Temporomandibular joint

Temporomandibular Joint

Dr. Ahmed M. Adawy Professor Emeritus, Dep. Oral & Maxillofacial Surg.

Former Dean, Faculty of Dental MedicineAl-Azhar University

Temporomandibular Joint

The temporomandibular joint is a unique joint in body. Being diarthrodial (which permits freedom of movement) and the articular surfaces are covered by fibrous tissues instead of cartilage like other joints in the body. It is the only joint in human body to have a rigid endpoint of closure

Dr. Ahmed M.Adawy

Anatomy of the Temporomandibular Joint

The TMJ is composed of the following structures:1. The mandibular condyle 2. Articular (glenoid) fossa and eminence3. The disc (Meniscus) 4. TMJ capsule5. Temporomandibular joint ligaments

Dr. Ahmed M. Adawy

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The size & shape of the condyle varies between individuals, the superior surface could be; flat, convex, round or angled. A roughened area is present on the lateral and medial walls of the condyle known as condylar poles that give attachment to the disc

Dr. Ahmed M. Adawy

The articulator surface is composed of dense cartilaginous, non-innervated connective tissuesHistologically five different zones could be seen in the condyle starting from the articular surface:1.Fibrous connective tissue layer2.Proliferative undifferentiated mesenchymal layer containing cartilage responsible of growth3.Transitional layer 4.Layer of compact bone5.The rest of the condyle is composed of spongy bone

Dr. Ahmed M. Adawy

2. Articular (glenoid) fossa and eminence

It is the concave area of the squamous temporal bone holding the condyle. The anterior part of the fossa is projected making the articular eminence. The articular surface is covered by nonvascularized, noninnervated dense fibrous tissue layer

Dr. Ahmed M. Adawy

3. The disc (Meniscus)

Generally, the shape of the disc is oval when viewed from above. It is pear shape with the apex projects anteriorly. The disc is attached anteriorly to the lateral pterygiod muscle which pulls the disc anteriorly during mouth opening keeping always the disc between the fossa and the moving condyle. The meniscus is attached to the condyle by collateral ligaments

Dr. Ahmed M. Adawy


The disc is composed of four transverse zones anterior, intermediate, posterior bands and the bilaminar zone. The intermediate zone is avascular and thinnest in the middle lacking healing capacity. The bilaminar zone is composed of two distinguished layers; the upper stratum, which is attached to the posterior wall of the glenoid fossa, and the lower stratum, which is attached to the back of the condyle

Dr. Ahmed M. Adawy


The upper stratum consists of a meshwork of elastic and collagen fibers and it is responsible of returning the disc posteriorly. The lower stratum is composed of C.T reach in collagen fiber and it is responsible of keeping the disc attached to the condyle. The zone between the two strata is reach in blood vessels and nerves

Dr. Ahmed M. Adawy

Tmj, lateral view

Dr. Ahmed M. Adawy

4. TMJ capsule

The different component of the joint is enclosed within fibrous capsule. The attachment of the disc to the capsule divides the joint space into two compartments; upper and lower. The joint cavity is filled synovial fluid secreted by the lining synovial membrane for lubrication

Dr. Ahmed M. Adawy

5. Temporomandibular joint ligaments

The TMJ ligament is the main ligament of the joint while stylomandibular, sephenomandibular, and capsular ligaments are accessory ligaments helping in prevention of condyle from traveling far away from the glenoid fossa

Dr. Ahmed M. Adawy

Temporomandibular joint ligaments

Dr. Ahmed M. Adawy

Temporomandibular joint ligaments

Dr. Ahmed M. Adawy

Blood supply Branches from Superficial temporal & Maxillary Artery

Nerve supply Auriculotemporal & Masseteric Nerve

Temporomandibular joint

Dr. Ahmed M. Adawy

Muscles of mastication

Dr. Ahmed M. Adawy

Diseases of the Joint1. Myofacial pain dysfunction (MPD) syndrome

It is not a disease entity rather than set of etiologically related disorders. It is defined as a functional disorder characterized by facial pain and jaw dysfunction and is independent of local disease involving the teeth or mouth

Dr. Ahmed M. Adawy

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Myofacial pain dysfunction (MPD) syndrome Signs and symptoms

