E2: Cysts of the Jaws Flashcards
What are the four essential features that make a “cyst”?
1. Pathological cavity (not natural)
#2. Filled with fluid
#3. Lined by epithelium
#4. Connective tissue wall
Which of the 4 characteristics of a cyst qualifier would be seen on a radiograph?
pathological cavity
Where is a typical location of a cyst?
- Usually inside bone, may be in soft tissues
- Rarely in condyle or coronoid process
- Odontogenic cysts in tooth bearing areas
The borders of a cysts are described as
- Well‐defined, smooth
- Corticated (any white line)
- Irregular or sclerotic if infected (crisp white line called sclerosis)
The shape of the cysts are described as
- Spherical (on cross‐sections)
- Circular (on 2‐D images)
- Oval, when contacts a hard surface, e.g., cortical bone or roots
- Scalloped border (seashell)
What are the effects of cysts?
- Slow growing
- Displaces roots, may resorb
- Displaces IAC (mandible) or sinus floor (maxillary)
- Sharp and smooth border
- Expands or perforates cortical plates
The radiographic appearance of cysts is described as
- Radiolucent: Loss of bone
- Distinct border: Slow growing, Fluid filled balloon or Soft tissue mass
- Fluid: hydraulic pressure (pushes in all directions)
At what size can you see the corticated borders of a cyst?
5mm or more
A small cyst that’s 2mm is not going to show a corticated border
What are the 3 different classification of cysts?
inflammatory, developmental and “other”
What are the two types of inflammatory cysts?
radicular and inflammatory collateral cysts
What are the different types of developmental cysts?
- Dentigerous
- Odontogenic keratocyst
- Lateralperiodontal
- Glandular odontogenic
- Nasopalatine
DO-NGL
What are the different types of radicular cysts?
apical and lateral
The lateral radicular cyst usually results from what part of the tooth?
accessory canals
The apical radicular cyst usually results from what part of the tooth?
main pulp canal
What are the different types of inflammatory collateral cysts?
buccal bifurcation and paradental
What type of cyst?
radicular
What type of cyst?
residual
What type of cyst?
dentigerous
What type of cyst?
lateral periodontal (between two roots)
What type of cyst?
glandular (a group of cysts between two roots)
What type of cyst?
OKC (oral keratinized cyst, elongated)
What type of cyst?
nasopalatine (only between incisors, only from nasopalatine canal)
What type of cyst?
simple bone cyst (not a true cyst because it’s not fluid filled)
What type of cyst?
mucous retention cyst (not a true cyst because it’s mucus, not fluid)
What are the different names for a radicular cyst?
- Radicular cyst
- Periapical cyst
- Apical periodontal cyst
- Dental cyst
Generally, when would you see a radicular cyst?
carious lesion, fractured crown or trauma
from lecture
What is the disease mechanism for a radicular cyst?
- Inflammatory products of nonvital tooth (MUST be nonvital - this is CRITICAL)
- Epithelial cells of Malassez proliferate and undergo cystic transformation
- Hydraulic/osmotic pressure (to become larger and pushes upon nearby structures)
What are the clinical features of a radicular cyst?
- Any age, but more common in the third to sixth decade
- Nonvital tooth: caries, trauma, large restoration
- No symptoms unless infected (most radicular cysts are found by chance)
What are the imaging features of a radicular cyst?
Location, border, shape, size, internal content and effects
- Location: Epicenter related to apex, Lateral when related to an accessory canal, About 60% in maxilla (but can be on any tooth)
- Border: Well defined, corticated, Loss of cortication when infected, Thin cortex of small cysts (can’t see margin)
- Shape: outline is circular, larger lesions are oval
- Size: small lesions difficult (similar to granuloma or abscess), larger lesions, greater than 2cm in diameter are more likely to be a cyst
- Internal content: no radiopacity, long-standing cyst may have discrete calcifications
- Effects: displace and resorption of roots, displaces cortex, sinus floor and inferior alveolar canal
What is the differential diagnosis for radicular cysts?
- granuloma or abscess
- lateral periodontal cyst - VITAL tooth
- odontogenic keratocyst - VITAL tooth
radicular cysts are non-vital
What is the management for radicular cyst?
- Endodontic therapy (root canal)
- Apicoectomy
- Extraction
- Recurrence is uncommon (but if you don’t remove it, it becomes a residual cyst)
Describe the cyst seen in this radiograph
Large carious lesion indicates tooth is non-vital. It has a well corticated oval lesion that is pushing on the nearby structures (the roots of the first and second molar), and the inferior alveolar canal.
