Post on 14-Apr-2017
Imaging of the Temporomandibular Joint &Pathology
Dr Sekhar
• Unique joint that it constitutes of two separate joints anatomically and they function together as a single unit
• Consists of: Condyles
Articular DiscMandibular Fossa
• Has a fibrous capsule that surrounds and encloses the joint
• CONDYLE: - Shape of condyle varies considerably- Superior aspect maybe flattened, rounded or markedly convex - Mediolateral contour is usually slightly convex- Variations in shape may cause difficulty with radiographic interpretation- Extreme aspects of the condyle are the medial pole and lateral pole
• MANDIBULAR FOSSA: Composed of the glenoid fossa and atricular eminence.
• INTERARTICULAR DISK: - Between condylar head and mandibular fossa - Biconcave shape
Disorders of the temporomandibular joint are abnormalities that interfere with the normal
form or function of the joint
Disorders of the Temporomandibular Joint1- Developmental Abnormalities
2- Soft Tissue Abnormalities
• Developmental Abnormalities:1- Condylar Hyperplasia2- Condylar Hypoplasia3- Juvenile Arthrosis 4- Coronoid Hyperplasia 5- Bifid Condyle
1- Condylar Hyperplasia: - Enlargement and deformity of the condylar head - Secondary effect on the mandibular fossa as it remodels to accommodate the abnormal condyle Etiology: Trauma, infection, hereditary• More common in males• Self limiting • Progresses slowly or rapidly• Mandibular asymmetry • Chin deviated to the affected side
• Radiographic Features: • May appear normal but symmetrically enlarged • Maybe more radiopaque due to additional bone present• Condylar neck may be elongated• Glenoid fossa may also be enlarged • Ramus and mandibular body on the affected side also may be enlarged,
resulting in a characteristic depression of the inferior mandibular border• The affected ramus may have increased vertical depth and may be
thicker in the anteroposterior dimension• D/D: - Osteochondroma - Condylar osteoma or osteophyte that occurs in chronic degenerative joint disease
• Treatment: • Orthodontics combined with orthognathic
surgery
• 2- Condylar Hypoplasia• Failure of the condyle to attain normal size because
of congenital and developmental abnormalities or acquired diseases that affect condylar growth.
• The condyle is small, but condylar morphology is normal
• Underdeveloped ramus and occasionally mandibular body
• Unilateral or bilateral
• Radiographic Features:• The condylar neck and coronoid process usually are very
slender and are shortened or elongated in some cases • The ramus and mandibular body on the affected side may also
be small, resulting in a mandibular asymmetry and occasional dental crowding, depending on the severity of mandibular underdevelopment
• D/D: Juvenile rheumatoid arthritis and arthritic conditions • Treatment: orthognathic surgery bone grafts orthodontic therapy maybe required
• 3- Juvenile Arthrosis:• Manifests as hypoplasia and characteristic
morphologic abnormalities • May be a form of condylar hypoplasia • It affects children and adolescents during the
of mandibular growth• More common in females• Incidental finding in a panoramic projection
• Radiographic appearance:• Condylar head develops a characteristic “toadstool” appearance • Condylar neck is shortened or even absent in some cases• D/D: developmental hypoplasia
rheumatoid arthritis * Treatment: orthrognathic surgery orthodontic therapy
• 4- Coronoid Hyperplasia:• - acquired or developmental • - elongation of the coronoid process• - developmental -> bilateral• acquired -> uni or bilateral • - inability to open mouth• - painless
• - Radiographic features:• Best seen in panoramic, Waters, and lateral tomographic views and on CT scans• TMJs usually appear normal• -D/D: Unilateral cases should be differentiated from a tumor of the coronoid process
(osteochondroma or osteoma)• Unlike coronoid hyperplasia, tumors have an irregular shape• -Treatment: surgical removal or the coronoid process and postoperative physiotherapy
• 5- Bifid Condyle:• Vertical depression, notch, or deep cleft in the center of the condylar head• Rare, often unilateral • Incidental finding• Some patients may have sings of TMDs (noises + pain)• Radiographic Features:• Depression on the superior condylar surface giving a heart
shape
• D/D: Vertical fracture through the condylar head
• Treatment: Not indicated unless pain or functional impairment is present
Soft Tissue Abnormalities• Internal Derangements - abnormality in the articular disc
and may interfere with normal function• - Cause is unknown• - Internal derangements can be diagnosed by MRI• Clinical Features:• - found in both symptomatic and healthy pts• - symptomatic pts may have a decreased range of
mandibular motion• -displacements may be unilateral or bilateral
• Radiographic Features:• - MRI is the technique of choice• Disc Displacement:• - Anterior displacement is most common• - The articular disc is located anterior to the condylar head• Disk reduction and nonreduction:• - reduction is when an anteriorly displaced disk may reduce to
a normal relationship with the condylar head during any part of the mouth opening movement
• - nonreduction is when the disk remains anteriorly displaced and will undergo permanent deformation.
