Download Classification of Temporomandibular disorders - Clinical Jude

Classification of Temporomandibular disorders
Temporomandibular disorder (TMD) is any disorder that affects or is
affected by deformity, disease, misalignment, or dysfunction of the
temporomandibular articulation. This includes occlusal deflection of the
temporomandibular joints (TMJs) and the associated responses in the
musculature.
*So any disorders in the TMJ are either related to malocclusion, problems in
the related muscles or problems in the TMJ itself
*Wide range of conditions diversely presented as pain in the face or jaw joint
area
* There are many reasons for pain in the TMJ, those reasons are related to
each other, one thing leads to another, so its very important to establish a
proper diagnosis. For examples, malocclusion might lead to muscle spasms,
muscle spasm might leads to disk interference disorders and so on and so
forth.
*Recently, tremendous amount of confusion exists about many of the
symptoms that are related to the area of the TMJ, and because of failure to
differentially diagnose the problem and determine its cause, which is the
most important thing before we start the treatment, failure to do so might
worsen the problem, some of the treatments are often more harmful than the
symptoms themselves.
*Many patients are forced to leave their lives under unnecessary medication
or under the care of psychiatrist; they teach them how to live with pain!
*A lot percentage of TMJ disorders are actually caused by a dentist who
doesn’t understand the cause and effect relationship that is involved with the
symptoms
Dentists should be taught to:
1- Recognize the symptoms
2- Identify the cause
3- Treat the problem in the most conservative way that is practical
Since the symptoms are not always isolated to the TMJ, some authors suggest
that the term “Craniomandibular Disorder” is more accurate.
Epidemiology:
Dr. yara demonstrated a study of TMJ disorders published by doctors in JU
Entitled “Prevalence of temporomandibular joint disorders among
students of the university of jordan.”
BACKGROUND:
This study aimed to investigate the prevalence of temporomandibular disorder (TMD) among students of
the University of Jordan.
RESULTS:
The results of the present investigation showed that pain in or about the ears or cheeks was the most
prevalent symptom whereas locking of the temporomandibular joint (TMJ) was the least prevalent. Nearly
one-third of the investigated sample (31.4%, 346/1103) had no symptoms of TMD whereas 68.6%
(757/1103) had at least one symptom. Students of health science studies had significantly the highest risk
in developing TMJ clicking compared to students studying pure science or humanitarian studies.
CONCLUSIONS:
TMD is of a high prevalence among students of the University of Jordan, particularly among students of
health and science studies, which signify the role of stress in the development and/or progression of
TMD. The findings of this study are alarming and entailing further investigations to identify risk factors
associated with TMD in order to establish measures for prevention and treatment.
Types of TMJ disorders:
Each structure related to the joint can cause one of the temporomandibular
disorders
Each structure can tolerate certain amount of increased force, so the teeth
have their limits, joint structure have their limits….
The initial breakdown occurs in the tissue with the lowest structural
tolerance, the weakest point in the chain where it’s the muscles, TMJ or the
teeth or the supporting structures
If the teeth are weak ----- wear occurs, cracks, mobility …..
Periodonium is weak ------ bone loss occurs
Muscles are weak-------pain, spasm
If the TMJ is the weakest --------facial and jaw movement, tenderness, pain in
the joint are and some such as clicking or crepitus
*Analysis of orofacial pain for any treatment approach to be effective it must
identify each respect disorder, so we have to make a diagnosis of the first
source of pain
A logical diagnostic procedure requires structure by structure analysis to
determine which tissue was the source of pain
In the diagnosis of TMJ we should first look for any asymmetry such as chin
deviation and muscle hypertrophy, then mouth opening and lateral excursions
(we have to know the norms) , mandibular displacement , and then we listen
to the TMJ, and then we palpate the muscles, the joint area and look for pain,
tenderness….
