hypermobility and ankylosis

Temporomandibular Joint:Hypermobility and Ankylosis

Hanan Shanab- SBOMFS-R4

99Chapte

r

ETIOPATHOGENESIS

• HYPERMOBILITY• Subluxation

• Dislocation .

• Recurrent joint dislocation is associated with severe pain and loss of function.

PATHOLOGIC ANATOMY

Hypermobility:• lateral TMJ ligament,and retrodiscal tissue may be lax

and allow excessive condylar movement anterior to the articular eminence.

• Patients with subluxation and dislocation is a relatively small articular eminence.

DIAGNOSTIC STUDIES

HYPERMOBILITYClinically:• the patient has anterior open bite of several centimeters• Palpable depression immediately in front of the tragus (empty glenoid

fossa).

DIAGNOSTIC STUDIES

Radiographically:OPG:• The condyle anterior to the articular eminence in the infratemporal

fossa.• Used to confirm adequate reduction of the dislocation.

CT:MRI:• will provide soft tissue imaging that allows the magnitude of joint

translation and disc position to be seen.• it has little to offer in the acute setting.

TREATMENT

HYPERMOBILITY

Recurrent dislocation can be treated according to one of three basic philosophies: 1-First:

to provide a mechanical barrier to joint translation through bony augmentation of the articular eminence or down-fracture of the root of the zygomatic bone (Dautrey procedure).

2- The second philosophy :• Eliminates the mechanical barrier to relocating

the condyle when it translates past the articular eminence by an eminectomy.

• Lateral pterygoid myotomy.

The third philosophy:also reduces joint translation but through plication..

-Intra-articular injection to create excessive fibrous tissue :• sclerosing agents such as sodium tetradecyl sulfate and

sodium morrhuate• Autologous blood

-arthroscopic scarification of the capsule, retrodiscal tissue, and disc with the use of sclerosing agents, cautery, and laser has been reported. These techniques are difficult.

1- Create a mechanical obstruction

The Dautrey procedure (Le Clerc)

•is a simple extra-articular surgical procedure. •Indicated for

patients who have no symptoms of intra-articular pathology.

•Disadvantage:• bone remodeling and the potential for recurrent

dislocation.


•Technique:• A standard preauricular incision • Subperiosteal dissection to

expose the lateral aspect of the articular eminence and root of the zygoma.

• A periosteal elevator is then used to elevate only the most inferior aspect of the temporalis muscle medial to the root of the zygoma.


• The same elevator is then passed deep to the root of the zygoma just into the infratemporal fossa to protect the soft tissues.

• A reciprocating saw is used to osteotomize the root of the zygoma in an oblique manner from post. to ant.

• The displaced zygoma usually maintains its new position without any fixation.

2- Arthroplasty

Arthroplasty

Indication: • intra-articular pathology in addition to

hypermobility. • patients with symptomatic internal

derangement and recurrent dislocation.• The internal derangement should be confirmed

with MRI before the surgical procedure.

Procedure of arthroplasty

• After exposing the joint.• Placement of 0.054 Kirschner wires in the lateral aspect

of the articular eminence and neck of the condyl. • incision 2 mm below the the fossa accessing the

superior joint space. Then to the inferior joint space by incising vertically through the joint capsule and horizontally through the lateral collateral check ligament. The disc can then be mobilized with a periosteal elevator.

• The most frequent location of adhesions:• within the superior joint space are often the anterior

slope of the eminence or the lateral aspect of the eminence.

• within the inferior joint space is the medial pole.


•adequate disc mobility must be achieved.• The redundant retrodiscal tissue can then be assessed and excised with tenotomy scissors, and •plication of the disc to the retrodiscal tissue is begun medially (mini–bone anchor), several 5-0 Vicryl sutures (Ethicon, Inc., NewJersey) sutures are placed through the posterior aspect of the discand the retrodiscal tissue.


•perforation is present, there may be insufficient tissue to plicate the•disc.• Retrodiscal tissue can he horizontally divided as far as the tympanic plate to transect the vertical collagen fibers & allows greater forward movement of the tissue. •Plication:• 1- may require a double-layered closure, one for the

superior lamina and one for the inferior lamina of the retrodiscal tissue.

• 2-Retrodiscal tissue can be elevated off the tympanic plate and pedicled inferiorly closed as single-layered.


•Lateral plication is performed by attaching the lateral aspectof the disc to the inferior/lateral joint capsule. Three or four horizontalmattress sutures using 4-0 Vicryl are placed in this fashion.The Wilkes retractor is then closed and the lateral aspect of thesuperior joint space closed with similar suture material. Subsequentto the plication, only a limited degree of joint translation should bepossible.

