tmj assessment and evaluation

2. SYNOPSIS
 INTRODUCTION
 UNIQUENESS OF TMJ
 ANATOMY OF TMJ
 ANATOMY OF MASTICATORY
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MUSCLES.
BIOMECHANICS OF TMJ
ASSESSMENT AND EVALUATION
- Range of movements
- Pathway of jaw opening
- Maxillary and mandibular midlines
- TMJ palpation
- Masticatory muscles palpation
- Joint sounds
- Functional activities
DIAGNOSTIC AIDS
CONCLUSION

3. INTRODUCTION
 The Temporomandibular joint is a
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synovial diarthrodial joint.
Also called the ginglymodiarthrodial joint
Gingylmus means hinge joint
Diarthrodial means the joint space is divided into two
separate compartments by means of intra-articular
disc.
Both hinge action(rotation)
Slide action(translation)

4. UNIQUENESS OF THE JOINT
 Bilateral diarthrosis→right and left functions
together.
 Articular covered by fibrocartilage instead of
hyaline cartilage.
 This reflects a non-load bearing functional role for
TMJ.
Covering of the condyle is derives from
intramembraneous ossification that normally lacks
the endochondral template from which hyaline
cartilage is derived.
 The only joint in human body to have a rigid
endpoint of closure that of the teeth making
occlusal contact.

5. ANATOMY OF TMJ
 Superiorly,the mandibular fossa of the temporal bone
articulates with the disc
 Inferiorly,the disc articulates with the condyle of the
mandible.
 Basic components includes,
- mandibular condyle
- articular surfaces of temporal bone
- joint capsule
- synovial membrane
- ligaments
- intra-articular disc
- masticatory muscles

6. ANATOMY

7. JOINT CAPSULE
 Envelops the articular disc
 Attached
- superiorly to rim of glenoid fossa
- inferiorly to neck of condyle
anteriorly continous with
muscle attachment of lateral pterygoid.
- posteriorly,attached to bilaminar zone
-

8. SYNOVIAL MEMBRANE
 Inner surface of the capsule comprises the synovial
membrane.
 Functions:
regulatory
secretory
phagocytic

9. LIGAMENTS
 Temporomandibular ligament
 Stylomandibular ligament
 Sphenomandibular ligament

10. INTRA-ARTICULAR DISC
Disc acts as the “shock absorber”
4 ZONES:
Anterior band
Intermediate band
Posterior band
Bilaminar zone

11.  “At rest” mandibular positon .the condyle is separated
from the temporal bone by posterior band
 As the head of the condyle moves forwards the
artiucular eminence.it is seperated from the temporal
bone by intermediate zone
 As anterior movement progresses ,the head of the
condyle moves forwards until it is resting on the
anterior band
 The forward movement of the disc is permitted by the
loose fibroelastic tissue of bilaminar zone;

12. MASTICATORY MUSCLES
MASSTER
TEMPORALIS
MEDIAL
PTERYGOID
LATERAL
PTERYGOID

13. MASSETER
 Origin:
-Superficial portion-anterior 2/3rd of
lower border of zygomatic arch.
-Deep portion-medial surface of
zygomatic arch
Insertion:
-Lateral surface of the angle of
mandible.
Function:
- Elevates mandible

14. TEMPORALIS
 Fan shaped muscle
 Origin:
-Temporal fossa
 Insertion:
-Coronoid process and anterior border of
ramus
Function:
-Elevates and retracts mandible

15. LATERAL PTERYGOID
 Origin:
-Superior head-infratemporal surface of greater wing of
sphenoid.
-Inferior head- lateral surface of lateral pterygoid plate.
 Insertion:
-superior head-anterior part of capsule and intra-articular
disc.
-Inferior head-anterior portion of head of the condyle.
 Function:
-depression of the mandible.
-protrusion of the mandible.
-lateral movements of mandible.

16. MEDIAL PTERYGOID
 Origin:
-Medial surface of lateral pterygoid
plate
 Insertion:
-medial surface of the angle of the
mandible.
 Function:
-elevation of the mandible.
-protrusion and lateral movements.

