Head and Neck 5 Flashcards
Imaging features of Chronic Sinusitis
- A characteristic feature on CT sinuses is sclerotic thickened bone (hyperostosis) involving the sinus wall from a prolonged mucoperiosteal reaction.
- Intrasinus calcification may be present.
- The presence of opacification is not a good discriminator from an acute sinus infection.
7 DDx of
Infections and Idiopathic Processes Affecting Intraglandular or Juxtaglandular LNs
- TB,
- atypical mycobacterial infections,
- syphilis,
- cat-scratch disease,
- toxoplasmosis,
- actinomycosis, and
- sarcoidosis
what is the metabolic effect of hyperparathyroidism?
- Increased renal calcium resorption -> hypercalcaemia
- increased vitamin D metabolism
- increased bone turn over
- Decreases renal phosphate resorption -> hypophosphatemia
Radiographic findings of hyperparathyroidism
- Radiographic Features
- Parathyroid
- Single parathyroid adenoma, 80%
- Multigland disease and/or hyperplasia, 20%
- Bone
- Osteopenia
- Subperiosteal resorption (virtually pathognomonic)
- Brown tumors
- Soft tissue calcification
- Renal
- Calculi (as a result of hypercalciuria)
- Parathyroid
Subglottic SCC
what is uncommon in this cancer?
what is common?
- 5-10% of laryngeal cancers
- uncommon as an isolated lesion
- long asymptomatic stage with tendency to present at an advanced stage
- Cricoid cartilage invasion is common (T4)
- Poor lymphatic drainage of subglottis, therefore nodal mets relatively uncommon
- 1st branchial cleft cyst
- embryological cyst can be derived from:
- 1st,
- 2nd (most common),
- 3rd (rare) or
- 4th (rare) branchial apparatus
-
1st branchial cleft cyst
- EAC/periauricular or parotid
- Case Discussion
The branchial apparatus develops during the second to sixth weeks of fetal life. The first branchial cleft develops into the external auditory canal. First branchial cleft cysts are subdivided base upon location: type I cysts are located near the external auditory canal usually inferior, posterior and medial to the tragus/pinna.
All types of 1st branchial cleft cysts are intimately associated with the facial nerve and the parotid gland. Clinical manifestations range from a palpable mass to those associated with infection.
The main differential diagnostic consideration in our case is a lymphatic malformation.
Laryngeal Wegeners
Axial NECT shows the typical features of subglottic stenosis secondary to Wegener granulomatosis. Asymmetric circumferential soft tissue produces smooth stenosis of the tracheal lumen.
https://radiologykey.com/wegener-granulomatosis-airways/
USS features of Graves disease
- Ultrasound
- thyroid gland is often enlarged and can be hyperechoic
- heterogeneous thyroid echotexture
- Prominent pyramidal lobe
- relative absence of nodularity in uncomplicated cases
- hypervascular; may demonstrate a thyroid inferno pattern on colour Doppler 1
4D CT features of parathyroid adenoma.
What are the main differentials?
4D-CT:
- Parathyroid four-dimensional (4D) CT refers to multiphase computed tomography of the neck used to localise abnormal parathyroid glands (i.e., involved with adenoma, hyperplasia, or, rarely, carcinoma).
- The “4D” indicates that imaging is performed in multiple phases of contrast, with time being the fourth dimension in addition to the multiplanar format of CT
- the number of phases is not necessarily four.
-
Indications
- Parathyroid 4D CT is performed in patients who have a biochemical diagnosis of primary hyperparathyroidism.