Describe the cyst seen in this radiograph
radicular cyst: Non-vital tooth (Endo treated tooth), oval small cyst, touching nasopalatine canal, radiolucent
Describe the cyst seen in this radiograph
radicular cyst: circular, has not pushed on any adjacent structures
Describe the cyst seen in this radiograph
radicular cyst: oval
What is the disease mechanism for a residual cyst?
- A remaining cyst after removal of the original cyst
- Usually a remaining radicular cyst
- History of extraction
What are the clinical features of a residual cyst?
- Mostly asymptomatic
- Incidental finding on a radiograph
- Occasional pain if infected
What are the imaging features of a residual cyst?
- Location: edentulous area, at the level of apices of neighboring teeth
- Border, size, shape, internal content and effects: same as radicular cyst - only difference is there is no tooth.
What is the differential diagnosis of a residual cyst?
- odontogenic keratocyst
- salivary gland depression (inferior to the canal) - (Stagne’s cyst –> defect, not a true cyst) and is only in the mandible
What is the treatment/management of residual cysts?
- surgical removal
- marsupialization if lesion is large (make a pocket in the bone, but you don’t remove the whole cyst)
Describe the cyst in this radiograph
residual cyst: circular cyst in an edentulous area with missing molars
This is a radiograph of the mandible. What “cyst” would occur here?
Stagne’s cyst (not a true cyst)
A biopsy is not recommended for what kind of cyst?
buccal bifurcation
What does a sclerotic border of a cyst signify?
infection
What are the requirements for buccal bifurcation cyst?
Must be on the buccal and in a bifurcation
What is the disease mechanism for a buccal bifurcation cyst?
unknown etiology, epithelial cells rests in PDL
What are the different names for buccal bifurcation cyst?
- BBC
- mandibular infected buccal cyst
- paradental cyst
Paradental cyst is sometimes regarded as not an accurate name.
What are the clinical features of buccal bifurcation cysts?
- children: 5-13 years
- delayed eruption of the 1st or 2nd mandibular molar
- lingual cusps higher than buccal
- vital teeth
- buccal swelling
What are the location of buccal bifurcation cysts?
- Buccal to the mandibular first molar
- Less commonly with the second molar
- Little distal to the furcation
- Bilateral: BBBC
What is the border of buccal bifurcation cysts?
Well defined, corticated,
Often infected, sclerosis of the wall
What is the effect of buccal bifurcation cysts?
- Tipping of the crown
- Lingual cusps higher than the buccal
- Roots closer to the lingual cortex
What are the differential diagnosis for buccal bifurcation cyst?
- Radicular cyst (in the same area but is non-vital)
- Paradental cyst: third decade of life
- Dentigerous cyst
Remember that BBC occur in vital teeth & in children
What is the management of buccal bifurcation cyst?
- Microscopic features are nonspecific, histopath (biopsy) not recommended
- Conservative curettage
- Spontaneous resolution
- No extraction
No root canal bc tooth is vital, may heal on its own.
What are the different names for a dentigerous cyst?
- eruption cyst (in soft tissues)
- follicular cyst
What is the disease mechanism for a dentigerous cyst?
- Developmental, can be inflammatory
- Fluid between the crown and the epithelium or fluid in the
layers of the epithelium
What are the clinical features for a dentigerous cyst?
- Most common developmental cyst
- Associated with crown of an impacted or unerupted tooth
- Mostly in permanent dentition. Rarely in deciduous dentition
- Occurs with supernumerary tooth too
What are the imaging features of a dentigerous cyst?
Location, border, shape, size, internal content and effects
- Location: around the crown of a tooth, Mn 3rd molar and Mx canine, at CEJ (central, lateral or circumferential)
- Border: well defined, corticated (loss of cortication when infected), thin cortex of small cysts
- Shape: circular outline, large lesions are oval
- Size: follicular space >3mm on PA, can be very large
- Content: radiolucent (except for crown of impacted tooth)
- Effects: considerable tooth displacement, resorption of roots of adj teeth when it becomes big, displaces sinus floor and inferior alveolar canal, moderate expansion of cortex
What type of shape is this?
central
tooth at center
What type of shape is this?
lateral
What type of shape is this?
circumferential
big cyst, but still starts at CEJ
Biopsy can help us if the cyst look like it does not start at the CEJ
What is the differential diagnosis for the dentigerous cyst?
- Hyperplastic follicle
- Odontogenic keratocyst
- Unicystic ameloblastoma
FOR EXAM: 2 conditions that may look similar: odontokeratic cyst (mild), ameloblastoma (HUGE expansion)
What is the treatment/management of the dentigerous cyst?
