Temporomandibular Joint Radiology Notes (Dr N Nzima-Chiloane, 2023)

A comprehensive set of vocabulary-style flashcards covering TMJ anatomy, pathology, and imaging concepts from the provided radiology notes.

Temporomandibular joint (TMJ)

A synovial joint between the squamous portion of the temporal bone and the mandibular condyle; the smallest joint in the body.

Synovial joint

A joint characterized by a synovial cavity; TMJ is an example of a synovial joint.

Squamous portion of the temporal bone

The flat, vertical part of the temporal bone that forms part of the TMJ articulation.

Mandibular condyle

The rounded end of the mandible that articulates with the glenoid fossa of the temporal bone.

Glenoid fossa (glenoid fossa of temporal bone)

The concave surface in the temporal bone that receives the mandibular condyle.

Articular eminence

The anterior bony prominence of the temporal bone that forms part of the TMJ architecture.

Articular disc

A fibrocartilaginous disc contained within the TMJ that divides the joint into upper and lower compartments.

Ligaments

Fibrous structures that serve as boundaries and stabilize the TMJ.

Joint capsule

The fibrous capsule enclosing the TMJ.

Temporomandibular joint dysfunction (TMD)

A group of conditions causing TMJ pain and dysfunction; affects about 25% of the population and is more common in females.

Pain in the region of the TMJ

A clinical symptom of TMD indicating discomfort around the jaw joint.

Headaches (related to TMJ)

Head pain associated with TMJ disorders.

Earaches (TMJ related)

Ear-associated pain or discomfort linked to TMJ dysfunction.

Muscle tenderness (TMJ)

Tenderness of jaw muscles associated with TMJ disorders.

Joint noises (clicking, popping, grating)

Audible sounds produced by the TMJ during movement indicative of dysfunction.

Limited opening

Reduced mouth opening due to TMJ dysfunction.

Deviation on opening/closing

Asymmetrical jaw movement caused by TMJ pathology.

Locking (TMJ)

Inability to fully open or close the mouth due to TMJ obstruction or disc displacement.

Occlusal changes

Alterations in bite or dental occlusion due to changes in mandibular positioning from TMJ pathology.

Imaging indications for TMJ imaging

To evaluate TMJ osseous integrity, confirm disease presence, monitor progression, and assess treatment outcomes.

Challenges in TMJ radiography

Proximity of adjacent bony structures and the frequent soft-tissue component of TMJ complaints, which radiographs may not fully reveal.

Panoramic imaging

A broad dental radiograph used to assess gross osseous changes in the TMJ; may show asymmetry, erosions, osteophytes, fractures, or tumors.

TMJ open-close panoramic technique

Panoramic view captured in open and closed mouth positions to assess joint changes.

Limitations of panoramic image

Superimposition of zygomatic arch and skull base; distortion, especially posterior areas.

Cone Beam Computed Tomography (CBCT)

3D imaging modality used to evaluate extent of ankylosis, fractures, and neoplasms in the TMJ.

Multidetector Computed Tomography (MDCT)

CT imaging capable of detailed assessment of hard and soft tissues in the TMJ.

Magnetic Resonance Imaging (MRI)

Imaging modality that provides detailed information on soft tissues (and to some extent hard tissues) of the TMJ.

TMJ tomography: open-close

Technique to visualize the condyle, articular eminence, and glenoid fossa and to assess joint space and condylar movement.

Open-mouth vs closed-mouth tomography

Comparison views in tomography showing the condyle position in different mouth openings.

Condylar hyperplasia/hypertrophy

Enlargement of the condylar head, usually unilateral; common in females under 20; self-limiting growth.

Condylar hyperplasia (imaging features)

Large condyle of normal or irregular shape; may show unilateral enlargement.

Condylar hypoplasia

Underdevelopment of the condyle; small size, often unilateral with midline shift and facial asymmetry.

Juvenile arthrosis

Early-onset degenerative joint changes in the TMJ, more common in females in the second decade.

Osteoarthritis (TMJ OA)

Most common cause of TMJ pathologic changes; early joint space decrease, later osseous changes and possibly ankylosis.

Bird beak osteophyte

A characteristic osteophyte appearance seen in TMJ osteoarthritis on radiographs.

Flattening (TMJ OA)

Loss of normal joint surface contour in the TMJ due to degenerative changes.

Sclerosis

Thickening and hardening of subchondral bone in the TMJ associated with OA.

Subchondral cysts

Cyst-like lesions in the subchondral bone adjacent to TMJ joints.

Ankylosis

Complete or partial fusion of the mandibular condyle to the temporal bone, usually from trauma or infection; results in restricted mouth opening.

Radiographic sign of ankylosis

Lack of normal joint space with osseous mass at the TMJ region.

Dislocation of the disc (TMJ dislocation)

Subluxation where the condyle moves anterior to the articular eminence; often caused by yawning or extended dental procedures; mouth appears widely open.

Clinical presentation of TMJ dislocation

Mouth wide open with posterior depression of the condyle and patient difficulty speaking.

TMJ trauma

Traumatic injury to the TMJ that can cause fracture of the condylar head or neck; may be unilateral or bilateral.

Chondromatosis (synovial chondromatosis)

Formation of cartilaginous nodules within the TMJ synovium.

Chondrosarcoma

Malignant cartilaginous tumor affecting the TMJ region.

Osteosarcoma

Malignant bone tumor that can involve the TMJ region.

Fibrous dysplasia

Bone development anomaly where fibrous tissue replaces bone in the TMJ area.

Ameloblastoma in the condyle

Benign odontogenic tumor occurring in the mandibular condyle.

Toadstool appearance (TMJ OA)

A radiographic appearance described in TMJ osteoarthritis on panoramic images.

Osteophyte

Bone spur associated with degenerative changes in the TMJ.