The Temporomandibular Joint (TMJ) is a common site of complaint. Clicking sounds and pain are
indicators of a frequent condition called internal derangement, most often affecting females. As a
general term, internal derangement describes a structural abnormality within an articulation.
The internal derangement of the temporomandibular joint (TMJ) is a specific term defined as an
abnormal positional and functional relationship between the disk and articulating surfaces.
Emshoff R. and Rudisch A. (2003) defined internal derangements of the temporomandibular joint as an
abnormal relation of the articular disc to the mandibular condyle and the articular eminence. Jaw pain,
clicking of the joint, irregular and limited movement of the jaw are the characteristic symptoms of this
Internal derangement and associated complications are the most common pathologic entities affecting
the jaw. Solberg W.K. (1979)
Nebbe et al (2000) in his study on prevalence of TMJ disc displacement found normal joints in only
50% of boys and in 23%–29% of girls. The rest of the study population presented with different degrees
of slight to full disk displacement with or without a change in morphology. In other studies,
asymptomatic disk displacement was documented in approximately 30% of adolescents.
82% of patients presenting with pain and functional disturbance of their TMJ will have displaced disks
when examined with magnetic resonance imaging. The overall prevalence of symptomatic disk
displacement or internal derangement may range between 20% and 30%, making them frequently
The National Institute of Dental and Craniofacial Research indicates that 10.8 million people in the
United States suffer from TMJ problems at any given time. Both men and women experience TMJ
problems; however, 90 percent of those seeking treatment are women in their childbearing years.
Anterior disk displacement of the TMJ is a malrelationship of the disk to the condylar head and articular
eminence. Although the disk may displace medially, laterally, or (rarely) posteriorly to the condyle, it
generally displaces anteriorly.
First stage in the sequence of events leading to osteoarthritis.
TMJ morphology, have shown a path of progression that includes changes not only in the disc position,
but also in its configuration. The interpretation of the process leading up to a dislocated disc as
portrayed in the literature does not always stand on firm evidence and at times is contradictory.
Disc displacement is considered to be associated with clinically noticeable clicking noises on opening
and closing of the mouth as long as the disc reduces to its normal position on opening. When it
becomes nonreducible, the clicking noise disappears and instead there is a certain degree of limitation
in mouth opening.
Classification of Disc Displacements
Internal derangements can be divided into 2 categories: anterior disk displacement with reduction and
anterior disk displacement without reduction. The condition in which the disk is located anteriorly and
slips back into its normal position during opening of the mouth is called anterior disk displacement with
reduction; the opposite condition is dubbed anterior disk displacement without reduction.
Anterior disk displacement with reduction
Anterior disk displacement without reduction
TMJ disc displacement results from its inability to slide smoothly due to increased friction or
degenerative changes in the joint surfaces.
The sequence of events, starting with increased friction in the upper joint compartment and
culminating in disc displacement
Activation of various parafunctions, such as clenching, compromises the lubrication system in the
upper TMJ compartment.
The resulting increased friction prevents the disc from sliding together with the condyle.
On jaw opening, the condyle is pulled away from the disc by the inferior head of the lateral pterygoid
muscle. As a result, the ligaments joining the disc to the condyle are gradually stretched, and the
‘mobilized’ disc gravitates slightly downward and forward.
Subsequently, on clenching, the unstable disc is propelled forward by pressure from the condyle. At
this point, the force on the slightly displaced disc is shared between two vectors, one of which is
directed forward. Apparently, on mouth closure, the superior belly of the lateral pterygoid muscle pulls
the disc anteriorly
Subsequently, during mouth opening, the condyle, which is now posterior to the loose disc, gradually
pushes it down the slope of the eminence, displacing it further forward
Since the lateral articular disc bears the bulk of the shearing and compressive loads, persistent loading
tends to drive it in a medial direction, which is the ‘path of least resistance’.
MASTICATORY MUSCLE SPASM
Disc Displacement With Reduction:
Joint sounds (single, short duration)
Catching sensation during mouth opening
Deviation in opening pathway
Disc Displacement Without Reduction:
Limited mandibular opening
Normal eccentric movement to the ipsilateral side
Restricted eccentric movement to the contralateral side.
Joint sounds ( long duration sounds )
Limitation of mandibular opening
Magnetic Resonance Imaging
Nitzan et al (1991) described a technique of irrigation of the upper compartment of the TMJ with
Ringer's lactate solution to treat limited mouth opening due to internal derangement. The authors
called this technique `arthrocentesis'.
They reported an increase in mouth opening from a range of 12±30 mm prior to the procedure, to
35±50 mm following it. On a visual analogue scale of 0±15, the pain decreased from a mean rating of
8.75 to 2.3. This technique marked an evolution towards less surgical treatment.
