2. CLASSIFICATION SYSTEM:
1. Masticatory muscle disorders
-
Protective co-contraction
Local muscle soreness
Myospasm
Myofascial pain
2. TMJ disorders
a. Derangement of condyle-disc complex
A. Disc displacemet
B. Disc dislocation with reduction
C. Disc dislocation without reduction
b. Structural inciompatibility of articular surfaces
A. Deviation in form
B. Adherence & adhesions
C. Subluxation
D. Spontaneous dislocation
c. Inflammatory disorders of TMJ
A. Synovitis & capsulitis
B. Retrodiscitis
C. Arthritis
- Osteoarthritis
- Osteoarthrosis
- Polyarthritis
d. Inflammatory disorder of associated structure
A. Temporal tendonitis
B. Stylomandibular ligament inflammation
3. Chronic mandibular hypomobility
a. Ankylosis
3. b. Muscle contracture
- Myostatic
- Myofibrotic
c. Coronal impadance
4. Growth disorders
-
Aplasia
Hypoplasia
Hyperplasia
5. TMJ tumors
a. Benign tumors
- Chondroblastoma
- Chondroma
- Fibrous dysplasia
- Giant cell tumor
- Hemangioma
- Osteochondroma & Osteoma
b. Malignant tumors
- Chondrosarcoma
- Multiple myeloma
- Osteosarcoma
- Synovial sarcoma
MASTICATORY MUSCLE DISORDERS:
1. Protective co-contraction:It is the initial response of a muscle to altered sensory or
proprioceptive input or injury, also called protective muscle
splinting or co-activation.
Altered sensory input → antagonist muscle group seem to fire
during movement → attempt to protect the injured part. It is not
a pathologic condition.
4. CAUSE:-
Altered sensory or proprioceptive input.
Presence of constant deep pain input.
↑ Emotional stress.
HISTORY: - It remains a few days. If not resolved, local
muscle soreness is likely follows;
-
A recent alteration in local structure.
A recent source of constant deep pain.
A recent ↑ in stress.
CLINICAL FEATURES:↓ Movement but can achieve a relatively normal range when
requested to do so. Minimal pain at rest, ↑ pain to function,
feeling of muscle weakness.
DEFINITIVE TREATMENT:Normal CNS response, so treatment is not indicated. Treatment
is directed towards reason of co-contraction.
Poorly fitting restoration – Altering the restoration
Deep pain – pain to be addressed appropriately.
SUPPORTIVE THERAPY:Instructing the pt to restrict the use of mandible within
painless limit. Soft diet, short term pain medication. Muscle
exercises & physiotherapy contraindicated.
2. LOCAL MUSCLE SORENESS:It is primary non-0inflammatory myogenous pain disorder. It is
first response of muscle to continued co-contraction.
CAUSE:-
5. Protective co-contraction secondary to a recent alteration in
local structure.
Local tissue trauma of unaccustomed use of muscle.
↑ stress.
HISTORY:Pain begin several hours after event asso, with protective cocontraction.
Pain begin asso. with tissue injury (injection, opening widely)
Pain begin secondary to another source of deep pain. ↑ stress.
CLINICAL FEATURES:↓ velocity & range of movement. Minimum pain at rest which ↑with
function. Actual muscle weakness. Local tenderness when
involved muscle is palpated.
DEFINITIVE TREATMENT:- Primary goal : ↓ sensory input
should be eliminated.
Any altered sensory input should be eliminated. Any source of
deep pain is eliminated. Restricted mandibular use within
painless limit.
↓ non functional teeth contact, occlusal appliance at night
for bruxism.
SUPPORTIVE THERAPY:NSAIDs, manual physical therapy – passive muscle stretching &
gentle massage. Relaxation therapy also helpful.
3. MYOSPASM:An involuntary CNS induced tonic muscle contraction often
asso. with local metabolic condition within muscle tissue.
6. CAUSE:Continued deep pain input.
Local metabolic factors within muscle tisslue asso. with
fatigue or overuse.
Idiopathic myospasm mechanics.
HISTORY:- A sudden onset of restricted jaw movement
accompanied by muscle rigidity.
CLINICAL FEATURES:Marked restriction in range of movement according to muscle
involved, acute malocclusion. Pain at rest which ↑ with function.
Affected muscle is firm & painful to palpation with gen. muscle
tightness.
DEFINITIVE TREATMENT:-
Reduction of spasm itself.
Addresses the cause.
Reducing the pain & passively lengthening/stretching of
involved muscle. Reduction of pain with manual massage,
coolant spray, ice or injection of LA into muscle. Once pain is
reduced, muscle is passively stretch to full length.
When obvious cause is present, eliminate it. If secondary to
fatigue/overuse, rest is advised.
SUPPORTIVE THERAPY:- Physical therapy
4. MYOFASCIAL PAIN:Referred from a localized tender area, a trigger point, is a
taut band of skeletal muscle. Any skeletal muscle of body
7. including masticatory muscle. head and neck, shoulder & lower
back is most involved.
Area to which pain is referred – ‘Zone of referrance’
Occurs due to acute injury or frequently overuse and chronic
micortrauma.
Travel in 1940s first theorized that skeletal muscle is spasm
could be source of pain. Schwatz postulated the TMJ pain
dysfunction syndrome. He was first to implicate psychologic
makeup as predisposing factor.
In 1969, Laskin gave more comprehensive explanation of the
problem. Stress was the significant cause of clinching &
grinding habits which cause spasm of the muscle. occlusal
abnormalities also has secondary role in etiology.
SIGNS & SYMPTOMS:Unilateral dull pain in ear or preauricular region that is
commonly worse on awaking. Tenderness of one or more
muscle of mastication, on palpation. Limitation or deviation of
mandible on opening.
Degenerative changes in TMJ if become chronic. Irregularity in
occlusion → Precipitating factor → Occlusal interfere post.
Bite collapse & deep overbite – overjet.
Overuse of muscle, general sign of bruxism, tooth wear,
mobility, thickening of PDL, hyperactivity of muscle of
mastication.
INITIAL TREATMENT:1. EDUCATION: Explanation of diagnosis & treatment.
