TMJ imaging beyond TMD Margaret N Chapman MD

TMJ imaging beyond TMD Margaret N. Chapman MD 1, Vanesa Carlota Andreu MD 1, Qamar Mala’Beh MD 1, Khairuddin Memon MD 2, Benjamin P. Liu MD 2, Osamu Sakai MD, Ph. D 1 1 Boston Medical Center, Boston University School of Medicine 2 Northwestern Memorial Hospital, Feinberg School of Medicine of Northwestern University Contact information: Margaret. Chapman@bmc. org

Disclosures There are no conflicts of interest to disclose 2

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Introduction • Temporomandibular joint (TMJ) imaging is most often performed to evaluate temporomandibular joint disorder (TMD), specifically to evaluate disc morphology and location, condylar morphology, range of motion, and dynamic function. • Standard MRI sequences including oblique sagittal proton density weighted imaging in closed and open mouth positions are the key sequences at most institutions. • Although the clinical symptoms are similar or almost identical to TMD, the TMJ may be affected by a variety of other conditions. 3

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Introduction • Dedicated TMJ MR imaging precisely depicts abnormality of disc location and morphology, osteoarthritic changes, abnormal dynamic function and range of motion, and joint effusions. • Disadvantages of dedicated TMJ MR imaging includes limited field of view and limited sequences, and pathologies outside of the TMJ may be missed. 4

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Introduction • CT and MR imaging performed for other reasons often show TMJ abnormalities such as: degenerative changes fracture infection congenital anomalies synovial osteochondromatosis inflammatory conditions such as rheumatoid arthritis (RA) and calcium pyrophosphate dihydrate deposition (CPPD) • malignancy - primary and metastases • • Marrow abnormalities are often seen in patients with systemic disorders/hematological disorders, including anemia, sickle cell disease, leukemia, and chemotherapy. 5

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Purpose • Review the imaging anatomy of the TMJ • Illustrate the current MR imaging technique of the TMJ • Through an illustrative case based review, discuss various pathologies that can affect the TMJ • Discuss other conditions that can mimic TMD syndrome 6

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Anatomy The TMJ is a synovial joint comprised of the articulation of the mandibular condyle with the articular fossa of the temporal bone. Disc 1. Positioned between the mandibular condyle and glenoid fossa • Superior and inferior compartments 2. Biconcave with three segments: • Anterior band, intermediate zone, posterior band Muscles 1. Lateral pterygoid opening 2. Temporalis, medial pterygoid, masseter closing Bone 1. Mandibular Condyle 1. Glenoid Fossa 1. Articular Eminence Joint 1. Articular capsule: attaches to the edges of the glenoid fossa and to the neck of the mandible 7

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Disc Anatomy in More Detail • The articular disc is a biconcave avascular fibrocartilaginous structure with three segments: • • • Anterior band (AB), intermediate zone (IZ), and posterior band (PB) The thicker peripheral AB and PB are connected by the thinner IZ. AB: smaller; attaches to the capsule, condylar head, and lateral pterygoid PB: larger; continuous with the bilaminar zone (BZ) BZ: rich neurovascular collagen fibers and fibroelastic tissue, provides stability to disc during motion As the disc is made of fibrous tissue, it is hypointense on all MR sequences, although the IZ may be slightly higher in signal AE MC Sagittal proton density (PD)-weighted image of the TMJ in the closed mouth position. The disc is biconcave, with the thicker anterior and posterior bands (blue arrows), separated by the intermediate zone. 8

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References CT Anatomy GF MC MC Coronal and axial CT images in bone window. Note the symmetric appearance of the mandibular condyles with smooth cortical margins. There is absence of subcortical sclerosis, cysts, and osteophytic changes. There is symmetric articulation with the glenoid fossa, with no asymmetric joint space widening or narrowing. GF: glenoid fossa, MC: mandibular condyle 9

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References MR Anatomy GF AE MC LPM Sagittal PD-weighted image in the closed mouth position demonstrates normal anatomic structures: GF: The glenoid fossa should be concave AE: Smooth cortical margin MC: Mandibular condyle with smooth cortical margin and no abnormal bone marrow signal LPM: Lateral pterygoid muscle with normal signal. 10

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Biomechanics • The TMJ is a hinge and glide joint with anterior translation of the mandibular condyle with respect to the temporal bone, and also side to side motion • The muscles of mastication are responsible for opening and closing the jaw • Jaw opening: lateral pterygoid, stylohyoid, mylohyoid and geniohyoid • Jaw closing: temporalis, medial pterygoid, and masseter muscles • Anterior translation: lateral pterygoid, masseter, and medial pterygoid • Closed mouth: condyle is centered in the glenoid fossa, with the disc interposed between the two. • Normal disc position: anterior band is in front of the condyle, and the posterior margin of the posterior band is immediately superior to the condylar head in the 12 o’clock position • Open mouth: the condyle lies immediately below the apex of the articular eminence with disc centered between the two. • Intermediate zone is always positioned between the condyle and 11 temporal bone.