1. Facial pain especially with jaw movement. The pain my be acute or chronic

2. Tenderness of the masticatory muscles and muscles of the neck especially strenomastiod and trapezius

3. Limited mouth opening4. Absence of radiological or clinical evidence of

organic changes of the TMJ as disc displacement or disc dislocation

Dr. Ahmed M. Adawy

Myofacial pain dysfunction (MPD) syndrome Etiology The etiology of the MPD syndrome is controversial, but mostly

associated with some predisposing factors like: 1. Occlusal disharmony2. Psychological stress3. Bruxism4. Loss of vertical dimension due to teeth loss All these factors exert abnormal stress on the masticatory

muscles leading to their spasm due to lactic acid accumulation. The long-standing muscle spasm causes pain and tenderness as well as limit movement of the joint.

Dr. Ahmed M. Adawy

Myofacial pain dysfunction (MPD) syndromeTreatment

The condition should be treated once diagnosed. Otherwise, the joint will suffer more serious pathological changes as internal derangement. The treatment of this case is totally conservative involving correction and removal of the etiologic factors and control of pain and muscle spasm

Dr. Ahmed M. Adawy

1. Occlusal rehabilitation. 2. Splint therapy usually eliminate the muscle spasm

and pain caused by hyperactive muscles.


Dr. Ahmed M. Adawy

3. Physiotherapy in the form of muscle exercise to remove muscle spasm or by application of ultrasound or short waves to increase blood flow into the affected muscles helping in removal of the accumulated toxic products inside the spastic muscles.

4. Medication. Analgesic, anti-inflammatory and muscle relaxants are prescribed to control pain and break the pain-spasm-pain cycle.

5. Psychological counseling in some cases


Dr. Ahmed M. Adawy

Diseases of the Joint 2. Internal derangement

It is defined as abnormal relationship of the articular disc to the condyle so that the disc no longer moves in harmony with it.

Etiology1.Untreated MPD syndrome2.Acute trauma to the mandible3.Bruxism4.Malocclusion

Dr. Ahmed M. Adawy


These factors cause spasm of the superior belly of the lateral pterygiod muscle with chronic anterior pull of the meniscus leading to elongation and dysfunction of the collateral ligament as well as the distortion of the elastic fibers of the upper stratum of the bilaminar zone. Finally they will not be able to retract the disc posteriorly

Dr. Ahmed M. Adawy

So, the disc is either anteriorly displaced but is reduced to normal position during mouth opening (disc displacement with reduction) or is completely located anterior to the condyle with no reduction (disc dislocation)


Dr. Ahmed M. Adawy

Signs and symptoms of anterior disc displacement with reduction

1. Initial limited mouth opening with pain2. Pain associated with wider opening followed

by click sound3. Deviation of the jaw to the affected side4. After clicking the jaw return to normal path

resulting in zigzag condylar path

Dr. Ahmed M. Adawy

Disc position, normal

Anteriorly displaced disc with reduction

Dr. Ahmed M. Adawy

Signs and symptoms of disc dislocation without reduction

1. History of clicking sound of the joint before limitation of mouth opening

2. Limited mouth opening in bilateral cases3. Pain is experienced by attempts to increase

the range of the opening4. Jaw deviation to the affected side

Dr. Ahmed M. Adawy

Displaced disc without reduction

Dr. Ahmed M. Adawy

Diagnostic aids 1. Clinical data2. Plain radiographs provide information about the bony

component of the joint3. Tomogram, eliminates superimposition4. Computerized tomogram is considered the best

technique for evaluating the bony architecture of the TMJ

5. Arthrogram is an invasive technique and rarely used now It is useful in diagnosis of disc perforation

Dr. Ahmed M. Adawy

6. Magnetic Roasence imaging MRI . Recently it becomes the technique of choice to visualize the disc position. It is precise and noninvasive technique

