Ankylosis
Inability to open the mouth beyond 5mm of interincisal opening due to fusion of the head of the condyle of the mandible with the articulating surface of the glenoid fossa and termed as ankylosis of the Temporomandibular joint. It may be partial or complete or either fibrous or bony.
Classification:
1. Partial or complete ankylosis
2. Fibrous or bony ankylosis
3. False ankylosis or true ankylosis
4. Extra-articular or intra articular ankylosis
5. Unilateral or bilateral ankylosis
Causes of Ankylosis:
1. Causes of mechanical interfere with opening (pseudo-ankylosis):
Trauma: due to fracture of Zygomatic bone or arch
Hyperplasia: developmental over growth of the coronoid process
Neoplasia:
Osteoma
Osteochondroma
Osteosarcoma
Miscellaneous: congenital anomalies
2. Causes of extra caplsular ankylosis (false-ankylosis):
Trauma: wounds or burns which causes periarticular fibrosis
Infection: chronic periarticular suppuration
Neoplasia:
Chondroma
Chondrosarcoma
Fibrosarcoma of the capsule
Particular fibrosis due to:
Irradiation
Oral submucous fibrosis
Progressive systemic sclerosis
3. Causes of intra caplsular ankylosis (true-ankylosis):
Trauma:
Intra-capsular comminuted fracture of condyle
Penetrating wounds
Forcep delivery at birth
Infection:
Otitis media
Osteomyelitis of jaw
Pyogenic arthritis
Systemic juvenile arthritis:
Psoriatic arthropathy
Osteo arthritis
Rheumatoid arthritis
Neoplasia:
Osteoma
Chondroma
Osteochondroma
Miscellaneous:
Synovial chondromatosis
Clinical features:
It occurs in any age but commonly occurs below 10 years.
Both sexes are equally affected.
Inability to open the jaw.
Difficulty in mastication the food.
Compromised oral hygiene and speech.
Disturbance in respiration leading to breathing distress.
Patient has multiple carious teeth in the mouth and seeks consultation for tooth-ache.
A scar on the chin can be seen with history of trauma.
In the unilateral ankylosis, some degree of movement is possible because of the normal joint on the
opposite side. In this case, face is asymmetrical with fullness on the affected side of the mandible
and flattening on the unaffected side.
In bilateral ankylosis, it develops a typical ‘bird face’ appearance with a retruded chin.
In fibrous ankylosis, some degree is also possible.
In bony ankylosis, interincisal opening is invariably less than 5mm.
Radiological examination:
X-rays for TMJ both in open and closed mouth position should be taken.
In fibrous ankylosis, the joint space is visible but no movement of the condyle is seen.
In bony ankylosis, a bony mass is seen in the area of the joint with obliteration of the joint space
along with restricted movement of the condyle.
Cephalometric radiograph is helpful in assessment of the mandibular and maxillary skeletal defects.
Management:
1. Condylectomy
2. Gap arthroplasty
3. Inter positional arthroplasty:
Autogenous:
Temporal muscle
Temporal fascia
Dermis
Cartilaginous grafts-
Costochondral
Sternoclavicular
Auricular cartilage
Alloplastic materials:
Stainless steel
Silastic
Titanium
Tantalum foil/plate
.
