Cysts of the Jaw Flashcards
Objectives: • Know the classification of cysts of the jaws • Know the basic pathology of cysts • Know the sources of odontogenic epithelium • Know basic mechanisms of cyst formation • Be aware of mechanisms for growth & expansion Know the clinical and pathological aspects of: • Radicular cyst • Paradental cyst • Dentigerous cyst • Odontogenic keratocyst Be aware of the basic facts about remaining cysts
What is a cyst? (1)
A pathological cavity with fluid, semi-fluid or gaseous contents and which is not created by the accumulation of pus; it is frequently but not always lined by epithelium
What does the enamel organ develop from? (1)
The dental lamina
What do radicular cysts form from? Draw a diagram (1+diagram)
Hertwigs root sheaf
What do dentigerous cysts form from? (1+diagram)
Reduced enamel epithelium
What do keratocysts and gingival cysts form from? (1+diagram)
Dental lamina
Where are the epithelial remnants of hertwig’s root sheaf? What are they called?
- Periodontal ligament
- Rest cells of Malassez
List the five odontogenic tissues of the epithelium
- Oral epithelium
- Dental lamina
- Enamel organ
- Reduced enamel epithelium
- Rests of malassez
List the three odontogenic tissues of the mesenchyme
- Dental papilla
- Dental follicle
- Periodontal ligament
Name all the Odontogenic epithelium only lesions (3)
a. Ameloblastoma
b. Squamous odontogenic tumour
c. Calcifying epithelial odontogenic tumour
Name all the Odontogenic epithelium PLUS odontogenic mesenchyme lesions (5)
a. Ameloblastic fibroma
b. Ameloblastic fibro-odontome
c. Adenomatoid odontogenic tumour
d. Calcifying odontogenic cyst
e. Odontomes - complex and compound
Name all the Odontogenic mesenchyme onle lesions (3)
a. Cementoblastoma
b. Fibroma
c. Myxoma
Name all the Odontogenic carcinomas (epithelium) (4)
a. Malignant ameloblastoma
b. Primary intraosseous carcinoma
c. Clear cell odontogenic carcinoma
d. Malignant variants of other tumours and cysts
Name all the Odontogenic sarcomas (connective tissue) (3)
a. Ameloblastic fibrosarcoma
b. Ameloblastic fibrodentinosarcoma
c. Odontogenic carcinosarcoma
Name all the Osteogenic neoplasms (3)
a. Cemento-ossifying fibroma
b. Osteoblastoma
c. Osteosarcoma
Name all the Fibroosseous lesions (4)
a. Fibrous dysplasia
b. Periapical cemental dysplasia
c. Florid cemento-osseous dysplasia
d. Focal cemento-osseous dysplasia
Name all the Epithelial cysts (9)
a. Radicular cysts
b. Paradental cyst
c. Follicular cysts
d. Dentigerous
e. Eruption
f. Odontogenic keratocyst
g. Lateral periodontal cyst
h. Gingival cysts
i. Glandular odontogenic cyst
Name the Other lesions not mentioned above (5)
a. Melanotic neuroectodermal tumour of infancy
b. Cherubism
c. Giant cell granuloma
d. Aneurysmal bone cyst
e. Solitary bone cyst
What is the order of prevalence of non-odontogenic cysts, odontogenic tumours, bone lesions and odontogenic cysts – in most to least common (1)
Odontogenic cysts > Odontogenic tumours > Bone lesions > Non-odontogenic cysts
What are the percentage prevalence of odontogenic cysts, odontogenic tumours, fibro-osseous lesions and bone tumours? (4)
Odontogenic cysts 70%
Odontogenic tumours 15%
Fibro-osseous lesions 10%
Bone tumours 5%
What two categories can epithelial cysts be divided into? (2)
- Odontogenic
- Non-odontogenic
What classifications of odontogenic cysts are there? (1)
Inflammatory or developmental
What inflammatory odontogenic cysts are there? (3)
- Radicular cyst
- Residual cyst
- Paradental cysts
What developmental odontogenic cysts are there? (1+2, 6)
- Follicular cysts
- Dentigerous cyst
- Eruption cyst - Odontogenic keratocyst
- Gingival cysts
- Lateral periodontal cyst
- Botryoid odontogenic cyst
- Glandular odontogenic cyst
- Calcifying odontogenic cyst
What non-odontogenic cysts of the jaws are there? (2)
- Nasopalatine duct cyst
- Nasolabial cyst
Draw diagrams of the following cysts: (9)
- Apical radicular
- Lateral radicular
- Lateral periodontal
- Dentigerous
- Eruption
- Keratocyst
- Residual
- Nasopalatine duct
- Nasolabial
Draw a diagram of the following cysts and their sites: (5)
- Residual
- Solitary
- Keratocyst
- Gingival cyst (adults)
- Alveolar Cyst (infants)
Describe the frequency, in percentages, of Radicular, Follicular, Keratocyst, Nasopalatine and Other cysts: (5)
- Radicular 65%
- Follicular 20%
- Keratocyst 5%
- Nasopalatine 5%
- Others <5%
What do jaw cysts need to develop? (3)
- Source of epithelium
- Stimulus for proliferation
- Growth and bone resorption
What is the inflammatory stimulus for proliferation of a radicular cyst? Diagram (1)
Apical granuloma
What is the inflammatory stimulus for proliferation of an inflammatory
lateral periodontal cyst? Diagram (1)
Periodontitis
What is the inflammatory stimulus for proliferation of a paradental cyst? Diagram (1)
Pericoronitis
What are the stimuli for proliferation of developmental cysts? (1)
Largely unknown
What could the stimuli for proliferation of a Dentigerous cyst be? (2)
- Eruptive force and proliferation?