Arthrocentesis is the most recent surgical approach for internal derangement of the TMJ. In the past
many cases of anterior displacement of the disc or closed lock that did not improve with medical
treatment (bite plates, muscle relaxants, diet and physical therapy) were initially treated with surgical
repositioning of the disc and arthroplasty of the mandibular fossa.
Arthrocentesis has an intermediate place between the medical and the surgical forms of treatment.
Ease, lower cost of materials and excellent published results so far include this technique in the
international protocol for the treatment of TMJ dysfunction.
Arthrocentesis is a simple yet effective treatment of temporomandibular joint disorders, and it requires
minimal invasion. Significant improvements in width of mouth opening have been reported with
proven long-term results. It is speculated that the increase in mouth opening results from the
elimination of the vacuum effect within the joint compartment.
In 2003, Reston and Turkelson
performed a meta-analysis of surgical treatments for
temporomandibular articular disorders. They concluded that among patients refractory to nonsurgical
therapies, surgical arthrocentesis and arthroscopy were most effective for patients with disc
displacement without reduction.
It is suspected that lavage under sufficient hydraulic pressure could widen the narrowed joint space
and release adhesion in the joint space. Arthrocentesis with sufficient pressure could be effective for
closed lock cases with adhesions in the upper joint compartment.
Mechanism of Action
Reduction in pain level:
Arthrocentesis reduces pain by removing inflammatory mediators from the joint. The combined
treatment of arthrocentesis and Sodium Hyaluronate injection may improve the results due to the
long-term lubricating effect of Sodium Hyaluronate, which prevents the onset of inflammatory
mediators that are responsible for pain.
Maximal Mouth Opening:
Arthrocentesis under high pressure is an effective method to regain normal mouth opening in closed
lock cases. This effect is usually due to elimination of the adhesions around the disc. Also the
lubricating effect of Sodium Hyaluronate which either maintains lubrication and minimizes wear and
tear mechanically, or plays a role in nutrition of the avascular parts of the disc and condylar cartilage.
Usually disappears due to decreased friction and lubricating effect.
Nearby Vital Structures
The frontal branch of the facial nerve is located a mean distance of 20 mm from the anterior margin of
the bony external auditory canal as it crosses over the posterior aspect of the zygomatic arch (a range
of 8 to 35mm). The main trunk of the bifurcation of the facial nerve is located a mean distance of 23
mm (a range of 15 to 28 mm) inferior to the lowest concavity of the bony external auditory canal.
Greene MW et al found the tympanic plate to be located at a range of 6 to 9 mm anterior to the
posterior tragus and perpendicular to the skin at a mean depth of 25.4 mm (range = 19 to 32 mm).
. In 2006, Betre et al designed a biologically based drug delivery vehicle for intra-articular drug
delivery using elastin-like polypeptides (ELPs), a biopolymer composed of repeating pentapeptides that
undergo a phase transition to form aggregates above their transition temperature. The ELP drug
delivery vehicle was designed to aggregate upon intra-articular injection at 37 °C, and form a drug
‘depot’ that could slowly disaggregate and be cleared from the joint space over time.
Myofascial Pain Dysfunction Syndrome
Dr. Wael M. Talaat
Assistant Professor of Oral & Maxillofacial Surgery
University of Dammam
Myogenous TMD (muscle-related)
Usually caused by overwork, fatigue or tension of the jaw and other muscles in the head and neck.
This type of TMD commonly causes jaw ache, toothache, headache and/or an ache in the back of the
Myofascial pain disorders
Acute inflammation with pain, edema and decreased ROM. Usually secondary to overuse, but no
infection or trauma seen
TX: rest, NSAIDs
Acute contraction from overuse, overstreching
Tx: rest, NSAIDs, massage, heat, relaxants
End stage of untreated muscle spasm
Due to fibrosis of muscle and connective tissue
Tx: NSAIDs, massage, vigorous physical therapy,
occasional surgical release of scar tissue
More common in females
Diffuse, systemic process with firm, painful bands (trigger points)
Usually seen in weight bearing muscles
Often associated sleep disturbance
More common in females
known path of pain for trigger points
6. Collagen vascular disorders
xerostomia, xeropthalmia with keratitis
sometimes muscle and joint pain , including the TMJ
diagnose with minor salivary gland biopsy
autoimmune, butterfly rash, fever, rheumatoid arthritis
autoimmune characterized with gradual muscle and joint
pain, tightening of skin
limited jaw expansion with pain may be initial presentation
The ETIOLOGY of MPDS is multifactorial.
