Anatomical and physiological Anatomical and physiological features of the structure of features of the structure of

the salivary glands, the salivary glands, skronevo-mandibular joint in skronevo-mandibular joint in

children of all ages. Acute children of all ages. Acute and chronic inflammatory and chronic inflammatory

diseases of the salivary diseases of the salivary glands and TMJ in glands and TMJ in

children. children. Patterns of clinical Patterns of clinical course, diagnosis, course, diagnosis,

differential diagnosis and differential diagnosis and treatment. treatment.

Temporomandibular joint, (TMJ), an essential joint of the face, required for speech and nutrition; a synovial joint formed by the mandibular fossa of the temporal bone and the head of the condyle of the mandible with an intervening articular disc. The joint surface is completely covered by a thick fibrous capsule that allows for range of movements.

Ankylosis (joint stiffness) is the pathological fusion of parts of a joint resulting in restricted movement across the joint

Ankylosis of the Temporomandibular joint, an arthrogenic disorder of the TMJ, refers to restricted mandibular movements (hypomobility) with deviation to the affected side on opening of the mouth.

•Affects all age group but more in the first decade of life (0 – 10 years)

•There’s equal male and female distribution

•Almost all cases are unilateral.

Trauma-At birth (with forceps)-Blow to the chin (causing haemarthrosis)-Condylar fracture

Infections and Inflammatory-Rheumatoid Arthritis-Septic arthritis-Otitis media-Mastoditis-Parotitis-Osteomyelitis-Osteoarthritis-Tonsillitis

Systemic disease-Small pox-Ankylosing spondylitis-Syphilis-Typhoid fever-Scarlet fever

Others-Malignancies-Post radiology-Post surgery-Prolonged trismus

TRAUMA

Extravasation of blood into the joint space

haemarthrosis

Calcificatiion and obliteration of the joint space

Intra-capsular ankylosis Extra-capsular ankylosis

•Intra-capsular ankylosis

•There’s destruction of the meniscus and flattening of the temporal fossa

•thickening and flattening of the condylar head and a narrowing of the joint space.

•Opposing surfaces then develop fibrous adhesions that inhibit normal movements and finally, may become ossified.

•Extra-capsular ankylosis

•There’s an external fibrous

encapsulation with minimal

destruction of the joint

itself.

•Inability to open the jaws

•In unilateral ankylosis, the lower jaws shifts towards the affected

side on opening of the mouth•In severe cases, there is complete immobilization•There may be Abnormal forward protrusion of the mandible as the excess tissues occupies the space•Facial deformity

Others are related to the underlying cause of the ankylosis•Fever •Pain •Other bones and joints deformities

Fibrous Ankylosis Produced by adhesions within the TMJ affecting the fibrous components

Bony ankylosisThe union of bones of the TMJ by proliferation bone cells, resulting in immobility of the joint

•Not usually associated with pain

• Limited range of motion on

opening

•Deviated to the affected side

• Limited laterotrusion to the

contralateral side

•No radiographic findings other

that absence of ipsilateral

condylar translation

• Not usually associated with

pain

• More marked limitation on

opening

• There’s more marked

ipsilateral deviation

• There’s more marked

limitation of contralateral

lateral movment

• There’s a radiographic

evidence of bone

proliferation

•Speech impairment

•Facial growth distortion

•Nutritional impairment

•Respiratory disorders

•Malocclusion

•Poor oral hygiene

•Multiple carious and impacted

teeth

Non surgical management

Surgical treatment

Aims and Objectives of surgery

To release ankylosed mass and creation of a gap to mobilize

the joint Creation of functional joint (improve patient’s oral hygiene,

nutrition and good speech)To reconstruct the joint and restore the vertical height of the

ramusTo prevent re-occurrenceTo restore normal facial growth patternTo improve esthetic appearance of the face (cosmetic reason)

Physiotherapy follow-up

Procedures

1.Condylectomy

2.Gap arthroplasty

3.Interpositional arthroplasty

CONDYLECTOMY

•This procedure is usually indicated when the joint space is obliterated with the deposition of fibrous bands; but, there hasn’t been much deformity of the condylar head. Usually employed in cases of fibrous ankylosis.•Pre-auricular incision is made•Horizontal cut carried is out at the level of the condylar neck•The head (condyle) should be separated from the superior attachment carefully•The wound is then sutured in layers•The usual complication of this procedure is an ipsilateral deviation to the affected side. And anterior open bite if the procedure was bilaterally.

GAP ARTHROPLASTY

This procedure is employed in an extensive bony ankylosis.

The section here consists of two horizontal osteotomy cuts

And removal of bony wedges for creation of a gap between

the roof of the glenoid fossa and the ramus of the mandible.

