Download LECTURE FOR 3RD YEAR - CYSTS OF JAW BONES

CYST / CLASSIFICATION / DIAGNOSIS
SURGICAL MANAGEMENT
• DEFINITION;
A cyst is a pathological cavity having
fluid, semifluid, or gaseous contents and which is not
created by the accumulation of pus.
It is frequently ,but not always lined by epithelium.
[KRAMER—1974]
EPITHELIAL ORIGIN
ODONTOGENIC EPITHELIAL
NON-ODONTOGENIC EPITHELIAL
1.DEVELOPMENTAL
a—Primordial cyst / KERATOCYST
b—Dentigerous cyst /FOLLICULAR
c—Lateral periodontal cyst,
BOTRYOID
d—Calcifying odontogenic cyst,
GORLIN CYST
2.INFLAMMATORY
a—Radicular cyst,
APICAL/LATERAL PERIODONTAL
b—Residual cyst
1.FISSURAL
a—Median mandibular
b—Median palatal
c—Globulomaxillary
2. { INCISIVE CANAL /
NASOPALATINE DUCT /
MEDIAN ANTERIOR
MAXILLARY } CYST
NON-EPITHELIAL CYSTS
1.Solitary bone cyst / TRAUMATIC
2.Aneurysmal bone cyst
3.Stafne’s bone cavity
Depending on the presence or absence of epithelial
lining, they can be
True cyst: Lined by epithelium
Pseudo cyst: Not lined by epithelium
General features of jaw cysts
Cawson’s essentials of oral medicine & oral pathology 7th edition
INVESTIGATIONS
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Radiographic examination
Vitality tests
Contrast studies
Aspiration
Biopsy
CT/MRI
ODONTOGENIC KERATOCYST
• Incidence: 3-11% of all odontogenic cysts
• Age
: 10 – 40 years
• Sex
: Males > females
• Site
: Mandible [ post. Body & ascending ramus ]
• Symptoms : painless – small
painful - if secondarily infected
• Other ftrs : Usually asymptomatic, paresthesia can occur
in case of pathological fracture / Aggressive
• Expansion : Antero-posterior expansion, through
medullary spaces, less bony expansion
• Aspirate : Cheesy keratin content
• Teeth
: Occasionally un-erupted teeth
RADIOGRAPHIC FEATURES
• Keratocyst can be unilocular or multilocular
• TYPICAL “ SOAP-BUBBLE” APPEARANCE
• Margins can be smooth or scalloped, which suggest an
unequal growth activity.
CYST CONTENTS
• ASPIRATE: O.K.C contains a dirty white or straw coloured
viscoid suspension of keratin, which has an appearance of
pus, but without offensive smell.
• Smear should be stained & examined for keratin cells.
• ELECTROPHORESIS, will reveal low protein content, which
is mostly albumin.
• Total protein is found to be below 4gm/100ML.
MANAGEMENT
• Treatment should be based on PROPER CLINICAL
ASSESSMENT, ACCURATE DIAGNOSIS, APPROPRIATE TESTS
OF THE CYSTIC ASPIRATE.
• MARSUPIALIZATION is incorrect principle in treatment of
O.K.C, because of their high incidence & tendency of
recurrence.
• Care should be taken to ensure that all fragments of the
extremely thin lining are removed.
AGGRESSIVE TREATMENT
• Enucleation with curettage is the best treatment for OKC.
• Resection
DENTIGEROUS [FOLLICULAR] CYST
• It results because of enlargement of the follicular space of
the whole or part of the crown of an impacted or an unerupted tooth & is attached to the neck of the tooth.
• It involves teeth of the adult dentition or occasionally
supernumerary teeth.
PATHOGENESIS
• Dentigerous cysts develop by accumulation of fluid
between the reduced enamel epithelium or within the
enamel organ itself of unerupted or impacted teeth.
• Another possibility for development of cyst, is
degeneration of STELLATE RETICULUM at an early stage of
development and is likely to be associated with ENAMEL
HYPOPLASIA.