Reassurance about good prognosis for recovery &
natural course. Explanation of doctor’s & pt’s role in
therapy. Information to enable pt to perform self care.
2. SELF CARE: Eliminate oral habits (clinching, chewing),
provide information on jaw care asso. with daily activity.
8. 3. PHYSICAL THERAPY: Education regarding biomechanics of
jaw, neck & head posture. Passive modalities (Heat & cold
therapy, ultrasound, TENS), range of motion exercises
(Active & passive), posture therapy, passive stretching,
general exercises, conditioning programme.
4. INTRAORAL APPLIANCE: Cover all teeth in arch the appliance
is seated on. Adjust to achieve simultaneous contact.
Adjust stable, comfortable mandibular posture. Avoid
long term use.
5. PHARMACOTHERAPY: NSAIDs, acetoaminophen, muscle
relaxants, antianxiety agents.
6. BEHAVIORAL/RELAXATION TECHNIQUES: relaxation therapy,
hypnosis, biofeedback, cognitive behavioral therapy.
7. TRIGGER POINT THERAPY: Cooling of skin (Flomethane) &
stratching, injection of LA, saline or sterile water
(procaine diluting with 0.5% saline – low toxicity).
- Spray & stretch therapy – 3-5 weekly sessions.
INFLAMMATORY JOINT DISORDER
Characterized by deep pain usually accentuated by function.
1. SYNOVITIS & CAPSULITIS:An inflammation of synovial tissue or capsular ligament which
differentiate only by arthroscopy.
CAUSE:- Followed by trauma to tissue (Microtrauma &
macrotrauma) or inflammation from adjacent tissue.
HISTORY:- Incidence of trauma or abuse. Continuous pain
originates in the joint area & with movement it increases.
CLINICAL FEATURES:- Capsular ligament can be palpated by
finger pressure over lateral pole of the condyle. Pain caused
by this indicates capsulitis. Limited opening secondary to pain.
9. Soft end feel noted. If edema present, condyle displaced
inferiorly causing disocclusion of ipsilateral posterior teeth.
2. RETRODISCITIS:Inflammation of retrodiscal tissue due to macrotrauma. This
trauma suddenly forces the condyle posteriorly into
retrodiscal tissue & secondary inflammation may results.
Microtrauma may also cause this, such as in the progressive
phase of disc displacement. During this condyle gradually
encroached on inferior retrodiscal lamina.
HISTORY:- Incidence of trauma. Constant pain, accentuated by
movement. Clenching of teeth → ↑ pain.
CLINICAL FEATURES:- limited opening, soft end feel. If
retrodiscal tissue swells, condyle moves forward &
downwards which cause malocclusion or disocclusion of
ipsilateral post & heavy contact of contralateral side.
3. ARTHRITIS:- Inflammation of articular surfaces of the
joint. Several types of arthritis affect the joint.
a. OSTEOARTHRITIS & OSTEOARTHROSIS:CAUSE:OSTEOARTHRITIS: A destructive process by which the bony
articular surfaces of condyle & fossa become altered.
It is body’s response to loading. Due to loading the articular
surfaces become soften, subarticular bone begun to resorb.
Progressive destruction results in loss of subchondral
cortical layer, bone erosion & radiographic evidence of
osteoarthritis.
OSTEOARTHROSIS: Once loading is ↓, the arthritic condition
becomes adaptive, yet morphology remains altered.
Most commonly osteoarthritis associated with disc
dislocation or perforation. Once disc is dislocated &
10. retrodiscal tissue breakdown, condyle begins to articulate
directly with fossa accelerating the destructive process.
Overloading of joint may be result of high levels of
parafunctional activity.
HISTORY:- Unilateral joint pain aggravated by movement. Pain is
constant but may be worsen in late afternoon or evening. In
osteoarthrosis. it represents a stable adaptive phase, the pt
doesnot report symptoms.
CLINICAL FEATURES:- Joint pain, limited opening, soft end
feel, crepitation typically felt.
TMJ radiographs ; evidence of structural changes in
subarticular bone.(erosions, flattening)
4. POLYARTHRITIS:A group of disorders in which articular surfaces become
inflamed. Each is identified according to causative factors.
A. TRAUMATIC ARTHRITIS:- Macrotrauma to jaws can cause
surface changes that produce inflammation.
Positive history of macrotrauma & can be closely related to
onset of symptoms. Reports constant arthralgia accentuated
with movement.
Limited opening secondary to pain, soft end feel, acute
malocclusion if swelling is present.
B. INFECTIOUS ARTHRITIS:- Asso. With a systemic disease as
immunologic response. Non sterile type results from
bacterial invasion by penetrating wounds.
HISTORY:- Infection of adjacent tissue or wound with
constant pain accentuated with movement. Joint swelling with
increase temp sometimes.
C. RHEUMATOID ARTHRITIS:- The precise cause is unknown.
Inflammation of synovial membrane that extends into
11. surrounding CT & articular surfaces which become thicken
& tender.
As force is placed of this surface, synovial cells release
enzymes that damage joint tissue especially cartilage. In
severe cases, osseous tissue can resorb with significant loss
of condylar support.
HISTORY:- always bilateral, multiple joints complaint. Acute
malocclusion in severe cases with heavy posterior contacts &
anterior open bite.
INTERNAL DERRANGEMENT OF CONDYLE-DISC COMPLEX
Derangements of the condyle-disc complex present as a range
of conditions, most of which can be viewed as a continuum of
progressive events. They occur because the relationship
between the articular disc and the condyle changes.
The disc is laterally and medially bound to the condyle by the
discal ligaments; thus translatory movement in the joint can
occur only between the condyle-disc complex and the
mandibular fossa. The only physiologic movement that can
occur between the condyle and the articular disc is rotation.
The disc can rotate on the condyle around the attachments of
the discal ligaments to the poles of the condyle. The extent of
rotational movement is limited by the length of the discal
ligaments and by the inferior retrodiscal lamina posteriorly
and the anterior capsular ligament anteriorly. The amount of
rotation of the disc on the condyle is also determined by the
morphology of the disc, the degree of interarticular pressure,
and the superior lateral pterygoid muscle, as well as the
superior retrodiscal lamina.
