Temporomandibular joint/ dental courses

Temporomandibular Joint
Anatomy, History taking &
Examination of TMJ
Part-I
INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.com

Contents-I
 Functional Anatomy
 Biomechanics of the Masticatory System
 Etiology and Identification of functional
disturbances in the masticatory system.
 Causes
 Signs and symptoms
 History and examination
 Investigations

Contents-II
 General considerations in treatment.
 Treatment of Masticatory muscle disorder
 Treatment of TMJ disorders
 Treatment of Chronic Mandibular
hypomobility and growth disorders
 Treatment sequencing

Temporomandibular Joint
Anatomy, History taking &
Examination of TMJ
Part-I
Shweta Ujaoney
Guided by:
Dr Mukta Motwani Dr Shirish Degwekar
(Prof & Guide) (Prof & HOD)

Functional Anatomy & Biomechanics
of the Masticatory System
 Dentition and supporting structures
 The skeletal components of the TMJ
 The ligaments
 The muscles

Dentition and supporting structures

The skeletal components the TMJ

TMJ
 Ginglymoid joint
 Arthrodial joint
Therefore, ginglymoarthroidal joint
 Compound joint
 Synovial joint

The ligaments
 Collateral ligament
 Capsular ligament
 Temporomandibular ligament
 Sphenomandibular ligamant
 Stylomandibular ligament

The muscles
 Masseter
 Temporalis
 Pterygoideus medialis
 Pterygoideus lateralis
 Inferior lateral pterygoid
 Superior lateral pterygoid
 Digastricus

Nerve supply:
 Dense plexus of unmyelinated fibres
that weaves throughout the fibrous
capsule and related fibrofatty tissue
 The small diameter afferent pain
fibres enter the regionally related
articular branches of
 Auricotemporal
 Masseteric
 Deep temporal
 Sometimes lateral pterygoid nerves–
pass into the sensory root and spinal
tract of the trigeminal nerve.
 No nerve endings of any type are
present in the fibrous articular
surface, the fibrocartlage, disc or
synovia--- pain is probably only
produced by mechanical or chemical
irritation of the sensitive capsular
tissues surrounding the joint.

Biomechanics of TMJ

Function of the neuromuscular system
 Muscle- Motor Unit
 Major function of the masticatory system

Muscle- Motor Unit
 The number of muscle fibres innervated by one motor neuron
varies greatly according to the function of the motor unit.
 The fewer the muscle fibres per motor neuron, the more
precise the movement.
 The inferior lateral pterygoid muscle has a relative low
muscle fibre/motor neuron ratio; therefore it is capable of the
fine adjustments in length needed to adapt to horizontal
changes in the mandibular position.
 By contrast the masseter has a greater number of motor fibres
per motor neuron, which corresponds to the more gross
function of providing the force necessary during mastication.www.indiandentalacademy.com

Muscle-
Motor Unit

Local event:
 Trauma-
1. post injection response to local anesthesia
2. mouth opened too widely (strain).
 Bruxism.
 Constant deep pain input
(pain felt in the masticatory or associated structures often alter normal muscle
function by way of the central excitatory effects)
Systemic events:
Increased levels of emotional stress.
Acute and chronic disease
Normal function +event > physiologic tolerance = TMD
symptoms
Etiology and identification of functional
disturbances in the masticatory system

Normal function +event > physiologic tolerance =
TMD symptoms
Physiologic tolerance:
 Each patient has a ability to tolerate certain
events without any adverse effect.
 Physiologic tolerance can be influenced by
both local and systemic factors.

Etiology
Five factors that are related to TMDs are
Occlusal condition:
1. Presence of skeletal open bite
2. Retruded contact position & ICP slides of greater than 4mm.
3. Overjets greater than 4mm
4. Five or missing and unreplaced posterior teeth.
Trauma
Emotional stress
Deep pain input
Parafunctional activities

Trauma
 Trauma seems to have a greater influence on the intracapsular
disorder than muscular disorders. Trauma can be divided
into:
 Macrotrauma
 Microtrauma
Macrotrauma is considered any sudden force that results in
structural alterations, such as direct blow to the face.
Microtrauma refers to any small force that is repeatedly applied
to the structures over a long period of time. Activities like
bruxism or clenching can produce microtrauma to the teeth,
joints and muscles that are being loaded.www.indiandentalacademy.com