- Surgical removal, with or without the tooth
- Histopath (biopsy) because it may be a tumor (ameloblastoma)
- Mural ameloblastoma (arises from the walls of the dentigerous cyst)
- Squamous cell carcinoma
- Mucoepidermoid carcinoma
What type of cyst is this?
dentigerous cyst
What type of cyst is this?
dentigerous cyst
What type of cyst is this?
dentigerous cyst
What type of cyst is this?
dentigerous cyst
What type of cyst is this?
dentigerous cyst
What is the disease mechanism for lateral periodontal cyst?
- Rare
- Epithelial rests on the lateral aspects of a tooth
- Usually a single lesion (98% of the cases), may be a cluster—botryoid
What are some similar conditions of lateral periodontal cyst?
- Gingival cyst of the adult
- Botryoid odontogenic cyst
OKC
Lateral radicular cyst
What are the clinical features for lateral periodontal cyst?
- Tooth is vital
- Asymptomatic (88% cases)
- Mean age is ~50 years, seen in second decade of life or later
- No gender predilection
What are the imaging features of a lateral periodontal cyst?
Location, border, shape, size, internal content and effects
- Location: 70% in mandible, lateral incisor to PM area, lateral aspect of root (between 2 roots)
- Size: usually ~1cm, some up to 3 cm (rare)
- Shape: oval (large) or circular (small)
- Border: corticated
- Effects: loss of lamina dura, displacement of tooth (not always), expansion of cortex (50% of cases)
What are the differential diagnosis of a lateral periodontal cyst?
- Radicular cyst from an accessory canal (non-vital) on the side of a tooth
- Odontogenic keratocyst (has a hot dog shape)
What is the management for lateral periodontal cyst?
- Start with a vitality test
- Simple enucleation
- Recurrence is low (if it’s OKC, it’d have a high recurrence)
- Botryoid variety has more aggressive behavior
Biopsy recommended to differentiate from OKC
What type of cyst?
lateral periodontal cyst
What type of cyst?
lateral periodontal cyst
What type of cyst?
lateral periodontal cyst
What type of cyst?
lateral radicular cyst
What is the disease mechanism of glandular odontogenic cyst?
rare, originated from odontogenic epithelium with salivary gland
features (related to mucoepidermoid carcinoma?)
What is another name for glandular odontogenic cyst?
sialo-odontogenic cyst
“Sialo” because of salivary origin
What are the clinical features of a glandular odontogenic cyst?
- 4th to 5th decade of life, mean age is about 48 yrs.
- Aggressive behavior
- M>F
What are the imaging features of a glandular odontogenic cyst?
Location, border, shape, size, internal content and effects
- Location: Mandibular anterior region, Less commonly - maxillary anterior region, Mandible: Maxilla = 3:1
- Border: Well defined, corticated, Scalloped, Multilocular, may be unilocular (Lit. search: ~60% unilocular!)
- Effects: Displacement of the roots, Cortical expansion (73% cases) and perforation if severe (26% cases), Root resorption (14% cases)
What is the differential diagnosis for glandular odontogenic cyst?
- Ameloblastoma (multiocular/multicystic) - but causes high displacement
- Odontogenic keratocyst (due to scalloped appearance)
- Central mucoepidermoid carcinoma
- Solitary lesion: lateral periodontal cyst (if in the cervical)
What is the management for glandular odontogenic cyst?
- High recurrence
- Aggressive treatment
- Enucleation or resection
- Follow‐up imaging (because of high recurrence)
What type of cyst?
glandular odontogenic cyst
What type of cyst?
glandular odontogenic cyst
Odontogenic keratocyst affect which demographic?
- About 10% of all odontogenic cysts
- Slightly more in male
- Any age, infancy to old age
- Frequent age range of 10‐40 years
What is the typical location of an odontogenic keratocyst?
- 60‐80% of OKC in mandible
- Posterior body of the mandible (90% distal to canines)
- Superior to alveolar canal
- Sometimes with an unerupted tooth, similar to a dentigerous cyst
What is the border of an odontogenic keratocyst?
- Well‐defined smooth corticated border
- Large lesions may have multilocular appearance (cyst compartments)
What is the shape and size of an odontogenic keratocyst?
- Tends to grow along the length of the bone (so if in mandible, will follow mandible)
- Forms tunnel or sausage shape
- Can become large (asymptomatic and no cortical expansion)
What is the internal content of an odontogenic keratocyst?
- Radiolucent
- Presence of keratin does not make the lesion radiopaque (no calcification)
- Some septa (some vertical lines)
What are the effects of odontogenic keratocyst?
