CYST OF THE JAWS
BDS FINAL YEAR
SIGNS OF CYST
RADIOGRAPHS FOR CYST
DIAGNOSIS BASED ON TYPE OF
COMPLICATIONS OF CYST
CYST OF THE JAWS
A cyst is defined as an abnormal cavity in
hard or soft tissue which contains fluid,
semifluid or gas and is often encapsulated
and lined by epithelium (Killey and Kay
In 1974, Kramer defined cysts as a
pathological cavity having fluid, semi-fluid
or gaseous contents that are not created by
the accumulation of pus, frequently but not
always, is lined by epithelium.
Various classifications have been given to describe
1. Robinson (1945)
2. WHO classification (1971)
3. Shear's classification (1983)
A. Developmental cysts
a) Primordial cyst (keratocyst)
b) Gingival cyst
c) Eruption cyst
d) Dentigerous cyst (folificular)
a) Nasopalatine (incisive canal)
Robinson „s Classification
From odontogenic tissue
1. Periodontal cysts
a) Radicular cysts
b) Lateral cyst
c) Residual cyst
2. Dentigerous cyst
3. Primordial cyst
From non-odontogenic tissues
1. Median cyst
2. Incisive canal cyst
3. Globulomaxillary cyst
1.Cysts of the jaws
2.Cysts associated With maxillary antrum
a)Benign mucosal cyst of maxillary antrum.
b)Surgical ciliated cyst of the maxilla.
3. Cysts of soft tissues of mouth, face
a)Dermoid and epidermoid cyst
b) Branchial cyst
c)Thyroglossal duct cyst
f)Cysts of salivary glands
--> Median palatine, alveolar, mandibular
--> Simple bone cysts
-->Traumatic bone cyst
--> Solitary bone cyst
--> Hemorrhagic bone cyst
--> Aneurysmal bone cyst
Steps in Cyst Formation
The formation of a cyst takes place in
generally three stages:
2. Cyst formation
3. Enlargement or expansion of cyst cavity
The factors initiating the formation of the
cyst may be different depending on the type
of cyst that is formed.
A chronic low grade infection due to the
bacterial invasion of the pulp may cause
activation of the usually dormant cell rests of
Mallessez. This causes initiation of the cyst
It is proposed that during this stage, the cyst
cavity gets lined by stratified squamous
epithelium.The blood supply is rich at the
periphery and the cells present in the centre
lack nutrition. As a result, these cells tend to
desquamate into the centre of the mass. This
produces a fluid with increased osmolarity in the
centre surrounded by an epithelial lining
The basic mechanism for enlargement is the same for most
Various factors involved are:
1. Production of raised internal hydrostatic pressure
The most commonly accepted mechanism is that the
desquamated epithelial cells undergo autolysis and release
a large number of low molecular weight molecules. This
increases the osmolarity of the fluid within the cyst.
2. Attraction of fluid into the cystic cavity
This increased osmolarity of the fluid draws fluid from the
surrounding tissue spaces into the cystic cavity due to the
osmotic differences. It is also believed that acute
inflammation makes the capillaries in the region highly
This results in exudation of protein rich fluids into the
cystic cavity. This is considered another mechanism
for accumulation of fluids into the cyst cavity.
3. Retention of fluid within the cystic cavity
It is believed that the cyst lining acts as a semipermeable membrane allowing fluid to enter the
cavity .but preventing it from going out.
Toller's experiments have shown that the osmotic
imbalance resulted in the inability of the large
molecules in the fluid to escape because of lack of
access to the lymphatic system.
4. Epithelial growth
Mural growth or the growth of the cells of the cystic
lining itself helps in expansion of the size of the cyst.
5. Resorption of surrounding hone
A positive internal pressure transmitted to the adjacent
bone causes resorption and enables enlargement,
Osteoclastic factors such as PGE.
Further enlargement of the cystic lesion within the bone
produces microcracks on the further thinned out cortical
plates. When the cortical plates are palpated, it produces a
grating noise described as 'egg shell crackling'.
In a later stage, thinned out alveolar bone completely
resorbs and the cyst lining lies just beneath the oral
mucosa. Fluctuation may be elicited at this stage.
Later perforation of the cyst lining and oral mucosa may
cause drainage of cyst contents into the oral cavity
producing a salty taste2, PGE3 play a role in bone
Signs of cyst:
1. Bone expansion
2. Fluctuant swelling under oral mucosa
3. Non vital tooth (if radicular cyst)4. Missing tooth in normal series
5. Sinus formation with discharge
6. Large cyst distortion of adjacent
7. Hollow sound on percussion
Radiographs for cyst
1. IOPA for small periapical cyst to see
2. Occlusal view to check lingual cortical
3. PNS view (occipitomental) to show
relation to maxillary antrum and nasal
4. Lateral oblique (mandible) to check
proximity to lower border
5. PA view to check expansion of ramus of
6. OPG recommended in most cases; entire
extent, size etc. can be assessed
Dentigerous cyst-unilocular ,well defined
radiolucency with sclerotic border around the
crown of an unerupted tooth.
