sx management of odontogenic cysts Flashcards
most common odontogenic cyst?
PA cyst
when is it a good idea to refer PA cysts?
when they are close to vital structures such as IAN
how is PA border on radio?
well defined opaque rim= slow growing
what can occur with extraction if sockets are not well debrided?
residual cysts, must be removed if found
dentigerous cysts
occur around crown of unerupted teeth, often 3rd molars
what cysts like to recur?
OKC
OKC destruction
can destroy lots of bone
common pattern with okc on radio
scalloped
can dentists tx odontogenic cysts
in some cases yes, but must be able to know when to refer
What is a Cyst ?
* def?
* The cystic cavity, within the oral regions, is almost always lined by?
* The cyst’s lumen usually contains?
“A benign pathologic cavity within bone or in soft tissues, generally formed by a connective tissue wall.”
The cystic cavity, within the oral regions, is almost always lined by epithelium.
The cyst’s lumen usually contains fluids, keratin or cellular debris
Histopathology of cysts
“A” points to the connective tissue wall that forms the cyst.
“B” points to the various types of epithelium that can line a cyst developing within the oral regions.
Odontogenic Cyst - Introduction
* Odontogenic cyst can be defined as a cyst in which lining of lumen is derived from?
* Variety?
Odontogenic cyst can be defined as a cyst in which lining of lumen is derived from epithelium produced during tooth development.
Variety of odontogenic cysts.
Uniquely derived from tissues of developing teeth
Classification of Odontogenic Cysts
Histogenic Classification (Based on where the cyst is derived from)
Inflammatory vs Developmental
Cyst derived from rest cell of Malassez
Periapical cyst
Residual cyst
Cyst derived from reduced enamel epithelium
Dentigerous cyst
Eruption cyst
Cyst derived from dental lamina (Rest of Serrae)
Odontogenic keratocyst
Dental lamina cyst of new born
Lateral periodontal
Glandular cyst
Unclassified cyst
Paradental cyst
inflammatory cysts
Radicular Cyst
Paradental Cyst
developmental cysts
Dentigerous Cyst
Odontogenic keratocyst
Developmental lateral periodontal Cyst
Glandular odontogenic Cyst
most common developmental cyst
dentigerous cyst
odontogenic cysts diagnosis
Complete history
Thorough clinical examination
Plain radiographs
CT Scan/ MRI
Complete history: Pain, loose teeth, occlusion, swellings, delayed tooth eruption. Dysesthesia and Paresthesia (Not so common, tend to displace not compress nn)
Thorough clinical examination: Inspection, palpation.
Plain radiographs: Panorex, Occlusal, Periapical radiographs
CT Scan/ MRI: For larger lesions
when removing a tooth with cyst what should always be done
tissue sample of cyst sent for histo exam to confirm diagnosis
1st step to cyst exam
radiogrpah
what should be done when planning a biopsy of cyst
Aspiration To rule out vascular lesions, cystic Lesions, solid tumors and inflammatory conditions.
best with large lesions, can help to establish a dif dx
what needle gauge is used for aspiration
18g
obtaining tissue samples for odontogenic cyst diagnosis
Obtain tissue sample
Incisional biopsy – Larger lesions prior to definitive therapy
Excisional biopsy – Smaller cysts
Odontogenic Cysts – Common Surgical Treatment options
Curettage
Enucleation
Marsupialization
Marsupialization followed by cystectomy
Enucleation followed by Peripheral ostectomy
Resection a possibility
Curettage
Curettage describes a surgical scraping of the cyst from the bony walls of the maxilla or mandible with a special instrument called a curette that has a scoop, at its tip.
For this procedure, it is important to create a bony window to expose the cyst in the maxilla or mandible.
Marsupialization
Marsupialization refers to creating a surgical window in the wall of cyst & evacuation of cystic contents.
This process decreases intracystic pressure & promotes shrinkage of cyst & bone fill (endosteal bone formation)
**used when close to vital strucutures **
how do we prevent infection with marsuprialisation
acrylic plug
what is placed in cyst, esp. OKC, to prevent recurrence
often use iodophorm gauze
another tx options for OKC
- Enucleation followed by use of Carnoys solution
- Enucleation followed by peripheral ostectomy and removal of overlying attached mucosa + use of Carnoys solution
- Surgical resection for very large –recurrent lesions
follow up schedule for OKCs
- 1st year: every 6mo
- after year 1: once sa year
- after 5 yrs: every 2 years
Carnoy solution
substance used as a complementary treatment after the conservative excision of odontogenic keratocyst. The application of Carnoy’s solution promotes a superficial chemical necrosis and is intended to reduce recurrence rates.
The application of Carnoy’s solution, a chemical solution composed of 60% ethanol, 30% chloroform, and 10% acetic acid, in conjunction with surgery, is known to reduce the rate of KOT recurrence. An FDA ban in 2013 on the use of chloroform for compounding led a number of surgeons to adopt a modified Carnoy’s solution in the use of Odontogenic Keratocyst
Marsupialization: Indications
Anatomical considerations
Surgical access
Assistance in eruption of teeth
Extent of surgery
Size of cyst
Anatomical considerations – Proximity of cyst to vital structures like maxillary sinus, Neurovascular bundle.
