A PROTOCOL FOR
LEONARD B. KABAN ET AL
J ORAL MAXILLOFAC SURG
Mandibular hypomobility results from a variety of disorders affecting
the temporomandibular joint (TMJ) and surrounding structures.
It may be classified by a combination of:
• Location (intra- or extra- articular).
• Type of tissue involved (bony, fibrous, or fibro-osseous).
• Extent of fusion (complete, incomplete).
Ankylosis is most commonly associated to:
• Trauma (31% to 98% of cases).
• Local or systemic infection (10% to 49%).
• Systemic disease (1O%).
TRAUMA Intra-articular hematoma + scarring and excessive bone
LOCAL Hematogenous spread including tuberculosis, gonorrhea,
and scarlet fever.
SYSTEMIC Ankylosing spondylitis, rheumatoid arthritis, and
The TMJ approach
Through a curvilinear preauricular incision.
After exposure and identification of the site
of ankylosis Aggressive excision of the
fibrous or bony mass was carried out.
Coronoidectomy, and dissection and
stripping of muscle (temporalis, masseter,
and medial pterygoid)
Excision of the ankylotic tissue and
coronoidectomy usually resulted in loss
of one third of the ramus height.
Following excision of the ankylotic mass and coronoidectomy
If the MIO was less than 35 mm (without the use of force), a contralateral
coronoidectomy was performed via an intraoral approach.
After optimal interincisal opening was achieved, the joint was
LINING OF GLENOID FOSSA
If an intact disc
During the resection of the mass, it was maintained to line the glenoid fossa.
In other cases, the TMJ was lined with a finger-shaped temporalis fascia
flap rotated over the arch into the joint.
The thickness of the flap was dictated by the joint space requirement. A
minimum of 4 mm is necessary.
Following resection of the fibrous mass + coronoidectomy + lining of the
Maxillomandibular fixation (MMF) using a prefabricated occlusal
splint to establish the occlusion.
A 2mm posterior open bite was created to compensate for
remodeling of the costochondral graft.
Reconstruction of the condyle was
achieved with a 6-cm costochondral graft.
The cartilage was contoured to be 5-mm
thick and round in shape.
The lateral ramus was exposed via a
submandibular incision and both the
ramus and rib were trimmed and
contoured to produce a good bony
The top of the graft was then placed
against the temporalis flap and rigidly
secured to the mandible with two or
three 2.7-mm tapped bone screws.
A drain was placed, the incisions
were closed, and a pressure dressing
DIET & PHYSIOTHERAPY
After release of MMF, patients were started on a soft diet and jaw-
Active hinge opening, lateral excursions and manual finger stretching.
During the next 3 to 4 weeks, the diet was advanced to a solid
Many operative techniques have been described in the literature, but
results have been variable and often less than satisfactory.
1. Gap arthroplasty.
2. Interpositional arthroplasty.
3. Joint reconstruction with autogenous or alloplastic materials.
When performing a gap arthroplasty, the surgeon bypasses the intra-
articular ankylosis and creates a gap distal to the fused TMJ.
1. Simplicity and short operating time.
1. Creation of a pseudo-articulation and a short ramus.
2. Failure to remove all the bony pathology.
3. Increased risk of reankylosis.
MIO greater than 30 mm was reported in only 5 of 20 (25%) patients
by Topaziann and 11 of 17 (65%) by Rajgopal et al.
In the case of an interpositional arthroplasty, autogenous or
alloplastic materials are placed in the ostectomy site to prevent
recurrent ankylosis. Acrylic resin, skin, and dermis have all been
used for this purpose.
1. Similar as GAP ARTHROPLASTY.
1. Donor site morbidity if autogenous materials.
2. Risk of foreign-body reaction if alloplastic materials.
3. Failure to remove all the bony pathology.
MIO of greater than 35 mm was reported in 2 of 70 (2.8%) patients
32 of 76 (42%) by Popescu et al and 12 of 17 (70%) patients by Hili.
TMJ ankylosis also has been treated by excision and total joint
reconstruction with alloplastic or autogenous materials.
1. Lack of a donor site.
2. Immediate return to function.
1. Foreign-body reaction to some materials.
2. Erosion of metal condylar prothesis into the glenoid fossa.
3. Suboptimal postoperative range of motion.
4. Loosening of the screws and loss of stability.
Kent et al reported an increased MIO in 44 of 76 (58%) patients.
For autogenous materials, eg, costochondral rib grafts,
sternoclavicular joints, iliac crest grafts.
1. Biologic acceptability and remodeling by appositional growth,
especially in children.
1. Donor site morbidity, such as pneumothorax and pleuritic pain,
potential overgrowth of the graft, and suboptimal postoperative range
Lindquist et al reported a mean MIO of 30.5 mm in a series of 27
Munro et al reported an MIO of greater than 35 mm in 3 of 17 (18%)
Regardless of the technique used, a mean post- operative MIO
greater than 35 mm is rarely achieved.
For this study, they have defined normal function as an MIO greater
than 35 mm, the ability to make lateral excursions, minimal to no
pain during function and resumption of a normal diet.
The approach described in this study includes seven steps:
1. Aggressive resection of the bony or fibrous ankylotic segment.
2. Ipsilateral coronoidectomy.
3. Contralateral intraoral coronoidectomy when necessary.
4. Consists of creating a new joint lining.
5. Reconstruction of the ramus with a costochondral graft.
6. Securing it with rigid fixation.
7. Consists of early mobilization and aggressive physiotherapy.
1 pediatric patient did develop a contour abnormality and required
revision for cosmetic reasons
On exploration the graft had developed lateral overgrowth at the
The results of this study indicate that this protocol is effective for
treatment of TMJ ankylosis.