Introduction Purpose Anatomy Imaging Protocol Closed Mouth AE Cases Conclusion References AE MC MC Sagittal PD (A) and T 2 (B) weighted images of the TMJ in the closed mouth position. The disc is biconcave, with the thicker anterior and posterior bands (blue arrows), separated by the intermediate zone. Note the position of the disc, with the posterior band centered at the 12 o’clock position. Condylar position: should be centered in the glenoid fossa Disc position: The posterior margin of the posterior band should be located near the 12 o’clock position 12

Introduction Purpose AE MC Anatomy Imaging Protocol Cases Opened Mouth Conclusion References AE MC Sagittal PD (A) and T 2 (B) weighted images of the TMJ in the open mouth position. The disc is biconcave, with the thicker anterior and posterior bands (blue arrows), separated by the intermediate zone. Note the position of the disc, centered between the mandibular condyle and apex of the articular eminence. Condylar position: translate anteriorly, and lie below the apex of the articular eminence 13 Disc position: should be centered between the two

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Imaging Protocol • MRI: • Survey in coronal and axial planes • Sagittal T 1 survey • Sagittal oblique T 2/PD weighted images in open and closed mouth positions • Coronal T 1 weighted images • CT: • Usually imaged as part of a maxillofacial CT examination. • 1. 25 mm axial images without contrast • Coronal and sagittal reformations • Cone beam CT: • Comparable osseous detail to CT • Lower dose • Increased noise 14

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Imaging Interpretation Calcified Loose Bodies Surgical Reconstruction CT Internal Derangement Trauma Marrow MRI Effusion/ Inflammation Degenerative OA Complementary 15

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Imaging Checkpoints Disc 1. Location: a. Anterior, posterior, medial, lateral 2. Morphology: a. b. Shape Thinning, desiccation, volume a. b. Recapture Condylar translation 3. Function: 1. Signal Muscle 2. Space occupying lesion Joint 1. Synovium 2. Capsule 3. Fluid 4. Loose Bodies Bone 1. Condylar Shape 2. Marrow Signal 3. Traumatic injury 16

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Temporomandibular Joint Disorder (TMD) • Idiopathic process describing acute and chronic inflammation and/or dysfunction of the TMJ • TMD is the second most common musculoskeletal and neuromuscular disorder • Prevalence 5 -12% • Most common in women in their 2 nd through 4 th decades of life • Female: Male – 2 to 8: 1 • Internal derangement is the MOST COMMON TMJ disorder • “Risk” factors include trauma, altered anatomy or physiology, and psychosocial factors • Symptoms: jaw pain and dysfunction, earache, headache, and facial pain 17

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Internal Derangement Abnormal position and functional relationship between the disc and condyle, articular eminence and glenoid fossa • Described as a mechanical process preventing smooth motion and function of the joint • The disc is usually dislocated anteriorly, and is often recaptured with mouth opening • Often associated with clicking, crepitus, and locking • In more severe cases, no recapture is observed • Limited range of motion, with diminished anterior translation • The disc can be dislocated in any position (medial, lateral, and posterior), although lateral and posterior disc dislocation are rare 18

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Anterior subluxation with recapture Closed Opened Sagittal PD-weighted images of the TMJ in the closed and open mouth positions. In the closed mouth position the mandibular condyle is concentrically seated within the glenoid fossa. However, the posterior margin of the posterior disc is situated far anterior to the 12 o’clock position (arrow), and the anterior band is located inferior to the articular eminence (arrow). The intermediate zone is also located anteriorly to the condyle. In opened mouth position, there is adequate anterior translation of the condyle, located inferior to the apex of the articular eminence. The disk is anatomically positioned. 19