When the mouth opens and the condyle moves forward, the
superior retrodiscal lamina becomes more tight, rotating the
disc posteriorly on the condyle. Interarticular pressure
12. provided by the elevator muscles maintains the condyle on the
thinner intermediate zone of the articular disc and prevents the
thicker anterior border from passing posteriorly through the
discal space between the condyle and the articular surface of
the articular eminence. When a person bites on something
resistant, the interarticular pressure decreases on the biting
side. To stabilize the joint during this power stroke, the
superior lateral pterygoid muscle pulls the condyle-disc
complex forward. The fibers of the superior lateral pterygoid
muscle that are attached to the disc produce a forward
rotation of the disc, allowing the thicker posterior border to
maintain intimate contact between the two articular surfaces.
The superior retrodiscal lamina is the only structure that can
retract the disc posteriorly. In the healthy joint the surfaces
of the condyle, disc, and mandibular fossa are smooth and
slippery and allow easy friction less movement. The disc
therefore maintains its position on the condyle during
movement because of its morphology and interarticular
pressure. Its morphology (i.e., the thicker anterior and
posterior borders) provides a self positioning feature that, in
conjunction with the interarticular pressure, centers it on the
condyle.
If the morphology of the disc is altered and the discal
ligaments become elongated, the disc is then permitted to slide
(translate) across the articular surface of the condyle. In
the normal closed joint position and during function,
interarticular pressure still allows the disc to position itself
on the condyle and no unusual symptoms are noted. Alteration
in the morphology of the disc accompanied by elongation of
the discal ligaments can change this normal functioning
relationship. In the resting closed joint position the
interarticular pressure is very low. If the discal ligaments
become elongated, the disc is free to move on the articular
surface of the condyle. As the mouth opens and the condyle
moves forward, a short distance of translatory movement can
13. occur between the condyle and the disc until the condyle once
again assumes its normal position on the thinnest area of the
disc (intermediate zone), in which, the interarticular pressure
maintains this relationship and the disc is again carried
forward with the condyle through the remaining portion of the
translatory movement.
The important feature of this functional relationship is that the
condyle translates across the disc to some degree when
movement begins. This type of movement does not occur in the
normal joint. During such movement, the increased
interarticular pressure may prevent the articular surfaces
from sliding across each other smoothly. The disc can stick
or be bunched slightly, causing an abrupt movement of the
condyle over it into the normal condyle-disc relationship,
often accompanied by a clicking sound.
During closing of the mouth, the normal relationship of the
disc and the condyle is maintained because of interarticular
pressure. However, once the mouth is closed and the
interarticular pressure is lower, the disc can once again be
displaced forward by tonicity of the superior lateral
pterygoid muscle. The single click observed during opening
movement represents the very early stages of disc
derangement disorder what is also called internal
derangement.
If this condition persists, a second stage of derangement is
noted. As the disc is more chronically repositioned forward
and medially by muscle action of the superior lateral
pterygoid muscle, the discal ligaments are further elongated.
Continued forward positioning of the disc also causes
elongation of the inferior retrodiscal lamina. Accompanying
this breakdown is a continued thinning of the posterior border
of the disc, which permits the disc to be repositioned more
anteriorly, resulting in the condyle being positioned more
posteriorly on the posterior border. The morphologic
changes of the disc at the area where the condyIe rests can
create a second click during the later stages of condylar
14. return just prior to the closed joint position. This stage of
derangement is called the reciprocal click.
Reciprocal clicking is characterized as follows:
1. During mandibular opening a sound is heard that
represents the condyle moving across the posterior
border of the disc to its normal position on the
intermediate zone. The normal condyle-disc relationship is
maintained through the remaining opening movement..
2. During closing the normal disc position is maintained until
the condyle returns to very near the closed joint
position.
3. As the closed joint position is approached, the posterior
pull of the superior retrodiscal lamina is decreased.
4. The combination of disc morphology and pull of the
superior lateral pterygoid muscle allows the disc to slip
back into the more anterior position, where movement
began. This final movement of the condyle across the
posterior border of the disc creates a second clicking
sound and thus the reciprocal click.
The opening click can occur at any time during that movement
depending on condyle-disc morphology, muscle pull, and the
pull of the superior retrodiscal lamina. The closing click
almost always occurs very near the closed or intercuspal
position. The longer the disc is displaced anteriorly and
medially, the greater the thinning of its posterior border and
the more the lateral discal ligament and inferior retrodiscal
lamina will be elongated. Also, protracted anterior
displacement of the disc leads to a greater loss of elasticity
in the superior retrodiscal lamina. The more the shape of the
disc changes to accommodate the pull of the muscle and
position of the condyle, the greater the likelihood that the
disc will be forced through the discal space, collapsing the
joint space behind. In other words, if the posterior border of
15. the disc becomes thin, the superior lateral pterygoid muscle
can pull the disc completely through the discal space.
When this occurs, interarticular pressure collapses the discal
space, trapping the disc in the forward position. Then the next
full translation of the condyle is inhibited by the anterior and
medial position of the disc. The person feels the joint being
locked in a limited closed position. Since the articular
surfaces have actually been separated this condition is
referred to as a functional dislocation of the disc.
Some persons with a functional dislocation, of the disc are
able to move the mandible in various lateral directions to
accommodate the movement of the condyle over the posterior
border of the disc, and the locked condition is resolved. If the
lock occurs only occasionally and the person can resolve it
with no assistance, it is referred to as a functional
dislocation with reduction. Often a patient reports that the
jaw "catches" when opening wide. This condition may or may not
be painful depending on the severity and duration of the lock
and the integrity of the structures in the joint. If it is acute,
having a short history and duration, joint pain may only be
associated with elongation of the joint ligaments (such as
trying to force the jaw open). As episodes of catching or
locking become more frequent and chronic, ligaments break
down and innervations is lost. Pain becomes less associated
with ligaments and more related to forces placed on the
retrodiscal tissues.
The next stage of disc derangement is known as functional
disc dislocation without reduction. This condition occurs
when the person is unable to return the dislocated disc to its
normal position on the condyle. The mouth cannot be opened
maximally because the position of the disc does not allow full
translation of the condyle. Typically the initial opening is only
25 to 30 mm interincisally, which represents tile maximum
rotation of tile joint. The person usually is aware of which
16. joint is involved and can remember the occasion that led to the
locked feeling. Since only one joint usually becomes locked,
a distinct pattern of mandibular movement is observed
clinically.