Commonly accepted cause is BRUXISM resulting from stress & occlusion being an aggravating factor.
MPDS can also result from internal joint problems, such as disc displacement disorders, or
degenerative joint disorders.
When the pain source is purely in the muscles
it has been termed: ‘Myofascial pain dysfunction’ ( MPDS ) by Laskin.
However, when the TMJ itself is also involved, it
is called ‘TMJ pain dysfunction syndrome’ by
( MPDS )
The MPD syndrome is :
Common cause of TMJ pain
Psycho-physiologic disease involving muscles of mastication.
There is an increase in mandibular muscle tension in tandem with teeth grinding and/or clenching
resulting in spasm, pain, and dysfunction.
The condition is characterized by:
- PAIN - unilateral, dull, aching pain, which increases with muscular activity, and progressively worsens
towards the end of the day.
- Patients experience limitation of mouth opening.
- Complaints associated with referred pain include
sometimes decreased hearing.
Increased stress levels result in poor habits, like :
clenching of teeth, and even
excessive gum chewing.
leading to muscular overuse, fatigue and spasm, and subsequently pain.
Many symptoms may not appear related to TMJ itself. They are:
Pain becomes worse while opening and closing the jaw.
Exposure to cold weather or air-conditioned air may increase muscle contraction and facial pain.
Pts with TMJ disorder notice ear pain but there are no signs of infection.
The ear pain is usually described as being in front of or below the ear.
Because of this -many a times, patients are treated for a presumed ear infection, which can
often be distinguished from TMJ by an associated hearing loss or ear drainage.
Because ear pain occurs so commonly, ENT specialists are frequently called on to make the
diagnosis of a TMJ disorder.
Grinding, crunching, clicking, or popping sounds are common in patients with a TMJ disorder.
These sounds may or may not be accompanied by increased pain.
A majority of patients with a TMJ disorder report a vague dizziness or imbalance (vertigo).
The cause of this type of dizziness is not well understood.
Ringing in the ear (Tinnitus):
For unknown reasons, patients with a TMJ disorder experience noise or ringing in the ear (tinnitus).
More than half of those patients, will have resolution of their tinnitus after successful treatment of
Compare both sides of the jaw, face and head for symmetry
Feel the TMJs, jaw bones and head and neck muscles to find painful areas
Inspect the gums, mouth tissue and teeth for disease and excessive tooth wear facets from
Look for jaw deviation on opening
Listen for joint noises
Measure mouth opening and check side-to-side movements
Systemic evaluation of muscles of mastication
Palpation for presence of tenderness ,spasm or trigger point
Evaluation of TMJ tenderness and noise
1.point of tenderness
2.form of joint noise : clicking or crepitus
Measurement of range of jaw motion
cm in vertical
1 cm in protusively and laterally
Clinical signs on examination of myofacial
Limitation of jaw opening (normal range is at least 35 mm as measured from lower to upper anterior
Palpable spasm of facial muscles
Clicking or popping sound in the TMJ
4. Tenderness on palpation of the TMJ via the external
Crepitus over the joint
Lateral deviation of the mandible.
The aim of management should be:
Control the factors that worsen TMD
Decrease harmful pressure or “loading” on the joints
Restore jaw function
Help resume regular daily activities
Pain reduction techniques
The treatment of myofascial pain dysfunction syndrome is divided into four phases.
Phase I treatment is initiated upon diagnosis, and consists of :
- educating the patient on muscle fatigue and spasm as the cause of pain and dysfunction. It helps to
explain referred pain.
- the avoidance of clenching and grinding is emphasized
- a soft diet is instituted.
The appliance is usually worn at night, but can also be worn during the day, if necessary.
Care should be taken to instruct the patient not to wear the appliance at all times, as the
posterior teeth may become displaced.
If the patient remains asymptomatic, the appliance is discontinued.
If symptoms return, the appliance may be resumed at night, and its use continued as long as
Phase III Therapy
Phase III includes
Physiotherapy of the muscle groups, including Ultrasonic therapy, Electro galvanic stimulation,
Recently, it has been reported that pulsed radio frequency energy therapy (PRFE) in patients
with TMJ arthralgia is safe and effective and also increases mandibular motion.
These therapies focus beams of heat, sound or radio waves into the TMJ to increase blood flow
and relieve pain.
Phase IV Therapy
Phase IV involves
Psychological counseling to identify stress factor and referral to a TMJ center. The TMJ center
employs psychological counseling and trigger-point injections, for treatment.
Biofeedback helps patients to recognize times of increased muscle activity and spasm, and
provides methods to help control them.
