Cysts of jaw

Cysts of jaw

2. CYSTS OF JAW

3. OVERVIEW
Definition

Classification

Pathogenesis

Signs and symptoms (general)

4. DEFINITION

A cyst is an abnormal cavity in hard or soft tissues
which contains fluid, semi-fluid, or gas and is
often encapsulated and lined by epithelium.
- Killey & Kay (1966)

 A cyst is a pathologic cavity having fluid, semi-
fluid or gaseous contents that are not created by the
accumulation of pus; frequently, but not always
lined by epithelium.
- Kramer (1974)

5. SHEAR’S CLASSIFICATION

Cyst of jaw oral and facial soft tissue

Intra osseous cysts Soft tissue cysts

Epithelial Non epithelial Cyst of maxillary
cyst cyst antrum

Odontogenic Non odontogenic


Developmental Inflammatory

6. CLASSIFICATION WHO- 1992
Epithelial cysts

Odontogenic origin
Developmental

Primordial cyst
Dentigerous cyst
Lateral periodontal cyst
Calcifying odontogenic (Gorlin) cyst

7. CLASSIFICATION WHO- 1992
Inflammatory

Radicular cyst
Residual cyst

9. CLASSIFICATION WHO- 1992
Non odontogenic

Fissural:
Median palatine cyst
Median mandibular cyst
Globulomaxillary cyst

Incisive canal:
Nasopalatine cyst
Median anterior maxillary cyst

10. CLASSIFICATION WHO- 1992
Non epithelial (pseudocyst)

Staffney bone cyst
Solitary bone cyst
Aneurysmal bone cyst

11. CLASSIFICATION WHO- 1992
Cyst of maxillary antrum:

Surgical ciliated cyst of maxilla
Benign mucosal cyst of maxillary antrum

12. CLASSIFICATION WHO- 1992
Soft tissue cysts:
Odontogenic
 Gingival cysts
1. Adult
2.Newborn
Non odontogenic
1.Anterior median lingual cyst
2.Nasolabial cyst
Retention cyst
Salivary gland cyst
1. Mucocele
2. Ranula

13. CLASSIFICATION WHO- 1992
Developmetal cyst:
1.Dermoid and epidermoid cysts
2.Lymphoepithelial cyst
3.Thyroglossal duct cyst
4.Cystic hygroma

Parasitic cyst:
1.Hydatid cyst
2.Cysticercosis

Heteropic cyst

14. PATHOGENESIS

Cyst initiation Cyst formation
Cyst enlargement

15. Pathogenesis

Cyst initiation

Initiation results in the proliferation of the epithelial cells
and the formation of small cavity.

a. Cell Rests of Malassez :
Remanants of Hertwigs epithelial root sheath in the PDL
after the root formation is completed.

16. PATHOGENESIS
b. Reduced Enamel Epithelium :
Residual epithelial cells surrounds the crown of the tooth
after enamel formation is complete.

c. Cell Rests of Serres (Dental Lamina) :
Islands of epithelial cells that originate from the oral
epithelium and remain in the tissue after inducing tooth
development

Basal layer of oral epithelium

Tooth germ

17.  Cyst formation

Formation of cavity lined by stratified squamous epithelium
could occur by :
 Cleft produced by accumulation of purulent exudate in the
form of a microabscess then the epithelial cells would be
expected to line the cleft.

Stimulated epithelium proliferated to form a sphere of cells.

Epithelial cells become oriented in relation to their source of
nutrition and the adjacent connective tissue. In normal
situation they cover a surface and are finally desquamated.

18. Cyst enlargement


 Once cyst formation initiated it
continues to grow and large irrespective
of its type and origin

MECHANISM:

 Increase volume of contents
 Hyperosmosis
 Increase in surface area of cyst
 Resorption of surrounding bone
 Displacement of surrounding
soft tissues

19. Increase in volume of contents

Due to
Accumulation of mucous as in mucus secreting ccyst
PGE2
Lymphokines,Osteoclast activating factor,
 Interleukin 1 Fibroblast Prostaglandin
Enlargement determined by:
Continuous stimulation of
Epithelial proliferation

20. Increased osmolarity of cyst fluid play a role in cyst
enlargement

Osmotic difference between cyst and serum is related
to protein present in cystic fluid (Albumin,
Fibrinogen and fibrin degrading products).

21. OSMOTIC THEORY OF ENLARGEMENT
MAIN ,HARRIS AND TOLLER (1975)
Epithelial cell break down products

Hyperosmolar cyst fluid

Draws in fluid from surroundng tissues

 Hydrostatic pressure

 Oncotic pressure

 Cyst permeability

Cyst enlargement

22. Bone resorption:

Cyst gets enlarged within bony cavity , as epithelial cells
divide


Release PGE2 ,leukotriene


Osteoclast function


Size of cyst determined by - Quantity of prostaglandin
released and bone resorbing factors.

23. INCREASE IN CYST SURFACE AREA
Mural growth :Epithelial proliferation

Area of sac


Peripheral cell division/ accumulation of
cellular contents
Multicentric gowth pattern
Collagenase activity
Unremitting growth of high mitotic epithelial linings

24. Cyst regression

Extraction of tooth / Reduction of intra
cystic pressure

Involution of cyst

Regression of connective tissue

Cavity gets filled by bone or scar tissue.

25. SIGNS AND SYMPTOMS

Pain and swelling in involved region
Salty /Unpleasant taste in mouth
Bone expansion.
 Fluctuant swelling under oral mucosa
 Non vital tooth (if radicular cyst)

26. SIGNS AND SYMPTOMS

 Missing tooth in normal series
 Sinus formation with discharge
Pathological fractures
 Large cyst distortion of adjacent structures
 Hollow sound on percussion

27. SIGNS AND SYMPTOMS

Ill fitting dentures
Displacement of teeth
Discoloration

Initially lateral bone expansion turns to thinning of
cortex and can be depressed like a tennis ball or egg shell
crackling to palpation

Later the outer shell disappears and the cyst lining is
present beneath oral mucosa

Greater distension of cystic wall eventual discharge of
fluid into mouth secondary infection and abscess

28. RADIOGRAPHS
Small sized cyst:
IOPA -small periapical cyst
Occlusal radiograph –cortical expansion/perforation
Large sized cyst:
OPG – entire extent, size
Waters view -relation to maxillary antrum and nasal
cavity
Lateral oblique view -to check proximity to lower
border of mandible
PA view - expansion of ramus of mandible
CBCT

29. RADIOGRAPHIC FEATURES
 Radiolucent with a well defined Radio
opaque margin