17. BIOMECHANICS OF TMJ
 Complex combination activity.
 Both left and right joints must function together in the
coordination of jaw movements.
 3 motions occurs at the mandible
Depression/elevation
Protrusion/retrusion
Lateral excursion

18. ACCESSORY MOTIONS
 Rotation is the only physiologic movement that can
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occur between the surfaces.
Rotation in the TMJ usually occurs in lower joint space
between the head of condyle and the undersurface of
intra articular disc
Occurs only during the opening of mouth upto 20 to
25 mm
Translation or sliding movement occurs in the upper
joint space between the upper surface of the disc and
inferior surface of glenoid fossa.
Occurs when the mouth opens more than 25 mm

19. ROTATION AND TRANSLATION

20. ASSESSMENT AND EVALUATION OF
TMJ
MEDICAL
HISTORY
CASE
HISTORY
MEDICATIONS
AND SOCIAL
HISTORY
HISTORY OF
PRESENTING
ILLNESS

21. CLINICAL EXAMINATION
 OBSERVATION:
- Opening and closing of the mouth
- alignment of the teeth
- symmetry of facial structures

22. RANGE OF MOVEMENT
 Involves examining the interincisal opening and
lateral excursions.
 Normal opening: female-35mm
male -42mm
 Protrusion of mandible: 5mm

24.  Lateral movement should be measured from midline
to midline,the patient moving the mandible to their
maximum extent,from one side to other.
 Range of lateral excursion of mandible: 8 to 10mm

25. PATHWAY OF JAW OPENING
 Mandibular pathway is observed by standing in front
of the patient and asking the patient to repeatedly
open and close the mouth.
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DEVIATION
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Pain in the mandibular muscles or tmj
or
Physical obstruction to movement

27.  If the pathway is straight
joints are acting
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synchronously.
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 If there is deviation to one side
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,then back to midline
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or
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alternating first to one side and then across another and
again back to midline
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temporary obstruction to the movement
Disc displacement with reduction

29.  If the mandible moves vertically during the first phase
of movement followed by an abrupt deviation
 Disc displacement without reduction
 In this case,mouth opens normally until the head of
the condyle on the affected side encounters the disc in
a displaced position
 Further translation is prevention resulting in marked
lateral deviation.

31. MAXILLARY AND MANDIBULAR
MIDLINES
 Patient with straight pathway or transient deviation
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at maximum opening upper and lower
midlines coincide

32. Disc displacement without reduction
the midlines would coincide until a point at which the
head of the condyle encounters the displaced disc
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Lateral shift occurs
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discrepancy in the midlines are noted

33. TMJ PALPATION
TMJ PALPATION
LATERAL
PALPATION
INTRAAURICULAR
PALPATION

34. LATERAL PALPATION
IMMEDIATE PREAURICULAR AREA
IS PALPATED BY PRESSING GENTLY
OVER IT BOTH AT REST AND
DURING MOTION

35. INTRA – AURICULAR PALPATION
PLACE YOUR LITTLE FINGER IN THE
EXTERNAL AUDITOR MEATUS ON
ONE SIDE AT A TIME AND
APPLYING FORWARD
PRESSURE,WHILE ASKING THE
PATIENT TO OPEN AND CLOSE
MOUTH

36. MASTICATORY MUSCLES
PALPATION
MASSETER
IT CAN BE PALPATED BIMANUALLY
BY PLACING ONE FINGER
INTRAORALLY AND ANOTHER
EXTERNALLY ON THE CHEEK

39. TEMPORALIS
IT CAN BE EXAMINED BY PALPATING ITS
ORIGIN EXTRAORALLY.ASK THE
PATIENT TO CLENCH THE TEETH AND
THE OUTLINE OF THE MUSCLE ORIGIN
CAN BE IDENTIFIED.ESPECIALLY THE
ANTERIOR FIBRES
DIGITAL PALPATION CAN BE
PERFORMED BETWEEN THE SUPERIOR
AND INFERIOR TEMPORAL LINES.

43. LATERAL PTERYGOID
EXTRAORAL:
THE PATIENT IS ASKED TO OPEN
THE MOUTH.THE EXAMINERS
HAND IS PLACED UNDER THE
PATIENTS CHIN AND PRESSURE IS
APPLIED TO TRY TO CLOSE THE
MOUTH WHILE THE PATIENT
TRIES TO RESIST

44. INTRA-ORAL:
PLACING THE FOREFINGER OR
THE LITTLE FINGER,OVER THE
BUCCAL AREA OF THE
MAXCILLARY THIRD MOLAR
REGION AND EXERTING
PRESSURE IN A POSTERIOR
,SUPERIOR AND MEDIAL
DIRECTION BEHIND
MAXILLARY TUBEROSITY.

