OKC-1

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ODONTOGENIC

KERATOCYST

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HISTORY

• The term primordial cyst was first mentioned

in 1945 by Robinson, because the cysts were

believed to have a more primordial origin

because they arose from remnants of dental

lamina or the enamel organs before enamel

formation had taken place.

Philipsen (1956).

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CLINICAL FEATURES:

• Age: Any age.

• Sex: Frequently males than in females. • Site: The mandible is involved more

frequently than maxilla.

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CLINICAL PRESENTATION:

• Patients with odontokerato cysts complain of

pain, swelling or discharge. Occasionally

they experience parasthesia of the lower lip or

teeth.

Some patients have been unaware of the lesion.

Accidental findings.

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• Cyst is sometimes painless because the

keratocyst tends to extend in the medullary

cavity and clinically observable expansion of

the bone occurs late.

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• Voorsmit (1984) Lund (1985) have describedthe occurrence of large keratocyst, whichinvolved the maxillary sinus led todisplacement of floor of the orbit and proptosis of the eye balls. Neurologicalsymptoms are occasionally seen.

• One third of maxillary cysts cause buccal

expansion, but palatal expansion was veryrarely seen.

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Classification of OKC

• MAIN (1970) has classified odontogenic keratocystdepending on it’s position.

• “Envelopmental” : When OKC embraces an adjacentunerupted tooth.

• “Replacement”: When OKC forms in the place of normal

tooth.• “Extraneous”: When OKC forms in the ascending ramus

away from teeth.

• “Collateral”: When OKC forms adjacent to the roots of theteeth.

• “Follicular” OKC : • According to Altini and Cohen, A tooth surrounded by it’s

follicle erupts into a keratocyst cavity in the same way as itwould erupt into the mouth.

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Toller regarded as benign neoplasm’s.

Foresell (1980) Rate of growth varies from

2 to14mm a year.

Growth rate is slow in patients

over 50 years of age.

The epithelium of keratocyst shows

a higher rate of proliferation

Toller (1970) osmolatity of the cyst fluid

in enlargement of the keratocysts

ENLARGEMENT

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• Collagenolytic activity with in the fibrous

capsule cause resorption of bone.

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Keratocyst contains

• Low quantities of protein (High molecularweight)

• Predominantly albumin and small

quantities of immunoglobulins.

• Other Fluids like

• Glycosaminoglycans

• Heparin sulphate

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RADIOLOGICAL FEATURES:

• Small round ,ovoid shape.

• Distinct sclerotic margins

• Scalloped margins - may be mis-interpreted asmultilocular lesions.

• Unilocular or multilocular.

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• Downward displacement of the inferior

alveolar canal and resorption of the lower

cortical plate of mandible may be seen as well

as perforation of bone.

• Occasionally pathological features.

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PATHOGENESIS

• Derived from odontogenic epithelium.

• Rests of dental lamina or dental lamina.

• Consists of epithelium lining + connective tissuewall.

• Epithelium is stratified squamous and keratinized

and 5 to 8 cell thickness without retepegs.• Parakeratin or orthokeratin.

• Basal layer well defined palisaded basal layerconsists of columnor or cuboidal cells.

• Connective tissue consists of daughter cyst orsatellite cysts

SURGICAL MANAGEMENT OF

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SURGICAL MANAGEMENT OF

ODONTOGENIC

KERATOCYST

• Several authors suggested that odontogenickeratocyst should be considered as “Benign

Cystic Tumor”.

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CONVENTIONAL SURGICAL

OPTION

• Conservative methods

• Enucleation

• MarsupilizationLess than optimal results.

Including curettage, peripheral Osteotomy,

Removal of overlying mucosa in cases ofcortical perforations and

osseous resections

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ENUCLEATION AND

CURETTAGE

• Simple cyst enucleation is not advocated.

Recurrence rate high

• Enucleation of cyst as single piece reduce the

recurrence rate.

• Ramus and angle regions are difficult.