Surgical access – If access to all portions of cyst is difficult.
Assistance in eruption of teeth – In a young patient with a dentigerous cyst, it permits eruption of unerupted teeth.
Extent of surgery – Marsupialization is preferred in a unhealthy or debilitated patient , because it is simple & less stressful for patient.
Size of cyst – In a very large cyst, there is a risk of fracture of jaw during enucleation procedure
Marsupialization: Relative Contraindications
Recurrent Odontogenic Keratocyst
Recurring Cysts
Smaller Cysts (< 2X2 cm)
Marsupialization: Advantages
Simple?
Spares?
Even quite large cyst?
eruption?
Prevents what in maxilla?
Simple procedure to perform (biggest pro)
Spares vital structures eg. blood vessels, nerves
Even quite large cyst can be dealt under Local anesthesia as anesthesia of deeper recesses is not essential.
Allows eruption of teeth (no damage to tooth)
Prevents oronasal, oroantral fistulae in the maxilla
Marsupialization: Advantages
Reduces?
Prevents?
blood loss/ shrinkage
bone formation?
Alveolar ridge?
Reduces operating time.
Prevents intraoperative fractures.
Reduces blood loss, helps in shrinkage of cystic lining.
Allows for endosteal bone formation to take place.
Alveolar ridge is preserved.
Marsupialization: Disadvantages
Pathologic tissue?
Histologic examination of entire cystic lining?
post op care?
tastes and smell?
pack/plug?
Secondary surgery?
healing time ?
Pathologic tissue is left in situ.
Histologic examination of entire cystic lining is not done.
The need for regular postoperative care, occurs over a substantial period of time.
Unpleasant taste and smell may occur due to accumulation of stagnant saliva & food debris in cystic cavity.
Changing of pack and adjustment of plug.
Secondary surgery may be needed.
Longer healing time.
Enucleation
Enucleation means?
This procedure is usually indicated for removal of cyst that is?
Enucleation allows for cystic cavity to be covered by? which allows?
Enucleation means shelling out the entire cystic lesion without rupture.
This procedure is usually indicated for removal of cyst that is not very large in size and has minimum risk of injury to vital anatomical structures during the surgical procedure.
Enucleation allows for cystic cavity to be covered by a mucoperisteal flap & the space fills with blood clot, which will eventually organize & form normal bone.
eunucleation tool
currete
Enucleation: Indications
Treatment of?
Recurrence?
Should be employed with any cyst that can be?
Treatment of Common types of odontogenic cysts (odontogenic keratocysts, Radicular cysts, Dentigerous cyst etc.,)
Recurrence of cystic lesions of any cyst type.
Should be employed with any cyst of jaw that can be safely removed without unduly sacrificing the adjacent structures.
Enucleation: Relative Contraindications
Dentigerous cyst associated with?
pt ages?
Medically compromised or debilitated patients?
Proximity?
size of cysts?
Dentigerous cyst associated with teeth other than the third molars that would erupt normally in the oral cavity and be functional.
Young patients with erupting teeth.
Medically compromised or debilitated patients who require extensive surgical
procedure to treat the cyst.
Proximity to vital structures.
Very large cysts, may cause fracture of jaw.
Enucleation: Advantages
pathological tissue?
Tissue available for?
recurrence?
Healing time?
Enucleation with primary closure eliminates need for?
Entire pathological tissue is removed.
Tissue available for histopathological examination.
Chances of recurrence are less.
Healing time is reduced.
Enucleation with primary closure eliminates need for repeated appointments for packing, irrigation, adjustment of plug etc
Enucleation: Disadvantages
In young patients?
Removal of large cyst?
Damage to?
Adjacent tooth?
In young patients, the unerupted teeth in a dentigerous cyst will have to be removed
with the lesion.
Removal of large cyst may make mandible more prone for fracture.
Damage to adjacent vital structures.
Adjacent tooth may be devitalized.
Combination of Marsupialization and Cystectomy
Cystectomy after Marsupialization (decompression) is a conservative technique that decreases the size of the cystic cavity and reduces the risk of intrabony defects, which could be induced by primary enucleation.
In addition, it can also save the adjacent anatomic structures- As the surgery is carried out in 2 stages
stages of combined marsupialization and cystectomy
Stage 1 – Marsupialization
Stage 2 - Cystectomy
Combination of Marsupialization and Cystectomy
Stage 1
In these cases, the Marsupialization(decompression) is performed usually on on huge cystic lesions of the mandible.
During this process, a decrease in the size of the lesion and the growth of normal oral tissues was observed. The size of the lesion decreased until the time of cystectomy.
Combination of Marsupialization and Cystectomy
stage 2
Cystectomy is carried out later after the size of the cyst decreases considerably in size over a period of time and surgery could be performed under local anesthesia.
Enucleation followed by Peripheral ostectomy
exactly what it says, prevent recurrence is main goal
Curretage followed by Peripheral ostectomy
Peripheral ostectomy is defined as a peripheral bone. reduction with
powered hand-piece and rotary instruments, done after enucleation of the cystic lesion
