DENT 623A Midterm


No Sinus or no aeration of the sinus.


Small Sinuses

Extensive Pneumatization

Sinus expands towards the alveolar crest

Antral Projections

Bony projection or exostosis


Create divisions within the sinuses, thinner compared to antral projections.


Well defined band of increased radiopacity paralleling the bony walls of the sinus (thickness up to 10-15mm). In most cases patient is asymptomatic.


- Generalized thickening of the sinus mucosa along the walls with near complete or complete opacification of the sinus.
- Air-fluid level resulting from accumulation of secretions may also be visualized depending on the type of imaging.

Acute Sinusitis

Sinusitis present for 4wks or less.

Chronic Sinusitis

Sinusitis present for more than 12 consecutive weeks.

mucus retention pseudocyst

- From blockage of secretory ducts of seromucous glands in the sinus mucosa.
- Rarely causes any signs or symptoms (pt unaware), occurs more in early spring or fall.
- Well-defined, non-corticated, smooth, dome-shaped radiopaque mass.
- Common on floor of


- Thickened membrane of chronically inflamed sinus forms into these irregular folds.
- May cause displacement or destruction of bone.
- Present in ethmoid air cells may destroy medial wall of orbit -> Ipsilateral Proptosis.
- May mimic benign or malignant


- Deposition of mineral salts around a nidus which can be intrinsic or extrinsic.
- Small = asymptomatic
- Large = sinusitis, blood-stained nasal discharge, nasal obstruction, facial pain.

TMJ Flattening

Flattening is not normal but because there can be variation in anatomy it mayyyy be normal for that patient.

TMJ Sclerosis

Thickening of the cortex surrounding the condyle.

TMJ Erosion

Parts of the cortex are missing.

TMJ Osteophytosis

Happens after flattening of the TMJ and is the formation of triangular projections in the anterior-superior aspect of the condyle (makes it look like a beak).

Subchondral Cyst and Erosion

Cyst forms as a low-density area, when it gets larger may associate it with erosion because the cortex is interrupted.

Bifid Condyle

The condyle tries to form two heads (developmental)

Anterior Concavities

Depressions on the anterior condylar neck

Anterior Protuberences

The condyle looks different but is symmetric. Is a variation of normal.

Carotid Calcifications

45deg from angle of mandible toward cervical spine. Near C3 and C4. This is where the carotid a. bifurcates.

Calcified Stylohyoid Ligaments

Goes from styloid process, beyond earlobe, and towards the angle of the mandible.

Eagle Syndrome

Radiographic evidence of calcified stylohyoid ligaments PLUS symptoms (pain when turning head or swallowing, dizziness from impingement of vagus nerve). If symptoms are severe may need referral for removal of the calcifications.



Calcifications in salivary glands.
- Parotid Gland Sialoliths usually fewer compared to tonsilloliths and may have laminated appearance. Clinical exam may reveal gland swelling, pain at meal times, and decreased salivary flow.

Calcified Lymph Nodes

May be associated with chronic infection, inflammation, or metastatic disease. Irregularly shaped, cauliflower appearance, in all areas of lymph nodes in head and neck.


Increased cementum production around the roots of teeth, makes them look bulbous. If the PDL and lamina dura completely surround the root it is likely this.

Paget's Disease

Changes the trabecular pattern, contains linear lines



Example with perforation of the cortical bone and lots of sequestra (necrotic bone within the spaces). Inflammatory condition of the bone secondary to infection.

Periosteal Reaction (Sunray/Sunburst)

Bone formation coming from the periosteum and going perpendicular from the cortex of the bone. It has a spicule/sunray appearance.
*Characteristic of osteosarcoma, metastatic breast cancer, and prostate cancer.

Periosteal Reaction (Onion Skin)

Appears where the cortical and trabecular bone meet. When there is a pathology the periosteum will begin to make more bone which causes layered bone deposition.


Produce bone but are typically not homogenous, mixed RL-RO and tend to grow rapidly.

Periapical cemento-osseous dysplasia

When follow the PDL space and lamina dura, it's still present but there are multiple lesions surrounding the apices of the anterior Mandibular teeth. Teeth are VITAL and Asymptomatic! Goes through three stages: early/RL, Mixed, and RO. More common in midd

Periapical Lesion

Non-vital tooth and the lamina dura is gone where the lesion is present. Tx: Endo or extract if non-restorable.

