TMJ Flashcards
Stats
- 35% of population
- 5-10% seek treatment
- ages: 20-40
- women>men
Comorbid conditions
- whiplash or associated trauma
- severe headache
- moderate headache
- neck pain
- LBP
TMD causes
- dental
- msk
- psychosocial
3 axes of research diagnostic criteria
Axis 1: clinical/diagnosis
Axis 2: behavior/psychosocial (poorer prognosis)
Axis 3: prognosis
We primarily treat axis 1
Areas to examine
- cervical screening
- look for concordant sign
- OA and AA assessment
- TMJ mobility assessment
- Jaw opening/deviation
Treatment options
- splinting/orthoses - OTC=custom, minimal effectiveness
- Joint mobs - caudal, AP, PA, regional interdependence
- Soft tissue intervention - manual, TDN
- Exercise - posture, relaxed jaw position, breathing, DNF retraining
Opening- normal value
30mm
2 knuckles, 3 fingertips
TMJ bite test
1 cm width applied to molars
- tongue depressors
- TMJ ipsilateral side UNLOADED
- contralateral side is LOADED
Protrusion normal value
8mm
Lateral deviation normal values
8-10 mm
TMJ accessory motions
- inferior distraction
- inferior/anterior
- caudal (inferior/posterior)
TMJ Anatomy
- diarthrodial
- temporal bone and mandibular bone joined through fibrocartilagionous disk, ligaments, and joint capsule
- TMJ and disk are covered with fibrocartilage that has a reparative property
- inferior and superior cavities
- rotation of condyle occurs in the inferior cavity and translation occurs in superior cavity
Superior cavity
between the temporal fossa and superior aspect of disc
-translation
Inferior cavity
between inferior aspect of disk and mandibular condyle
-rotation
Disc
- biconcave shape
- allows congruency of TMj during ROM
- provides lubrication to articular surfaces
- transmits force
- stabilizes joint
- endures long term stress
Disc divisions
- anterior - attached to superior condylar neck, ant. capsule, sup. lat. pterygoid, temporal bone
- intermediate
- posterior - bilmainar connective tissue connecting to bone
A&P have innervation and vascular supply
-Densest area is bw condylar head and articular eminence
Capsule
- capsule thickens inferiorly due to medial and lateral collateral ligaments
- more mobility in the AP direction than ML
Temporomandibular ligament
- supports lateral wall of capsule
- limits rotation of condylar head during jaw opening
Collateral ligaments
- attach to medial and lateral borders
- restrict excessive m/l movement of disc
Stylomandibular ligament & Sphenomandibular ligament
- limited function other than assisting in suspending the mandible from the cranium and preventing excessive protrusion
Masseter
Origin: anterior 2/3 of zygomatic arch
Insertion: lateral border of mandibular angle
Action:
1. Unilateral contraction - causes lateral deviation to same side
2. Bilateral contraction - elevation of mandible with force added for chewing/grinding hard foot
3. Bilateral superficial fibers = protrusion
4. Bilateral deep fibers = retraction
Temporalis
Origin (proximal): entire temporal fossa
Insertion (distal) : coronoid process and medial border of mandibular ramus
Action:
1. Bilateral contraction - elevate and retract mandible
2. Unilateral contraction - lateral excursion/deviation to same side
Medial pterygoid
Large head:
Origin (proximal): medial surface of lateral pterygoid plate of sphenoid bone
Small head:
Origin (proximal): tuberosity of maxilla
Insertion (distal): Both insert on medial surface of mandibular angle
Action:
1. Bilateral contraction - elevation and protrusion
2. Unilateral contraction - contralateral deviation
Lateral pterygoid
Superior head:
Origin (proximal): from greater wing of sphenoid bone
Insertion (distal): anterior aspect of disk
Inferior head:
Origin (proximal): lateral border of lateral pterygoid plate of sphenoid
Insertion (distal): condylar neck
Action:
1. Unilateral - contralateral deviation
2. Bilateral - protrusion
3. Inferior head - depression of mandible
4. Superior head - contracts eccentrically during mouth closing to monitor disc and avoid displacement
Suprahyoids
Digastric, mylohyoid, geniohyoid, stylohyoid.
All are responsible for depression and retrusion when the hyoid bone is fixed.
Infrahyoids
sternohyoid, sternothyroid, thyrohyoid, omohyoid.
Action:
stabilize hyoid and form a firm base for suprahyoid muscles.
