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).
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.
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).
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.