- Hydrostatic pressure?
What could the stimuli for proliferation of a Keratocyst be? (3)
- Epithelial proliferation
- Hydrostatic pressure?
- Tumour?
Where/how do radicular cysts arise and what are they always associated with? (2)
- Arise in the periodontal ligament from the epithelial rests of Malassez as a result of inflammation following death of the pulp.
- Always associated with a non-vital tooth.
Describe an apical radicular cyst (1) Diagram
At the apex of a tooth associated with the opening of the root
Describe a Lateral radicular cyst (1) Diagram
At the side of a tooth associated with a lateral branch of the root canal
Describe a Residual radicular cyst (1) Diagram
A radicular cyst which has persisted after extraction of the associated
What are the most common decade of ages to have radicular cysts? (1)
30-39yrs > 40-49yrs > 20-29yrs
Describe the very basic pathogenesis of a radicular cyst (5)
- Caries of tooth
- Leads to non-vital pulp
- Leads to apical granuloma
- Proliferating odontogenic epithelium of apical granuloma
- Leads to radicular cyst
What is mucous metaplasia? How often is it seen in radicular cysts? (2)
- Mucous cells, change in the type of cells to form abnormal
- Seen in about 15% of radicular cysts
What do cysts ‘tend’ to be in relation to granulomas? (5)
- Larger
- More radiolucent
- Well defined
- Corticated outline
- Painless
What percentage of cysts are correctly diagnosis preoperatively? (1)
50%
What is a paradental cyst? Describe a particular type (2)
- A cyst which arises on the lateral aspect of a tooth as a result of inflammation in a periodontal pocket. It arises from pocket epithelium.
- A particular type of paradental cyst arises at the buccal aspect of partially erupted third molars.
What is the histology of a paradental cyst similar to? (1)
- Histology is similar to the radicular cyst
What is a follicular cyst? (1)
A cyst which surrounds the crown of an unerupted tooth and arises from the reduced enamel (follicular) epithelium.
What is a dentigerous follicular cyst associated with? (1)
Associated with an impacted tooth
What is an eruption follicular cyst associated with? (1)
Associated with an erupting tooth
What is the basic pathogenesis of a follicular cyst? Use diagrams (3)
- Impacted tooth
- Follicular epithelium proliferates
- Cyst forms
Where does an eruption cyst lie? (1)
Just beneath the oral mucosa
What is an odontogenic Keratocyst? What does it arise from? (2)
- A cyst arising in the tooth bearing area and characterised by a thin lining of keratinised epithelium.
- It arises from the dental lamina or its remants and may replace a tooth.
What is the basic pathogenesis of a Keratocyst? Use diagrams (3)
- Remnants of dental lamina - Epithelial proliferation, genetic? trauma? - Cyst develops
What is jaw cyst/basal cell naevus syndrome? What occurs? (6)
- ‘Gorlin-Goltz syndrome’
- Multiple and recurrent odontogenic keratocysts
- Basal cell carcinomas of skin
- Frontal bossing
- Skeletel abnormalities (eg. bifid ribs)
- Cranial abnormalities (eg. calcification of falx cerebri)
What can odontogenic keratocysts occasionally be? (1)
‘Solid’
What evidence is there that an odontogenic Keratocyst may be a benign neoplasm? (6)
- High rate of cell proliferation in the wall
- High rate of recurrence
- ‘Aggressive’ and infiltrative growth
- Association with basal cell carcinoma in ‘Gorlin-Goltz syndrome’
- Molecular changes similar to basal cell carcinoma
- PTCH (chromosome 9q) mutation in BCC and Gorlin’s syndrome
What did WHO change the odontogenic Keratocyst classification to in 2005? What happened? (2)
- ‘Keratinising cystic odontogenic tumour’
- New terminology not accepted
What is a lateral periodontal cyst? What can occur occasionally, what is it then called? (2)
- Occurs on the lateral aspect or between the roots of vital teeth. It is developmental in origin but the source of epithelium is unclear.
- Occasionally it is multilocular and called botryoid odontogenic cyst
What can occur with lateral periodontal cysts? What is common? (2)
- May be multilocular
- Localised thickening of the wall is common
What are gingival cysts of infants? (2)
- Arises from dental lamina rests in the alveolar mucosa of infants
- Lined by thin parakeratinised epithelium
What are Gingival cyst of adults? (2)
- Arises from dental lamina rests in the attached gingiva
- Lined by thin non-keratinised epithelium
What is a glandular odontogenic cyst? What is it also called? (2)
- Also called sialo-odontogenic cyst
- A cyst characterised by cuboidal or columnar epithelium with mucous production and forming duct-like or glandular structures
What occurs in the histology of a glandular odontogenic cyst? (2)
- Epithelial thickenings
- Mucous cells and ducts
What kinds of non-odontogenic cysts are there? (2)
- Nasopalatine duct cyst
- Nasolablial cyst
What is a Nasopalatine duct cyst? (2)
- Arise in the nasopalatine (incisive) canal from epithelial residues of the nasopalatine duct
- They are lined by respiratory epithelium or sratified squamous epithelium, or often both.
What is a Nasolabial cyst? Where does it arise? (2)
- Arises in the soft tissue overlying the alveolar process at the base of the nostril, deep to the nasolabial fold.
- It probably arises from remnants of the nasolacrimal duct and is usually lined by pseudostratified columnar epithelium
What are cystic lesions? Give three examples (4)
- Cystic lesions in the jaws, without an epithelial lining
- Solitary (simple) bone cyst
- Aneurysmal bone cyst
- Stafne bone cavity