The joint with the functionally dislocated disc without
reduction does not allow complete translation of its
condyle, whereas the other joint functions normally.
Therefore when the patient opens the mouth widely, the midline
of the mandible is deflected to the affected side. Also the
patient is able to perform a normal lateral movement to the
affected side (the condyle on the affected side only rotates).
However, when movement is attempted to the unaffected side, a
restriction develops (the condyle on the affected side cannot
translate past the anterior functionally' dislocated disc). The
dislocation without reduction has also been termed a closed
lock. Patients may report pain when the mandible is moved to
the point of limitation, but pain does not necessarily
accompany this condition.
Any condition or event that leads to elongation of the discal
ligaments or thinning of the disc can cause these
derangements of the condyle-disc complex disorders.
Certainly one of the most common factors is trauma. Two
general types of trauma must be considered: Macrotrauma and
microtrauma.
Macrotrauma:- Macrotrauma is considered any sudden force
to the joint that can result in structural alterations.
Macrotrauma can be subdivided into two types: direct trauma or
indirect trauma.
Direct trauma: There is little question that significant direct
trauma to the mandible, such as a blow to the chin, can
instantly create an intracapsular disorder. If this trauma
occurs when the teeth are separated (open mouth trauma) the
17. condyle can be suddenly displaced within the fossa. This
sudden movement of the condyle is resisted by the ligaments.
If the force is great, the ligaments can become elongated,
which may compromise normal condyle-disc mechanics. The
resulting increased looseness can lead to discal
displacement and to the symptoms of clicking and catching.
If trauma occurs to the mandible when the teeth are together,
the intercuspation of the teeth maintains the jaw position,
resisting joint displacement. Closed mouth trauma is not likely
to be without some consequence.
Although ligaments may not be elongated, articular surfaces
can certainly receive sudden traumatic loading. This type of
impact loading may disrupt the articular surface of the
condyle, fossa, or disc, which may lead to alterations in the
smooth sliding surfaces of the joint, causing roughness and
even sticking during movement. This type of trauma therefore
may result in adhesions
Direct trauma may also be iatrogenic. A few common examples
of iatrogenic trauma are intubation procedures, third molar
extraction procedures, and a long dental appointment. In fact,
any extended wide opening of the mouth (e,g., a yawn) lias the
potential of elongating the discal ligaments.
Indirect trauma: Indirect trauma refers to injury that may
occur to the TMJ secondary to a sudden force, that does not
directly Impact or contact the mandible.
The most common type of indirect trauma reported is
associated with a cervical flexion-extension injury (whiplash
injury).
Microtrauma:- Microtrauma refers to any small force that is
repeatedly applied to the joint structures over a long period
of time. The dense fibrous connective tissues that cover the
articular surfaces of the joints can well tolerate loading
forces. In fact, these tissues need a certain amount loading to
survive, since loading forces drive synovial fluid in and out of
18. the articular surfaces passing with it nutrients coming in and
waste products going out. If, however, loading exceeds the
functional limit of the tissue, irreversible changes or damage
can result.
When the functional limitation has been exceeded the collagen
fibrils become fragmented, resulting in a decrease in the
stiffness of the collagen network. This allows the
proteoglycan water gel to swell and flow out into the joint
space, leading to a softening of the articular surface. This
softening is called chondromalacia. This early stage of
chondromalacia is reversible if the excessive loading is
reduced. If, however, the loading continues to exceed the
capacity of the articular tissues, irreversible changes can
occur. Regions of fibrillation can begin to develop, resulting
in focal roughening of the articular surfaces. This alters the
frictional characteristics of the surface and may lead to
sticking of the articular surfaces, causing changes in the
mechanics of condyle-disc movement. Continued sticking or
roughening leads to strains on the discal ligaments during
movements and eventually disc displacements.
Microtrauma can result from joint loading associated with
muscle hyperactivity such as bruxism or clenching. Another
type of microtrauma results from mandibular orthopedic
instability. As previously described, orthopedic stability exists
when the stable intercuspal position of the teeth is in harmony
with the musculoskeletally stable position of the condyles.
When this condition does not exist, microtrauma can result.
FACTORS THAT PREDISPOSE TO DISC DERANGEMENT
DISORDERS :-
1) Steepness of the articular eminence: The degree of
steepness of the posterior slope greatly influences condyle
disc function. In a patient with a flat eminence, there is a
minimum amount of posterior rotation of the disc on the
19. condyle during opening. As the steepness increases, more
rotational movement is required between the disc and the
condyle during translation of the condyle. Therefore,
patient's with steep articular eminence are more likely to
demonstrate greater condyle disc movement during function.
This exaggerated condyle-disc movement may increase the risk
of ligament elongation that leads to disc-derangement
disorders.
2) Morphology of the condyle and fossa: Flat or gable
like condyles that articulate against inverted V-shaped
temporal components seem to have an increased incidence of
disc derangement disorders and degenerative joint diseases.
3) Joint Laxity: Ligaments act as guide wires to restrict
certain movements of the joint. Although the purpose of
ligaments is to restrict movement, the quality and integrity of
these collagenous fibres vary from patient to patient. As a
result, some joints show slightly more freedom or laxity than
others. Several studies suggest a relationship between
generalized joint laxity and certain TMD symptoms. Some
generalized laxity may be due to increased levels of estrogen.
For e.g. women's joints are generally more flexible and lax
than men's.
The derangements are divided into two subcategories for the
purpose of treatment :(1) disc displacement and disc dislocation with reduction, and
(2) disc dislocation without reduction.
A. DISC DISPLACEMENT AND DISC DISLOCATION WITH
REDUCTION
These represent the early stage of disc derangement
disorders.
Clinical characteristics:
20. The clinical examination reveals a relatively normal range of
movement with restriction only associated with the pain. Discal
movement can be felt by palpation of the joints during opening
and closing. Deviations in the opening pathway are common.
Definitive Treatment:
It aims at re-establishing a normal condyle-disc relationship.