Innervation
- Mandibular division of trigeminal nerve
- Deep temporal nerve
- masseter nerve
- auriculotemporal nerve
Normal values for movement
Depression: 40-45mm for males, 45-50mm for females (approximately 4 finger width of nondominant hand)
- Functional opening = 3 fingers, 35 mm
- Lateral deviation: 1/4 opening range
- Protrusion: 6mm to 9mm
- Retrusion: 3mm
Depression arthrokinematics
- rotation and translation occur simaltaneously
- posterior rotation of the condyle (condylar head moves anterior, body posterior) in early depression
- anterior translation occurs in late phase of opening
- disc rotates posteriorly
Elevation
- initiated by tension of retrodiscal lamina that retracts disc
- condylar head translates posteriorly w/ disc, condyle body rotates anteriorly
- at end range - disc rotates slightly anterior
Protrusion
-mandibular condyle head and disk translate anterior and inferior
Retrusion
-mandibular condyle and disc translate posterior
Lateral deviation
-rotation of ipsilateral condyle and horizontal translation of contralateral condyle
Causes of pathology
- imbalance of soft tissue
- mechanical derangement
- both
2 major classifications of disc derangement
- anterior disc displacement with reduction
2. anterior disc displacement without reduction
Anterior disc displacement with reduction
- the disc rests in front of the condylar head while mouth is closed
- during opening, it “reduces” back to the top of the condylar head causing a click and then translates anteriorly with the condyle
- at end of closing range disc displaces again causing a 2nd click
- “reciprocal clicks”
- limited opening
- mandible deflects to ipsilateral side
- “c” or “s” curve
Anterior disc displacement without reduction
- disc will stay displaced in front of condyle and not be able to return to normal resting position
-no clicking during opening/closing
-pateint may have limited opening (when disc is blocking condylar head)
OR no limitation in opening (when disc is completely anterior)
-hx of reciprocal joint noises
-limited opening
-deflection and pain
Posterior disc displacement
- very rare
- usually occurs after wide opening of mouth (aka yawn)
- inability to close the mouth (open-lock)
- may report closing clicks if reduction occurs
Disc-condyle incoordination-internal derangement
- localized mechanical fault in snovial joint that interferes with smooth action
1) anterior disc displacement w/ reduction
2) “ “ w/o reduction
Subluxation/discloation of condyle
- Dislocation - mouth is kept in open position
- may be caused by trauma, muscular hyperactivity, connective tissue disorder, hypermobility - Subluxation - temporary dislocation.
- systemic laxity
- systemic hypermobility
Ankylosis
- restricted mandibular mobility and ROM
- limited translation of involved side
- deviation to ipsilateral side is observed with opening
Masticatory muscle disorder
- caused by direct or indirect macrotrauma
- forward head posture
- psychosocial factors
Myofascial pain disorder
-trigger points
Myositis
- acute inflammation of muscle
- palpable tenderness, pain during ROM, limited opening of jaw
Myospasm
- spasm of masticatory muscles caused by overstretching, trismus (spasm of masster muscle) from a dental proecdure
- can also be cause by overuse (excessive gum or hard foods0
Dystonia
- neurological condition
- CNS
- unable to voluntarily control movement of the jaw, lips, tongue
- function of chewing/swallowing/speech affected
- botox injection may be beneficial
Capsulitis
- caused by trauma or poor oral habits
- inflammatory process
- pain upon palpation and with jaw movement
- “C” curve opening with deflection and protrusion towards ipsilateral side (tight/stretched side)
Objective assessment
- thorough upper quadrant screen
- posture
- abdominal and cervical muscles
- postural retraining recommended
“S” curve
- mandible deviates in “s” shape with opening
- without pain may indicate muscle imbalance or improper muscle coordination
- if painul or with limited opening, may indicate involvement of disc or capsule
“C” curve
- mandible deviates to one side in middle of opening and returns to center at end of opening
- indicative of capsular pattern
Deflection
- mouth deflects to one side during opening and does not return to center at end range
- indicative of ipsilateral disc involvement
- limited opening, protrusion to ipsilateral side, and limited lateral excursion to C/L side also common
Clinical progression of internal derangement
- reciprocal clicks
- absent joint noise with limited opening (locked joint)
- osteoarthrosis
Cotton roll test
- used to differentiate between muscular and joint involvement
- bite down on an object with back molars = gap in ipsilateral side and compress contralateral side
- have patient bite down on side of complaint
- PAIN INCREASE: cause is muscular
- PAIN DECREASE: cause is joint related
Ultrasonography
-reliable in IDing internal derangement, condylar erosion, articular effusion, degenerative OA
Intervention
- relaxation
- postural correction
- oral habit modifiation (resting position of tongue)
- soft diet
- modalities for pain control
- AVOID IONTOPHORESIS due to skin breakdown in the facial area
- STM
- joint mobs
- dry needling
