Jaw Opening
first 50% roll is posterior, until disc sits upon mandible like a hat - gets tensioned by collatleral ligs and lateral pterygoid
50-65% slides anteriorly and inferiorly- following slop of the mandibular eminence
Full opening- stretchs disc anterior but protursion limited (requires mandible rotation > swing)?
Jaw Opening
(Rotation Occurs in the inferior cavity, translation occurs in superior cavity) first 50% roll is posterior, until disc sits upon mandible like a hat - gets tensioned by collatleral ligs and lateral pterygoid
50-65% slides anteriorly and inferiorly- following slop of the mandibular eminence
Full opening- stretchs disc anterior but protursion limited (requires mandible rotation > swing)?
Disc rotates POSTERIORLY
Jaw Closing
Opposite of opening- sup/posterior translation and anterior rotation
Done by masseter, temporalis and medial pterygoid (“MMT”)
DIsc goes ANTERIORLY
lateral deviation
- 11mm (etermined by contact of teeth)
- slight anterior and medial roll of TMJ
Muscles- contralateral pterygoids, ipsil mass/temp
left lat dev- right pyterygoids and ipsil mass/temp
Anterior disc displacement with reduction
opening click first 25mm opening is reduction
- mandibular condyle rotates posteriorly
( disc is sitting anteriorly to condyle. when it rolls posteiriorly, it catches up to disc that is already forward and positions hat on condyle (reduction), but when it keeps opening and you get the anterior translation is displaces again- 2nd click).
anterior disc displacement without reduction
- disc is still anterior, but posterior roll of mandible is not sufficient to relocate disc on top (hat) of the condyle. because of this you may have ROM limitations.
C or reversed C opening deviation
hypermobile capsule TOWARDS side of convexity
- as you open, should go straight down, but if you deviate towards that side, you are more lax in that direction
Special Tests for TMJ
- Tongue thrust
2. Mouth breather
TMJ Treatment
- total replacement TMJ - improvements in pain but NOT function or ROM
- Impairment based treatment approach
- Postural Retraining
- DNF retraining
- Manual therapy- contract relax stretches and mobs
Posterior disc displacemnet
- usually occurs with prolonged mouth opening ( during a dental procedure) lateral pterygoid is overstretchedand results in posterior displacement of the disc
- pt demonstrates open lock (inability to close th emouth) and reports clicking with reduction
Closed lock
anterior disc displacement - harder to open mouth
Open Lock
- mouth stays open, harder to close, posterior disc derangement
Headaches
strong correlation to bruxism and bruxism to increase in stress
- greater occipital nerve and trigeminal nerve can get impinged with tension type headaches
Scalloping of the tongue
sign of bruxism
Joint vs muscular
cotton roll test
- have pt bite down on cotton with back molars
- if cotton on R side, and biting causes more pain, think muscular. If there is less pain, think joint related (biting down will cause gapping on biting side and compression on non cotton side)
- to confirm, switch cotton sides and bite. If biting causes contralateral pain, think joint bc it should be compressing more
hypomobility
< 30mm (should be able to get 2-3 fingers)
- due to trauma, OA, operation
hypermobility
> 50 mm
TMJ treatment
- education is always the first step
- optimal alignment/posture
- activity modification - decrease muscular act
- relaxation training- reduce muscular hyperactivity
- mouth guard- 1`
Trismus
Acute closed lock of the jaw after a dental procedure, spasm of massetter muscle, limited ROM
myofascial pain syndrome
chronic; noted by trigger points
treating trigger points
Spray-stretch with ethyl-chloride
TMJ innervation
Trigmeninal nerve
condylar remodeling exercises
helps with anterior displaced disc, the opening with protrusion closing with protrusion then retracting to help relocate disc
anterior repositioning spint
used for anteriorly displaced discs
