Cysts Of Odontogenic Origin
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CYSTS OF ODONTOGENIC ORIGIN Surabhi Sarkar
What is a cyst?
A cyst is defined as a pathologic cavity lined by epithelium.
Cyst is an entity that constitutes an epithelium lined sac filled with fluid or semi-fluid material. Killey & Kay (1966) A cyst is an abnormal cavity in hard or soft tissues which contains fluid, semi-fluid, or gas and is often encapsulated and lined by epithelium. Killey & Kay (1966) A cyst is a pathologic cavity having fluid, semifluid or gaseous contents that are not created by the accumulation of pus; frequently, but not always, is lined by epithelium. Kramer (1974)
Connective tissue
Lumen
Epithelial lining
Classification, WHO 2017 I. Cysts of the jaws
A. Epithelial lined B. Not epithelial lined
II. Cysts associated with the maxillary antrum III. Cysts of the soft tissues of the mouth, face, neck and salivary glands i. ii. iii. iv. v. vi. vii.
Dentigerous cyst Odontogenic keratocyst Lateral periodontal and botryoid odontogenic cyst Gingival cyst Glandular odontogenic cyst Calcifying odontogenic cyst Orthokeratinized odontogenic cyst
(a) Odontogenic (b) Non-odontogenic 1. Developmental origin 2. Inflammatory origin
i. ii. iii.
Radicular cyst Residual cyst Collateral inflammatory cyst
4th Edition of the World Health Organization Classification of Head and Neck Tumours: Odontogenic and Maxillofacial Bone Tumors
What changes?
Reincorporation of odontogenic keratocyst and calcifying odontogenic cyst in the cyst classification when they had been classified in 2005 as neoplasms. Under inflammatory cysts, inflammatory collateral cysts are included. Primordial cysts have been dropped and are no longer used synonymously for odontogenic keratocysts.
What changes?
Orthokeratinized odontogenic cysts are now recognized as an odontogenic cyst distinct from OKC. New diagnostic criteria for glandular odontogenic cysts (GOC) are presented, and the histologic overlap between GOC and cystic mucoepidermoid carcinomas acknowledged. No MAML2 gene in GOC.
Histogenic Classification The epithelial lining origins of odontogenic cysts Epithelial residue
Origin of Epithelium
Cyst
Rests of Serres
Dental lamina
OKC, Glandular odontogenic cyst, Gingival cyst of infants and adults
Reduced Enamel Epithelium
Enamel organ
Dentigerous cyst, Eruption cyst, Botryoid odontogenic cyst, Paradental cyst
Rests of Malassez
Hertwig’s root sheath
Radicular cyst, Residual cyst
Distribution of odontogenic cysts according to diagnosis. From Jones et al. (2006), Sheffield. Cysts
Number
%
Radicular cyst
3724
52.3
Dentigerous cyst Odontogenic keratocyst Residual cyst
1292 828 573
18.1 11.6 8.0
Paradental cyst
402
5.6
Unclassified odontogenic cysts Lateral periodontal cyst
210 28
2.9 0.4
Calcifying odontogenic cyst Gingival cyst Eruption cyst
21 16 15
0.3 0.2 0.2
Glandular odontogenic cyst Epstein pearl Total
11 1 7121
0.2 0.0 100.00
Pathophysiology “A Surgeon must be a pathologist who does operations.” Eric Carlson
How does a cyst develop and grow? Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity for bone resorption and cyst growth.
Odontogenic epithelium derived from the basal epithelium of the stomatodeum. • Remnants of the dental lamina(rests of Serres),
• Reduced enamel epithelium, • Hertwig’s epithelial rooth sheath(rests of Malassez)
Cyst Initiation Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity for bone resorption and cyst growth.