Emotional stress
Increased levels of emotional stress –
 increases the tonicity of head and neck muscles
 increase levels of non-functional muscle activity, such as bruxism or tooth
clenching.
Another systemic factor that can influence an individual’s physiologic tolerance to
certain events
 - his/her sympathetic activity or tone.
 It is closely related to the fight or flight reflex activated by the stressor.
 In the presence of stress, the capillary blood flow in the outer tissues is
constricted, permitting increased blood flow to the more important
musculoskeletal structures and internal organs.
 It has been suggested that increased sympathetic activity or tone can influence
TMD symptoms and plays an important role in chronic pain.
 Deep pain input
 Parafunctional activities

History
 The purpose of history and examination is to identify
any area or structure of the masticatory system that
shows breakdown or pathologic damage.
 Pain and dysfunction both signify breakdown in the
masticatory system.
History can be obtained by
 Direct conversation
 Written questionnaire

 Features to be included in a thororugh orofacial pain history
 I. Chief complaint
 A. Location of pain
 B. Onset of pain
 Associated with other factors
 Progression
 C. Characteristics of pain
 1. Quality of pain
 2. Behaviour of pain
 a.Temporal
 b. Duration
 c. Localization
 3. Intensity of pain
 4. Concomitant symptoms
 5. Flow of the pain

 D. Aggravating and alleviating factors
 1. Function and parafunction
 2. Physical modalities
 3. Medication
 4. Emotional stress
 5. Sleep disturbances
 6. Litigation
 E. Past consultations and /or treatments
 H. Relationship to other pain complaints
 II. Medical history
 III. Review of systems
 IV. Psychological assessment

Symptoms
 If the weakest structures in the system are the muscles, the
individual commonly experiences muscle tenderness and pain
during mandibular movements-limited jaw movements with
related pain.
 If TMJ’s are the weakest link, joint tenderness and pain will
often be reported. The joints then produce sounds such as
clicking or grating.
 Sometimes the muscles and joints can tolerate the changes,
but because of increased activity of the muscles(e.g bruxism)
the weakest link is either the supportive structures of the teeth
or the teeth themselves. The teeth then show mobility or
wear.

To summarize them some of
the most common
symptoms are:
1. Tooth wear
2. Pulpitis
3. Tooth mobility
4. Masticatory muscle pain
5. TMJ pain
6. Ear pain
7. Headache

 The clinical signs and symptoms are grouped
into three categories according to structures
that are affected:
 Muscles
 TMJ’s
 Dentition

Functional disorder of muscle
Two major symptoms that can be observed are:
 Pain
 Dysfunction
 Muscle pain may range from slight tenderness to extreme discomfort.
Pain felt in muscle tissue is called myalgia.
 Myalgia can arise from increased levels of muscular use. The symptoms
are often associated with a feeling of muscle fatigue and tightness.
 Some authors suggest it is related to vasoconstriction of relevant nutrient
arteries and the accumulation of metabolic waste products in the muscle
tissues. within the ischemic area of the muscle, certain algogenic
substances like bradykinins, prostaglandins are released causing muscle
pain.

 e.g when a pt reports of pain during chewing or speaking, these functional
activities are not usually the cause of the disorder, instead they heighten
the patients awareness of it. More likely some type of activity or central
nervous system effect has lead to the muscle pain. Thus the need to be
directed at diminishing the hyperactivity of the muscle or the CNS effect.
 Also the myogenous pain is a deep type of pain and if it becomes constant
it can produce central excitatory effects, thus muscle pain can reinitiate
more muscle pain called the cyclic muscle pain.
 Another very common symptom commonly associated with muscle pain
is headache.

Dysfunction
 It is a common clinical symptom associated with myalgia.
 It is usually seen as a decrease in the range of the mandibular
movement. When the muscle tissues have been compromised
by overuse, any contraction or stretching increases the pain.
Thus to maintain comfort the pt restricts the range of
movement.
 Acute malocclusion is another type of dysfunction. It refers
to sudden change in the occlusal condition that has been
created by a disorder. It may result from a sudden change in
the resting length of a muscle that controls jaw position.

 E.g slight shortening of inferior lateral pterygoid will
cause disocclusion of the posterior teeth on the
ipsilateral side and premature contact of the ant teeth
esp canines on the contralateral side.
 Thus acute malocclusion is the result of rather than
the cause of muscle disorder and thus the treatment
should be aimed at eliminating the muscle disorder.
 Some intracapsular disorders can also lead to acute
malocclusions.