The main differentials are thyroid gland (THY) and LN
-
Parathyroid adenomas are distinguished based on their differential perfusion characteristics:
- Non-Contrast
- adenomas have similar attenuation to LN
- but typically hypoattenuating compared with THY
- Post Contrast
- adenomas have relatively more rapid enhancement
- relatively more rapid washout compared with THY
- LNs show slow progressive enhancement
- Non-Contrast
- The classic pattern of parathyroid adenomas is present in only a minority of cases:
- low attenuation on non-contrast imaging
- intense enhancement on arterial phase,
- washout of contrast on delayed phase
- Several morphologic features can support the diagnosis of an abnormal parathyroid gland:
-
polar vessel sign:
- an enlarged feeding artery or draining vein leading to the end of a hypervascular parathyroid [pattern - most neuroendocrine tumours (eg carcinoid, paraganglioma, carotid body tumour, phaeochromocytoma etc) are hypervascular. (as opposed to hilar vessel like a LN)
-
larger lesion:
- single adenomas tend to be larger than multiglandular disease and size increases diagnostic confidence
- on non contrast imaging
- iodine deplete (compared to thyroid, so is less dense)
-
polar vessel sign:
what sign is this?
what is the associated condition?
- Black turbinate sign
- acute fulminant invasive fungal sinusitis
- mostcommonly begins as mucosal inflammation around the middle tubrinate
- Nonenhancing hypointense turbinate
Epidemiology of thyroid Cancer
% in Autopsies
death 2ndary to Thyroid cancer in USA
- Thyroid Cancer
- Thyroid cancer is common (in 5% of all autopsies)
- death because of thyroid cancer is uncommon (only 1200 deaths/year in the United States; the total number of cancer deaths/year in the United States is >500,000).
- There is actually emerging evidence that overdiagnosis may lead to unnecessary harm. Most common presentation of thyroid cancer is a solitary thyroid nodule. Incidence of thyroid cancer:
Frontal cells
what are the complications?
- Frontal cells
- four types
- frantal recess cells that sit on top of agger nasi cells and or may extend into lower frontal sinus (types 3 and 4)
- can result in narrowing of the frontal sinus drainage pathway
DDx of signal voids on MRI in the paranasal sinuses
- aerated sinus
- highly desicated secretions
- calcificaitons
- fungal concretions (myecetoma)
- Foreign body
- ectopic tooth
Two conditions associated with this
Lymphoepithelial cysts.
Benign lymphoepithelial lesions (BLL or BLEL), also misleadingly known as AIDS-related parotid cysts (ARPC), are mixed solid and cystic lesions that enlarge the parotid glands, and are usually associated with cervical lymph node enlargement, and nasopharyngeal lymphofollicular hyperplasia.
Terminology
Benign lymphoepithelial lesions refer specifically to a histopathological finding that is non-specific and seen in the context of lymphoepithelial sialadenitis (typical of Sjögren syndrome) and HIV-associated salivary gland disease 5. This article focuses on the findings in the latter condition.
Epidemiology
Despite their aforementioned alternative name, benign lymphoepithelial lesions are seen usually in HIV positive patients without AIDS, and are not an AIDS defining illness. It is relatively common in the HIV population, with 5% of patients eventually developing benign lymphoepithelial lesions.
Pathology
Thought to arise from dilatation of intraglandular ducts from obstruction due to lymphoid hypertrophy. They are bilateral in ~20% of cases.
Location
BLLs most commonly arise in the parotid gland, and are only rarely seen in the submandibular glands or sublingual glands.
What diseases are Nasal/sinus polyps associated with?
6
- Chronic rhinosinusitis
- Allergy
- asthma
- Primary cillary dyskinesia
- aspirin sensitiviety
- CF
Opacification of all paranasal sinuses, nasal cavity and ethmoidal air cells bilaterally by polypoid mucosal thickening and retained secretions.
Numerous sinonasal polyps are noted with intermediate to high signals on T1 and intermediate to low signal intensity on T2 are noted with smooth outline. A nasopharyngeal polypoidal extension is noted compromising airway is noted. Following gadolinium, thin linear mucosal enhancement is noted, the polyps are non-enhancing. No suspicious masses.
No sinus walls bony erosions. Clear peri-antral fat planes. Intact skull base and lamina papyracea. No intra-cranial or orbital extensions.