Three radiographic typecircumcoronal,circumferential and lateral.
radiolucency and give “soap bubble
Radicular cyst-solitary well circumscribed
radiolucency attached to the apex of the nonvital tooth.
Diagnosis based on type
1. Clear, pale, straw coloured fluid with
cholesterol crystals. Dentigerous cyst
2. Creamy white, thick aspirate
3. Yellowish, foul smelling fluid (pus)
4. Blood on aspiration Needle in a blood
vessel Vascular lesion ABC
5. Air on aspiration Maxillary antrum
Traumatic bone cyst
6. Negative aspiration Solid tumor
Basically two types of procedures for
Partsch I Operation (cystotomy)
• In 1892 Partsch described a type of
decompression procedure for the treatment of
• In this procedure, a window or a fenestration is made in the bone and the cystic con-tents
are evacuated. The cyst lining is left behind.
• Once the cyst contents are evacuated, the
intracystic pressure reduces. The hollow cavity is
then packed till it gets obliterated by bone
slowly over a period of time.
• The cystic lining then becomes continuous
with the normal oral mucosa
1. Once the liquid contents of the cyst are re-leased,
there is an inherent tendency for the cyst lining to
contract probably due to myofibrils in the walls. This
stimulates endosteal bone formation.
2. As the cyst lining shrinks, there is a marginal
ingrowth of normal mucoperiosteum which replaced
the capsule with its resorptive potential.The
ingrowing mucoperiosteum may provide it with
additional bone re-generation factors.
3. This is a more conservative method.
4. Not much surgical skill is required.
5. There is no risk of oroantral or oronasal fis-tula.
6. No damage to the adjacent vital structures.
7. No risk to adjacent vital teeth.
Disadvantages of Marsupialisation
. Entire pathological tissue is left behind.
2. High chances of recurrence of the cyst.
3. As the bony cavity is large, healing and
fill-ing up with normal bone takes a long time.
4. Use of cyst plug is required with repeated
5. Time consuming and repeated appointments
for the patient.
Indications for Marsupialisation
1. Extremely large cyst
2. Risk of cyst opening into maxillary sinus or
nose due to surgical removal of complete lesion
Enucleation is the surgical removal of the
entire cystic lining in toto.
By definition, it means shelling out of the
entire cystic lining without rupture.
This surgical procedure leaves behind a
hollow cavity in bone covered by oral
mucoperiosteum. This gets filled up with
blood clot which even-tually organizes to
form healthy bone.
1. Entire pathological tissue is removed
from the lesion.
2. Tissue available for hi stopathological
3. Chances of recurrence are less.
4. Healing time is faster and less
appointments for the patient
5. Enucleation with primary closure
eliminates the need for repeated
appointments for pack-ing medicated
gauze, irrigation, fabrication of plug etc.
1. Relatively radical procedure
2. Chances of devitalising the adjacent teeth
3. Chances of fracture of the jaw
4. Risk of creation of oroantral/oronasal
Indications for Enucleation
Enucleation is the treatment of choice for
re-moval of cysts of the jaws and should be
employed with any cyst of the jaw that can
be safely removed without unduly sacrificing
the under-lying structures.
Small cysts can be removed under local
an-esthesia whereas large cysts close to vital
structures and blood vessels should be taken out
under general anesthesia.
After achieving adequate anesthesia, a
mucoperiosteal incision is made such that the
incision rests on sound bone.
Mucoperiosteal flap is reflected taking care not to
perforate the cystic lining.
If the bone is perforated by the cyst, the lining will
be adherent to the periosteum and will be difficult
to reflect it.
Cystic lining is exposed and now carefully teased
away from bone. Its easy to separate the cystic
lining from bone because there is a layer of fibrous
tissue between the two.
After the cyst is removed completely the cavity is
irrigated throughly,hemostasis ensured,sharp bone
margin are filed and flap replaced and sutured.
Enucleation open packing:Gauze impregnated with bismuth iodoform parraffin
paste (BIPP) or whitehead varnish.
Enucleation with bone grafting:• Bone grafting with autogenous cancellous bone
grafts can be done in case of large bony defects.
• The bone graft obliterates the cavity and
• There is, however, a risk of wound breakdown
and infection of the bone graft which may lead to
Composition of carnoy's
1. Glacial acetic acid
3. Absolute alcohol
4. Ferric chloride
It is indicated mainly in cases of odontogenic
keratocyst. Afterenucleation, to remove any
re-maining lining of the cyst chemical
cauterising agent Carnoy's solution is applied
along the walls of the cystic cavity. It is left for
about 5-7 minutes and then irrigated
thoroughly with saline.
Complications of cyst
1. Injury to inferior alveolar nerve
2. Injury to adjacent teeth
3. Fracture of jaw
4. Oro antral fistula communication
5. Hematoma formation
7. Dead space
8. Incomplete removal
10. Malignant transformation