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ENUCLEATION AND

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ENUCLEATION AND

PERIPHERAL OSTEOTOMY

• Peripheral osteotomy is primarily used as an

adjunctive for osseous removal when

resection can be avoided.

• As cyst size increases, the cyst borders may

become irregular or scalloped or surgical

access to the cyst may become compromised.

• Rotating instruments - burs

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• Dye the residual cystic bony cavity with

methylene blue to ensure that the entire cavity

has received treatment beyond simple

enucleation. (Depth is not conformed).

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OSSEOUS RESECTION

• Perhaps the most extensive form of treatment

indicated for the management. Of select

odontogenic keratocyst that of osseous

resection, marginal or segmental.

• “Zero recurrence rate”.

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Indications:

• Thin cystic lining.

• In the conjunction with poor access.

• Frequent multilocular or scalloped edges.

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THE USE OF LIQUID NITROGEN

CRYOTHERAPY IN THE MANAGEMENT OF

ODONTOGENIC KERATOCYST

• For centuries, extreme cold has been used

clinically to destroy the cells.

• Robert Boyle has been credited with reporting

more than 300 years ago that freezing could

be used to destroy cells.

• Cryosurgery is not simply the application of

the freezing temperature to tissues. The aim

of cryosurgery is to kill and destroy cells.

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RESPONSES OF ORAL

TISSUES TO CRYOSURGERY

• Oral mucosa

• Any oral mucosa that comes in contact with

liquid nitrogen becomes necrotic. The

necrotic tissue not evident immediately. After

thawing, normal tissue and the tissues that has

been frozen appear identical.

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• By 3 days the tissues become necrotic and

often the underlying bone is exposed.

• Odontogenic keratocyst treated with

enucleation and cryosurgery, the most

common complication of wound dehiscence -

wound healed after routine oral saline rinses

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BONE

• One of the unique advantages of cryosurgery

is that frozen bone loses its vitality but

remains its skeletal properties.

• With in 40 to 72 hours the cellular elements

with in the bone undergo necrosis.

• Disadvantage is pathological fracture

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• To overcome the problem use bone graft after

cryosurgery for all most all lesions, regardless

of size.

• Recommended a soft diet for 8 to 10 weeks.

• The presence of bone graft seems to aid with

healing of the soft tissue

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TEETH:• Consideration also must be given to the effect of

cryotherapy on teeth.• The effect of cryotherapy on adult human teeth.

• Chronic inflammatory changes andspontaneous recovery

• If tooth buds present – prevent the odontogenesis.

• Inform patients the teeth in bone adjacent to thecryosurgical site will most likely remain

asymptomatic.

• Direct contact with liquid nitrogen --effects areunknown (RCT )

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INFERIOR ALVEOLAR NERVE

• Nerve sheath and axon were both affected.

• The connective tissue of the sheath remainedas a collagenous tube, the nerve re-vitalization

began approximately 12 days after injury. Normal nerve architecture was restored by 25to 30 days.

• Patient showed altered sensation post-operatively ,improvement in sensation wasobserved after 91 days

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ORAL CRYO-SURGICAL

TECHNIQUES

Prediction of extra oral sites is

Under general anesthesia

All exposed skin should be covered with

moist towels

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Enucleation

• Careful enucleation.

• Removal of involved teeth.

• Excision of overlying mucosa.

• Surgeon should not be tempted to retain teeth

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Exposure and retraction of intra

oral soft tissue

• For protection of normal tissue.

•

• To avoid possible damage to surroundingtissue.

• A recurrence that is most likely secondary to

retractor placement.

• Moist gauze and tongue blades can be placed

between the cavity and mucosa.

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CRYOSURGICAL TECHNIQUE

Cryoprobe with water-soluble jelly.

Liquid nitrogen spray

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Cryoprobe with water-soluble

jelly

• Fill the defect with water-soluble jelly. The

nitrogen oxide Cryoprobe is activated once itis immersed in the jelly filled cavity.

• The freeze process is continued for 2 minutes – perform 3 times.

