
- normalize the disc and then tx like reducing ADD
- surgery
- splint, self-exercise
- education
Peds & TMJ
- JRA
- often associated with c-spine involvement
- unilateral involvement-mandibular asymmetry
- undergrowth (micrognatihia)
- malocclusion of teeth
sugeries
- arthrocenteis
- arthroscopic surgery
- open joint surgery: joint reconstruction, prosthetic joint replacement
BRAIN BREAK
read all that good EBP starting on page 17 of your cut up copy
and while you’re at it, look at the subjective history on page 19
who’s likely to be a non-responder?
pretreatment mouth opening less than 30 mm in combination with MRI struck disc and unchanged disc shape with opening