3- remove the obstruction

Eminectomy

Eminectomy

is a procedure that eliminates the articular eminence. It can be combined with arthroplasty,(rare)•useful when other surgical procedures have failed. •Technique:• Entry is made into the superior joint space. A

combination of fissure burrs, osteotomes, or a reciprocation rasp can be used to remove the inferior aspect of the articular eminence.

Procedure of Eminectomy

•During eminectomy the medial soft tissues envelope should not be breached because of the potential for substantial bleeding.• A reciprocating rasp or bone file can then be used to smooth the residual articular eminence. •Irrigation •Closure of the superior joint space •At the completion of the procedure the condyle should be manipulated & move freely without restriction.

POSTOPERATIVE CARE

POSTOPERATIVE CARE

• In the 1st 3 weeks Patient should be instructed to limit opening while eating and yawning.

• Beginning in the 4th week encourage physical activity to prevent excessive fibrosis and limited opening.

• The use of moist heat and non-steroidal antiinflammatory medication before physical therapy can be a tremendous advantage.

POSTOPERATIVE CARE

• Patients should open maximally by using the thumb and middle finger on the incisal edges of the anterior teeth to stretch, and this position should be held for 10 seconds.

• repeated 10 times.• Lateral excursive movements should also be

performed. • The exercise should be performed bilaterally

ANKYLOSIS

ANKYLOSIS

• Ankylosis is a Greek terminology meaning 'stiff joint’. It can be defined as "inability to open mouth due to either a fibrous or bony union between the head of the condyle and the glenoid fossa".

• It can also causes disturbances of facial and mandibular growth, and acute compromise of the airway invariably resulting in physical and psychological disability .

DIAGNOSTIC STUDIESClinically Radiographicaly

Fibrous Ankylosis:

• Limited MIO and,•when unilateral, reduced lateral excursion toward the unaffected side.

no significant finding

Bony Ankylosis: •no incisal opening•no lateral excursions.

OPG:•heterotopic bone formation and no joint spaceCT:• best imaged with axial and coronal &(3D) reconstructedimages provide the most detail. For all but the most simple bonyankyloses,

Classification of ANKYLOSIS

Type I – decreased joint space with dense fibrous adhesion

(The condyle is present and there are only fibrous adhesions)

Type II –decreased joint space with dense fibrous adhesion , which also exhibits lateral lipping and bony bridge.

(There is bone fusion, the condyle is remodeled, and the medial pole is intact)

Type III – broad bony bridging from the lateral ramus to the zygomatic arch .(There is an ankylotic block, the mandibular ramus is fused to the zygomatic arch, the medial pole remains intact)

Type IV - complete bony fusion.(There is true ankylotic block and the anatomy is deranged because the ramus is fused to the skull base.)

Sawhney classification

Stage I Ankylotic bone limited to condylar process.

Stage II – ankylotic bone reach the sigmoid notch .

Stage III - ankylosis extends to the coronoid process.

Topazian Classification

Clinical picture

• Restricted mouth open and its associated sequelae including poor oral hygiene and caries.

• Facial asymmetry • Mandibular micrognathia and bird face deformity

• Class II malocclusion with posterior cross bite / anterior open bite.

Radiographic features

• After inability to open the mouth ,repetitive isometric contraction of the temporalis muscle can lead to muscle hypertrophy and subsequent elongation of the coronoid process

• Repetitive isometric contraction of the massetric muscle can lead to muscle hypertrophy and subsequent accentuation of antigonial noutch.

• Union between the head of the condyle and the glenoid

• fossa

Radiographic features

• Widening of the ramus

treatment

Treating of fibrous ankylosis

•Fibrous ankylosis of the TMJ can generally be treated more conservatively than bony ankylosis. •depend on:• the degree of fibrosis and the residual anatomy of the

joint. • This is often determined by the degree of movement

possible on clinical examination, • the number of previous joint procedures.• findings on CT.

Treating of fibrous ankylosis

• Accessing intracapsular,,,• The degree of fibrosis is often variable. • It may be possible to explore the superior& inferior joint

space and lyse the adhesions and fibrosis.• Evaluate the disc for plication or discectomy with

interpositional graft. • Postoperative physical therapy is crucial to help prevent

recurrence

Treatment of BONY ankylosis

1- Gap arthroplasty with /out reconstruction with autogenous or alloplastic material.

DisadvantagesGenerating a pseudo-articulation, shortening of the mandibular ramus and ,Increase the risk of recurrence

Complications: • The development of an open-bite in bilateral

cases.• Premature occlusion on the affected side with

contralateral open bite in unilateral cases. • limited mouth opening post-operatively are

possible

• autogenous tissue • possible recurrent ankylosis at a rate that may be as high as

20-30%• first episode of ankylosis. • Pediatric patients, • Fascia lata,dermis, cartilage, fat, and temporalis

fascia/muscle have all been used.

Treatment of BONY ankylosis

2-total joint replacement

• For recurrent ankylosis.• Aggressive postoperative physical therapy is the key to reduce this risk

for recurrent ankylosis.