From the Cell Rests of Mallasez (Hertwig’s Epithelial Root Sheath):
From within apical granuloma(round/ovoid cellular islands) > extension of proliferating epithelium strands > the arcades and rings surround the inflamed necrotic part. > a hollow sponge-like structure which consolidates to form a continuous epithelium lining to the cavity > forms barrier to pulpal irritants from surrounding tissues. Eg: Radicular Cyst, Residual Cyst
Cyst Initiation Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity for bone resorption and cyst growth.
From Reduced Enamel Epithelium (Enamel organ): Clefts arise from within layers of REE > enlarges and encloses tooth crown
> impaired tooth eruption, or a disturbance in the mucosal epithelial component of the eruption process, could lead to continued enlargement of this programmed crevicular cleft arising from proliferation of the outer layers of the reduced enamel epithelium, and hence to the formation of a follicular cyst.
Eg: Dentigerous cyst, paradental cyst, Lateral periodontal cyst, eruption cyst, botryoid odontogenic cyst
Cyst Initiation Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity for bone resorption and cyst growth.
From Cells Rests of Serre (Dental lamina): Develops from remnants of dental lamina rather than from aborted primordial tooth germs as it was believed before. The abundance of these lamina remnants in the third molar region correlates well with the high frequency of occurrence of keratocysts in this area. Impacted or absent wisdom teeth would predispose to the preservation of these rests and to cyst formation. Eg: OKC, Glandular odontogenic cyst, gingival cyst
Cyst Enlargement Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity of cyst enlargement and bone resorption.
The mechanisms concerned with their enlargement can be divided roughly into three groups: a. Mural growth i. Peripheral cell division ii. Accumulation of cellular contents
b. Hydrostatic enlargement i. Secretion ii. Transudation and exudation iii. Dialysis
c. Bone-resorbing factor
Mural Growth
Hydrostatic Enlargement i. Secretion: Goblet cells have intracystic secretions ii. Transudation and exudation: owing to the protein content of cystic fluids iii. Dialysis: accumulation of low-molecular weight protein forms a gradient with net inflow of fluid from capillaries into cystic lumen.
Bone Resorption Vital cyst tissue(capsule and its leukocyte content, contribution from vascular structures) prostaglandin E2 (PGEj) and prostaglandin E3(PGE3) That production takes place in the capsule under the influence of epithelial proliferation, lysosomal phospholipases from fibroblasts and polymorphonuclear leucocytes breaking down phospholipid cell membranes to produce arachidonic acid, which is converted by the ubiquitous enzyme prostaglandin synthetase to prostaglandin. Keratocysts contain matrix-solubilizing enzyme, collagenase, in their walls contributing to cyst growth.
Diagnosis
Clinical Presentation Symptoms:
Completely symptomless, chance finding, swelling intraoral discharge- tasteless, salty or sweet, acute abscess of infected cysts, dull throbbing pain in less severe infections,
impaired sensation of lower lip in mandibular cysts, discomfort or difficulty in wearing dentures in edentulous patients,
tilted or shifted teeth in the mouth.
On Examination Signs:
Swelling, frankly fluctuant or bony hard on palpation,
egg-shell crackling effect, springy in consistency,
bluish tinge or dark red colour of soft tissues,
infected cysts tender on touch,
rarely lingual plate involvement in mandible,
sinus opening,
glairy cholesterol containing fluid or yellow purulent discharge,
vitality of teeth may be compromised.
Investigations
RADIOLOGY CT SCAN MRI RADIOPAQUE DYES
ASPIRATION BIOPSY
Radiographic Appearances
Area of radiolucency surrounded by radioopaque line of condensed bone. Confirm with aspiration of cystic fluid, diagnostic biopsy.
Is it a cyst?
Periapical Radiolucency
Periapical granuloma Scar Chronic or acute dentoalveolar abcess Osteomyelitis Hyperplasia of maxillary sinus lining Periapical Cementoosseous Dysplasia in its lytic or fibroblastic stage Traumatic bone cyst Periodontal disease
Wide array of odontogenic cysts and tumors including carcinomas and fibroosseous diseases can begin and develop radiolucencies that may appear periapically.