• In case of a DILATED FOLLICLE, pericoronal width of more
than 3—4 mm is considered as a cyst.
CLINICAL FEATURES
• INCIDENCE; More commonly seen than primordial cysts.
• AGE; 1ST ,2ND , & 3RD decades of life and gradually it
declines in occurrence.
• SEX; Equal in both sexes, slight more in male’s
• SITE; It occurs more frequently in mandible than in maxilla
• Late erupting teeth are the most frequently involved in
descending order as; Lower 3rd molars, upper cuspids,
upper 3rd molars, & lower bicuspid teeth.
• Dentigerous cysts have the potential to attain a large size,
often it is pronounced facial asymmetry or the problem of
ill-fitting dentures that forces a patient to seek treatment.
• Pain may be present if secondarily infected.
• Clinically, a tooth from the normal series, will be found to
be missing, unless the cause is a supernumerary tooth.
• The lateral expansion causes a smooth, hard, painless,
prominence, later as the cyst expands the bone covering
the center of the convexity becomes thinned & can be
indented with pressure on palpation, with further
expansion.
• This fragile outer shell of bone becomes fragmented and
the sensation imparted & sound produced on palpation
over the area is described as “EGG-SHELL CRACKLING”.
• Still later the cyst lining may come to lie immediately
beneath the oral mucosa & fluctuation can be elicited.
RADIOLOGICAL FEATURES
• Radiographs reveal a unilocular radiolucency associated
with crowns of unerupted impacted teeth; at times a
multilocular effect can be seen when the cyst is of
irregular shape due to bony trabeculations.
• Cysts have well-defined sclerotic margin unless when they
are infected, then margins are poorly defined.
• With the pressure of an enlarging cyst, the unerupted
tooth can be pushed away from its direction of eruption.
• Dentigerous cysts have a higher tendency to cause root
resorption of adjacent teeth.
RADIOLOGICAL TYPES
Radiologically, the dental follicle may expand around the
unerupted or impacted tooth in three variations, i.e;
1.CIRCUMFERENTIAL: when the cystic cavity, radiographically
ENCLOSE’S ENTIRE TOOTH
2.LATERAL: in this case, cystic cavity is located on ONE SIDE
OF INVOLVED CROWN
3.CENTRAL / CORONAL: when cystic cavity, ENVELOPS THE
CROWN OF IMPACTED TOOTH SYMMETRICALLY FROM ALL
THE SIDES. This type of cyst may push the involved tooth
away from its direction of eruption.
CYSTIC CONTENTS
ASPIRATE
• Contains clear yellowish / straw colored fluid in which
cholesterol crystals may be present & cystic contents have
5 gm % OR more of soluble protein.
TREATMENT
• TREATMENT IS DECIDED BY THE SIZE OF THE CYST,
ADEQUATE ACCESS, AND WHETHER IT IS DESIRABLE TO
SAVE THE INVOLVED TOOTH.
• Aspiration of cyst & incisional biopsy
• MARSUPIALIZATION of larger cyst along with extraction of
tooth.
• Decompression.
• Orthodontic treatment to allign the tooth.
MARSUPIALIZATION [ Partsch Surgery ]
• Indicated in children, if the cyst is very large in size &
involved tooth / teeth are to be maintained.
• The tooth may erupt into occlusion as the defect heals
with normal bone, or orthodontic forces may be used to
bring the tooth into occlusion.
ENUCLEATION
• The cyst can be enucleated together with the involved
tooth in adults, as the possibility of tooth erupting is low.
• In children, an attempt could be made to save the tooth,
in this case, the lining is separated from the neck of the
tooth with a scalpel.
• This procedure is worth attempting, when root formation
is complete, so that risk of tooth dislodgement is low.