Incidentally noted left sphenoid ridge wide dural-based lesion with intense homogeneous enhancement denoting left sphenoid ridge meningioma.
Case Discussion
Features are suggestive of benign sinonasal polyposis on top of chronic sinusitis. Contrast-enhanced MRI helps to differentiate it from probable malignant sinonasal tumours.
What is an Agger Nasi cell?
- Agger nasi air cells are the most anterior ethmoidal air cells
- lying anterior, lateral and inferior to the frontal recess
- anterior and superior the attachment of the middle turbinate.
- They are located within the lacrimal bone
- Lateral relations include the orbit, the lacrimal sac and the nasolacrimal duct.
- They are identified in 90% of patients,
- should not be confused with
- Haller cells
- (located along the medial floor of the orbit
- Supraorbital air cells
- located in the orbital roof).
- Haller cells
- They may contribute to chronic frontal sinusitis
Case courtesy of Dr Roberto Schubert, Radiopaedia.org, rID: 14035
https://radiopaedia.org/articles/agger-nasi-cells?lang=us
DDx of Destructive sinus lesion
5
- Malignant sinonasal tumours
- invasive fungal sinusitis
- mucormycosis
- aspergillosis
- Wegeners Granulomatosis (GPA) (picture)
- Sinonasal sarcoidosis
- Langerhances cell histiocytosis
What are the serology results for graves disease?
Serology
TSH: suppressed
T4: elevated
T3: elevated
TSH receptor antibodies (TSI, TGI, TBII): positive
Nasal glioma
Hamartomatous/dysplastic trapped brain tissue (not neoplasm), which unlike encephalocele, has no connection to the intracranial subarachnoid spaces or brain.
Two types: intranasal (40%) and extranasal (60%)
Extranasal: most occur at bridge of nose or in and around nasal cavity but rarely other sites (ethmoid sinus, middle ear, pharynx)
Radiographic features of this condition
Hypoparathyroidism
- musculoskeletal
- focal (~25%) and generalised (~10%) osteosclerosis
- dense metaphyseal bands
- skull vault thickening 2
- diffuse idiopathic skeletal hyperostosis-like changes
- subcutaneous calcification (around shoulders and hips)
- CNS
- intracranial calcifications: most commonly basal ganglia but also subcortical white matter, corona radiata and thalamus
- head and neck
- cataract
- https://www.orthobullets.com/basic-science/9028/hypoparathyroidism
What are the glands of the neck and their ducts?
5 glands
3 ducts
- Glandular Structures in the Neck
- Salivary glands
- Parotid glands
- anterior and inferior to external ear
- Stenson duct
- SMGs
- medial to body of mandible
- Wharton duct
- Sublingual glands
- deep to mandibular symphysis
- Bartholin duct
- Parotid glands
- Thyroid gland
- Parathyroid gland
- Salivary glands
vocal cord papiloma
Papillary (lobulated) mass arising from the right vocal cord extending into the laryngeal airway
Case Discussion
Laryngeal papillomatosis is a condition associated with human papilloma virus infection and is characterised by recurrent papillomas in the laryngeal airway including the vocal cord as in this case. It is not thought to be sexually transmitted (by oral sex). It is treated by repeated surgical excision and antiviral medications. If left untreated it can cause substantial airway obstruction as in this case. It is not thought to be premalignant.
Types of Thyroid Maligancy
- Papillary 80% Metastases to cervical nodes, good prognosis
- Follicular 5% Aggressive, higher mortality (5-year survival is 50%)
- Medullary <5% Arises from C-cells (calcitonin); MEN association
- Anaplastic <10% Very aggressive, occurs in older patients
- Epidermoid <1% –
- Other (lymphoma, metastases) <1% –
Which types of thyroid cancer have solid, cystic or calcific nodal mets?
Papillary thyroid cancer (in image, small primary in right thyroid lobe, cystic mets)
Follicular thyroid cancer
What cells does Medullary thyroid cancer arise from?
what components may be seen on histo?
What hormone is elevated in MTC?