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Advantages

• Can freeze an irregular, gravity dependent portion the cavity can be performed

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Liquid nitrogen spray

• Liquid nitrogen boils at 196 on the other

hand nitrous oxide at 89.7C.

• Carbon dioxide at 78.5C each of these

liquids is capable of achieving the critical

temperature of -20C necessary for cellular

death.

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Cryosurgical indication for managing

the odontogenic keratocyst

• Recurrent odontogenic keratocyst.

• Large complex mandibular lesions.• Conventional treatment might involve vital

structures.

• Non-complaint patient.

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EXCISION OF THE

OVERLYING, ATTACHEDMUCOSA, IN CONJUNCTION

WITH CYST ENUCLEATION

AND TREATMENT OF BONY

DEFECT WITH CARNOY

SOLUTIONPaul J.W. Stocklingh MD, DDS]

O.M.S. Clin. N. 15 (2003)

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• Recurrence – 20% to 60%

• Enucleation or curettage massuplialization

• give rise to higher recurrence rates.

• Wright JM. Odontokeratocyst; orthokeratinized variant (Oral Surgery 1981; 51:609-615).

• Para-keratinized variant recurrence rate – 47.8.

• Ortho keratinized – 2.2%

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DIAGNOSIS

• Approximately 60% of all Odontogenic

keratocysts are located in the 3rd molar region

extending into the ascending ramus.

• 40% in tooth bearing area maxilla and

mandible

TYPICAL RADIOGRAPHIC

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TYPICAL RADIOGRAPHIC

FEATURES:

• Scalloped margins.

• Uni or multi locular appearance.

• Features may be difficult to identify in themaxilla, in which over projections of themaxillary sinus or nasal cavity tends to maskthe sometimes suffle radiographic signs.

• Ordinary odontokeratocysts• Amelobalstoma present the same radiographic

features

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Decompression and

marsupialization.M. Anthony Pogrel, O.M.S. Clin. N

Am,. 15 (2003)

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• Suggested by Partsch in German literature.

• This treatment was put forward at that time as

a definitive treatment for cysts.

• It consists of the removal of the overlying

epithelium and bone and deroofings the cyst.

If possible suture the cyst lining to the oral

epithelium with initial packing of the cyst tokeep the hole open.

MARSUPIALIZATION

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MARSUPIALIZATION

• Para-keratinized Odontokeratocysts was

opened widely so that the residual cystic

cavity becomes a pouch. Where possible the

cyst lining was sutured to mucosa, and noattempt was made to remove any of the cystic

lining apart from which is needed to remove

as part of deroofing procedure. Maxillarycysts were marsupliazed into the oral cavity

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DISCUSSION

• From this study, para-keratinized version of

the Odontokeratocyst may restore completely

after true marsupialization. Teeth with in thecyst also may become upright and erupt.

• No failures were reported.

RECURRENCE

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RECURRENCE

• There was no correlation between the size orlocation of the cyst and its tendency to recur.

• No age correlation also

• Browne (1970) could find no statisticallysignificant correlation between thefrequency of recurrence and the age of the patient location of the cyst, the method oftreatment, the nature of cyst lining and the presence of cortical perforations.

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• Satellite cysts (Removal)

• Recurrences were more frequent with cystsin patients with the naevoid based cell

carcinoma syndrome than with cysts is

patients without the syndrome.• Radiographic multilocular had a higher

recurrence rate than those with a unilocular

appearance. (Scalloped Margins).• Some instances new cyst rather than

recurrence.

VARIOUS REASONS FOR

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VARIOUS REASONS FOR

RECURRENCE

• Satellite cysts, which are retained during anenucleation procedure.

• Keratocyst linings are very thin and fragile

particularly when the cyst is large, more difficultto enucleate. So portions of lining may left

behind and constitute the origin of recurrence.

• An attempt to save vital adjacent teeth or nervesduring the operation may lead to incomplete

eradication and hence to recurrence.

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THANK YOU

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