2. The Temporomandibular Joint And
Internaldislodgement
a. The temporomandibular joints (TMJ)
are among some of the most frequently
used joints in the body.
b. it allowing us to talk, chew, yawn,
swallow and sneeze.
c. The two bones that form the TMJ are
the mandible (jaw) located inferiorly,
and the temporal bone of the skull (located more
superiorly).
d.The articular fossa. Between these two bony components is the joint disc or meniscus,
which is made of cartilage. This disc allows for smooth function and aids as a cushion
between the condyle and the articular fossa.
Ligaments support and stabilize the disc and condyle and together with the surrounding
muscles allow for proper movement of the lower jaw during functions such as chewing,

3. speaking and swallowing.
fig2
Tmj are located on both sides of the face in front of
the ears, connecting the jawbone (mandible) to the
skull (temporal bone). They're the most complicated
joints in the human body, providing rotation
(pivoting) movement like all joints, as well as sliding
movement, called translation. It serve as shock
absorbers, protecting the bones from hitting each
other.
MOVEMENT OF TMJ:Both TMJ must work in
coordination in order to allow normal movement to occur.
The TMJ allow us to open and close the mouth, protrude,
retract, and laterally move the jaw (mandible) right and left.
Normally, opening of the mouth should be 35-40mm.

4. Muscles Acting on the TMJ are muscles of mastication,
allowing the mandible to move for the purpose of
chewing and speaking. The primary muscles
involved are the following: temporalis, masseter,
medial pterygoid, and lateral pterygoid . The
muscles of each TMJ must work together.
Dysfunction occurs
when the Muscle are out of the synchrony leading to
muscle spasm, pain and inflammation of the TMJ.
When in a state of muscle imbalance, subluxation of
the joint is also possible.

5. Nerves present around the tmj:
Temporomandibular Joint Dysfunction:
The mostcommon dysfunctions associated
with the tmj inflammation,muscle imbalances,
hypomobility, and hypermobilty. The synovium,
retrodiscal tissue and the capsule are some of the
tissues that can become inflamed in the TMJ.
Possible causes for TMJ dysfunction:
1. Trauma to the joint–blow to the jaw or head

6. 2. Excessive stress to the joint from gum chewing, fingernail biting,
yawning, chewing on a pen, chewing on ice, and grinding teeth
3. Jaw abnormalities, missing teeth, poor bite (malocclusion)
4. Resting the head in the hand
5. Arthritis of the TMJ
6. Dislocation of the disc
7. Myofascial pain dysfunction
8. Postural abnormalities, especially with a forward head posture
9. Whiplash injury
10.Prolonged mouth and upper respiratory breathing
11.Thumb sucking
12.Ligamentous laxity
13.Birth/Congenital trauma
Common signs and symptoms of TMJ dysfunction :1.Clicking or
popping with o Pain at rest or with opening/closing of jaw
2.Decreased ability to open the jaw (hypomobility)
3.Neck pain
4.Tooth sensitivity
5.Dry or burning sensation in mouth
6.Uncomfortable bite
7.Forehead or temple headache
8.Buzzing or ringing in ears
9.Hearing loss
Self-care for Management of Symptoms:
1. Habit Modification: Try to avoid the activity that is causing the increased stress
to the joint such as nail biting, gum chewing, and ice biting.
2. Diet Modification: Eat a diet of soft foods in addition to chewing evenly.
3. Pharmacological: Anti-inflammatory medications such as aspirin or ibuprofen
can help to decrease pain and inflammation.
4. Hot compresses: Use a washcloth soaked in warm water or a commercial moist
hot pack over the area of pain or tenderness. This will help reduce any muscle
spasm which may be experiencing.
5. Dental Appliances: some type of intra-oral splint, nightguard or other appliance.
This may help to stabilize the TMJ so the muscles, teeth, and joints work together
without adding additional strain to the TMJ.