Five types of muscle disorders
 Protective co-contraction
 Local muscle soreness
 Myofascial pain
 Myospasm
 Chronic centrally mediated myalgia
 Fibromyalgia

TMJ signs n symptoms
 Pain
 Dysfunction
Pain in any joint structure is called arthralgia.
It would seem that arthralgic pain would originate from the articular surfaces
when the muscles load the joint, however this is impossible in a healthy
join because there are no innervations of the articular surfaces.
Arthralgia therefore originates only from the nociceptors located in the soft
tissue surrounding a joint.
Three pre-articular tissues contain such nociceptors
 The discal ligaments
 The capsular ligaments
 The retrodiscal tissues

When these ligaments are elongated or retrodiscal tissue compressed the
nociceptors send out signals and pain is perceived.
Stimulation of the nociceptors creates inhibitory action in the muscles that
move the mandible. Therefore when pain is suddenly and unexpectedly
felt mandibular movement immediately ceases (nociceptive reflex).
When chronic pain is felt, movement becomes limited and very deliberate
(protective co-contraction).
Arthalgia from normally healthy structures of the joint is a sharp, sudden, and
intense pain that is closely associated with joint movement. When the
joint is rested, the pain resolves quickly.
If the joint structures breakdown, inflammation can produce a constant pain
that is accentuated by joint movement.

Dysfunction:
 It usually presents as a disruption of the normal condyle-disc
movement with the production of joint sounds may be a
single event of short duration known as a click.
 If the sound is loud, it may be referred to as a pop.
 Crepitation is a multiple rough gravel-like sound described as
grating and complicated.
 Dysfunction of the TMJ may also present as catching
sensations when the patient opens the mouth.
 Sometimes jaw can actually lock.
 Dysfunction of the jaw is always directly related to jaw
movement.

TMJ disorders are
 Derrangement of the condyle-disc complex
 Structural incompatibility of the articular
surfaces…
Both these are also called Disc-interference
disorders by Welden Bell.
 Inflammatory joint disorders

Cranial nerve examination
CN V: Trigeminal
Setup
 Patient sitting over edge of bed.
 Motor: pt opens mouth, clenches teeth (pterygoids).
• Palpate temporal, masseter muscles as they clench.
 Test jaw jerk:
 Dr's finger should be placed on tip of jaw.
 Grip patellar hammer halfway up shaft and tap Dr's finger
lightly.
 Usually nothing happens, or just a slight closure.

Cervical examination
 Cervico spinal pain and dysfunction can be referred to the masticatory
apparatus .
 The mobility of the neck is examined for range and symptoms.
 The pt is asked to look first to the right and then to the left.
 There should be atleast 70 degree of rotation in each direction. Next the
patient is asked to look upwards as far as possible.
 The head should normally extend backwards some 60 degree and flex
downwards 45 degree.
 Finally the pt is asked to bend the neck to the right and to the left.
 This should be possible approximately 40 degrees each way.
 Any pain recorded and any limitation of movement carefully investigated
to determine whether its source is a muscular or a vertebral problem.www.indiandentalacademy.com

 When pts with limited range of movement can be passively stretched to a greater range the
source is usually muscular. Pts with vertebral problems cannot be stretched to a greater
range.
 If the clinician suspects that the patient has a cranio cervical disorder, proper referral for a
more complete evaluation is indicated.
The masticatory apparatus examination consists of evaluating three major structures
 Muscles
 Joints
 Teeth.

Examination of TMJ
Inspection:
 Asymmetry
 Presence of any swelling/growth
 Depression
 Discharge
 Colour change of the skin over the TMJ area
 Surface of the overlying skin in the preauricular
area.
 Mouth opening- normal/ restricted.
 Deviation/deflection

Palpation
 Tenderness over the TMJ during movement.
 Palpation of the TMJ- joint sounds
 Hypermobility/ Hypomobility
 Palpation of the muscles

Muscle examination
 Temporalis

Masseter

SCM

Posterior cervical muscles

Clinical trigger points

Inferior lateral pterygoid

Superior lateral pterygoid

Medial pterygoid
 Contraction:
It is an elevator muscle and hence contracts when the
teeth are coming together. If it is a source of pain
then clenching the teeth together will increase the
pain. When the tongue blades is placed between the
posterior teeth and the patient clenches against it, the
pain is still increased because the elevators are still
contracting.
Stretching: it stretches when the mouth is opened
widely. Therefore if it is the source of pain, opening
mouth wide will increase the pain.

Maximum interincisal distance

TMJ examination

 Joint sounds can be perceived by placing the fingertips over
the lateral surfaces of the joint and having the patient open
and close the mouth.
 For more careful examination, the clinician can place a
stethoscope over the joint area. If a stethoscope is used, the
clinician must appreciate that this instrument will detect
many more sounds than mere palpation, and the significance
of these sounds needs to be assessed.
 Not all joint sounds should be considered a problem worthy
of treatment.