Pathology
Thought to arise from parafollicular C cells of the thyroid
Amyloid components may be seen on histology.
It is characterised by consistent production of a hormonal marker (calcitonin)
Mnemonic:
Medullary -> middle
parafollicular C-cells are in the middle/inbetween the follicles/colloid.
Which thyroid cancer are Coarse calcificaitons a/w?
Medullary thyroid cancer
Mnemonic: Coarse Calcs -> Calcitonin elevation all a.w Medullary thyroid ca
- Case discussion:
- The left lobe of the thyroid is expanded by a low attenuation mass which demonstrates internal calcification. Elsewhere, the thyroid has a normal CT appearance. Numerous prominent and mildly enlarged lymph nodes are demonstrated on both sides of the neck. These are relatively symmetrical.
- Case Discussion
- The patient was submitted to US-guided FNA:
- MICROSCOPIC DESCRIPTION: The smears contain dispersed atypical cells with round to oval, eccentric nuclei with stippled chromatin and a small amount of delicate cytoplasm. Occasional cells have intracytoplasmic granules and intranuclear pseudoinclusions. There are also scattered large cells with hyperchromatic, pleomorphic nuclei. Dense proteinaceous material is seen in the background. The atypical cells are Calcitonin, Chromogranin and Synaptophysin positive. CD56 is equivocal.
- The smears contain a mixed population of lymphoid cells, dendritic reticulum cells and tingible body macrophages. The lymphoid cells show no nuclear atypia. No malignant cells are identified.
- DIAGNOSIS:
- FNA left thyroid: Medullary carcinoma.
- FNA left level 3 lymph node: No evidence of malignancy.
- Case courtesy of Dr Bruno Di Muzio, Radiopaedia.org, rID: 50080
Periapical (radicular) cysts:
- most common odontogenic cyst
- caused by caries and infection;
- usually <1 cm;
- round/pear-shaped
- unilocular periapical lucency
- sclerotic margins;
- can become periapical abscess.
- Usually asymptomatic unless secondary infection.
- No malignant potential.
Residual Cyst
Inflammatory fibrous and granulation tissue at the apex / periapical region of a tooth not removed / curetted at the time of dental extraction may give rise to residual cyst
- Residual Cyst
- Inflammatory odontogenic cyst remaining in bone following extraction of tooth
- Caused by incomplete removal of original radicular cyst
- Maxilla most common, missing tooth
What is this finding A/W?
- Odontogentic Keratocyst
- Basal cell Naevus Syndrome
- Gorlin/Goltz syndrome
- Gorlin–Goltz syndrome
- autosomal dominant inherited condition comprising the principle triad of
- basal cell carcinomas,
- multiple jaw keratocysts, and
- skeletal anomalies.
- autosomal dominant inherited condition comprising the principle triad of
- Prevalence ranges from 1:6000 subjects in England, and to 1:164000 in Australia
- males and females equally affected [1,2].
- The syndrome, first delineated by Gorlin and Goltz, is characterized by:
- basal cell carcinoma,
- odontogenic keratocysts,
- palmar and/or plant pits and
- ectopic calcification of the falx cerebri [2-4]
- Bifid ribs
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813242/
A primordial cyst is a developmental odontogenic cyst. It is found in an area where a tooth should have formed but is missing. Primordial cysts most commonly arise in the area of mandibular third molars.
Primordial Cyst
- Developmental cyst, typically found in an area where a tooth should have formed but is missing
- Most commonly in the area of third mandibular molar
- Previously term used as synonym for odontogenic keratocyst but considered distinct now.
What is this?
Rad Features?
5 Complications
- Image description
- Dentigerous cyst. Lateral oblique radiograph shows a well-defined expansile lucent lesion in the left mandible. Note unerupted third molar with the crown lying inside the cyst (arrow).
- Dentigerous Cyst (Follicular Cyst)
- Most common pericoronal radiolucency
- formed by excessive accumulation of fluid between enamel and dental capsule.