7. 6. Cold packs: These can be used to help reduce any swelling, pain and muscle
spasm.
7. Stress Management: Stress is a common contributing factor to TMJ dysfunction.
In this, condition deep relaxation training, breathing, meditation or biofeedback
are of great benefit.
8. Posture: A forward head posture is a big contributor to TMD. Try to practice
good posture, especially when sitting for long periods of time.
9. Massage: Try to gentle massage over and around the area of discomfort. This
helps in relieving any muscle spasm.
When to seek professional help?
If your symptoms last for more than 2-3 weeks, you should seek professional
assistance. For a true diagnosis of TMJ dysfunction, a comprehensive history
and physical exam along with other diagnostic procedures such as a x-ray and lab
tests are necessary.CT and MRI scan are taken.
∙ TMJ
disorders are separated into two main categories
based on the anatomic origin of the problem:
1.Articular disorders: include the articular surface, intraarticular disk, or articulating bones.
2.Masticatory muscle disorders: are problems within the
muscles surrounding the TMJ.

8. TMJ Evalution and examination: In order to make a proper diagnosis,
information is obtained in three ways.
1. Medical History
2. Clinical Examination
3. Radiographic Examination.
Medical history: This examination begins with a detailed review of the
history of the presenting problem. This includes the onset, duration, location and
character of the pain or dysfunction.
Clinical examination: A physical examination involving the head,
neck and TMJ regions would follow to further evaluate the degree of dysfunction.
Radiographic examination:In some cases it is necessary to order
a specific test to confirm diagnosis of a TMJ disorder.
1.Imaging Tests: Imaging Tests help show parts of the face, neck and head that
can't be seen during a physical exam.
2.CT Scan: Shows slices of the jaw joint. The images can be used to diagnose
arthritis, injuries and fractures.
3.Magnetic resonance imaging (MRI): Creates images of soft tissue, muscles, disc
and ligaments of the jaw and head.
4.Panoramic x-ray: provides a wide view of the jaws, including the teeth and their
roo

10. orthopantomogram
demonstrating bilateral temporo-mandibular joint dislocation (red
circle).

11. Tmj mild dislocation
Indications for surgery: FAILURE TO RESPOND TO CONSERVATIVE
MEASURES:
¨ Internal joint derangement
¨ Degenerative and inflammatory joint disease
¨ Recurrent dislocation
¨ Ankylosis
¨ Fracture dislocation of neck of condyle
¨ Neoplasia
Chronic recurrent dislocations
In the long term, however, surgery in the form of enlarging the eminence by osteotomy,
or grafting bone to stop the condyle slipping over it. A capsulorrhapy (tightening the
capsule) can also be of help to such patient

12. DIAGNOSIS:
All TMJ Dysfunction patients should be divided into two basis classifications.
These are
internal derangement cases and external derangement
cases.
The Internal derangement means that there is a mechanical problem within
the T.M.J. capsule.
The
external derangement indicates that there is a problem within the muscleskeletal system outside of the T.M.J. capsule.
Internal Derangement:it can be 2 types 1.slef reducing 2.non
reducing.