This gap permits mobility

The minimum gap should be 1cm to avoid re-ankylosis

INTERPOSITIONAL ARTHROPLASTY

This is actually an improvement/modification on gap

arthroplasty

Currently the surgical protocol of choice

Materials are used to interpose between the ramus of the

mandible and base of the skull to avoid re-ankylosis

The procedure involves the creation of gap, but in addition, a

barrier is inserted between the two surfaces to avoid

reoccurrence and to maintain the vertical height of the ramus

INTERPOSITIONAL ARTHROPLASTY

MATERIALS USED IN INTERPOSITIONAL ARTHROPLASTY

Autogenous Heterogenous Alloplastic

I. Temporalis muscles

II. Temporalis fascia

III. Fascia lata

IV. Cartiligenous graftsCostochondralMetatartsalSternoclavicularAuricular graft

V. Dermis

I. chromatised submucosa of pig’s bladder

II. lyophilized bovine cartilage

Metallic: tantalum foil and plate, 316L stainless steel, Titanium, Gold.

 Nonmetallic: silastic, Teflon, acrylic, nylon, ceramic

Advantages of this procedure (interpositional arthroplasty)

Autografts, such as skin, temporalis muscle, or fascia lata, are

presently considered the material of choice for interposition.In more recent years, a pedicled temporalis myofascial or

temporalis fascia flap has been advocated in TMJ surgery to treat

the TMJ ankylosis. Advantages of these flaps in TMJ reconstruction include

close proximity to the TMJ without involving an additional

surgical site, adequate blood supply, autogenous origin grafts can be used, and maintenance of attachment to the coronoid process,

which provides movement of the flap during function,

simulating physiologic action of the disc.

Advantages of this procedure (interpositional arthroplasty)

Post -OP

Complications of the surgery

AnaesthesiaAspiration of blood clot, tooth or foreign bodyFalling back of the tongue causing airway obstruction

Intra-OperativeHaemorrhage (damage of any superficial temporal vessels, transverse facial artery, etc)Damage to the external auditory meatusDamage to the Zygomatic and temp. branch of facial nerveDamage to the Glenoid fossaDamage to the Auriculotemporal nerveDamage to the Parotid glandDamage to the teeth

Post Operativeinfection open bitere-occurrence of ankylosis

A restricted ability of the lower jaw to move is designated as contracture.

Forms of contracture:Inflammatory contracture Muscular contracture Arthrogenous contracture Fibrous contracture Neurogenic contracture

Intra-Articular CausesAnkylosisArthiritis SynovitisMeniscus Pathology

Extra-Articular CausesInfection:Odontogenic- PulpalPeriodontalPericoronalNon-Odontogenic- Peritonsillar abscessTetanusMeningitisBrain abscessParotid abscess

TraumaFractures, particularly those of the mandible and Fractures of zygomatic arch and zygomatic arch complex,Accidental incorporation of foreign bodies due to external traumatic injury Treatment: fracture reduction, removal of foreign bodies with antibiotic coverageTMJ DisordersExtra-capsular disorders – Myofascial Pain Dysfunction SyndromeIntra-capsular problems – Disc Displacement, Arthritis, Fibrosis, .. etc.Acute closed locked conditions – displaced meniscus

Tumors and Oral careRarely, trismus is a symptom of nasopharyngeal or infratemporal tumors/ fibrosis of temporalis tendon, when patient has limited mouth opening, always premalignant conditions like oral submucous fibrosis (OSMF) should also be considered in differential diagnosis.Drug TherapySuccinyl choline, phenothiazines and tricyclic antidepressants causes trismus as a secondary effect. Trismus can be seen as an extra-pyramidal side-effect of metaclopromide, phenothiazines and other medications.

Radiotherapy and ChemotherapyComplications of Radiotherapy:Osteoradionecrosis may result in pain, trismus, suppuration and occasionally a foul smelling wound.When muscles of mastication are within the field of radiation, it leads to fibrosis and result in decreased mouth opening.Complications of Chemotherapy:Oral mucosal cells have high growth rate and are susceptible to the toxic effects of chemotherapy, which lead to stomatitis.