In preliminary studies, Botulinum toxin has been used successfully to treat various pain
syndromes, including TMDs.
ANKYLOSIS OF TEMPEROMANDIBULAR JOINT
Dr. Wael M. Talaat
Assistant Professor of Oral & Maxillofacial Surgery
University of Dammam
Inability to open the mouth beyond 5mm of inter-incisal opening due to fusion of head of
the condyle of the mandible with the articulating surface of the glenoid fossa.
Inability to open the mouth on account of muscular spasm or trismus is called as
‘ false ankylosis ’ as the cause here is
extra - articular.
Ankylosis, or Anchylosis
( from Greek αγκυλος, bent, crooked )
Ankylosis is a stiffness of a joint, as a result of injury or disease and results in hypomobiliy or no
When the structures outside the joint are
involved, it is termed "false ankylosis”.
- in contrast when the disease involves the TMJ itself, it is called "true ankylosis”.
- When inflammation causes the joint-ends of the bones to be fused together the ankylosis is termed “
osseous” or complete.
CLASSIFICATION OF ANKYLOSIS:
1. False ankylosis or true ankylosis.
2. Extra - articular or intra - articular.
3. Fibrous or bony.
4. Unilateral or bilateral.
5. Partial or complete.
False ankylosis results from pathological condition outside the joint and leads to limited mandibular
CAUSES OF FALSE ANKYLOSIS
1. MUSCULAR TRISMUS
It can be established because of pericoronitis, infection adjoining the muscles of mastication
involving submasseteric, pterygomandibular, infra - temporal or submandibular spaces.
2. MUSCULAR FIBROSIS
Muscular fibrosis from any long standing dysfunction like arthritis and myositis.
3. MYOSITIS OSSIFICANS
When there is progressive ossification after injury and hematoma formation especially of
the masseter muscle, inability to open the mouth develops. This can be confirmed
radiologically as well.
When there is hypocalcaemia, the spasms in the muscles are produced hampering the
opening of the mouth.
Acute infectious disease caused by Clostridium tetani is represented by an early symptom of
lock-jaw because of persistent tonic spasm of the muscles.
6. NEUROGENIC CAUSES
Neurogenic causes like epilepsy, brain tumour and embolic hemorrhage in medulla
oblongata are also represented by hypomobility of the jaw.
7. TRISMUS HYSTERICUS
It is disease of psychogenic origin.
8. DRUG INDUCED SPASMS
Drug induced spasms like in drug poisoning.
9. MECHANICAL BLOCKADE
Mechanical blockade on account of osteoma or elongation of the coronoid process of the
mandible there by reducing it's movement under the zygomatic arch.
10. FRACTURE OF THE ZYGOMATIC ARCH
Fracture of the zygomatic arch with inward buckling.
11: FRACTURE OF THE MANDIBLE
Trauma causing fracture of the mandible leads to reflex spasm of the muscles and hence
12. SCARS AND BURNS OF THE FACE
Scars and burns of the face also, restrict the movements of the jaw. Post irradiation fibrosis
lead to hypomobility of the mandible.
13. CLEFT PALATE OPERATIONS
can produce fibrosis of the pterygomandibular raphe and, consequently, limitation of mouth
14. SUBMUCOUS FIBROSIS
Submucous fibrosis results in tense fibrous bands in the cheeks which stretch from mandible
to maxilla limiting movement of the mandible, tongue and soft palate.
True ankylosis, is a condition that produces
- fibrous adhesions or
- bony union
between the articulating surfaces of TMJ
and may be classified as:
- Fibro - osseous and
- Bony ankylosis.
Further, it may be unilateral or bilateral and partial or complete.
1. Birth Trauma
Birth trauma producing so-called congenital ankylosis and occurs in cases of difficult
delivery, particularly forceps delivery.
At times, other bones are fractured as well.
The injury of the jaw caused by the use of forceps may not be discovered until later when it
is noticed that the child could open his jaw only slightly.
Haemarthrosis is another cause of ankylosis.
It is generally, due to:
- fracture of the base of skull extending
through the mandibular fossa
- may also be caused by an intracapsular
Cortical bone in a child is very thin - as a result of intracapsular fracture of TMJ, bleeding
takes place within the joint – known as hemarthrosis
à The hematoma within the joint organises slowly
à which is then converted to fibrous tissue and
then à bone à resulting in bony ankylosis
3. Suppurative arthritis
Suppurative arthritis, may be due to infection of the ear or mastoiditis or it may be of
hematogenous origin leading to ankylosis
4. Rheumatoid arthritis
Rheumatoid arthritis, may cause great limitation of motion or complete ankylosis
There is associated atrophy of the muscles generally accompaning ankylosis, if contracted
early in life.