- Minimal cortical expansion in the body
- High recurrence
- Some cortical expansion in ramus
- Displaces or resorbs teeth, but less than dentigerous cyst
What type of cyst is this?
odontogenic keratocyst
What type of cyst is this?
odontogenic keratocyst
What type of cyst is this?
odontogenic keratocyst
What type of cyst is this?
odontogenic keratocyst
What type of cyst is this?
odontogenic keratocyst
What are the different names for Gorlin-Goltz syndrome (multiple OKC)?
- Gorlin syndrome
- Basal cell nevus syndrome
- Nevoid basal cell carcinoma syndrome
What are the clinical features of Gorlin-Goltz syndrome?
- Starts early in life, after 5 years
- Multiple OKCs
- Recurrence rate of OKCs in Gorlin‐Goltz is higher than non‐
syndromic OKCs - Skin cancer
- Bifid rib and other abnormalities
What are the imaging features of Gorlin-Goltz syndrome?
- Multiple OKCs
- Radiographic features same as solitary OKC
- Size: a few mm to several cm
- Calcification of falx cerebri
What is the differential diagnosis for Gorlin-Goltz syndrome?
Multiple dentigerous cysts
Other conditions with multiple radioluciencies include
- Cherubism
- Multiple myeloma
However, the clinical symptoms are VERY different.
What type of cyst is this?
Gorlin-Goltz syndrome
What is the management for Gorlin-Goltz syndrome?
- Thorough image analysis, using CT or CBCT
- Aggressive surgery, as recurrence is high
- Follow‐up imaging
- Genetic analysis
What is the disease mechanism for nasopalatine duct cyst?
Arises from epithelial remnants of the nasopalatine duct
What are the different names for nasopalatine duct cyst?
Incisive canal cyst
Median palatine cyst
What are the clinical features for nasopalatine duct cyst?
- Most common between 40 and 60 years.
- About 10% of the jaw cysts
- More in male
What is the location for the nasopalatine duct cyst?
- Midline of maxilla between centrals
- Extends to hard palate (median palatine cyst)
- May not be symmetric
What is the border and shape for nasopalatine duct cysts?
- Circular or oval, well defined
- Sagittal view: curvature of the anterior wall of the canal
- Heart shape, when ANS is superimposed on occlusal or
periapical view
Which anatomic variation of the canal is it?
cylindrical
Which anatomic variation of the canal is it?
hourglass
Which anatomic variation of the canal is it?
funnel
Which anatomic variation of the canal is it?
spindle
What is the size for a nasopalatine duct cyst?
- Large foramen, wider than 6 mm may appear as a cyst
- Some canals are uniformly wide (5‐6 mm), less likely to be a
cyst (Clue: Curvature of the anterior wall of the canal on a cross
sectional image)
What are the effects of a nasopalatine duct cyst?
- May cause expansion of maxilla, discomfort or pain
- May flare the roots of the central incisors
What is the differential diagnosis for nasopalatine duct cyst?
- Large nasopalatine canal
- Radicular cyst
What is the management of nasopalatine duct cyst?
- Enucleation
- Marsupialization if the lesion is large
What type of cyst?
nasopalatine duct cyst
What is the disease mechanism for simple bone cyst?
- Etiology unknown
- No epithelial lining, not a true cyst
- Localized aberration of bone remodeling
- Cavity in bone lined with connective tissue
What are the different names for simple bone cyst?
- Traumatic bone cyst (wrong - not trauma)
- Hemorrhagic cyst (wrong - no bleeding)
- Solitary bone cyst (SBC)
- Idiopathic bone cavity (IBC - best name)
SBC or TBC are better names
What are the clinical features for simple bone cyst?
- Incidental finding
- Mean age: 17 years
- Male/female: 2:1
No relationship with trauma, common in 17 yr old males (but not 19 or 20) probably due to spontaneous healing
What is the location for simple bone cyst?
- Mandible
- Ramus and posterior mandible
The border of a simple bone cyst is described as
- Well‐defined or ill‐defined
- Scallops between roots of teeth
What is the shape of simple bone cyst?
- Outline is smooth
- Large lesions are oval
- Tends to grow along the length of the bone
What is the internal content of simple bone cyst?
- Radiolucent
- May be empty, or contain fluid
What is the effect of simple bone cyst?
- Vital teeth
- Usually no displacement of teeth (because cavity is empty)
- May expand the cortex
What is the differential diagnosis for simple bone cyst?
Odontogenic keratocyst
OKC may displace teeth, or resorb the roots
What is the management for simple bone cyst?
- Conservative opening and curettage (see if it’s cavity or if there is fluid)
- Spontaneous resolution
If there is “cheesy” filling = OKC
What type of cyst?
simple bone cyst
What type of cyst?
simple bone cyst
What type of cyst?
simple bone cyst