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Anterior subluxation without recapture Closed Opened Sagittal PD-weighted images in open and closed mouth positions. Note the anterior subluxation of the disk with the posterior band located at the 8 -9 o’clock position with respect to the mandibular condyle (arrows). With mouth opening, there is limited range of motion of the condyle which is situated slightly posterior to the articular eminence. The disc remains anteriorly positioned with respect to the condyle, with posterior margin remaining at the 9 o’clock position, indicative of no recapture. Images courtesy of Takashi Kaneda, DDS, Ph. D 20

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References “Stuck disc” Closed Opened Sagittal oblique T 2 -weighted images of the TMJ. The mandibular condyle is anatomically situated within the glenoid fossa in the closed mouth position. Note the normal location of the disc, with the posterior margin of the posterior band at the 12 o’clock position (arrow). On open mouth position, there is mildly limited anterior translation, with the mandibular condyle posterior to the articular eminence. The position of the disc remains the same on mouth opening, with the posterior band at 12 o’clock. Note also the irregular appearance of the condylar head with mild cortical thickening. 21

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Osteoarthritis (OA) • TMJ osteoarthritis often results from chronic internal derangement or trauma • Present in up to 20% of patients with internal derangement • OA is the second most common cause of TMD • The presence of osteoarthritis may not correlate with joint function or clinical symptoms • Older patients with imaging features of OA may be asymptomatic • Signs: joint space narrowing, sclerotic change, osteophyte formation, and subcortical cysts • CT is the best imaging modality to evaluate the osseous structures. 22

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Osteoarthritis A B Axial (A) and coronal (B) CT images through the TMJs. There is extensive osteophyte formation of the mandibular condyle and glenoid fossa. Additional findings of OA include loss of joint space, cortical sclerosis and irregularity, and subcortical cysts. There is no osseous erosion or joint space widening to suggest a joint effusion. 23

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Congenital Anomalies – Bifid condyle • Congenital processes or syndromes may affect the TMJ • Condylar aplasia/hypoplasia • Condylar hyperplasia • Bifid condyle: etiology unknown, but likely congenital. Characterized by abnormal morphology of the condyle with a “double-headed” appearance. • Asymptomatic incidental diagnosis, with no clinical significance • Imaging normal aside from abnormal contour of the condyle • Syndromes: Hemifacial microsomia, Goldenhar syndrome, Treacher Collins, Morquio syndrome, and auriculocondylar syndrome 24

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Congenital Anomalies – Bifid condyle A B Coronal CT through the condyles (A) demonstrates a double headed appearance with a central notch. Coronal T 1 -weighted image (B) through the condyle shows a similar morphology. Note the absence of degenerative changes (including osteophytes, subcortical cysts) and normal bone marrow signal on the MR image. 25

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Congenital Anomalies A B C Nager Syndrome. Rare inherited disorder characterized by craniofacial malformations and abnormalities of the thumb and forearm. Craniofacial abnormalities include micrognathia and mandibular hypoplasia. Affected individuals may develop TMD due to the abnormal development of the condyle and altered biomechanics. In this case of a 12 year old girl with Nager Syndrome and micrognathia, axial (A), sagittal (B), and coronal (C) CT images demonstrate abnormal morphology of the condyle and flattening of the glenoid fossa. There is ankylosis across the TMJs bilaterally, best seen on the coronal reformatted CT image (arrows). 26

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Inflammatory Conditions Multiple inflammatory arthropathies can affect the TMJ • Rheumatoid arthritis (RA): autoimmune inflammatory disease that affects multiple organ systems and involves soft tissues and bones. • TMJ is affected in > 20% of patients with RA. • Inflammatory soft tissue (pannus) results in destruction of the disk, which can be abnormally positioned or destroyed. • Joint effusions are often seen, although nonspecific, as an effusion can be seen with internal derangement, OA, or other inflammatory processes. • Imaging Findings: osseous erosion, secondary arthritic changes, synovial proliferation, joint effusion • Symptoms: pain, tenderness, swelling, and limited range of motion 27

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Rheumatoid Arthritis (RA) A B C Axial STIR image (A) through the TMJs demonstrates hyperintense signal centered within the joints bilaterally (arrows). On a coronal PD-weighted image(B) through the left TMJ, there is extensive hypointense signal within the joint space due to effusion and synovial proliferation (arrowheads). Note the flattening and abnormal bone marrow signal in the mandibular condyle (arrow). A sagittal oblique PD-weighted image (C) also shows the deformity of the condylar head, as well as flattening of the articular eminence. Note thickened and globular disc, anteriorly displaced (arrow). 28 Images courtesy of Takashi Kaneda, DDS, Ph. D