- Most frequently seen in mandible (80%) with unerupted third molars or maxilla (20%).
- Radiographic Features
- Well-defined unilocular pericoronal radiolucency
- Follicular space >3 mm presumes development of pathology
- May become very large and occupy entire ramus
- Expansion of mandibular cortex
- May displace teeth with roots of the tooth often outside the lesion.
- Complications:
- Infection,
- pathologic fractures
- mural ameloblastoma,
- SCC,
- mucoepidermoid CA
Most dentigerous cysts manifest in adolescents and
young adults, and often occur in the region of maxillary or
mandibular third molar. On radiographs, it is seen as a well
defined, expansile, unilocular lucent lesion, associated
with an unerupted teeth.(4) An important diagnostic point
is that the cyst attaches to cemento-enamel junction of the
involved tooth with the crown projecting inside cystic
cavity (Fig. 3). No associated periosteal reaction or soft
tissue is seen.
Neyaz, Zafar & Gadodia, Ankur & Gamanagatti, S & Mukhopadhyay, S. (2008). Radiographical approach to jaw lesions. Singapore medical journal. 49. 165-76; quiz 177.
Developmental lateral periodontal cyst
AKA botryoid cyst
“Lateral periodontal cysts (LPCs) are defined as non-keratinised and non-inflammatory developmental cysts located adjacent or lateral to the root of a vital tooth.”[1] LPCs are a rare form of jaw cysts, with the same histopathological characteristics as gingival cysts of adults (GCA). Hence LPCs are regarded as the intraosseous form of the extraosseous GCA.[2][3] They are commonly found along the lateral periodontium or within the bone between the roots of vital teeth, around mandibular canines and premolars.[3] Standish and Shafer reported the first well-documented case of LPCs in 1958, followed by Holder and Kunkel in the same year although it was called a periodontal cyst.[2][3] Since then, there has been more than 270 well-documented cases of LPCs in literature.[2]
Odontoma
- Hamartomatous malformation.
- Most common odontogenic tumor.
- Located in tooth-bearing areas.
- Two types:
- compound (more common),
- contains multiple teeth or tooth-like structures;
- complex:
- well-defined lesions with amorphous calcifications but without resemblance to teeth.
- May be associated with a follicle/cyst 1–3 cm in size.
- compound (more common),
osteoradionecrosis
Develops months to years following radiation therapy or in association with bisphosphonate use in the absence of radiation therapy. May see both sclerotic and lytic components with ill-defined borders and enlarged trabecular spaces. A sequestered bone may also be present. Can be associated with pathologic fractures.
Case courtesy of Prof Oliver Hennessy, Radiopaedia.org, rID: 33517
There are changes of lysis and sclerosis involving the mid mandible on the right compatible with changes of previous radiotherapy.
Case Discussion
Many cancers of the oral cavity are treated with adjunct radiotherapy. Complications encountered in the mandible include radiation necrosis, infection and fractures.
Bone complications are best assessed with CT. Soft tissue involvement of infection or recurrence of an oral cancer is best imaged with contrast enhanced MRI.
AKA
benign or malignant
rad features
epidemiology
Pathology
Ameloblastoma
- AKA
- (Adamantinoma)
- Ameloblastomas are locally aggressive benign tumours that arise from the mandible, or, less commonly, from the maxilla.
- Usually present as a slowly but continuously growing hard painless lesion near the angle of the mandible
- 3rd to 5th decades of life
- an be severely disfiguring if left untreated.
- Multilocular,
- expansile,
- radiolucent lesion
- most commonly located in ramus area.
- “Soap bubble” pattern typical.
- Locally aggressive and may perforate the lingual cortex.
- May also appear unilocular and associated with an impacted tooth, thus indistinguishable from an odontogenic keratocyst and dentigerous cyst.
- Enhancing mural nodule on MRI in unilocular type.
- rare, noncancerous (benign) tumor that develops most often in the jaw near the molars.
- begins in the cells that form the protective enamel lining on your teeth.
