condylar injury

condylar injury

Mental foramen for V3 sensory branch

Coronoid process of mandible

Mandibular notch

neck

condyle

Mandibular fossa

Articular emminence

Categories of condylar injuries:
1- Contusion: Injuries to the soft tissues around the joint or an effusion within the joint.
2- Dislocation: Mean displacement of the condylar head from glenoid fossa but still within the capsule.
3- Fracture: Intracapsular( head or neck) and extra capsular (neck or subcondylar)

Classification of condylar fracture

1-unilateral or bilateral fracture.
2- intra capsular or extra capsular.
3- Lindahls classification:
1- Level of condylar fracture into :
a- Condylar head fracture ( intra capsular) . They are further classified into vertical fracture, compression fracture, and comminuted fracture.
b- Condylar neck fracture : Which is the thin constricted area located immediately below the condylar head .

c- Sub condylar fracture : the region below the neck .

2- relationship of the condylar segment to the mandible into :
a- un displaced ( hair line fracture).
b- deviated .
c- displaced with medial or lateral overlap.
d- displaced with anterior or posterior overlap.
e- no contact between the fracture segments.


Signs and symptoms of condylar fracture.

1 -Signs of trauma like wounds over the chin or ecchymosis or hematoma over the TMJ.
2- Swelling over the TMJ due to hematoma, edema, or dislocated condyle which is visible and palpable.
3- Bleeding from the external auditory canal (superior dislocation).


4- Battles sign which is ecchymosis of the skin below the mastoid process . This also occur with fracture of the base of the skull.

5- Deviation of the mandible towards the fractured side on opening the mouth.

6 - When there is medial dislocation of the joint, there will be a characteristic hollow is seen in the preauricular region.




7- Gagging of the occlusion( posterior pre mature contact) in the ipsilateral side with ipsilateral midline shift.
8- Pain and tenderness over the TMJ region .
9- Pain during lateral excursion to the opposite side and during protrusion.
10- Facial asymmetry.
11- Crepitation over the TMJ.
12- In bilateral fracture there is anterior open bite.


Investigations:
OPG
transcranial view of the TMJ
revers Townes view.
CT scan.
MRI.

Treatment of condylar fracture

It may be conservative or surgical :
1- Conservative treatment : It may simple observation and soft diet or may include IMF for a short period of time.
2- Surgical treatment or open reduction: the joint space is surgically exposed and the condyle fixed in its original position by wire or plate.

Conservative

1- Minimal displacement: No active treatment . A normal occlusion is maintained which allows bony union to occur. In fracture-dislocation a functional psuedoarthrosis may be produced.
2- Persistent malocclusion or severe pain indicated for a short period of IMF(7-10 days).until edema and muscle spasm disappear.
3- Bilateral fracture: a longer period of IMF (3-4) weeks with posterior distraction block.
Elastic traction may be necessary to close anterior open bite.

Indications for open reduction of condylar fracture

Absolute indication
1-Fracture dislocation of the condyle to the middle cranial fossa.
2- Lateral fracture dislocation of the condyle.
3- Impossibility to achieve adequate occlusion by closed reduction .
4- Invasion by foreign bodies.(compound fracture as in gun shoot)


Relative indications:
1- Patient in whom IMF is not recommended like mentally retarded patient , epileptic patient, or those having severe respiratory disorders.
2- Bilateral fracture condyle with comminuted midface fracture.
3- Bilateral fracture condyle of edentulous patient with atrophic ridges in whom splinting is not recommended.

Surgical approach to the TMJ

1- Pre auricular approach.
2- Sub mandibular approach .
3- Intra oral approach.
4- Bicoronal flap in bilateral condylar fracture.
Methods of surgical treatment include;
1- bone plating
2- transosseous wiring
3-K wire
4- external pin fixation.

Complications of condylar injuries

1- TMJ pain /dysfunction syndrome.
2- Disturbance of mandibular growth.
3- TMJ ankylosis.


Condylar fractures
Intraoral approach
Ramus incision

Extraoral approach

Preauricular approach
Retromandibular approach