Diagnostic aids

Normal MRI disk: Low signal intensity."Bow tie" configuration in sagittal plane

Dr. Ahmed M. Adawy

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Closed mouth

Open mouth

Closed

Open

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Treatment of internal derangement1. Conservative treatment It attempt to remove muscle spasm helping in return of the disc to

normal function. 2. Surgical Treatment of internal derangement This is undertaken if the conservative treatment fails or the disc is

dislocated. 3. Arthrocentesis Arthrocentesis is often the first surgical procedure that will be done

for a patient who has a displaced disc. It can be done as an in-office procedure. The main principle has been releasing the “stuck” disc from the fossa by irrigation of the superior joint space under local anesthesia

Dr. Ahmed M. Adawy

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Arthrocentesis, Tmj (lysis & lavage)

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Surgical exposure of the TMJThe joint could be approached through several incisions:1. Preauricular incision2. Endaural approach3. Post auricular approach

Dr. Ahmed M. Adawy

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Surgical Treatment of internal derangementA. Disc repositioning procedure The technique involves excision of a wedge of tissue from

the posterior band and re-sutures the disc in posterior position

B. Disc decompression The goal of the procedure is to remove a small part of the

articular surfaces, either from the condyle (High condylar shave) or from the articular eminence called eminectomy, to relieve the pressure on the nerve-rich posterior band

Dr. Ahmed M. Adawy

Surgical Treatment of internal derangementC. Menisectomy If the disc is completely distorted it is totally removed.

The joint is either left without replacing the disc or grafted with cartilage from the ear or nasal septum or other biomaterial

D. Repair of disc perforation (meniscoplasty) The disc is exposed and the perforation edges are excised

and the disc is grafted with dermal graft larger than the circumference of the perforation

Dr. Ahmed M. Adawy

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Diseases of the Joint 3. Condylar Hyper mobility

A. Hyper translation: excessive movement of the condyle during opening

B. Dislocation: movement of the condyle anterior to the articular eminence from which it cannot be reduced voluntary

C. Sublaxation: It is incomplete dislocation of the condyle in which the condyle moves anterior to the articular eminence and the patient is able to return it back to the fossa either spontaneously or after self manipulation

Dr. Ahmed M. Adawy

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Signs & symptoms of dislocation

1. In bilateral cases the mandible is fixed in anterior opened position

2. In unilateral case the patient cannot close his mouth with deviation of the jaw to the unaffected side

3. Depression anterior to the ear in the affected joint4. Pain in the TMJ area 5. Plain X-ray or C.T will reveals that the condyle is

anteriorly displaced with empty glenoid fossa

Dr. Ahmed M. Adawy

Dr. Ahmed M. Adawy

Treatment of dislocation

1. Immediate (emergency) treatment The mandible is manipulated to allow the condyle to move

posteriorly and reposition them in the fossa Reduction of a dislocation of several-days duration is

facilitated by injection of local anesthesia in the fossa and sedating the patient with diazepam

In resistant case the manipulation is carried out under general anaesthesia

After reduction the jaw is immobilized with intermaxillary fixation for two weeks

Dr. Ahmed M. Adawy

Reduction of dislocation

Dr. Ahmed M. Adawy

2. Non surgical treatment Injection of sclerosing solution e.g. sodium

psylliate into the TMJ and supporting structures can limit condylar hypermobility. This could be done with a needle or more precise with arthroscopy


Dr. Ahmed M. Adawy

3. Surgical treatment of recurrent dislocation The approach for treatment of condylar hypermobility

is divided into two main categories. The first is to make an obstacle against excessive translation. While the second is to remove any obstacle to the condylar translation


Dr. Ahmed M. Adawy

A. Surgical procedure to obstruct movement Increasing the height of the articular eminence will

prevent excessive movement of the condyle. This is accomplished by many means; fracture the zygomatic arch and fixing it inferiorly in front of the condyle; augmentation of the eminence by bone graft or alloplastic material


Dr. Ahmed M. Adawy

B. Surgical procedures that removes blocking factors Either total removal of the articular eminence

(eminectomy) or partial removal of the articular eminence (eminenoplasty) will remove the blocking factor to condylar movement. This will not correct excessive movement but let the condyle to move anteriorly and return back without any hindering. The advantage of this procedure is that it does not need opening the joint capsule