Costochondral grafts have the potential to provide additional growth.The supplementary use of low-dose radiation (10 cGy) has beenshown to reduce heterotopic bone formation and may be consideredin the postoperative period in patients reconstructed with autogenoustissue.

Technique of Gap arthroplasty

Kaban protocol:1-Wide intraoperative exposure is required, bony, fibrous, and granulation tissue are completely removed

• A 703 fissure burr is then used to remove2 mm of bone progressing in a lateral to medial direction at the cleavage plane between the original condyle and glenoid fossa or more inferior than the original location of the glenoid fossa.

• The medial extent of the bony ankylosis should not be breached with the burr & final separation of the bone is best achieved with a twist osteotome.


2- Dissection and stripping of the temporalis, masseter, and medial pterygoid muscles followed by ipsilateral coronoidectomy are performed in all cases.3- After this resection is completed, the MIO is measured. If it is found to be < 35 mm, contralateral coronoidectomy is performed via an intraoral approach to attain the desired level of opening


4-subsequent reconstruction must address this fact and attempt to restore occlusion as well as function.

A-temporalis muscle/fascia flap is harvested as a full-thickness flap, • teeth are placed into a prefabricated occlusal splint. • MMF for 10 days• after release a strict protocol of physiotherapy is employed


• B- If costochondral reconstruction is planned, removal of more bone (2 cm below the first cut)• This is usually combined with a temporalis

muscle/fascia flap.


C- Total joint replacement.• For recurrent ankylosis and most non-pediatric pt.• Advantages..• include early function and a reduced frequency of recurrent ankylosis.• Disadvantages.. include the potential need to replace the joints

throughout the life of the patient.

Total joint replacement

• Stock prostheses (Biomet Microfixation, Jacksonville, Fla) or • custom-fit joints (TMJ Concepts, Ventura, Calif) are available. Total

jointTechnique:

1- 3D model must be constructed from a standard CT scan. Gap arthroplasty should be performed on the model and then the mandible repositioned to create the desired occlusion.


2- Awake fiberoptic intubation or awake tracheostomy.3- Ivy loops, arch bars, or skeletal wires should then be placed. 4- A standard preauricular approach will provide adequateaccess to the ankylosis. 5- 2 osteotomies done-the second is 2 cm inferior to the 1st and creation of a “critical size” gap.6-Coronoidectomies


•7- total joint replacementA- If two-stage surgery is• Place additional sterile towels over the surgical sites. • the mandible should be placed in the correct

occlusion and secured with (MMF). • Before returning to the surgical field, the surgeon

should place a towel, OpSite, or other sterile drape to cover the oral cavity, as well as change gloves.

• The previous gap arthroplasty sites should be inspected forsmooth line angles and hemostasis.

• A Silastic block can then be carved to fill the gap and placed to maintain space.

• wound can then be closed and the patient left in MMF.


• A postoperative CT scan. A 3D model will be made & a custom TMJ prosthesis made.

• A second surgical procedure should be planned in 5 or 6 weeks•Stage II surgery • begins with release of the MMF. • fiberoptic intubation• A standard preauricular approach

•Silastic block which is easily removed.•any immature granulation tissue can be removed.•retromandibular incision.


• the parotid gland and branches of the facial nerve are swept forward and superiorly.

• Subperiosteal dissection from the angel to the ramus• The fossa and ramus prosthesis may be soaked in a topical antibacterial

solution prior to insertion. • Placing the patient back in MMF• attention can then be directed to the preauricular incision placing of

the fossa & fixation by 2mm screws..


•Retromandibular incision. The ramal/condylar component is positioned carefulyl to ensure that the condyle is seated in the most posterosuperior position within the fossa. •The component is then securedwith bicortical 2-mm screws.This requires a preoperative 3D stereolithographic model for planning .


•Stock prostheses require a relatively normalanatomy so that the fossa and condyle components fit appropriately. •When the anatomy is severely altered, a better choice is a custom-fit joint. •The potential use of autologous fat should be considered if concern for heterotopic bone formation and recurrent ankylosis is great. •The fat is easily harvested from the abdomen and packed around the condyle. •The wounds are then closed in standard fashion.

Post op care

• physical therapy regimen following release of ankylosis is important(minimum of 3 months) .

• Good analgesics.• Several devices have been manufactured to assist patients with

physical therapy. • All rely on patient compliance (pediatric population).

• TheraBite (Atos Medical, Inc., West Allis, Wisc.) • Dynasplint (Dynasplint, Severna Park, Maryland)• Tongue blades.

Thank you

hypermobility and ankylosis

Health & Medicine

recurrent joint dislocation

lateral aspect

superior joint space

inferior joint space

temporomandibular joint

small articular eminence

redundant retrodiscal

insufficient tissue