- M>F
Pathology
Unsurprisingly, ameloblastomas arise from ameloblasts, which are part of the odontogenic epithelium, responsible for enamel production and eventual crown formation. Four forms have been described in the literature: unicystic, solid (multicystic), desmoplastic, and peripheral (extraosseous).
http://www.bjorl.org//en-ameloblastoma-in-mandible-articulo-S1808869415305899
Case courtesy of Assoc Prof Frank Gaillard, Radiopaedia.org, rID: 2577
Odontogenic Myxoma
- Odontogenic Myxoma
- Uncommon benign neoplasm
- locally aggressive
- can destroy adjacent bone and infiltrate soft tissue.
- Painless.
- May appear multilocular with internal osseous trabeculae
- honeycomb or “tennis racket”-like internal structure,
- as well as with irregular calcifications.
The odontogenic myxoma is an uncommon benign odontogenic tumor arising from embryonic connective tissue associated with tooth formation. As a myxoma, this tumor consists mainly of spindle shaped cells and scattered collagen fibers distributed through a loose, mucoid material.
https://www.spandidos-publications.com/10.3892/ol.2014.2243/abstract
Epid and ddx of this lesion
Odontogenic myxoma of the maxilla
- Case discussion
- Bubbly lytic lesion in the right-side of the maxilla, maximal transaxial dimensions are approximately 26 x 20 mm.
- Further separate unilocular cystic lesion in the left side of maxilla just lateral to the midline. This measures approximately 12 mm in maximal dimension. Immediately adjacent to it, there is a cavity related to a recent extraction of the left maxillary tooth. The cystic lesion also surround the root of the second left maxillary incisor. It is presumably related to periapical disease. However, given the close proximity of the biopsy-proven malignant lesion, this is not definitive.
- There is no adjacent soft tissue abnormality on soft tissue windows. The deep structures of the neck appear unremarkable. The mucosal spaces appear unremarkable.
- Intro
- Odontogenic myxomas are rare tumours that involve the mandible or maxilla and account for 3-6% of odontogenic tumours.
- Epid
- Typically seen in the 2nd to 3rd decades of life (slightly earlier than ameloblastomas).
- Clinical
- They are usually not painful.
- Radfeatures
- The radiographic appearance is very similar to that of an ameloblastoma: a “soap bubble” lytic septated cystic lesion of the mandible.
- Treatment
- Wide marginal excision is the treatment of choice. Local recurrence can occur.
- Differential diagnoses:
- ameloblastoma
- calcifying epithelial odontogenic tumour
- Case courtesy of Dr James Sheldon, Radiopaedia.org, rID: 27313
Cementoma (Cementoblastoma)
- Self-limited lesion around the apices of teeth.
- More common in women.
- Can be solitary or multiple.
- Usually <1 cm
- Well-defined radiopaque mass or masses in continuity with the root apices of affected teeth.
- May have a thin lucent halo around each radiopaque lesion.
- Case discussion
- Sclerotic lesion involving the right premolars. Note the obliteration of the periapical ligament space.
- Probable cementoblastoma.
- Differential includes:
- ossifying fibroma
- Paget disease (less likely as patient is 25 years old)
- previous osteomyelitis
- Case courtesy of Assoc Prof Frank Gaillard, Radiopaedia.org, rID: 35938
What is this condition?
What are the main symptoms/signs?
What is the complication?
Whan cancers need to be screened for?
Basal Cell Nevus (Gorlin) Syndrome
- This syndrome, a phakomatosis, consists of:
- multiple basal cell nevi of the skin,
- odontogenic jaw cysts
- and a variety of other abnormalities.
- COMPLICATION
- Development of multiple basal cell CAs, especially after the age of 30 years.