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Inflammatory Conditions Multiple inflammatory arthropathies can affect the TMJ • Calcium pyrophosphate dihydrate deposition (CPPD): caused by the deposition of of calcium pyrophosphate dihydrate crystals in the articular cartilage and periarticular soft tissues • May deposit in the synovium, joint capsule, tendons, ligaments, in addition to the cartilage • Imaging findings: • CT: best modality to identify chondrocalcinosis in the joint or adjacent soft tissues, adjacent secondary arthritic changes including joint space narrowing, subcortical cysts, and osteophytes, and erosive changes • MRI: T 2 hypointense periarticular masses with heterogeneous enhancement can be seen 29

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References CPPD A B C Axial CT image in bone window (A) shows amorphous calcification involving the left TMJ, both the condyle and glenoid fossa (arrows). There is expansion and multiple lucent lesions seen in the left condyle. Coronal T 2 -weighted image (B) shows heterogeneous signal in the condyle with several small T 2 hyperintense cystic lesions (arrowhead). Note the expanded joint capsule with heterogeneous, mostly low signal, material (arrow). The coronal T 1 -weighted image (C) also demonstrates hypointense material filling the expanded joint capsule (arrow). Compare the abnormal marrow signal in the left mandibular condyle (arrowhead) with the normal fatty marrow signal on the right. 30

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Inflammatory Conditions Multiple inflammatory arthropathies can affect the TMJ. • PVNS: rare proliferative disorder affecting the synovium • Usually a monoarticular inflammatory process involving large joints of the extremities • Locally aggressive with osseous erosion or destruction, and potential for extracapsular extension of the inflammatory process • Imaging findings: • MRI: heterogeneous low signal areas on T 2 images due to hemosiderin deposition, regions of increased T 2 signal may represent joint effusion • CT: osseous erosion and cyst formation in the condyle, soft tissue masses • Symptoms: slowly growing non-tender swollen joint, often affect individuals in the 2 nd through 3 rd decade of life 31

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Pigmented Villonodular Synovitis (PVNS) A B C Axial T 2 -weighted image (A) through the TMJ. There is decreased T 2 signal within and surrounding the left TMJ (arrow). Axial T 1 -weighted image (B) also shows heterogeneous decreased signal within and surrounding the TMJ (arrow). Post-contrast axial T 1 -weighted image (C) demonstrates enhancement of the joint space surrounding the left mandibular condyle (arrows). 32

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Inflammatory Conditions • Infection: rare in the TMJ • Usually a monoarticular process resulting from hematogenous spread of distant infection or direct inoculation from trauma • In the TMJ, infection usually results from post-traumatic or iatrogenic causes, or secondary to other infections in the head and neck • Staphylococcus aureus is the most commonly reported pathogen • Predisposing factors: immunocompromised state, corticosteroid therapy, diabetes, IV drug use • Symptoms: pain and trismus • Imaging findings: • CT: joint effusion and enhancement, osseous changes that may represent osteomyelitis, and adjacent inflammatory changes • MRI: joint effusion, synovial enhancement, adjacent bone marrow changes including reactive edema or osteomyelitis, adjacent soft tissue inflammation 33

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Infection A B Coronal STIR image (A) demonstrates abnormal hyperintense signal within the right mandibular condyle (arrow), compared with the normal signal in the left mandibular condyle. There is additionally high signal within the joint capsule, consistent with an effusion (arrowhead). The axial post-contrast fat-suppressed T 1 -weighted image (B) demonstrates extensive avid enhancement within the right mandibular condyle and TMJ (arrow), and in the right masticator space including the lateral pterygoid and temporalis muscles. The small non-enhancing area within the joint may represent the effusion (arrowhead). 34

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Neoplastic Processes Neoplastic processes of the TMJ can arise from the osseous structures or adjacent soft tissues • Primary bone tumors include: • Osteochondroma (most common) • Osteoma, fibrous dysplasia, giant cell tumors, non-ossifying fibromas • Malignant bone tumors: osteosarcoma, chondrosarcoma • Synovium: synovial osteochondromatosis • Muscle/masticator space: primary tumors or metastases including from perineural spread of head and neck cancer • Metastases • Plasmacytoma 35