• Perforation and Deformities:• - perforations between the superior and inferior joint spaces
most commonly occur in the retrodiskal tissue, just behind the posterior band of the disk
• - Not reliably detected with MRI• Fibrous Adhesions and Effusion: • - Fibrous adhesions are masses of fibrous or scarred tissue that
form in the joint space, particularly after TMJ surgery• - Joint Effusion means fluid in the joint and is considered to be
and early change that may precede degenerative joint disease • - Both can be detected by MRI
Remodeling and Arthritic conditions• 1- Remodeling: • - Adaptive response of cartilage and osseous tissue to forces
applied to the joint that maybe excessive, resulting in alteration of the shape of the condyle and articular eminence
• - no destruction or degeneration of articular soft tissue occurs
• - occurs throughout adult life• - considered abnormal only if it is accompanied by clinical
signs and symptoms of pain or dysfunction
• - Radiographic Features:• - flattening • - cortical thickening of articulating surfaces• - subchondral sclerosis • -D/D: flattening and subchondral sclerosis maybe difficult to
differentiate from early degenerative joint disease• - Treatment:• - Only indicated when signs and symptoms are present. (ex. Splint
therapy)
• 2- Degenerative joint disease (osteoarthritis):• - non inflammatory disorder of the joints characterized by joint deterioration and proliferation• - can occur at any age (incidence increases with age)• - female predominance • - asymptomatic or pts may complain of signs + symptoms of TMJ dysfunction • - Radiographic features: • - more accurately seen in CT but gross osseous changes maybe evident in MRI studies• At the maximum intercuspation joint space may be narrow or absent • Loss of cortex or erosions of the articulating surfaces of the condyle or temporal component are
characteristics of this disease
• D/D:• - Erosive appearance inflammatory arthritides
(rheumatoid arthritis)• - Proliferative appearance with extensive osteophyte
formation benign tumor osteoma or osteochondroma • Treatment: • - Relieving joint stress (e.g. Splint therapy)• - relieving secondary inflammation with anti-
inflammatory drugs• - Increasing joint mobility and function physiotherapy
• 3- Rheumatoid Arthritis:• - Synovial membrane inflammation• - Patients with TMJ involvement complain of swelling,
pain, tenderness, stiffness on opening, limited range or motion, and crepitus
• - Radiographic Features:• - Osteopenia (decreased density) of the condyle and
temporal component• - erosion of anterior and posterior condylar surfaces• if erosion is severe condylar head is destroyed
• D/D: severe DJD and psoriatic arthritis and osteopenia
• Treatment:• - pain relief (analgesics)• - anti inflammatory drugs• - physiotherapy• - surgery (joint replacement)
• 4- Juvenile Arthritis:• - Inflammatory disease that is characterized by chronic,
intermittent synovial inflammation • - results in: synovial hypertrophy, joint effusion, and swollen,
painful joints• -pain and tenderness of affected joint or joints• - can be asymptomatic• - unilateral is common• - facial appearance known as “bird face”• - possible mandibular asymmetry if one side is more severely
affected
• Radiographic features:• - Osteopenia (decreased density) maybe only
an initial radiographic finding• - Impaired mandibular growth• - Severe cases: only pencil shaped small
condyle remains• - Abnormal disk shape is often observed in
patients with TMJ involvement
Psoriatic Arthritis and Akylosing Spondylitis
Septic Arthritis: Infection and inflammation of a joint that can result in joint destruction- Affects any age- No sex predilection - Occurs unilaterally - Redness and swelling over joint- Trismus - Severe pain on opening - Inability to occlude the teeth- Large, tender cervical lymph nodes- Fever and malaise
• Radiographic Features:- No radiographic signs may be present in early
stages of the disease- Osteopenic (radiolucent) changes of the joint
components and mandibular ramus may be evident (7-10 days after onset of clinical symptoms)
- Osseous ankylosis may occur after infection subsides
• D/D: radiographic changes caused by septic arthritis may mimic those of severe DJD or RA
• Treatment: - Antimicrobial therapy- Drainage of effusion and joint rest- Physiotherapy
Articular Loose Bodies- Radiopacities of varying origin located in the joint synoviom, within the capsule in
the joint spaces, or outside in soft tissue
1- Synovial Chondromatosis:- Uncommon disorder characterized by metaplastic formation of multiple cartilaginous
and osteocartilaginous nodules within connective tissue of the synovial membrane of joint
- Asymptomatic- May complain of preauricular swelling, pain, and decreased range of motion- Some patients have crepitus or other joint noises
• Radiographic Features:- Osseous components may appear normal or may exhibit
osseous changes similar to those in DJD- Sclerosis of glenoid fossa and condyle may be seen (chronic