In early 1970s, Farrar introduced the anterior positioning
appliance that provided an occlusal relationship that required
the mandible to be maintained in a forward position. The
position selected for the appliance is one that positions the
mandible in the least protruded position that re-establishes
the normal condyle-disc relationship. This is usually achieved
clinically by monitoring the clicking joint.
Although eliminating the click does not always denote
successful reduction of the disc, it is a good clinical
reference point for beginning therapy. The idea behind the
anterior positioning appliance was to reposition the condyle
back on the disc ("recapture the disc"). Joint sounds are very
common in the general population. In most cases, they do not
appear to be related to pain or decreased joint mobility. If all
clicking joints always progressed to more serious disorders,
this would be a good indication that each and every joint that
clicked should be treated. The presence of unchanging joint
sounds over time, however, indicates that some structures can
adapt to less than optimum functional occlusion.
It was also found that long term osseous changes in the
condyle were commonly associated with disc dislocation
without reduction and not so commonly associated with disc
dislocation with reduction.
The treatment goal of definitive therapy is to reduce
intracapsular pain, not to recapture the disc. A stabilization
appliance should be used whenever possible because adverse
long-term effects are minimized.
When this appliance is not effective, an anterior positioning
appliance should be fabricated. The patient should be initially
21. instructed to wear the appliance every night during sleep and
during the day only when needed to reduce symptoms. This
part-time use minimizes adverse occlusal changes. The patient
should be encouraged to wear the appliance more only if it is
the only way the pain can be controlled. As symptoms resolve,
the patient is encouraged to decrease use of the appliance.
With adaptive changes, most patients can gradually reduce the
use of the appliance with no need for any dental changes.
These adaptive changes can take 8 to 10 weeks or even longer.
Supportive Therapy:
The patient should be educated about the mechanics of the
disorder and the adaptive process that is essential for
treatment. The patient must be encouraged to decrease loading
of the joint whenever possible. Softer foods, slower chewing,
and smaller bites should be promoted. The patient should be
told, when possible, not to allow the joint to click. If
inflammation is suspected, an NSAID should be prescribed.
Moist heat or ice can be used if the patient finds either helpful.
Active exercises are not usually helpful, since they cause
joint movements that often increase pain. Passive jaw
movements may be helpful, and on occasion distractive
manipulation by a physical therapist may assist in healing.
B. DISC DISLOCATION WITHOUT REDUCTION
It represents the clinical condition in which the disc is
dislocated, most frequently anteromedially, from the condyle
and does not return to normal position with condylar
movement.
Clinical Characteristics:
Examination reveals limited mandibular opening (25- 30 mm) with
normal eccentric movement to the ipsilateral side and
restricted eccentric movement to the contralateral side.
Definitive Treatment:
22. In such cases, the anterior positioning appliance will only
aggravate the condition by forcing the disc even more forward
and is therefore contraindicated.
When the condition is acute, the initial therapy should include
an attempt to reduce or recapture the disc by manual
manipulation. In patients with a longer history, success begins
to decrease rapidly (as they are likely to present with disc and
ligaments that have undergone changes that will not allow
reduction of the disc).
If the disc is not successfully reduced, a second and possibly
a third attempt is needed. Failure to reduce the disc may indicate
a dysfunctional superior retrodiscal lamina. Once this tissue
has lost its elasticity and ability to retract the disc, the
dislocation becomes permanent.
Supportive Therapy:
It should begin with educating the patient about the condition.
If the patient's attempt to force their mouth strongly to open
wider, it only aggravates the intracapsular tissues, producing
more pain. Patients should be encouraged not to open wide
especially immediately following the dislocation. With time and
tissue adaptation, they will be able to return to a more normal
range of movement (usually more than 40 mm).
The patient should also be told to decrease hard biting, never
chew gum and generally avoid anything that aggravates the
condition. If pain is present, heat or Ice may be used. NSAIDs
are indicated for pain and inflammation. Joint distraction and
phonopheresis over the joint area may be helpful.
STRUCTURAL INCOMPATIBILITY OF THE ARTICULAR SURFACES
It can be divided into four categories;
I} Deviation in form
It depicts a group of disorders that is created by changes in
smooth articular surface of the joint and disc. These changes
23. produce an alteration in the normal pathway of condylar
movement.
Clinical Characteristics:
A repeated alteration in the pathway of the opening and closing
movements is seen. When a click or deviation in opening is
noted, it always occurs at the same position of opening and
closing. Deviations in form may or may not be painful.
Definitive Treatment:
Definitive approach is to return the altered structure to
normal form (often accomplished by a surgical procedure). In
the case of bony incompatibility, the structures are smoothed
and rounded. If the disc is perforated, it is repaired
(discoplasty).
Supportive Therapy:
The patient should be encouraged, when possible, to learn a
manner of opening and chewing that avoids or minimizes the
dysfunction. In some cases, the increased interarticular
pressure associated with bruxism can accentuate the
dysfunction associated with deviations in form. In such a case,
a stabilization appliance is indicted to decrease the muscle
hyperactivity. If pain is associated, analgesics may be
necessary to prevent the development of secondary central
excitatory effects.
2} Adherences and Adhesions
These represent a temporary sticking of the articular surfaces
during normal joint movements. Adhesions are more permanent
and are caused by a fibrotic attachment of the articular
surfaces. Adherences and adhesions may occur between the
disc and condyle or the disc and fossa.
Clinical Characteristics:
The presenting symptom for adherences is temporary
restriction in mouth opening until the click occurs, whereas
24. the presenting symptom in adhesions is a more permanent
restriction in mouth opening. If the adhesions affect only one
joint, the opening movement deflects to the ipsilateral side,
When adhesions are permanent, the dysfunction can be great.
Adhesions in the inferior joint cavity cause a sudden jerky
movement during opening. Those in the superior joint cavity
restrict movement to rotation. During mouth opening adhesions
between disc and fossa tend to force the condyle across the
anterior border of the disc.
With a posterior dislocation, the patient opens normally but
has difficulty getting the teeth back into occlusion. Pain mayor
may not be present. If pain is a symptom, it is normally
associated with attempts to increase opening that elongate
ligaments.