Dental examination

Diagnostic tests
 OPG
 Transcranial
 Transpharyngeal
 Transorbital
 Other extraoral technique-SMV, Reverse Towne’s view
 Arthrography
 CT
 MRI
 Arthroscopy
 Mounted Cast
 Electromyography
 Mandibular tracking device
 Sonography
 Vibration analysis
 Thermography

OPG

Transpharyngeal projection

Transcranial projection

Transorbital projection

Conventional tomography
Advantages:
 Tomograms are superior to conventional radiography because
of their ability to depict a greater portion of the joint.
 By providing a series of sectional radiographs, tomography
can reproduce changes in the central portion of the TMJ and
therefore decrease false-negative interpretations.
Limitations:
 Tomography however is limited in its ability to detect early
lesions.
 Although tomograms may supply superior diagnostic
information, patients undergoing tomography are exposed to
substantially more radiation, and the difference in cost is
considerable. www.indiandentalacademy.com

Arthrography
Arthrography is defined as the injection of contrast material, radiolucent and /
or radio opaque, into a synovial space followed by radiography of the
joint.
The following information can be obtained from an arthrogram
1. Position of the disc relative to the condyle and articular eminence
a. With mandible closed
b. At various positions of mandibular movements
2. Morphology of the disc
3. Presence of tears/perforations in the disc or its attachments.
4. Presence of adhesions in the joint spaces
5. Presence of “loose bodies” in the joint spaces
6. Irregularities in the posterior attachments of the disc.
7. Possibly synovial proliferations.

Indications:
To confirm the diagnosis before operating for a TMD.
To obtain an arthrogram to have information about soft tissues.
To obtain specific information about disc position and morphology to plan a surgical
procedure.
To some extent for documentary proof to avoid litigation.
Contraindication:
Allergic reaction to iodinated contrast medium.
Bleeding disorders and patients on anticoagulant medications.
In presence of localized skin infection.
Disadvantages:
Invasiveness
Pain (intra operative or postoperative)
Risk of infection
Potential damage to disc, capsule, and fibro cartilage
Allergy to contrast material (or local anesthetic)www.indiandentalacademy.com

CT
 Advantages:
 It provides images without
superimposition inherent in
conventional tomography and
permits a section of optimal
views through multiple plane
reconstructions
 CT may yield information
concerning the position of the
soft tissue disc in addition to
depicting the osseous structures.

 Limitations:
 The expense and radiation
involved is significantly greater
for CT than for conventional
tomography.
 Some studies have shown that
conventional tomography is
superior to CT in the diagnosis
of single structural bone changes
and comparable for the
comprehensive diagnosis of
TMJ disorders.

MRI
 MRI has overtaken
arthrography and CT as the
imaging modality of choice for
th diagnosis of joint
abnormalities.
 Using a strong magnetic field,
MRI can depict soft-tissue
anatomy with details through
its effect on tissues with high
water content.

Advantages:
 MRI does not use ionizing
radiation and is non-
invasive.
 It has been shown to be
superior to arthrography in
demonstrating medial and
lateral displacements of the
disc.

 The ability of MRI to depict
osseous changes in the TMJ may
prove to be better than originally
anticipated.
 The use of coronal MRI in
addition to the sagittal view, may
provide increased information
concerning bony changes.
Limitation:
 It does not detect perforation as
consistently.

Arthroscopy
Arthroscopy is the fundamental procedure in the diagnosis and traetment of
various orthopedic disorders for many years.
Arthroscopy of the upper compartment permits direct inspection of the
articular surfaces of the temporal bone and superior aspect of the disc.
Advantages:
 As a diagnostic tool it can help confirm the impression derived from
preceding clinical, radiographic and imaging findings.
 Most studies that have evaluated the diagnostic capabilities of TMJ
arthroscopy and have found arthroscopic diagnosis of Arthrosis,
remodeling, adhesions, or perforation to be reliable (high specificity)
 An additional diagnostic use for TMJ arthroscopy is the ability to perform
synovial biopsies to ascertain the presence of histologic changes, such as
inflammation (i.e synovitis) or proliferation.www.indiandentalacademy.com

Limitations:
 The risk of under-diagnosis of pathologic changes is
significant (low sensitivity).
 Under-diagnosis of perforations, especially when they occur
on the lateral aspect of the disc where good visualization is
difficult, appears to be a particular problem in arthroscopic
diagnosis.
 The size of the instrumentation prevents its use in the smaller
lower compartment where pathologic changes frequently
occur.