Congenital / Developmental CausesHypertrophy of coronoid process causes interference of coronoid against the anteromedial margin of the zygomatic arch.Trismus-pseudo-camtodactyly syndrome is a rare combination of hand, foot and mouth abnormalities and trismus.Miscellaneous disordersHysteric patients: Through the mechanisms of conversion, the emotional conflict are converted into a physical symptom. E.g.: trismusScleroderma: A condition marked by edema and induration of the skin involving facial region can cause trismus

Common causesLock-jaw caused due to muscle rigidity. Pericoronitis (inflammation of soft tissue around impacted third

molar) is the most common cause of trismus. Inflammation of muscles of mastication. It is a frequent sequel to

surgical removal of mandibular third molars (lower wisdom teeth). The condition is usually resolved on its own in 10–14 days, during which time eating and oral hygiene are compromised. The application of heat (e.g. heat bag extraorally, and warm salt water intraorally) may help, reducing the severity and duration of the condition.

Peritonsillar abscess, a complication of tonsillitis which usually presents with sore throat, dysphagia, fever, and change in voice.

Temporomandibular joint dysfunction (TMD).[8] Trismus is often mistaken as a common temporary side effect of many

stimulants of the sympathetic nervous system. Users of amphetamines as well as many other pharmacological agents commonly report bruxism as a side-effect; however, it is sometimes mis-referred to as trismus. Users' jaws do not lock, but rather the muscles become tight and the jaw clenched. It is still perfectly possible to open the mouth.[8]

Submucous fibrosis.

Lock-jaw caused due to muscle rigidity.

Dislocation

Dislocation is a complete separation of the articular surfaces with fixation in an abnormal position.

Anterior dislocation of the condyle in which the normal anatomic relationships within the joint have been completely disrupted occurs with the condyle displaced and fixed anterior to the articular eminence.

mandibular dislocation -- the condyle (c) is anterior to the articular eminence (e)

Causes:

•Deep yawning•Prolong Dental procedures•Airway manipulation particularly in an

anaesthetised patient. •Dislocation can occur during

laryngoscopy, transoral fiberoptic bronchoscopy and intubation.

Clinical features:Clinical features:

TMJ dislocation may occur with trauma, but TMJ dislocation may occur with trauma, but most often follows extreme opening of the most often follows extreme opening of the mouth during yawning, laughing, singing, mouth during yawning, laughing, singing, vomiting, or dental treatment . vomiting, or dental treatment .

Dislocation also can result from dystonic Dislocation also can result from dystonic reactions to drugs .reactions to drugs .

Symmetric mandibular dislocation is most Symmetric mandibular dislocation is most common, but unilateral dislocation with the common, but unilateral dislocation with the jaw deviating to the opposite side also can jaw deviating to the opposite side also can occur.occur.

TMJ dislocation is painful and frightening for TMJ dislocation is painful and frightening for the patient. the patient.

On examination:

• The patient is unable to close the mouth and there is excessive salivation .

• A depression may be noted in the preauricular area. • Palpation of the TMJ reveals one or both of the

condyles trapped in front of the articular eminence and spasm of the muscles of mastication.

• Patients prone to mandibular dislocation include those with an anatomic mismatch between the fossae and articular eminence, weakness of the capsule and the temporomandibular ligaments, and torn ligaments.

• Patients who have had one episode of dislocation are predisposed to recurrence .

Diagnosis:

•The dentist bases the diagnosis on the position of the jaw and the person's inability to close his or her mouth.

•Radiographs of the TMJ are not always necessary, but should be obtained to exclude condylar fracture if the dislocation is related to trauma

•The problem remains until the joint is moved back into place. However, the area can be tender for a few days.

Treatment :

• The muscles surrounding the temporomandibular joint need to relax so that the condyle can return to its normal position.

• Many people can have their dislocated jaw corrected without local anesthetics or muscled relaxants. However, some people need an injection of local anesthesia in the jaw joint, followed by a muscle relaxant to relax the spasms.

• The muscle relaxant is given intravenously (into a vein in the arm). Rarely, someone may need a general anesthetic in the operating room to have the dislocation corrected.

• In this case, it may be necessary to wire the jaws shut or use elastics between the top and bottom teeth to limit the movement of the jaw.

• To move the condyle back into the correct position, a doctor or dentist will pull the lower jaw downward and tip the chin upward to free the condyle .

• The doctor or dentist then guides the ball back into the socket.

• After the joint is relocated, a soft or liquid diet is recommended for several days to minimize jaw movement and stress.

• People should avoid foods that are hard to chew, such as tough meats, carrots, hard candies or ice cubes, and advice not to open their mouths too widely.

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, for example by placing their fist under their chin when they yawn to keep from opening their mouths too widely.

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, surgery may be necessary. Eminectomy removal of the articular eminence so

that the ball of the joint no longer gets stuck in front of it.

Another procedure involves injecting medications into the TMJ ligaments to tighten them.

Prognosis:

•The outlook is excellent for returning the dislocated ball of the joint to the socket.

•However, in some people, the joint may continue to become dislocated , If this happens, needs surgery.