45. MEDIAL PTERYGOID
GENTLY PALPATE THEM ON THE MEDIAL
ASPECT OF THE JAW,SIMULTANEOUSLY
FROM BOTH INSIDE AND OUTSIDE THE
MOUTH

46. CLINCICAL CONSIDERATIONS OF
MASTICATORY MUSCLES
MASSETER:
 There is a palpable difference between the affected
side and the unaffected side
 Unaffected side:muscle has a soft rubbery consistency
and the margin is less easy to define.
 Affected side:muscle tends to be bunched up,quite
easy to palpate and tenderness may be noted
 Masseter is found to be tender in patients who clench
their teeth.

47. TEMPORALIS:
 The anterior,more vertical fibres are the main elevator
muscles of the jaw and commomly tender on
palpation.
 Posterior fibres,horizontal fibres are less frequently
tender because their main function is to retrude the
mandible.
 Temporalis is tender in patients who grind their teeth.

48. LATERAL PTERYGOID:
 Most commonly involved muscle in MPDS.
 Unilateral failure of lateral pterygoid to contract
results in deviation of mandible towards the affected
side on opening.
 Bilateral failure results in limited opening.loss of
protrusion and loss if full lateral deviation.

49. MEDIAL PTERYGOID:
 It can be palpated only intra-orally
 Trismus following IANB is due to medial pterygoid
muscles
 Also involved in MPDS.

50. JOINT SOUNDS
JOINT SOUNDS
CREPITUS
CLICKING

51. CLICKS
 “Single explosive noise”
 Felt by the patient but inaudible to examiner
 Can be felt by palpating the TMJ in the preauricular
region or by intra- auricular palpation
 Auscultation can be done using stereo-stethoscope.
 Reciprocal click is seen in disc displacement with
reduction.
 No click is seen in disc displacement without
reduction.

53. WHY DO TMJ’S CLICK?
Joint is damaged or overloaded
increased tonicity in the pterygoid muscle
Disc is pulled forward
Rotational phase of mouth opening occurs
normal

54.  As the translation phase starts,the head of condyle
slides forwards and encounters disc in displacement
position.
 Friction is then built up until the head of the
condyle’jump past’ this portion of the disc.
 Audible release of energy is produced which is the
click.

56. CREPITUS
 “CONTINUOUS GRATING SOUND”
 Indicates degenerative joint disease.
 It can be auscultated using stereo-stethoscope

57. FUNCTIONAL ACTIVITIES
 Assess the chewing,swallowing,talking
 Ask the patient to demonstrate the task or ask for
subjective report.

58. DIAGNOSTIC AIDS
MRI
CT

60. ELECTROMYOGRAPHY
 Usede to explore the electrical activity of the muscle by
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recording a electromyogram from a volunteer.
The skeletal muscle fibre is innervated by branch of
motor axon.
Under normal circumstances,a neuronal action
potential activates all of the muscle fibres
Contraction of muscle takes place.
The electrical signal recorded from a contracting
muscle is called electromyogram.

61. ELECTROMYOGRAPHY

62. MANDIBULAR TRACKING DEVICES
 If a jaw tracking devices are used the exact movement
of the mandible can be recorded.
 Drawback: many disorders create deviation in
pathways.
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Because a particular deviation may not be
specific for a particular disease.
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so it has to be used in conjunction with
history and examination

63. VIBRATION ANALYSIS
 Used for diagnosing internal derangement in
particular
 This technique measures minute vibrations made by
the condyle and it translates
 It is reliable.

64. SONOGRAPHY
 Used to record and graphically demonstrate joint
sounds.
 Audio amplifying devices or ultrasound echo
recordings[doppler ultrasonography] are used.
 Drawback: cannot distinguish from the normal sound.

65. THERMOGRAPHY
 Records and graphically illustrates surface skin
temperature.
 Various temperatures are denoted by different colours
which produces a map that represent the surface being
studied.
 Normal subjects are said to have bilateral symmetric
thermogram.
 If they are not symmetric suggests a problem.

66. CONCLUSION
 Nature has blessed us with a marvelously dynamic
masticatory system , allowing us to function and
therefore exist.
 Articulatory system is an important part of the
masticatory system of our body.
 So as a dental care provider to treat the patients of
TMDs before knowing the pathology, this is essential
to know the normal anatomy and evaluation and
assessment of tmj.

67. REFERENCES
 TEMPOROMANDIBULAR DISORDERS: A PROBLEM
BASED APPROACH- ROBIN GRAY.
 MANAGEMENT OF TEMPOROMANDIBULAR
DISORDERS – OKESON.