1. Cysts of The Oral &
Paraoral Regions

2. Definition of Cyst
• A cyst is an epithelial lined pathologic
cavity occuring either in hard or soft
tissue and may contain a fluid or
semi-fluid material (True Cyst).
• Some cysts may not be epithelial-
lined & therefore are not true cysts
(Pseudocysts).

3. Cysts Classification
Non- Pseudo- Soft Tissue
Odontogenic cyst
Odontogenic Cysts
Naso- Dermoid, Ep
periodontal Traumatic
Palatine idermoid
Bone C.
Tract C.
Dentigerous Thyro-
glossal tract
Aneurysmal C.
Fissural Bone C.
Primordial
Benign
lympho-
Static
KCOC, epithelial
Bone C.
Gorlin’s
cyst Mucous
Retention
,Extravasat.

4. 1- Odontogenic Cysts
• Def.: these arise from epithelial remnants
associated with the development of teeth
odontogenic epithelium.
• Site: Affect the tooth bearing region of the jaw.
• Origin of epithelium:
- Enamel organ.
- Reduced enamel epithelium.
- Epithelial rests of Malassez.
- Epithelial rests of Serres (dental lamina
remnants).

5. Odontogenic Cysts Classification
Keratinized
Periodontal Dentigerous Primordial & calcifying
odontogenic
Odonto- (KCOC)
Inflamm. Central
genic
keratocyst Gorlin’s
Development Lateral cyst
(OKC)
Circumferential

6. Periodontal Cysts
Inflammatory Developmental
Apical Lateral
Lateral Gingival C.
adults
Gingival C.
Residual
newborn

7. Periodontal Inflammatory Cysts
• Cause: it results from inflammatory
hyperplasia of the epithelial rests of Malassez
in the periodontal ligament following death of
the pulp.
• Types according to its location:
- Apical or periapical or radicular : related to
root apex.
- Lateral: related to lateral root surface &
accessory root canal.
- Residual: left after extraction in edentulous
area of jaw.

8. 1-Inflammatory Periodontal
Apical (Periapical, Radicular) Cyst
Periapical Inflammatory ↑↑epith.
granuloma proliferation mass
Degeneration
Epith. Lined Separation
+
cavity filled of cells in
liquefication
with fluid the central
of central
formed portion
cells
Apical
periodont
al cyst

9. Mechanism of Cyst
Enlargement
Tissue ↑osmotic
breakdown pressure
Fuid Osteoclastic
transport to bone
cystic cavity resorption
Enlarging
the bony
cavity

10. Clinical Features of Inflamm. Apical
Cyst
• Age: adult (3rd -6th )decade.
• Sex: male ˃ female.
• Site: maxilla ( anterior area).
• Symptoms:
- No infection → painless.
- Infection occurs → painful.
- Rounded swelling
• Signs:
-non-vital tooth, eggshell crackling sensation
under pressure then fluctant swelling.

11. X-ray of Inflammatory Apical Cyst
•Shape: Round or
ovoid
• Margin: Well-
defined
•Radiolucency.
•Size : (5mm –
several cm).
•Related Tooth: may
has a large carious
cavity or large filling.

12. Histology of Inflammatory Apical Cyst
1-C.T
wall
2-
Epith.
lining
3-
Cyctic
fluid

13. Histology of Inflammatory Apical Cyst

14. The Epithlium Lining of Apical Cyst
• Stratified squamous
epith. Acanthosis (20
cell layer).
• Newly formed cyst:
• -Hyperplasic, forming
rings around
inflammatory cells.
• Fully formed cyst:
• - Regular, flattened
with few
inflammatory cells.

15. Connective Tissue Wall of Apical Cyst
• Collagen fibers bundles,
fibroblasts & B.capillaries.
• Acute inflamm. Cells (
PMNL) toward epith. &
macrophages.
• Chronic inflamm. Cells (
plasma cells &
lymphocytes) deeper in CT.
• Dystrophic calcification
foci.
• Cholesterol clefts.
• Multinucleated giant cells
• Russel bodies.
• Rushton bodies.
• Hemosidren &foam cells.

16. Cholesterol Crystals Cholesterol Clefts
Rushton Bodies Russel Bodies

17. Lumen Content or Fluid of Apical Cyst
•The lumen contains
fluid which stains
eosinophilic.
•Sometimes contains
cholesterol in great
amount.
•Chemically: contains
albumin, globulin,
cholesterol &
nucleoproteins.

18. Treatment of Inflammatory Apical Cyst
• Enucleation.
Small • Apicectomy.
• Enucleation.
Medium • Extraction of tooth.
• Marsupilization to avoid
imp. Structures e.g.
Large antrum & inf. Alveolar
nerve.

19. 2- Inflammatory Lateral Periodontal Cyst
• Less common ˃
periapical.
•Site: at the side of
the root of a pulpless
tooth.
•Cause: a result of
opening of a lateral
root canal & irritation
of periodontal tissue.

20. 3- Inflammatory Residual Periodontal Cyst
•Cause:
-The pulpless tooth from
which a periapical cyst
may persist in the jaw
bone.
•Complication:
-Interfering with the
fittness of dentures.
-Enlarge to the extent of
weakning of the jaw.
-Jaw fructure

21. Developmental Lateral Periodontal Cyst
•Def.: a non-inflammatory
developmental cyst which
occurs adjacent or lateral
to the root of vital tooth.
•Cause: proliferation of
rests of odontogenic
epithelium at lateral side
of adjacent vital tooth.

22. Clinical Features of Developmental Lateral
Periodontal Cyst
• Age: any age.
• Sex: male ˃female.
• Site: 2
543
• Signs : may cause a slight
bulge although the
overlying mucosa is
normal.
• Symptoms:
- Asymptomatic
- Vital tooth.

23. X-ray of Developmental Lateral
Periodontal Cyst
•Small , rarely over
1 cm.
•Radiolucent area.
•May or may not
well circumscribed
with an opaque
margin.

24. Histology of Developmental Lateral
Periodontal Cyst
•C.T wall: may have
inflammatory cell if
the cys get infected.
•Epith. Lining:
-Stratified squamous .
-Thin( 1-2)layers.
-Epith. Cells with clear
cytoplasm& small
deeply stained nuclei.
-Parakeratin or
orthokeratin.

25. Developmental Gingival Cysts
Of The New Born
Of Adulthood (Bohn’s Nodules)
• Origin: from dental • Origin: from dental
lamina remnants in the lamina remnants which
proliferate to form small
ST between the oral cyst.
epith.& periosteum.
• Shape: • Shape: multiple white
wellcircumscribed nodules.
swelling of the gingiva.
• Size: small ˃1cm. • Size: ˃ few mm.
• Site: on the alveolar
• Site: free & attached ridge of new born infant
gingiva or papilla(adult).

26. Developmental Gingival Cysts
Of The New Born
Of Adulthood (Bohn’s Nodules)

27. Developmental Gingival Cysts
Of Adulthood Of The New Born
• X-ray: (-ve) soft tissue & • X-ray: (-ve) soft tissue.
vital tooth. • Histology:
• Histology: - Thin epith.
- Thin epith., flattened st. - The lumen filled with
sq.cells. desqumated keratin.
- Non- keratinized.
• Treatment:
• Treatment: - No treatment &
- No treatment. discharge their content
into the oral cavity.

28. Developmental Gingival Cysts
Of Adulthood Of The New Born

29. Thanks
Presented by:
Marwa Assem Salama