Osteomyelitis affecting the mandibular condyle without involving the joint itself frequently results in
limitation of motion
peri-articular swelling, and suppuration often results in fistula formation.
6. Fracture of the condyle
Fracture of the condyle, especially comminuted fractures of the head of the condyle, may cause
Trauma to the condyle in children is more likely to cause ankylosis than adults.
This is because condylar structure of children is different than adults.
In a child the neck of the condyle is short & stubby but in adults its longer & narrower.
Due to this trauma - in an adult is likely to fracture the condylar neck but in a child it is likely
to cause intra-capsular fracture
Clinical manifestations vary according to:
(a) Severity of ankylosis,
(b) Time of onset of ankylosis,
1. Early joint involvement - less than 15 years: Severe facial deformity and loss of function.
2. Later joint involvement after the age of 15 years: Facial deformity marginal or nil. But,
functional loss severe.
Those patients in whom the ankylosis develops after full growth completion have no facial
The CLINICAL MANIFESTATIONS of ankylosis vary.
Pain is not an outstanding symptom, it is present only in the early stages of the disease.
On inspection see:
Healed chin laceration
Reduced interincisal mouth opening or NO mouth opening at all + neglected oral hygiene +
impacted / malposed /carious teeth.
Inability to open the jaw and difficulty or inability to masticate food.
In cases in which the disease was contracted early in life, a so-called ‘bird face’ results.
- a receding chin,
- impaction of teeth.
The maxilla may be narrow and protrude
There is underdevelopment of the mandible and is associated with a prominent angle of the
jaw and curve of the inferior border called ‘ante - gonial notching’.
This ante-gonial notching or curve denotes an attempt at bending the bone by the powerful
depressor muscles attached to the symphysis, which come into function when great force is
needed to open the jaw
In BILATERAL ANKYLOSIS you will observe the following:
1. Bird face deformity + micro gnathic mandible
2. Inability to open mouth + inability to masticate
3. Class II malocclusion
4. Deep ante - gonial notching
5. Poor oral hygiene
6. Severe malocclusion with crowding + protrusive upper anterior teeth + anterior open bite
So in UNILATERAL ANKYLOSIS you will find :
1. Facial asymmetry with affected side appearing normal & the opposite side appearing flat.
2. Chin is deviated to the ankylosed side.
3. This is because the normal side continues to grow & pushes the mandible to the affected
side giving appearance of fullness on the ankylosed side.
4. Ante-gonial notch on the affected side
5. Minimal condylar movements on palpation.
6. Class II malocclusion on affected side and cross bite may be seen
PROBLEMS ASSOCIATED WITH ANKYLOSIS
1. Interferes with the mastication of food and with nutrition
2. Prevents oral hygiene and prophylactic care, and treatment of dental caries,
3. As a result, patients with this condition generally suffer from extensive multiple caries and periapical
If the disease is contracted early in life,
4. There is destruction of the growth center [situated in the condyle] and with absence of functional
stimulation prevents normal development of the jaw
5. This, in turn prevents normal eruption of the teeth and causes micrognathia - a disfigurement which
handicaps the patient in many ways.
Diagnosis is based on:
1. History of infection or trauma
(birth trauma + falls + previous infection of the ear)
2. Findings at clinical examination
(reduced interincisal opening + diminished/no
TMJ movements + scar on the chin due to trauma)
3. Radiological findings
For proper evaluation several radiographic views are useful
Orthopantomograph: OPG will show both the joints for comparision – important in
unilateral cases –will also reveal ante-gonial notching.
PA view will show the mediolateral extent of the bony mass – also reveal any mandibular
Lateral oblique – will demonstrate the antero-posterior extent of the bony mass and the
elongation of the coronoid process
3D CT SCAN showing Bony Ankylosis
CONE BEAM 3D CT SCAN –The cone beam CT provides multiple images with unprecedented imaging of
the maxillofacial area with less radiation than traditional CT beam
Radiographic changes are of extreme value in diagnosis
In fibrous ankylosis à
1. there is evidence of destructive + proliferative changes seen in bony compartments of TMJ +
2. haziness or narrowing of joint space
In bony ankylosis à
1. overall obliteration of joint space.
2. It will also show antegonial notching anterior to the angle of mandible and
3. elongation of coronoid process.
What happens if Ankylosis is left untreated ?
1. Normal growth & development of face is affected
2. There is Nutritional impairment
3. Speech impairment
4. Sleep apnoea ( tongue falls back in sleep) in Bilateral Ankylosis.
6. Poor and neglected oral hygiene
7. Multiple carious and impacted teeth.