Definitive Treatment:
It is directed towards decreasing loading of the articular
surfaces. Loading may be related to nocturnal clenching. When
this is suspected, a stabilization appliance is indicated for
decreasing the muscle hyperactivity. .
When adhesions are present, breaking the fibrous attachment is
the only definitive treatment (can be achieved with arthroscopic
surgery) and the lavage used to irrigate the joint during the
procedure assists in decreasing symptoms.
Supportive Therapy:
The restriction of some adhesion problems can be improved
with passive stretching, ultrasound, and distraction of the
joint. These type of therapies tend to loosen die fibrous
attachments, allowing more freedom for movement. Too
aggressive stretching, however, can tear tissues and produce
inflammation and pam. When pain and dysfunction are minimal,
patient education is the most appropriate treatment. Having the
patient limit opening and learn appropriate patterns of
movement that do not aggravate the adhesions can lead to
normal functioning.
25. 3}Subluxation:
Also known as hypermobility is a clinical description of the
condyle as it moves anterior to the crest of the articular
eminence. It is not a pathologic condition but reflects a
variation in anatomic form of the fossa.
Clinical Characteristics:
During the final stage of maximal mouth opening, the condyle
can be seen to suddenly jump forward with a "thud" sensation.
This is not reported as a subtle clicking sensation.
Definitive Treatment:
Only definitive treatment is surgical alteration of the joint
itself. Eminectomy reduces the steepness of the articular
eminence and thus decreases the amount of posterior rotation
of the disc on the condyle during full translation.
Supportive Therapy:
It begins by educating the patient regarding the cause of
subluxation and which movements create the interference. The
patient must also learn to restrict opening. On occasion, when
the interference cannot be voluntarily resolved, an intraoral
crevice to restrict movement is employed that develops a
myostatic contracture of the elevator muscle, thus limiting
mouth opening to the point of subluxation.
4} Spontaneous Dislocation
It is commonly referred to as an open lock. It can occur
following wide open mouth procedures: This condition refers
to a spontaneous dislocation of both the condyle and the
disc. .
Clinical Characteristics:
The patient remains in a wide open mouth condition. Pain is
commonly present secondary to the patient's attempts to
close the mouth.
26. Definitive Treatment:
It is directed towards increasing the disc space, which allows
the superior retrodiscal lamina to retract the disc. Since the
mandible locked open, the patient generally tends to contract
the elevator muscles in an attempt to close it in the normal
manner. This activity aggravates the spontaneous dislocation.
When attempts are being made to reduce the dislocation, the
patient must open wide as if yawning. This activates the
mandibular depressor muscles and inhibits the elevator
muscles.
If the inferior lateral pterygoid muscle is in a myospasm,
preventing posterior positioning of the condyle, it is
appropriate to inject the muscle with local anesthetic without
a vasoconstrictor in an attempt to eliminate the myospasms
and promote relaxation. When spontaneous dislocation
becomes chronic or recurrent, definitive treatment may consist
of a surgical procedure directed towards correcting the
structures that contribute to the disorder.
Supportive Therapy:
The most effective method of treating spontaneous
dislocation is prevention. When a spontaneous dislocation is
recurrent, the patient is taught the reduction technique.
Chronic recurrent dislocations can be definitively treated by a
surgical procedure only after supportive therapy has failed to
eliminate or reduce the problem to an acceptable level.
HYPOMOBILITY OF JOINT:
1. TMJ ankylosis:
Ankylosis- greek word- stiff joint
- Incidence in india- high.
- Age distribution- 2- 6 years
Mean age: 10 years
- Classification:
1. False and true
27. 2.
3.
4.
5.
Extra articular or intra articular
Fibrous or bony
Unilateral or bilateral
Partial or complete
- Grading of ankylosis by sewhey (1986)
Type- 1: Condylar head is present without much distoetion
fibrous adhesions made movement imposible.
Type 2: bony fusion of misshaped head and articular surface.
No involment of sigmoid notch and coronoid process.
Type 3: bony block bridging across the ramus and zygomatic
arch. Medially an atrophic dislocated fragment of former head
is still found. Elongation of coronoid seen.
Type 4: normal anatomy is totally destroyed by complete bony
block between ramus and skull base.
Etiopathology:
1. Trauma(26- 75%)
2. Infection (44- 68%)
Joint infection: septicemia due to osteomyelitis, septic soar
throat, scarlet fever, TB, meningitis.
- Direct spread of infection: otitis media, mastoditis, soft
tissue abscess, skin infection.
- Diseases affecting joint: rheumatoid arthritis,
osteoarthritis, spondylitis.
Trauma: at brith: forceps delivery.
- Fracture of condyle
- Direct blow at joint or chin cause bleeding. Prolonged
immobilization of Condylar fracture.
Pathogenesis:
- Trauma – extravasation of blood in joint.
(hemarthrosis)
- Predisposes to calcification and obliteration of joint
space.
- Immobility of the joint for prolonged period- initially
fibrous bands lead towards bony consolidation to
ossification.
28. Clinical manifestation:
- Severity, time of onset, duration.
- Early joint involvement: < 15 yrs: severe deformity and
loss of function.
- Later joint involvement: after 15 yrs: facial deformity
marginal or nil, severe function loss.
UNILATERAL ANKYLOSIS:
- Obvious facial asymmetry.
- Deviation of mandible and chin of affected side.
- Chin is secreted on affected side.
- Roundness or fullness of face on affected side.
- Appearance of flatness and elongation on unaffected
side.
- Well defined antegonial notch on affected side.
- Some amount of oral opening. Crossbite may be seen.
- Affected side: class 2 malocclusion, on ipsilateral
side. Unilateral posterior crossbite.
- Affected side Condylar movement absent.
BILATERAL ANKYLOSIS:
- Inability to open mouth.(gradual decreasing )( < 5 mm)
- Mandible is symmetrical but micrognathic.
- Neck chin angle may reduced or absent. Bird face
appearance.
- Antegonial notch prominent bilaterally.
- Class 2 malocclusion.
- Upper incisors- protrusive with anterior open bite.
Maxilla may be narrow.
- Multiple carious teeth with bad periodontal health.
Severe malocclusion, crowding.
Diagnosis:
H/o trauma, infection
Clinical findings
Radiographs: OPG, Lat. Oblique, Cephalomatric radiographs, PA
skull, CT scan.