 Analysis of structural deformation:
Pain is a common symptom of structural deformation, when the pt. feels pain
then there is a structural deformation that caused this pain
Signs usually precede the symptoms, for example pt. Might not feel pain but
if we examined them we might find signs such as teeth wear, radiographic
signs , so we have always to check for TMJ disorders and not waiting the pt.
to complain
A clinician can run a lot by listening to the symptoms but will miss much if
careful observation and attention to the signs is not given the attention its
raised
The point that shouldn’t be missed is that masticatory system disorders are
rarely confined to a single structure; there will be always collateral effects
from disorders in the joint, muscles and teeth
Its usually found that a chain of cause and effect reaction as one disorder
leads to another, paroxysm leads to muscles spasm, severe muscle spasm
leads to disk interference disorders, disk interference disorders sometimes
cause muscle spasm , sometimes muscle spasm cause malocclusion
Classification:
Most commonly used classification is:
1- masticatory system disorders
2- structural intracapsular disorders
3- conditions that mimic temporomandibular disorders
Combination of two or three might occur, one problem can be caused or
cause another
Categories:
1- occlusomuscular disorders with no intracapsular defects --- no disk
interference disorder , its solely related to teeth and muscles
2- intracapsular disorders that are directly related to occlusal disharmony
i.e.: occlusal disharmony has led to intracapsular disorders, its reversible
because no deformation in the structures occurred it’s just transient, so if
we removed the cause the problem disappears
3- intracapsular disorders that are irreversible because of adaptive changes
can function comfortably if the occlusomuscular harmony is reestablished
4-non-adaptive intracapsular disorders that might be primary or secondary
to occlusal disharmony or maybe unrelated
We will discuss bells classification which includes:
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acute muscles disorders
disk interference disorders
joint inflammatory disorders
chronic hypo mobility disorders
growth disorders
occlusomuscular disorders are the most common , most correctable, most
prevalent, most misunderstood and ignored, mostly originated directly form
parafunctional disorders.
Symptoms:
Pain usually aggravated by manual palpation, pain in other structures due to
masticatory muscle incoordination and hyperactivity, for example joint
clicking (intracapsular due to muscle spasm and its reversible)
Premature or overloaded tooth contact can cause severe pain in the teeth,
intensified pain of sinusitis, activate tension headaches, muscle pain
especially in temporalis muscle which might radiate to ear pain, affect the
alignment of the disk of the condyle or cause painful displacement of the
TMJ, alter the TMJ rest position (when we feel pain on one side shift of the
join occurs to avoid pain), restricted jaw movement
Because of occlusomuscle pain always involves the relation between the TMJ
and the occlusal contact its necessary to relate the occlusal contact to the
completely seated position of the condyle (we should check that centric
occlusion is coincident with the condyle rest position, if not and we started
treatment and we did some occlusal changes, the pt. well have TMJ
problems), and this is one of the drawbacks of angles classification which
concentrate only on teeth.
Any problem with TMJ must be resolved before the occlusal problems can be
resolved as all occlusal relationship is also related to the TMJ
Ways to verify that TMJ is healthy:
History: for example do you have frequent headaches ??? if yes where, how?
We have to know if this headache is related to the muscles and the joint. Do
you have soreness in your muscles ? where, when, what cause it and what
relieves it. Have you ever been injure ( for example head injury). Do you
have joint noises, pain or discomfort, locks ???And we look for the bite of
teeth
Acute muscles disorders can be divided into:
1- muscle splinting: the first reaction to altered proprioception and
sensory input it may result from changes of sensory input from the
dentition and the surrounding structures ( for example unfinished
composite filling for one week, anesthesia and the pt felt tenderness in
a muscle, ill-fitting denture with increased vertical dimension ). Its
normally of short duration and disappears when the etiological factor is
resolved, usually without jaw restriction movement except to avoid
pain, no signs of disk-condyle interference in the joint, no acute muscle
induced malocclusion. (due to short period usually up to one week,
more than this period it will proceed into muscle spasm)
2- muscle spasm (myofacial pain dysfunction syndrome): the continued
presence of muscle splinting might lead to muscle spasm, maybe
caused by central excitatory effects of deep pain in the surrounding
areas, general or physical fatigue, systematic illness might lead to disk
condyle interferences during movement and might cause acute
malocclusion, spasm in the lateral pterygoid affects the rest position
leading to a change in the occlusion. (all of those changes are
reversible).