bone reaction to an active lesion)- MRI may be useful in defining the tissue planes between the
synovial chondromatosis and surrounding soft tissue* D/D: DJD with joint mice or chondrosarcoma or osteosarcoma* Treatment: Arthroscopic or open joint surgery remove loose bodies and resection of abnormal synovial tissue
2- Chondrocalcinosis:- Characterized by acute or chronic synovitis and
precipitation of calcium pyrophosphate dihydrate crystals in the joint space
- Most commonly affected joints are knee, wrist, shoulder, and elbow
- TMJ involvement uncommon- Unilaterally and more common in males- Asymptomatic or complaints of pain and joint swellings
• Radiographic Features:- May simulate synovial chondromatosis- Bone erosions and severe increase in condylar bone density- Erosions of the glenoid fossa may be present (detected with CT)- Soft tissue swelling and edema of the surrounding muscles may
be seen with MRI* D/D: DJD with joint mince or chondrosarcoma or osteosarcoma * Treatment:- Surgical removal of crystalline deposits- Steroids, aspirin, and non steroidal anti inflammatory agents
may provide relief
Trauma1- Effusion: - Influx of fluid into the joint as a result of
trauma (hemorrhage or inflammation)- Swelling over affected joint- Pain in TMJ, preauricular region, and limited
range of motion
• Radiographic Features:- Commonly seen in conjunction with internal
derangements- Joint space is widened * D/D: septic arthritis* Treatment:- Anti-inflammatory drugs- Surgical drainage
2- Dislocation:- Abnormal positioning of the condyle out of the
mandibular fossa but within the joint capsule- Unable to close mandible to maximal intercuspation * Radiographic Features:- In bilateral cases, both condyles are located anterior and
superior to summits of articular eminentia * Treatment: - Manual manipulation to reduce the dislocation- Surgery in the case of fracture dislocation
3- Fracture:- Usually occur at condylar neck and often are
accompanied by dislocation of the condylar head- Unilateral fractures more common- May be accompanied by parasymphyseal or
mandibular body fracture on contralateral side- Swelling over TMJ- Limited range of motion
• Radiographic features:- Radiolucent line limited to the outline of
the neck is visible- If bone fragments overlap, an area of
increase in radiopacity may be seen* D/D: Town’s view panorama is taken to view fractures* Treatment: Reduced surgically
4- Neonatal Fracture: - Use of forceps during delivery of neonates
may result in fracture and displacement of the rudimentary condyle
- Severe mandibular hypoplasia * D/D: Developmental hypoplasia * Treatment: Combination of orthodontic and orthognathic surgery
5- Akylosis: - Condition in which condylar movement is limited by a
mechanical problem in the joint or by a cause not related to joint components
- Restricted jaw opening or limited jaw opening* Radiographic Features:- In fibrous ankylosis articulating surfaces are usually irregular
because of erosions- In bony ankylosis joint space may be partly or completely
obliterated by the osseous bridge - Coronal CT images are the best to evaluate ankylosis* D/D: Condylar Tumor* Treatment: - Surgical removal of osseous bridge - Creation of pseudoarthrosis
Tumors- Intrinsic or extrinsic - Intrinsic develop in condyle, temporal bone or
coronoid process - Extrinsic tumor may affect the morphology,
structure and function of the joint without invading the joint itself
1- Benign Tumors:- Osteoma, osteochondroma, Langerhans histocytosis and
osteoblastomas- Chondroblastomas, fibromyxomas, benign giant cell lesions and
anneurysmal bone cysts also occur- Benign tumors and cysts of the mandible may involve the entire
ramus and condyle- Grow slowly- TMJ swelling- Pain and decrease in range of motion- Tumors of coronoid process are painless but may complain of
progressive limitation of motion
* Radiographic Features:- Condylar tumors condylar enlargement with irregular
outline- Osteoma and osteochondroma appear as abnormal,
pedunculated mass attached to the condyle * D/D: Condylar neoplasms may simulate condylar hyperplasia because of condylar enlargement although it might be irregular in appearance* Treatment: Surgical excision of tumor and occasionally excision of condylar head or coronoid process
2- Malignant Tumors:A- Primary (rare): - Intrinsic
- Extrinsic Intrinsic: Chondrosarcoma Osteogenic sarcoma
Senovial sarcoma Fibrosarcoma
Extrinsic: Direct extension of adjacent parotid salivary gland malignancies
B- Metastatic (more common)- May be asymptomatic or patients may have symptoms of TMJ
dysfunction (pain, limited mandibular opening, mandibular deviation and swelling)
* Radiographic Features: - Variant degree of bone destruction with ill defined, irregular
margins - CT modality of choice- MRI useful for displaying extent of involvement into surrounding
tissues * D/D: Osseous destruction of bone seen in severe DJD* Treatment: - Wide surgical removal of tumor- May include radiotherapy and chemotherapy
Thank you