FIBROUAS ANKYLOASIS: Reduced joint space, hazy appearance,
normal anatomy may be appreciated.
29. BONY ANKYLOSIS: Complete obliteration of joint space, normal
anatomy distorted, elongated coronoid process.
Management: Always surgical.
Aims & objectives:
- Release of ankylosed mass & creation of gap.
- Creation of functional joint.
- Reconstruct the joint & vertical height of ramus.
- To improve esthetics.
Techniques :
1. CONDYLECTOMY:
- Commonly used in fibrous ankylosis.
- Clinically after exposure can see the demarcation
between the roof & head on condyle.
- Osteotomy cut at level of condyle neck. Head should
be separated from the sup. Attachment carefully.
- Rest of the stump is smoothen & wound is closed.
- Unilateral condylectomy : Deviation towards operated
side.
- Bilateral : Ant open bite, loss height of vertical ramus.
2.
GAP ARTHROPLASTY:
- In extensive ankylosis, a broad thick area of bone
deposition obliterates the entire joint.
- The level of section is below that of previous joint
space and no substances is interposed.
- Two horizontal cuts to create minimum gap of 1 cm to
prevent reankylosis.
3. INTERPOSITIONAL GAP ARTHROPLASTY:
- Most authorities agree that recurrence is less likely
when something is interposed between to cuts. In gap
arthroplasty – 53% recurrence.
- Creation of gap but in addition a barriers is inserted
between the cut bony surfaces to minimize resk of
recurrence and to maintain the vertical height of ramus.
- Materials used,
30. -
AUTOGENOUS:
Cartilaginous grafts: costochondral, metatarsal,
sternoclavicular,.
Temporal muscle, temporal fascia, fascia lata, dermis.
HETEROGENOUS:
Chromatized submucosa of pig bladder, lypholized
bovine cartilage.
ALLOGRAFTS:
Metallic: tentalium foil, 318L ss, titanium. Gold.
Non-metallic: silastic, teflon, acrylic, nylon, proplast,
ceramic implants.
MUSCLE CONTRACTURE:
A painless shortening of muscle. Two types: 1. Myostatic 2.
Myofibrotic. Contracture of elevator muscles produce
hypomobility.
1. Myostatic contracture:
When a muscle is kept from fully lengthening for a prolong
time. Full lengthening cause pain in associated structures.
Sometimes secondary to other disorder.
Patient was on ant repositioning appliance continuously leads
to inf lateral pterygoid would not allowed to fully lengthen.
A myostatic contracture can develop that disallows the
condyle to immediately return to stable position.
History: Long distance of restricted jaw movement. It may
began secondary to a pain condition that has now resolved.
Clinical features: painless limitation of mouth opening.
Definitive treatment: Original cause is identified & resolved,
then treatment is directed towards the gradual lengthening of
involved muscle.
If pain : protective co-contraction- treatment will fail.
Exercises: passive stretching & resistant opening.
31. Passive stretching: it is accomplished when pt open to the full
limit & gently stretching beyond the restriction. Gentle &
momentary, not to traumatize the muscle.
Resistance opening: Take advantage of neurologic reflex
system to aid in relaxation. Mandibular elevators & depressor
function according to reciprocal inhibition. Neurologic stretch
reflex help in control of this activity.
Initiating mild contraction of antagonist muscle groups, when
elevators will not properly relax, contraction of depressor
provided by resistance to opening feeds neurologic input to
elevators tpo relax.
Supportive therapy: little use.
- Analgesics, thermotherapy, ultrasound.
TUMORS OF THE TMJ
Benign tumors :
Chondroblastoma
Chondroma
Condylar hyperplasia
Fibrous dysplasia
Giant cell granuloma
Hemangioma
Osteochondroma and Osteoma
Malignant tumors:
Chondrosarcoma
Multiple myeloma
Osteosarcoma
Synovial sarcoma
BENIGN TUMORS
1. Chondroblastoma
It is a distinct entity that usually involves the long bones but
sometimes occurs in the cranial bones and in the mandibular
32. condyle. This benign central bone tumor occurs predominantly
in young people. The incidence in males is roughly double that
in female. Conservative surgical excision is generally
acceptable treatment. Characteristic histological presentation
is called chiken-wire pattern.
2. Chondroma:
This neoplasm demonstrates no sex predilection and may
develop at any age. Chondroma generally presents as a
painless, slowly enlarging swelling. The radiographic
appearance is that of an irregular radiolucent or mottled
region of the bone.. The histopathologic distinction between
a chondroma and a well differentiated low grade
chondrosarcoma of the TMJ is often difficult, therefore, many
pathologists suggest that any chondroma of the jaws should
be regarded as potentially a low grade chondrosarcoma.
3. Condylar Hyperplasia
Although space-occupying benign or malignant lesions can
displace the condyle from the fossa and cause asymmetry with
malocclusion, Condylar-hyperplasia can have similar
presenting symptoms. Its etiology is not well understood. The
articular surface of a normal condyle is composed of
fibrocartilage that exhibits appositional growth incontrast to
endochondral ossification.
It has been categorized into two types :Type I deformity, or hemimandibular elongation, is the most
common variant. The mandible is asymmetric, with deviation of
the chin to the contralateral side and a concomitant dental
cross-bite.
Type II deformity, or hemimandibular hypertrophy, where
deviation of chin is not a prominent feature, but a marked
vertica1 open-bite is present on the ipsilateral side of the
hypertrophy. .
Condylar hyperplasia is not a truly neoplastic process but
actually a self-limited disorder. If the disorder is diagnosed
33. early in its active stage, removal shaving of only 5 or 6 mm of
the most superior condylar surface is usually adequate, and
condylectomy is unnecessarily aggressive.
Recontouring the inferior border and the angle of the
mandible is sometimes necessary to correct the inferior
component of the asymmetry. In an inactive process,
orthognathic procedures, such as a vertical subsigmoid
osteotomy can be useful in correcting an open bite while
maintaining a functional joint articulation.
4. Fibrous Dysplasia
This most commonly presents as an asymptomatic, slow
enlargement of the involved bone. Monostotic fibrous
dysplasia' accounts for up to 80 % of the cases. Jaw
involvement is common in this form of the disease. The entire
ramus-condyle-complex can be involved and present as facial
asymmetry.