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Synovial Osteochondromatosis Uncommon benign condition of synovial neoplasia with intraarticular proliferation of cartilaginous nodules arising from the synovial membrane • The nodular proliferation breaks off into the joint where the fragments can grow, calcify, and ossify. • Rare, presents more often in women in their 4 th through 6 th decades of life • Symptoms: pain, swelling, crepitus, limited range of motion • Imaging findings: • CT and MRI are complementary in evaluate for more aggressive changes including extracapsular and intracranial extension • CT: Expansion of the joint capsule, with multiple calcified or ossified fragments, joint effusion, soft tissue swelling, and irregular joint surfaces • MRI: better depicts joint effusion and adjacent soft tissue inflammation, the multiple loose bodies are hypo- to isointense on MRI 36

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Synovial Osteochondromatosis A B C Axial CT image (A) through the right mandibular condyle demonstrates multiple osseous fragments within the right TMJ capsule (arrow). Note that there is also widening of the joint space, suggesting an effusion (arrow). Sagittal T 2 GRE image (B) through the right TMJ in open mouth position demonstrates the joint effusion (arrows) with multiple internal foci of susceptibility artifact, correlating with the osseous bodies. A coronal T 2 -weighted image (C) also depicts the effusion and loose bodies very well (arrows). 37

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Metastases • Metastatic disease accounts for 32. 7% of the malignant tumors involving the TMJ • Second most common after sarcomas • The mandible is susceptible to metastatic tumors due to its abundant bone marrow • Most commonly located in the mandibular body and angle, but can be seen in the condyle • Most lesions are osteolytic, but they can also be sclerotic, expansile, depending on the pathology of the primary tumor • Can present as pathologic fracture • Imaging findings: • CT: osteolytic or osteoblastic lesions, pathologic fractures • MRI: demonstrates abnormal bone marrow signal, extraosseous extension of 38 lesion

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Metastases A B C Axial T 1 MPRAGE image (A) performed during a contrast enhanced brain MRI in a patient with metastatic neuroendocrine tumor demonstrates abnormally low signal within the left mandible near the condyle (arrow). The axial fat-suppressed T 2 -weighted image (B) demonstrated corresponding hyperintense signal (arrow). There was also restricted diffusion with hyperintense signal on the b 1000 DWI image (C, ADC not shown, arrow). There was associated enhancement (not shown). Note the absence of surrounding inflammatory changes. 39

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Hematologic Disorders Marrow abnormalities can be seen in patients with systemic disorders/hematological disorders, including anemia, sickle cell disease, leukemia, and chemotherapy A B C Bone infarct and subperiosteal hemorrhage in the setting of sickle cell disease. Axial unenhanced CT image through the mandibles (A) shows an ill-defined hypodense region adjacent to the left mandible (arrows). On the corresponding fat-suppressed T 2 -weighted image (B), there is fluid signal adjacent to the mandible (arrow). Note also the heterogeneous mildly increased signal and cortical irregularity in the mandible, consistent with a bone infarct (arrowhead). The axial T 2 FFE image (C) shows susceptibility 40 artifact in the region of the fluid, consistent with hemosiderin from subperiosteal hemorrhage.

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References Conclusion • TMD is not the only condition that affects the TMJ. • TMD is most often caused by internal derangement and osteoarthritis, the most common processes that affect the TMJ. • TMJ abnormalities are seen often on studies performed for other reasons. • Multiple neoplastic, inflammatory, congenital, and hematologic processes can involve the TMJ. • Incidentally found TMJ abnormalities may be a clue for unrevealed, serious underlying diseases or conditions. 41

Introduction Purpose Anatomy Imaging Protocol Cases Conclusion References • Morales H, Cornelius R. Imaging Approach to Temporomandibular Joint Disorders. Clin Neuroradiol. 2015 Sep 15. [Epub ahead of print] • Aiken A, Bouloux G, Hudgins P. MR imaging of the temporomandibular joint. Magn Reson Imaging Clin N Am. 2012 Aug; 20(3): 397 -412. • Petscavage-Thomas JM, Walker EA. Unlocking the jaw: advanced imaging of the temporomandibular joint. AJR Am J Roentgenol. 2014 Nov; 203(5): 1047 -58. • Bag AK, Gaddikeri S, Singhal A, Hardin S, Tran BD, Medina JA, Curé JK. Imaging of the temporomandibular joint: An update. World J Radiol. 2014 Aug 28; 6(8): 567 -82. • Makdissi J, Pawar RR, Radon M, Holmes SB. Incidental findings on MRI of the temporomandibular joint. Dentomaxillofac Radiol. 2013; 42(10): 20130175. 42