13. 1.self reducing internal derangement:The self-reducing anterior
displacement of the meniscus means that as the patient begins to open their
mouth the mandibular condyle is trapped distal to the meniscus relative to the
articular surface of the glenoid fossa. As the patient continues to open, tension
builds within the joint capsule. At some point in the opening process, the tension
within the capsule is sufficient to pull the head of the mandibular condyle into its
correct position upon the meniscus. From that point onward, the T.M.J. function is
normal because the condyle and meniscus are operating correctly as a unit.
There are two basic clinical observations that confirm the diagnosis of a selfreducing anterior displacement of the meniscus.
1.First, there is an opening deviation of the mandible ipsilateral to the joint
problem. As the condyle relocates itself properly upon the meniscus, the
mandibular deviation returns to normal. When the problem is bilateral, the
opening deviation of the mandible is sigmoid deviating from side to side and
returning to correct alignment, depending upon which joint complex returns to
normal function first.
2.The second very diagnostic clinical characteristic is an audible pronounced sound
within the joint capsule which usually presents itself as a “click”. This sound is
generated by the mandibular condyle relocating itself correctly upon the
meniscus.
The self reducing anterior displacement of the meniscus will have a full range of
normal motion. Very simply, at some stage in the opening cycle, one or both
mandibular condyles return to their correct relationship with the meniscus, and
from that point onward, function is totally normal.
2.non reducing internal derangement:
If the damage to the joint complex continues, most patients advance into what is
called a non-reducing anterior displacement of the meniscus. This means that no
matter how hard the patient attempts to open their mouth, or manipulate their
mandible, the mandibular condyles remain trapped distal to the meniscus.
The patient will have an opening deviation of the mandible ipsilateral to the
problem with no return to a normal skeletal midline. When the problem is
bilateral, there is no significant opening or closing deviation of the mandible, but
the patient will have limited vertical opening.
Another key diagnostic test is to align the skeletal midlines and check the patient
´s lateral motion. There will be limited lateral excursion to the side contralateral
to the non- reducing anterior displacement of the meniscus.

14. There is no joint noise when the patient has the nonreducing anterior
displacement of the meniscus since the condyle is unable to “snap” into its correct
position on the meniscus.
The non-reducing anterior displacement of the meniscus is usually best treated
with a pivot-splint. The pivot splint must be placed upon the lower arch.
PHARMACOLOGIC INTERVENTION: Acetaminophen and non-steroidal antiinflammatory drugs can help with acute and chronic pain. For muscle spasm and chronic
bruxism, muscle relaxants or benzodiazepines may be necessary if conservative
relaxation techniques fail.
INTRA-ARTICULAR INJECTIONS
Intra-articular injections of the TMJ with local anesthetics or corticosteroids can be used
for the treatment of inflammation within the TMJ capsule. Intra-articular injection should
only be used for severe acute exacerbations or after conservative therapies have been
unsuccessful.
DENTAL OCCLUSION THERAPY
Dental occlusal splinting and permanent occlusal adjustment have been the mainstays of
TMJ disorder treatment for years, although there is no clear evidence that malocclusion
of the upper and lower teeth causes TMJ pain. Two main types of splinting are available:
occluding and nonoccluding.
Prevention
TMJ dislocation can continue to happen in people with loose TMJ ligaments. To keep
this from happening too often, dentists recommend that people limit the range of motion
of their jaws, Conservative surgical treatments can help to prevent the problem from
returning. Some people have their jaws are wired shut for a period of time, which causes
the ligaments to become less flexible and restricts their movement. In certain cases,

15. surgery may be necessary. One procedure, called an eminectomy, removes the articular
eminence so the ball of the joint no longer gets stuck in front of it.
General TMJ (Disorder) Treatment
Dentists use a variety of treatment modalities which may be divided into Phase I, Phase II
and Phase III Therapy.
Phase I Treatment. Phase I treatment for TMJ is conservative treatment.. Generally, the
use of an intra oral splint, sometimes medication is required.
Phase II Treatment. Phase II treatment is, by definition of the American Dental
Association, non-reversible, invasive therapy. This is done when the patient have been
evaluated and released of Phase I treatment. Some of the recommendations are;
adjustment of the occlusion (adjusting the "bite") which is done by painlessly filing each
tooth until there is a precisely even and comfortable fit. It is rare but surgery of all types
may be necessary and most certainly produce changes which can't be reversed. Therefore,
it is most important that no one undergoes Phase II Treatment until a correct diagnosis is
established and proven as the cause of the symptoms.
Phase III Treatment. Phase III treatment is the long term management of a patient
following successfully completing Phase I and Phase II treatment. Phase III (the
maintenance phase) involves the use of a night time/stress splint. Regular personal TMJ
therapy and cautious use of the jaw to avoid new and additional injury to the jaw joints
and muscles.