Dr. Ahmed M. Adawy

Diseases of the Joint 4. TMJ ankylosis

It is defined as bony or fibrous union between the condyle and the glenoid fossa. It should be differentiated from pseudoanklosis which is inability to open the mouth due to causes outside the joint capsule e.g. muscle trismus, excessive scarring due to burn, and depressed fractured zygomatic arch

Dr. Ahmed M. Adawy

Etiology of ankylosis

1. Trauma mostly to chin with fracture condyle and intra-capsular hemorrhage followed by organization of the formed blood clot

2. Infection especially from the ear3. Rheumatoid arthritis4. Post-operative complication of TMJ surgery

Dr. Ahmed M. Adawy

Signs and symptoms The clinical appearance of the patients with TMJ

ankylosis depends largely upon the age of the patient at the time of affection and the duration of the ankylosis. The earlier the onset of the ankylosis the more severe is the facial disfigurement due to affection of the condylar growth center. Also the longer the duration of ankylosis, the severe is the deformity. Such deformity is due to destruction of the condoler growth center as well as loss of growth stimulated by mandibular function

Dr. Ahmed M. Adawy

1. Inability to open the mouth without pain2. In unilateral children there is facial asymmetry

with deviation of the jaw to the affected side, accentuated antegonial notch, flattening of the unaffected side and canting of the occlusal plane

3. In bilateral cases there is severe mandibular micrognathia sometimes with apnea especially in early childhood

4. Rampant caries

Signs and symptoms

Dr. Ahmed M. Adawy

Facial disfigurement, micrognathia micrognathia (bird face(bird face)

Dr. Ahmed M. Adawy

Radiographically, ankylosed joint is characterized with obliterated joint cavity, short ramus, and accentuated antigonial notch

Dr. Ahmed M. Adawy

Treatment of ankylosis poses Treatment of ankylosis poses a significant challenge to the a significant challenge to the anesthesiologist and to the anesthesiologist and to the maxillofacial surgeonmaxillofacial surgeon

Treatment of ankylosis

Dr. Ahmed M. Adawy

Treatment of ankylosis Excision of the ankylosed structure (condylectomy)

and creation of 1-1.5 cm gap (gap arthroplasty) between superior margin of the ramus and the zygomatic arch to prevent re-ankylosis. Placement of interpositional material has been recommended to prevent recurrence. Different materials and tissues have been tried e.g., temporal fascia, skin or dermal grafts

Dr. Ahmed M. Adawy

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Dr. Ahmed M. Adawy

References:1. Alomar X, et al: Anatomy of the temporomandibular joint. Seminars in Ultrasound,

CT, and MRI 28, 170, 2007.2. Dworkin SF, LeResche L: Research diagnostic criteria for temporomandibular

disorders: review, criteria, examinations and specifications, critique. J Craniomandibular Disorders. 6, 301, 1992.

3. CUNHA AL, et al : Magnetic Resonance Imaging in Temporomandibular Joint: Review of anatomy and major disorders in joint dysfunction. Poster No.: C-1702,Congress: ECR 2011.

4. Nitzan DW, Dolwick MF.: An alternative explanation for the genesis of closed-lock symptoms in the internal derangement process. J Oral Maxillofac Surg; 49: 810, 1991.

5. Al-Khayat A, Bramley P: A modified preauricular approach to the temporomandibular joint and malar arch. Br J Oral Surg 17:91, 1980.

6. Rongetti JR: Menisectomy: a new approach to temporomandibular joint. Arch Otol 60:566, 1975.

7. Alexander RW, James RB: Postauricular approach for surgery of the temporomandibular articulation. J Oral Surg 33:346, 1975.

Dr. Ahmed M. Adawy

References: 8. Trumpy IG , Lyberg T.: Surgical treatment of internal

derangement of the temporomandibular joint. Long-term evaluation of three techniques. J Oral Maxillofac Surg 53:740, 1995.

9. Kim CH, Kim H: Surgical correction of recurrent habitual temporomandibular joint dislocation. J Korean Assoc Oral Maxillofac Surg 24:365,1998.10. Vasconcelos B, et al: Surgical treatment of temporomandibular joint

ankylosis: follow-up of 15 cases and literature review. Med. Oral Patol. Oral Cir. Bucal 1: 34,2009.

Dr. Ahmed M. Adawy

Temporomandibular joint

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