This document describes surgical techniques for treating TMJ ankylosis in children, including: 1. Excising the ankylotic mass through a preauricular incision and reconstructing the ramus condyle unit with either a costochondral graft or distraction osteogenesis. 2. Lining the glenoid fossa with a vascularized temporalis fascia flap to prevent reankylosis. 3. An intensive post-operative physical therapy regimen to regain jaw mobility.

1. 2009 American Association of Oral and
Maxillofacial Surgeons
J Oral Maxillofac Surg 67:1966-1978,
2009

3.  The TMJ is approached through a
preauricular incision with a temporal
extension (hemicoronal incision) to expose
the temporalis fascia and muscle,
zygomatic arch, ankylotic mass, and
sigmoid notch.
 The periosteum over the arch is incised
horizontally, and the incision is continued
inferiorly over the bony or fibro-osseous
mass and extended to the identifiable
unaffected portion of the ramus.

4.  Aggressive excision of the fibrous and/or bony mass is performed.
 If any TMJ anatomy is identifiable, the superior osteotomy is extended
into the joint to separate the ramus from the skull base.
 If a sigmoid notch is identifiable, the inferior osteotomy is created from
the notch, extending posteriorly at least 1.5 to 2 cm below the margine
of the ankylotic mass.
 A bur is used to reshape the skull base into a glenoid fossa.

6.  A hole is made at the base of the
coronoid process, and a wire is placed
for traction .
 The osteotomy extends from the depth
of the sigmoid notch to the junction of
the horizontal and vertical rami of the
mandible.
 Once the osteotomy is completed,the
coronoid is placed on traction with the
wire,
 The remaining temporalis muscle and
tendon attachments are cut, and the
entire coronoid is removed.
 Coronoid tip removal – inadequate-
reforms and attaches to temporalis
tendon.

8.  If an intact disc is identified during
resection of the ankylotic mass, it is
dissected, mobilized, and repositioned
to line the roof of the new glenoid fossa.
 In other cases, the TMJ is lined with a
previously described inferiorly based
temporalis muscle fascia flap rotated
over the arch into the joint.
 The temporalis flap is pedicled
inferiorly on the deep temporal artery.

9.  The deep temporalis fascia and the superficial muscle layer are
transferred to construct a barrier  to support the function of the
reconstructed ramus/ condyle unit and to maintain flap vascularity.

10.  The flap is sutured medially, anteriorly, and posteriorly to the soft
tissue with 4-0 monocryl suture.

11. 1. Reconstruction with costochondral graft.
2. Reconstruction using distraction osteogenesis.

12.  Reconstruction of the ramus condyle
unit (RCU) is achieved with a CCG
obtained by an infra-mammary
incision.
 The cartilage is contoured to be no
more than 1 to 2 mm thick and should
be rounded at the edges.
 The rib is trimmed and contoured to
produce a good bony interface.

13.  The cartilaginous articulating surface of the graft is then placed
against the temporalis flap through the submandibular incision
and rigidly secured with a 2.0-mm titanium bone.
 The wounds are closed in layers.

14.  The mandibular stump is reshaped to
make it narrow and rounded at the top.
 A corticotomy is created distally, leaving
enough bone to serve as a transport
disc.
 The distraction device is secured, the
corticotomy completed, and mobility of
the segment tested by activating the
semiburied unidirectional distraction
device ..
 Active distraction starts 2 to 4 days after
the operation at a rate of1 mm/day
with a rhythm of 2 or 4 activations daily.

15.  Once the transport disc has contacted the skull base, the
distraction is stopped so as not to create pressure on the flap or
disc lining the joint.
 The advantages of reconstruction using transport DO are the
lack of donor site morbidity and the ability to start physical
therapy the day of the operation.

19.  It consists of active hinge opening
and lateral excursions combined
with manual finger stretching in
front of a mirror.
 The exercises are done 4 times
daily for 3 to 5 minutes by the
clock.
 At 6 weeks postoperatively, the
diet is advanced to solid foods, and
the “Thera- Bite Jaw Rehabilitation
System is used 4 to 5 times daily for
3 to 5 minutes .
 The physical therapy program also
includes heat, massage, and gum
chewing.
 If the patient is not able to
achieve the documented
intraoperative MIO, or if the
MIO shows no sign of
improvement at 6 to 8 weeks,
the jaw should be stretched
with the patient under general
anesthesia.
 The use of the TheraBite 3 to 4
times daily, gum chewing, and
finger stretching exercises
should be continued for 1 year,
and patients should be
followed closely for at least 1
year.

22.  In a more recent retrospective
analysis of 11 children younger
than 16 years of age treated by
this protocol
8 patients had ankylosis secondary
to trauma,
1 had hemifacial microsomia,
1 an infection,
and 1 congenital ankylosis.
 In 2 patients, both joints were
affected.
 The ramus condyle unit was
reconstructed with either a CCG
(n 6) or DO (n 5).
 The patients were followed for a
period of 4 to 74 months (mean
24.8).
 The mean preoperative MIO was
11.5 mm (range 1 to 23).
 Postoperatively, the mean MIO
was 38.2 mm (range 15 to 49).
 Ten of 11 patients had an MIO
greater than 30 mm after the
operation and 1 had to have
fibrous ankylosis release 6 years
after the first operation.

24.  Facial asymmetry progressively worsens because of the hypomobility
and abnormal muscle function.
 The short ramus condyle unit restricts mid-face growth.
 The longer the duration of hypomobility, the more severe will be the
muscle atrophy and facial asymmetry.
 If secondary elongation and hypertrophy of the coronoid process 
restricting jaw motion

25.  A vascularized temporalis myofascial flap is
desirable for lining the joint because the donor
site is in the surgical field, the muscle and fascia
are of adequate thickness, and its long-term
viability.
 It also acts as a barrier to excessive bone
formation, fusing the RCU to the skull base.

26.  The benefits of a CCG its growth potential, its biologic
compatibility, and its capacity to remodel into a neocondyle with
time.
 Its major drawbacks donor site morbidity and reported
unpredictable growth.
Perrott and Kaban described 2types of overgrowth:
1) linear overgrowth resulting in asymmetric or bilateral prognathism;
2) Tumor like overgrowth and reankylosis.
Both types of overgrowth are caused by an excessive cartilaginous cap
on the graft.
The rib growth center is the costochondral junction. A
cartilaginous cap greater than 1 to 2 mm transfers an excessive
portion of the growth center, resulting in linear overgrowth.

27.  DO has the advantage of eliminating donor site
 morbidity and allowing immediate mobilization ofthe
jaw.
 This allows the patient to begin mobilizing the jaw on
the night of the operation.
 A major disadvantage is that a growth center is not
transplanted.
 Additional surgeries might be necessary to correct any
residual asymmetry after the end of growth.