TEMPOROMANDIBULAR JOINT (TMJ) DISORDERS

Fadi Al-Zaitoun

Rana Al-Dous

Mohammad Al-Tari

Elias Azar

TMJ Disorders

Patients frequently consult a dentist

because of pain or dysfunction in the

temporomandibular region.

Etiology

The most common causes of

temporomandibular disorders (TMDs) are :

muscular disorders, which are commonly

referred to as myofascial pain and dysfunction:

These muscular disorders are generally

managed well with a variety of nonsurgical

treatment methods.

Could involve one or more of the TMJ elements.

Anatomy of TMJ.

TMJ as a functional joint consists of the

following elements :

1) Glenoid fossa of temporal bone.

2) Condyles of the mandible.

3) Joint capsule.

4) Disk of the joint.

5) Ligaments associated with the joint.

1-Glenoid fossa

It is a depression on

the temporal bone

posterior to the

auricular eminence.

Its depth differ from

person to person.

Covered with hard

layer of bone.

This depression is located 1 cm anterior to the external acoustic meatus.

It is about very few mm below the cranial cavity.

The bone in this area maybe a 1mm in thickness .

It is posterior to the articulating eminence.

2- The disk

The disk is consisted

of special stroma

tissue.

Has a good blood

supply in children, to

reseed out in adults.

This reduce its ability

to react to irritation

and trauma

Its upper surface is

convex specially at

its crest.

To concave at the

articulating

eminence.

Its inferior surface is adapted to the bony surface of the condyle.

It is less concave in the posterior part comparing with its superior part to convex at its anterior part.

Interiorly it is connected to a superior fibers of the lateral pterygoid muscle

Posteriorly it is connected to fibers that is stretch during the advancement of the condyle with the disk

Its outside surrounding is attached to the capsule of the joint

3- The condyle

The condylar process consists of two parts Head & neck.

It is oval in shape, the long excess is the transverse one.

Its posterior articulating surface is broad comparing with the anterior one.

At its lateral end a small process where the external pterygoid ligament is attached

The neck

It is narrow at the

anterior posterior

part.

Supported with a

strong bony line at

its lateral side.

This neck is convex

at its posterior part

to concave at its

anterior part to give

an attachment to

the external

pterygoid muscle.

Few books name it

the pterygoid fossa

4- The Ligaments

TMJ is the most

flexible movable joint

in the human body

For this it is

supported by

ligament to

coordinate this

movements

Any distortion in

these ligaments will

end with a TMJ

dysfunctions

The Ligaments

There are three groups of them

1) Capsule

2) Intracapsular

3) Extra capsule

The superior fibers of the pterygoid muscle as it is attached to the disk plays an important part coordinating these elements during the joint movement.

Dysfunction of this muscle has its effects on the function of the joint.

The posterior ones will stretch under the effect of PT.M. during the advancement of the condyle keeping the disk covering the articulating surfaces.

Anterior disk displacement

In this case the disk could not return to its starting position under the influence of the intracapsular posterior ligaments, It will stay anterior to the condyle or return in a delayed time.

Anterior disk displacement with reduction or without .if become chronic will end with distraction of the articulating bony surfaces.

This means ; the intra capsular ligaments function is to keep the disk with a good relation with the articulating surfaces during the joint movement

These ligaments are attached to the border of the joint fossa from one side and to the disk from its other side

The anterior and posterior ones are more active than the others

Diagnostic Radiography

The joint is situated between many of the cranio facial bones

This make it difficult to get a diagnostic radiographs.

This make us depend upon more than one view to build our diagnosis

Lateral jaw view

Will show the relation between the bony parts of the joint,

Position of the condyle to the articulating surface

It shows some time the compression of the disk

It shows also the anterior posterior displacement of fractured condyle

The severe distraction of the condyle

The skull basal view

Is used to view high

condylar fractures

The medial or lateral

fracture displacements

To compare the states of

both condyles

PA view

It is not a diagnostic

view because of the

overlapping specially

when it is taken and

the mouth is closed

CT scan view

Shows The Joint in

deferent sides and

levels

MRI views

It shows the state

and the relation of

soft and hard

tissues.

Management of TMJ disorders

Most cases of TMJ syndrome are

temporary; thus, treatment is usually

conservative.

Early therapy starts simply with resting the

jaw, using warm compresses (ice packs at

first if an injury is present), and pain

medication.

Management of TMJ disorders

Jaw rest can help heal temporomandibular

joints. Eat soft foods. Avoid chewing gum

and eating hard candy or chewy foods. Do

not open the mouth wide. Perform gentle

muscle stretching and relaxation

exercises. Stress-reduction techniques

may help manage stress and relax the jaw

along with the rest of the body.

Management of TMJ disorders

We may prescribe a splint or bite plate.

This is a plastic guard that fits over upper

and lower teeth, much like a mouth guard

in sports. The splint can help reduce

clenching and teeth grinding, especially if

worn at night. This will ease muscle

tension. The splint should not cause or

increase the pain. If it does, tell the patient

to stop using it.

Management of TMJ disorders

A more invasive procedure can be

performed in the doctor's office or clinic

under local anesthesia. This is carried out

by inserting two needles in the

temporomandibular joint to wash it out.

One needle is connected to a syringe filled

with a cleansing solution, and the fluid

exits via the other syringe.

Management of TMJ disorders

This procedure can be done in the office.

Most people find relief from the pain and

return to almost normal. Sometimes, pain

medication can be injected into the joint in

a similar procedure.

Management of TMJ disorders

Alternatively, a simple injection of

cortisone medication can be very helpful

in relieving inflammation and pain.

Management of TMJ disorders

A last option, surgery, is often irreversible

and should be avoided when possible. If

necessary, surgery can be used to replace

the jaw joints with artificial implants.