Mounted Cast
 If during the examination the
clinician finds significant
orthopedic instability, accurately
mounted study casts may be
helpful to further assess the
occlusal condition.
 Mounted casts are not indicated
for all patients being examined
for TMds.
 Dental study casts can be of
value not only as a baseline
record for tooth and jaw
relations but also for evaluating
the effects of bruxism over time.

Electromyography
 The use of EMG is based on the assumption
that certain pathologic or dysfunctional
conditions can be identified by abnormal
activity of the masticatory muscles.
 An analysis of literature conducted by Mohl
and colleagues have uncovered several major
deficiencies as :
 The lack of adequate control groups, the lack
of studies showing reliability and validity of
the methods, the inadequacy or non existence
of statistical comparisons, and the declaration
of conclusions that were not supported by the
study results.
 The most significant problem, however, was
the large inter-individual variability in normal
and patient groups, resulting in considerable
overlap between them.

 Advantages:
EMG has been proven to provide excellent
information on muscle function under
research conditions.
It is also useful with various biofeedback
techniques to enable the patient to monitor
muscle tension during relaxation training.

Mandibular tracking device
Computerised mandibular scanning
 It is a device to track the
movement of the entire
mandible relative to the
maxilla.
 It has been suggested that
these device can be used to
diagnose and monitor the
treatment of TMDs

 Several investigators have examined
jaw movement parameters that are
considered to be of potential
diagnostic value are:
 Amplitude of jaw movement
 Reproducibility or consistency of
jaw movements
 Velocity and smoothness of jaw
trajectories
 No evidence suggests that the
sensitivity and specificity of jaw
tracking devices are reliable enough
to be used for diagnosis or
treatment.

Sonography
 Sonography is a technique of recording and
graphically demonstrating joint sounds.
 Some techniques use audio-amplifying devices,
whereas others rely on ultrasound echo recordings
(Doppler ultrasonography)
 The joint sounds are often related to specific disc
derrangements; therefore there presence may have
meaning.
 Anterior disc displacement with reduction-
reciprocal click or popping sound
 Anterior disc displacement without reduction- less
discrete soft tissue sounds
 Degenerative joint disease- crepitation or grating
noises

 On the other hand, the presence of joint sounds does
not , in itself, denote a problem.
 If sonography is to have a meaning, it must be able
to separate sounds that have significance to
treatment from those that do not.
 Presently sonography does not provide the clinician
with any additional diagnostic information over
manual palpation or stethoscopic evaluation

Vibration analysis
 To help in diagnosing intracapsular TMD, internal
derrangements in particular.
 It measures the minute vibrations made by the condyle as it
translates and has been shown to be reliable.www.indiandentalacademy.com

 Although some studies
do report encouraging
accuracy in detection
of joint vibrations, little
data demonstrates that
vibration analysis is a
useful adjunct in the
selection of appropriate
patient therapy.

Thermography
 Thermography is a
technique that records and
graphically illustrates
surface skin temperatures.
 Recorded– different
colours producing a map
that depicts the surface
being studied.

 Normal- bilaterally symmetrical
thermograms
 Otherwise it reveals a problem such
as TMD
 Studies show variable results.
 The sensitivity and specificity of
identifying myofascial trigger points
with thermography has not been
demonstrated to be reliable.
 At this time– thermography is not a
useful technique for the diagnosis
and management of TMDs.

References:
 www.clinicalexam.com/pda/n_cranial_nerves_exam.htm
 Technological devices in the diagnosis of TMD; Gonzales etal oral
Maxillofacial Surg Clin N Am 20(2008) 211-220.
 Management of temporomandibular disorder and occlusion, Jeffrey P.
Okeson 5th
edition
 Temporomandibular disorders, classification, diagnosis, management, 3rd
edition, Welden Bell
 Colour Atlas Temporomandibular joint surgery, Peter D Quinn.
 Common disorders of TMJ, H.D Ogus, PA Toller, dental practitioner
handbook, 2nd
edition.
 Management of Temporomandibular Disorder in General Dental Practice,
Gunnar E. Carlsson, Tomas Magnusson.
 Burket’s Oral medicine diagnosis and treatment, ninth edition.
 Textbook of oral medicine, Ghom, first edition 2005
 B.D Chourasia’s Human anatomy fourth edition, HNF.

 Reliability and validity of diagnostic modalities for
temporomandibular disorders Mohl ND;Adv Dent Res. 1993
Aug;7(2):113-9

Thankyou !

Temporomandibular joint/ dental courses

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Temporomandibular joint/ dental courses

Similar to Temporomandibular joint/ dental courses (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Temporomandibular joint/ dental courses