Malignant lesion growing in PDL space

Residual Cyst

- Seen in edentulous space that at one point had a tooth. It is a periapical cyst that did not resolve following extraction of the affected Tooth.
- Unilocular, non-corticated or corticated.
- biopsy, extraction history, surgical removal with radiographic

Osteoporotic Bone Marrow Defect

Large bone marrow space. Radiographic followup will show no change in size or shape. Due to lack of trabeculation and more bone marrow tissue.

Lateral Radicular Cyst

- Same as periapical cyst but on the side of the root instead of at the apex.
- RL, unilocular, corticated or non-corticated.
- Loss of lamina dura
- Do pulp testing (biopsy only if the tooth doesn't respond to endo), and treat with extraction, endo, radi

Lateral Periodontal Cyst

- Lateral the root surface, forms from remnants of dental lamina
- Always associated with VITAL tooth.
- Age 40-50
- Location: mandibular canine/premolar region
- Unilocular RL or Multilocular RL
- May cause root divergence
- Tx: Curettage

Nasopalatine Duct Cyst

- From nasopalatine duct
- Swelling of incisive papilla, burning sensation
- Possible drainage & pain
- Unilocular RL, corticated, more than 6mm wide
- Diagnose w/biopsy & treat w/surgical removal
- May cause divergence of the central incisors

Traumatic (simple) Bone cyst

- Not a true cyst, blood filled cavity, young pts.
- Premolar/molar area
- Asymptomatic, may have painless swelling, may or may not have history of trauma.
- Well-defined RL, scallops between roots of teeth (still see PDL and lamina dura).
- Vital teeth,

Odontogenic Keratocyst (OKC) or Keratocystic Odontogenic Tumor (KOT)

- Benign
- Grow anterior-posterior direction, minimal B-L expansion.
- May resorb roots & be multilocular (soap-bubble).
- May cause endosteal scalloping
- Pericoronal (usually attached apical to the CEJ), interradicular, periapical, or not associated w/t

Nevoid Basal Cell Carcinoma (NBCCS)

- AKA Gorlin-Goltz Syndrome
- Multiple OKCs are associated with this autosomal dominant disorder.
- Caused by mutation in tumor suppressor gene
- Clinical findings: multiple basal cell carcinomas of the skin that begin in puberty, multiple OKCs, milia and

Unicystic Ameloblastoma

- Arises from odontogenic epithelium from remnants of the dental lamina and the enamel organ.
- Younger pts, less aggressive, less recurrence than ameloblastoma.
- Interradicular or pericoronal
- presents as single cystic entity or within lining of dentig


- From odontogenic epithelium
- Mandible > Maxilla
- Age: 20-60, average 33yo
- M=F
- 20% associated with impacted tooth
- Can cause painless Expansion (may cause significant B-L expansion, slow growing but locally aggressive)
- Small = unilocular RL
- La

Buccal Bifurcation Cyst

- AKA Paradental cyst
- From epithelial cell rests in the PDL of the buccal bifurcation of the mandibular molars.
- Inflammation may be the stimulus
- Lack of eruption of molar, lingual cusps protruding, roots displacing lingual cortex of mandible. May be


Borders are ill-defined and radiolucency may extend beyond PDL space.


- Mandible more common than maxilla
- May see multiple lesions
- Common primary sites: breast and lung cancer
- May start within the PDL space causing localized PDL space widening (not uniform)

Primary Intraosseous Carcinoma

- See thinning of the cortex in the buccal and lingual plate and the trabecular pattern is lost.
- In cross sectional view see lots of bone destruction and ill-defined borders

Squamous Cell Carcinoma

Bone loss is localized, helping to differentiate from periodontal disease.

Squamous Cell Carcinoma within Cyst Lining

- Arises from odontogenic cyst's epithelium
- May cause pain, paresthesia, pathologic fractures, soft tissue invasion.
- RL, ill-defined, ragged borders
- Loss of LD and supporting bone around the teeth (floating tooth)

Langerhans Cell Histiocytosis

- Aggressive bone loss with teeth floating in air appearance and no cortication = malignancy
- Non-malignant and malignant types
- Uni- or Multifocal
- epicenter of osteolysis is at mid root level
- Causes floating tooth appearance.


