TMJ

1. Pathogenesis of post-traumatic ankylosis
of the temporomandibular joint: a critical
review

2. Aetiology of ankylosis of the TMJ
 trauma(usually the most common)
 local or systemic infection (otitis media,
mastoiditis, through haematogenous spread
from diseases such as tuberculosis,
gonorrhoea, and scarlet fever)
 systemic disease (ankylosing spondylitis,
rheumatoid arthritis, and psoriasis)

3. Pathophysiology
Truma
Intra-articular haematoma
Fibrosis
Excessive bone formation
ankylosis(ultimately to hypomobility of the
joint)

4. Indicator of the severity of the
ankylosis
 Interinsical opening
 complete ankylosis is defined as a condition
when opening is less than 5 mm

5. Sequelae of TMJ ankylosis
antegoni
on
Fig. 1. Notching at the antegonion and the apparent distortion of the
mandibular structure resulting in characteristic “warping” because of
transarticular
bony adhesion.
condylar growth
arrest
forward and
downward movement
of the body
of the mandible does
not occur
localised thickening of
the bone at the angle
accentuates the
antegonion
warping

6. Aetiology of recurrence of
ankylosis
 Failure to have aggressive physiotherapy
 poor compliance by the patient
 Kaban et al. postulated that recurrent
ankylosis is primarily caused by inadequate
excision of the ankylotic mass.This results in
failure to achieve passive mouth opening
(without the need for excessive force) in
theatre. If excessive force
is necessary to open the jaw intraoperatively
then more force will be required
postoperatively

7. Methods of treatment
 gap arthroplasty,
 Interpositional arthroplasty
 osteotomy
 excision of the ankylotic mass within the TMJ
 Reconstruction of the ramus and condyle with
autogenous bone, such as costochondral
grafts, grafts using fibula, clavicle, iliac crest,
or metatarsal head, or alloplastic material
no single method has uniformly
produced successful results

8. Concept of ankylotic mass
 Salins described an ankylotic mass as being
abnormal bone
that replaces the articulation and results in
restriction of
mandibular movement
 Although it is not a neoplastic process,the bone is
capable of continued growth
 reparative process similar to that found in an
exuberant callus, typical of fractures in children or
of fractures that have not been mobilised
adequately

9. Concept of ankylotic
mass(Cont.)
• Remodelling does not occur in ankylosis of
the TMJ, and the joint is usually surrounded
by very dense fibrous tissue which further
limits mandibular movement
Fig. 2. Intraoperative view of post-
traumatic transarticular bony
adhesion
(primary ankylotic mass).
Fig. 3. Intraoperative view of
recurrence of ankylosis (secondary
ankylotic
mass).

10. Is formation of an intra-articular haematoma alone
the primary cause of ankylosis and its recurrence?
 intra-articular haematoma alone may lead to
ankylosis of the TMJ
 Oztan et al. concluded that trauma causing
haemorrhage in the joint space may not give rise
to ankylosis as it does not always progress to
form bone.

11. Does the meniscus play a prime role in the
adhesion
of articular surfaces?
 meniscus normally serves as a barrier to prevent
fusion
of the condyle with the glenoid fossa
 disc is damaged,the condyle and glenoid may
fuse if the bony surfaces are also damaged and
there is a haematoma between them
 contributing factors
 direct bone-to-bone contact
 close approximation of the articular components
 prolonged mechanical immobilisation
 muscular splinting

12. Does the meniscus play a prime role in the
adhesion
of articular surfaces (Cont.)
.
 The principle behind release of an ankylotic mass
with an
interpositional graft (either autogenous or
alloplastic) is to
prevent adhesion between the two bony cut
surfaces
 Aggressive excision of the mass alone with no
interposition might leave a dead space and allow
a haematoma to form, which, together with
opposing cut bony surfaces would lead to
scarring and repeated adhesion or ankylosis

13. Does ankylosis of the TMJ follow the characteristic
steps of distraction osteogenesis because of
traction of
the lateral pterygoid muscle?
 distraction osteogenesis caused by traction of the
lateral pterygoid muscle on the bone after sagittal
fracture of the mandibular condyle is an important
factor in the genesis of traumatic ankylosis of the
TMJ
 After a sagittal split of the condyle, the lateral
pterygoid muscle pulls the bony fragment in a
medial and upward direction away from the
condylar region, so its role in ankylosis is not
convincing

14. Medially dislocated condylar fracture and ankylosis
of the TMJ
Dislocation of the condylar head
fracture
Large haematoma fill in cavity
Ossification
BMP, TGFactivate osteoblasts

15. Does the formation of ankylosis after trauma follow
the characteristic events of fracture healing?
 Ankylosis cannot be correlated with fractures
because it involves the fusion of two different
bony surfaces (condyle with cancellous, and
glenoid with compact bone); one static, and one
constantly mobile)

16. Role of the sagittally split condyle in
transarticular
adhesion of the TMJ
 In 1982, Rowe reported that ankylosis can be a
result of
anteroposterior (sagittal) fracture of the condyle
 In 2008, He et al. suggested a strong relation
between
sagittal split condylar fractures and simultaneous
mandibular
fractures in the pathogenesis of ankylosis of the
TMJ
 juxta-articular type of ankylosis (The fractured
surface of the
ramus or lateral condylar pole displaces laterally
and possibly

17. Is protein-energy malnutrition a predisposing factor
for traumatic adhesion in the TMJ?
 Developing countries (China, Africa, or India)
 larger populations, genetic predisposition, the
lack of availability of proper care, or inadequate
care because of poorly equipped hospitals,
neglect of minor facial trauma
 rats that malnutrition results in impaired callus
formation, as well as fibrous ankylosis in the TMJ
on healing of a displaced condylar process
(proliferation of connective tissue, and atrophy of
condylar fibrocartilage that led to transarticular
fibrous adhesion)