- Skin
- Multiple nevoid basal cell CAs,
- palmar plantar dyskeratosis,
- sebaceous cysts,
- cutaneous fibroma
- Oral
- Multiple jaw cysts (odontogenic keratocysts),
- mandibular prognathism,
- cleft lip or palate,
- ameloblastoma,
- SCC
- Other
- CNS:
- agenesis of corpus callosum,
- congenital hydrocephalus,
- medulloblastoma,
- meningioma,
- cerebellar astrocytoma,
- craniopharyngioma,
- dural calcifications
- Skeletal:
- rib anomalies,
- short fourth metacarpal (50%),
- vertebral anomalies,
- polydactyly,
- clavicular and
- scapular deformities
- Eyes:
- congenital blindness,
- cataracts,
- glaucoma,
- coloboma
- Genital:
- uterine and ovarian fibromas (often with calcification),
- hypogonadism,
- cryptorchism
- CNS:
- Case courtesy of Dr David Cuete, Radiopaedia.org, rID: 26913
- There is bilamellar calcification of falx cerebri and tentorium cerebellum.
- Post surgical changes in posterior fossa and small calcifications in the basal nuclei.
- Hygroma in the left hemisphere is also observed.
- Case Discussion
- Gorlin’s syndrome is transmitted as an autosomal dominant syndrome having high penetrance, but with variable expressivity, such that not all findings are present in each patient
Malignant Tumors of the Jaw and Mandible
Primary odontogenic tumors 5
Primary nonodontogenic tumors 4
Malignant Tumors of the Jaw and Mandible
-
Primary odontogenic tumors
- Extremely rare tumors.
- Always rule out primary nonodontogenic bone tumors, which are more common.
- Odontogenic CA
- Malignant ameloblastoma
- Primary intraosseous CA
- Other CAs arising from odontogenic epithelium
- Odontogenic sarcoma
- Ameloblastic fibrosarcoma
- Ameloblastic odontosarcoma
- Odontogenic CA
-
Primary nonodontogenic tumors
- Osteosarcoma
- Chondrosarcoma
- Ewing sarcoma
- Multiple myeloma
- Others
- Metastases
- CAs, 85% (breast, lung, renal)
- Sarcomas
https://slideplayer.com/slide/9499640/
Describe the Temporomandibular Joint (TMJ)
Anatomy
- The TMJ is composed of two synovial compartments
- separated by a fibrocartilage disk.
- Posterior capsular attachment is very elastic (bilaminar zone).
- In the open-mouth position, the condyle and disk translate anteriorly.
Anterior TMJ Disk Displacement
Disk Displacement
Pain, clicking, and locked jaw occur.
- Types
- Anterior, anteromedial, or anterolateral displacement with reduction
- (most common type);
- disk is displaced anteriorly on the open-mouth view
- posterior band of the disk prolapses anteriorly relative to the superior surface of the condyle
- instead of remaining in position between the condyle and glenoid fossa).
- Recaptured on the closed-mouth view.
- Persistent anterior displacement; disk does not reduce closed lock
- Rotational displacement
- Medial displacement (uncommon)
- Anterior, anteromedial, or anterolateral displacement with reduction
Stuck TMJ Disc
The right tempromandibular disc shows normal position on closed mouth position , however it remains adherent to the temporal bone in open mouth after normal condylar anterior translation.
Degenerative Changes of TMJ
Degenerative Changes of TMJ
- Radiographic findings are similar to those of osteoarthritis in other joints:
- Joint space narrowing
- Subchondral sclerosis,
- spurring,
- pseudocyst formation
- deformity
- Osteoarthritis of the temporomandibular joint (TMJ) is the end point of long-standing TMJ dysfunction.
- It is a common finding incidentally on a base of skull imaging, and it should be remembered that TMJ pain does not correlate well with osteoarthritic changes.
- Indeed pain from TMJ dysfunction is often self-limiting.
- Radiographic features
- Changes are usually more evident on the condylar side of the joint:
- flattening: common (in one series 27%)
- osteophytes: common (27%)
- erosions: 13%
- sclerosis: less common (9%)
- subchondral cysts
- Changes are usually more evident on the condylar side of the joint:
- Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID: 61034