LATERAL PERIODONTAL CYST
• A developmental cyst
• Lateral periodontal cysts are found lateral to the roots of
vital teeth [erupted tooth]
• Types:
Inflammatory
Developmental
CLINICAL FEATURES
INCIDENCE; Cyst is usually found in adult males
AGE; No specific age
SITE; Occurs more often in mandible than in maxilla
Commonly seen in mandibular cuspids, bicuspids & 3rd
molar roots followed by anterior region of the maxilla
The associated teeth are vital
It never causes resorption of the root of the effected tooth
RADIOLOGICAL FEATURES
• Radiographs reveal a well-defined round or ovoid
radiolucency with a sclerotic margin, the lamina dura of
the involved tooth is destroyed.
• Most of the cysts are smaller than 1cm in size & are
present between the cervical margin & apex of the root.
• “Teardrop-shaped” radiolucent area.
• In case of lower 3rd molar roots, they seem to be present
in the bifurcation, bucally, or lingually or against the distal
surface of the root.
TREATMENT
• ENUCLEATION is generally method of choice, & is easily
performed, because of the small size & easy access.
• All attempts should be made to avoid sacrificing the
associated tooth.
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CALCIFYING EPITHELIAL ODONTOGENIC CYST
GORLIN CYST
[ CEOC]
WHO classifies it as benign tumor, but describes it as cyst.
Un-common, slowly growing benign lesions
Calcified tissues identified as dysplastic dentin, associated
with odontoma.
Location:
• 75% in bone, 25% in soft tissues related to jaws like
gingiva & alveolar mucosa.
• Can be Intraosseous or Extraosseous lesion.
• Symptoms : slow growing, painless swelling.
CLINICAL FEATURES
• Incidence - 1% of odontogenic cysts
• Age – 2nd & 6th decade
• Site–Maxilla 70 %, [ more common, usually does not cross
the midline, most common in maxillary premolar region ]
• Mandible-ANTERIOR REGION, sometimes crosses
midline.
• Seen usually anterior to 1st molar region in mandible
• Most common in mandibular canine region
• Signs: cortical plate destruction, cystic mass become
palpable
• Small lesions – Asymptomatic
• Large lesions
• Slowly enlarging bony hard swelling of jaw
• Displacement of regional teeth
RADIOLOGICAL FEATURES
• Unilocular / multilocular radiolucency
• Multiple small radio-opaque foci of varying density
• Resorption of roots of adjacent teeth
Internal structure:
• Completely radiolucent with foci of calcification
• May be large solid masses
• Rarely multilocular
Periphery & shape:
• Well defined corticated margins
TREATMENT
• Enucleation & curettage
RADICULAR CYST
• An inflammatory cyst.
• Usually associated with a non-vital tooth.
• It may develop apically, when it is termed as a PERIAPICAL
[PERIODONTAL] RADICULAR CYST.
• It may develop on the side of the root of a pulpless tooth,
when it is termed as LATERAL [PERIODONTAL]
RADICULAR CYST, this cyst should be differentiated from a
DEVELOPMENTAL LATERAL PERIODONTAL CYST which is
associated with a VITAL TOOTH.
• In a radicular cyst, if the involved tooth is exfoliated or
extracted, and the cystic lesion remains within the bone,
then it is known as RESIDUAL CYST.
Periapical (Radicular) Cyst Developmental sequence
Joseph A. Regezi. Oral Pathology: Clinical Pathologic Correlations, 4th Edition. Elsevier, 2002.
TREATMENT
• Nonvital teeth that are associated with the cyst, can either
be extracted or restored and treated by endodontic
treatment and apicoectomy.
• External sinus tracts should always be excised to prevent
epithelial ingrowth.
• The commonly employed surgical procedure for radicular
cyst is ENUCLEATION with PRIMARY CLOSURE
• Very small cysts can be removed through bony window or
tooth socket.
• Large cysts that encroach upon the maxillary antrum or
inferior alveolar neurovascular bundle or nose, may be
preliminary treated by MARSUPIALIZATION.
RESIDUAL CYST
• Less inflammatory than radicular cyst
• A residual cyst is a cyst that remains after incomplete
removal of the original cyst. The term residual is used
most often for a radicular cyst that may be left behind
most commonly after extraction of a tooth.