Clinical presentation is difficult to distinguish from that of
condylar hyperplasia. The radiographic presentation is
sometimes similar to that of' Garre's osteomyelitis. Once
pathologic diagnosis is confirmed by biopsy, the only
treatment required may be periodic follow-up. However, if
significant cosmetic or functional deformity has occurred,
surgical intervention with osseous recontouring may be
undertaken.
Aneurysmal bone cysts have also been reported in association
with fibrous dysplasia. Fibrous dysplasia shares many
microscopic features with ossifying fibroma.
5. Giant Cell Granuloma
This disease is seen predominantly in children and young
adults, with 75 % of the cases presenting before the age of 30
years. Females are affected approximately twice as frequently
as males. Lesions occur more frequently in the mandible than
in the maxilla. Giant cell granuloma typically presents as a
painless expansion or swelling of the affected jaw.
34. Radiographic appearance is frequently a unilocular or
multilocular radioluscency.
The clinical behavior is widely variable. Some may progress
slowly with only minimal destruction of bone. The more
aggressive variety may progress rapidly and result in massive
bone loss and cortical perforation. The treatment may vary
from simple enucleation of small, slowly enlarging lesions
to condylectomy or wide resection of aggressive, rapidly
enlarging lesions.
6. Hemangioma
The maxilla and the mandible are the most common sites of
occurrence of hemangioma of bones after the vertebrae and
skull. The posterior mandible is the most frequent site of
incidence in the jaws. The lesion commonly presents as a firm,
slowly enlarging, exp-ansile swelling of the bone.
Spontaneous intra-oral bleeding may occur. Bruits and
pulsations of large hemangiomas may be detected with careful
auscultation or palpation of the thinned cortical plates.
Common radiographic presentation is that of a multilocular
radioluscency. Its most significant feature if the lifethreatening hemorrhage that may occur if these lesions are
improperly managed. Management may include embolization,
sclerosing agents, and surgery.
7. Osteochondroma and Osteoma
These are the two most common tumors of the TMJ.
Radiographic studies frequently reveal an abnormally shaped
condyle or a tumor mass attached to an abnormally shaped
condyle. The condylar neck is usually of normal length. Also,
the growth rate is usually slower than that of Condylar
hyperplasia. The anatomic location and size of most benign
tumors of the condyle are such that a condylectomy is
usually warranted to ensure complete removal.
MALIGNANT TUMORS
1. Chondrosarcoma
35. Chondrosarcoma of the mandible and maxilla is extremely
rare, accounting for approximately 1 % of all
chondrosarcomas. Most mandibular chondrosarcomas
present in the mandibular body, with an occasional occurrence
in the condylar process. No gender predilection has been
noted, and it is present predominantly in adulthood. Although
the mean age of occurrence is 60 years, almost half of the
cases arise in the third and fourth decade of life.
The most common presentation is that of a painless swelling,
with expansion of the underlying bone. The radiographic
appearance varies from moth-eaten radioluscencies that are
solitary or multilocular to diffusely radiopaque lesions.
Because chondrosarcomas are radio-resistant neoplasms,
wide local or radical surgical excision is the treatment of
choice. The 5-year survival rate for chondrosarcoma of the
mandible is 17 %.
2. Multiple Myeloma
Plasma cell neoplasms are derived from bone marrow stem
cells of B-Iymphocyte. multiple myeloma occurs after the
fifth decade, with a mean range of occurrence of 63 years.
Involvement of the jaws may be asymptomatic or may produce
pain, swelling, expansion, numbness, and pathologic fracture.
The radiographic appearance is typically that of multiple
punched out but non-corticated radiolucent areas of bone
destruction. Occasionally, the lesions may be expansile or
radiographically sclerotic.
Treatment usually consists of chemotherapy with radiation
directed at painful lesions.
3. Osteosarcoma
Approximately 5 % of osteosarcomas occur in the jaws. These
are reportedly associated with several pre-existing bone
abnormalities, including Paget's disease, fibrous dysplasia,
giant cell tumor, multiple osteochondroma, bone infarct,
chronic osteomyelitis, and osteogenesis imperfecta. Other
36. osteosarcomas occur subsequent to radiation therapy to the
affected region for unrelated or antecedent disease.
The peak incidence of osteosarcoma of the jaw is in the third
or fourth decade, with a mean age of 34 years. The majority of
mandibular osteosarcomas arise in the body (60%), with those
arising in the TMJ accounting for a small percentage.
Osteosarcomas of the TMJ commonly present as rapidly
enlarging, painful localized swelling. Paresthesia may occur
secondary to involvement of the trigeminal nerve. Variants of
osteosarcoma that ma)' affect the TMJ are osteoblastic,
fibroblastic and chondroblastic osteosarcomas. The typical
radiographic appearance is that of a lytic lesion. Treatment
generally consists of radical wide excision. Radiotherapy and
chemotherapy are reserved for recurrence. The 5-year survival
rate for osteosarcoma of the jaws IS25% to 50%. The most
common sites for metastasis are the lung and the brain, with
extremely rare involvement of regional lymph nodes.
4. Synovial Sarcoma
Synovial sarcoma of the head and neck area is predominantly a
disease of young people, the median age being 19 years. A
painless, deep-seated swelling is commonly the presenting
complaint. Early radical excision is probably the best
treatment for synovial sarcoma of the head and neck. In other
sites; the 5year survival rate varies between 25% and 50%.
TMJ begins development in the 10th week of gestation
Two mesenchymal condensations develop- one for
temporal bone component(glenoid fossa) and one
for condylar component
The intervening mesenchyme also shows a
condensation of cells that diffrentiate into the
intervening disc(meniscus)
37. The temporal and condylar mesenchymal cells
diffrentiate into osteoblast to lay membranous
bone
The centre of the condylar component develop s
into white fibrocartilage that facilitates
subcondral bone formation thus contributing for
condylar growth till adulthood
The meniscus develpos into highly vascular disc
that continues anteriorly into the lateral pterygoid
muscle and posteriorly as discomalleolar
ligament (pintos ligament)