- May be RL or mixed
- Associated with Paget's Disease, fibrous dysplasia (rare) and Radiotherapy.
- May start as asymmetric widening of the PDL space
- May cause "sun ray" periosteal reaction.

Odontogenic Myxoma

- Age: young adults (some cases are older)
- Mandible>Maxilla
- Asymptomatic
- Mild expansion
- Multilocular, smaller compartments (Honeycomb appearance) - can also be soap bubble or tennis racket (straight septa) appearance.
- May displace teeth
- May ca


- Lytic lesions with loss of lamina dura and marrow infiltration
- ill-defined margins and root resorption at apex


- >60% of leukemia patients have jaw lesions
- May be RL or mixed.
- Diffuse osteopenia
- Bilateral, ill-defined, patchy RL, PDL widening
- Oral symptoms (if present): loose teeth, petechiae, ulceration, boggy enlarged gingiva.

Hyperplastic Follicles

- Follicle that is more than 4mm but non-pathologic
- Considered normal variation

Dentigerous Cyst

- Most common developmental odontogenic cyst
- Arises from reduced enamel epithelium, fluid accumulates between the crown and the REE
- Always associated with crown of impacted tooth (RL - always pericoronal)
- Site: mand 3rd molars (can be seen in associ

Eruption Cyst

- Soft tissue component of dentigerous cyst
- RL - unilocular (around crown of an erupting tooth)
- Tx: allow the tooth to erupt, cyst will resolve

Ameloblastic Fibroma

- from odontogenic epithelium & primitive mesenchymal components
- Pericoronal or in place of congenitally missing tooth
- Site: posterior mand/ramus
- Age: <20yo
- Clinical Findings: swelling, missing tooth, incidental finding.
- Usually in place of miss

Central Giant Cell Granuloma

- Multilocular, most common in the mandible & ramus area.
- Not a neoplasm but behaves like a benign (mand) or malignant (max) tumor because well and ill-defined.
- Age: 60% younger than 20
- Younger pts - anterior to 1st molar or max canine, Older pts -

Central Mucoepidermoid Carcinoma

- Epithelially derived malignant salivary gland neoplasm arising in bone
- May mimic a benign neoplasm/tumor or cyst
- Site: 3-4 times more common in mand (post), tooth bearing areas.
- F>M
- Clinical Findings: painless or tender swelling, tooth movement,


- Autosomal dominant trait
- kids with chubby cheeks
- Age: onset at 2-5yo, mild cases seen at 10-12.
- Bilateral expansion of the jaws, affects ramus and maxilla
- Rl, multilocular, corticated
- May cause tooth displacement or failure of eruption, and di

Glandular Odontogenic Cyst

- F>M
- Anterior mand > max
- Rl, uni or multilocular
- expansion, perforation, displacement, similar to ameloblastoma
- Clinical features: aggressive behavior, tends to recur
- Tx: may include resection

Central Hemangioma

- Proliferation of blood vessels
- F>M
- Mand>Max
- Enlargement of trabecular spaces (soap bubble or honeycomb), may be unilocular
- Sunburst or sun ray appearance, may be ill-defined.
- possible involvement of IAN canal
- Very significant expansion!
- In

Aneurysmal Bone Cyst (ABC)

- Not a true cyst or tumor.
- Vascular lesion caused by local change in hemodynamics or reparative response.
- Vascular and solid types (may be related to TBC and CGCG)
- Rapid growth, expansile, destructive, may perforate and invade soft tissues, possibl

Glandular Odontogenic Cyst

- AKA: Sialo-odontogenic Cyst
- Form odontogenic epithelial with salivary gland features. (may be related to mucoepidermoid Ca)
- F>M, Ant Mand>Max
- RL, uni- or multilocular
- Expansion, perforation, displacement, similar to ameloblastoma
- Clinical Feat

What are the 7 Multilocular Radiolucencies?

- Central Giant Cell Granuloma
- Odontogenic Keratocyst
- Myxoma
- Ameloblastoma
- Cherubism
- Hemangioma
- Aneurysmal Bone Cyst