Muscles involved: elevator muscles (masseter, temporalis, medial
pterygoid,and superior belly of lateral pterygoid), inferior head of the
lateral pterygoid and superior head
Inferior lateral pterygoid is attached below the condylar head and
originates from lateral pterygoid plate
Superior lateral pterygoid is attached to the disk
3- muscle inflammation (myositis): as muscle spasm continues, myositis
occurs
it might results from the same etiological factor contributing to spasm or
local injury and subsequent infection of the muscle tissue or from direct
extension of inflammation in nearby structures (ears, TMJ, sinus …)
Prolonged inflammation might lead to muscle contracture
Clinical characteristics, pain occurs when the muscle is at rest or in
function (usually in function)
Soreness, pain is increased when the teeth are clinched since the elevator
muscles are mainly affected and pain is not reduced with biting on a
separator, restriction of mandibular opening is common
Disk interference disorders:
Common symptoms: joint tightness, clicking, crepitation, locking
Pain is usually related to injury of the disk or other collateral ligaments
Symptoms associated with these disorders often are caused by micro or
macro trauma to the disk or ligaments
Muscle hyperactivity might increase intracapsular pressure and change the
disk position, leading to interference of the disk to the movement.
Disk interference disorders are divided into:
Class 1: that occurs before translation begins
Occurs at the closed joint position and is associated with clinching in
maximum intercuspation, when there is a discrepancy between maximum
intercuspation and the optimal joint position (maximum intercuspation is
not associated with the fully seated position of the condylar head and disk)
Maybe caused by occlusal contacts that deflects the mandible while
moving from the unclenched to the clenched position
Might also result from acute malocclusion due to muscle spasm
Symptoms of class 1 disk interference disorders:
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tight feeling on the joint area upon clinching on teeth
quick sharp pain and click can occur when clinching is released
symptoms are eliminated by biting on a separator on the same side
it doesn’t cause any restriction of movement
Class 2: as translation begins and characterized by click within the first 810 mm of mouth opening
Class 2 occur at the beginning of the translator cycle (beginning of mouth
opening
A frequent complaint is a click or pain when movement starts from
maximum intercuspation after a prolonged inactivity
Results from sticking of the disk to the condyle
Can also occur from chronic occlusal disharmony as a progression from
class 1 or micro trauma that cause elongation to the diskal ligaments
Clinching seats to displace the disk anteriorly or mesially
Clinical characteristic:
Patient usually shows a history of trauma or paroxysm
Distant click within first 8-10 mm
Symptoms can be eliminated by placement of a separator between the
teeth and it doesn’t create any restriction to movement
Class 3: during translation
Caused by excessive motion between the articular disk and the condyle
which results in catching or sticking, changing or restricting the
mandibular excursions
The stiffness of the articular eminence can be a contributing factor
If the articular eminence is too steep, it might goes problem between the
disk, the condyle and surrounding ligaments
3 factors can create class 3 interference
1- Incompatibility of the articular structures and or surfaces
2- Impaired condyle-disk function
3- Altered passive intracapsular pressure
Class 4 when translation extended to the normal limit (in full mouth
opening)
Occurs when the condyle and disk are forced anteriorly to the limits of
translation (the end of the mouth opening) during yawning
Because of the steep articular eminence and its referred to suplaxation or
hypermobility
Class 5 spontaneous anterior dislocation of the disk when the condyle
moves beyond the normal limit of translation (joint lock)
Movement due to a premature activity of the superior lateral ptyregoid
Patient report a history of excessive mouth opening
Paint which might result from excessive muscle spasm, or from stretching
of inferior lateral diskal lamina when force is applied to close the mouth
before properly reducing the disk
Question: is clicking itself a disorder?
There must be underlying cause, even if the pt. doesn’t feel pain (so there
is an abnormal function)
Inflammatory disorders of the TMJ
Common symptoms are :
Continuous deep pain might create secondary central excitatory effects like
referred pain, excessive sensitivity to touch, increased muscle spasm
(classical inflammation symptoms like other parts of the body)
Classified according to the structure that is imposed
Sinusitis, capsulitis, retrodiscitis, inflammatory arthritis
Chronic mandibular hypo mobility disorders:
 Contracture of the elevator muscles or capsular fibrosis, contractures
are mainly either myostatic or myofibrotic (reversible vs irreversible
respectively)
Growth disorders:
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Hypoplasia (underdeformed )
Hyperplasia (overformed)
Neoplasia (tumour)
Asymmetry ------ Severe midline shift, class3,
Radiographs and bone scans are extremely beneficial for the diagnosis
Radiographs can be used to detect hypo or hyperplasia
Bone scans can be used to detect tumors
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 Best wishes
 Your colleague Ahmad Tayel Khajil