Is it a cyst?
Pericoronal radiolucencies: Follicular
space Dentigerous cyst Unicystic Ameloblastoma(mural type) Adenomatoid odontogenic tumor Calcifying odontogenic cyst or tumor(early stage) Ameloblastic fibroma
Is it a cyst?
Solitray radiolucencies not contacting teeth Anatomic patterns Post extraction socket Residual cyst Traumatic bone cyst OKC Ameloblastoma Focal Osteoporotic defect of the jaws
Surgical defect Central Giant call granuloma Giant cell lesion Focal cemento osseous dysplasia Early stage of cementifying and ossifying fibroma Benign non-odontogenic tumors
Aspiration and Biopsy
Aspiration
Inability to aspirate, vacuum on suction indicates a solid mass within
Excisional biopsy for smaller cysts Incisional biopsy if cyst is bigger
Cyst
Aspirate
Features
Dentigerous cyst
Clear, straw colour fluid
Total protein more than 4mg/dl. Resembles serum.
OKC
Dirty, creamy white, viscoid suspension
Keratin squames Total protein less than 4mg/dl. Albumin in excess.
Periodontal cyst
Clear, pale, straw colour fluid
Cholesterol crystals Total protein 5-11mg/dl
Infected cyst
Pus, brownish fluid, foul smelling
PMNs, cholesterol clefts
Vascular lesion Needle in vessel
Blood
Traumatic bone cyst Antrum
Air
Inflammatory Odontogenic Cysts
Radicular Cyst
The most common odontogenic cyst
Usually symptomless, the most common cause of slow growing swellings in the jaw.
Pain and infection, Sinus opening
Inflammatory origin
A sine qua non for the diagnosis of a radicular cyst is the related presence of a tooth with a non-vital pulp. Radiographically only apical radiolucency. Rarely any bony expansion until secondary infection is there. Sclerotic bone lining d/d from periapical granuloma. Usually 0.5 to 1.5 cm but can become 5cm or larger. Infected radicular cysts will show resorption of adjacent tooth root.
Radicular Cyst
D/D:
periapical granuloma
In the anterior mandible, early osteolytic phase of periapical cementoosseous dysplasia
Aspiration: Soft brown material with glistening oily yellow flecks. Nodules of cholesterol.
Histopathology:
Proliferative nonkeratinising stratum squamous epithelium with plexiform arrangement.
Dense rich inflammatory infiltrate
Most odontogenic cysts that become infected can show similar features.
Residual Cyst
Refers to a radicular cyst that fails to involute after endodontic therapy or tooth removal. Failed endodontic treatment, residual periapical infection, tooth removal without radicular cyst enucleation. D/d:
Radicular cyst of another tooth OKC and Ameloblastoma or myxoma to be considered in case where it is present even after tooth removal.
Collateral Inflammatory Cyst
The inflammatory collateral cyst has previously been described as the inflammatory paradental cyst, the inflammatory lateral periodontal cyst, the paradental cyst, or the mandibular infected buccal cyst. It is an inflammatory odontogenic cyst which occurs in association with the root surface of partially or fully erupted vital tooth. Origin:
Rests of malassez Reduced enamel epithelium
Etiology: Inflammation due to periodontitis Pathogenesis: Occurs due to unilateral enlargement of dental follicle due to inflammatory destruction of periodontium and alveolar bone. The consistent finding of a hyperplastic, nonkeratinized stratified squamous epithelium with an intense inflammation in the connective tissue is in accordance with the hypothesis that inflammation is important for the development of these cysts.
Developmental Odontogenic Cysts
Dentigerous Cyst
A dentigerous cyst is one that encloses the crown of an unerupted tooth by expansion of its follicle, and is attached to its neck. The dentigerous cyst is attached to the tooth at the cementoenamel junction. Clinical Features:
AGE : 1st to 3rd decades.
GENDER : More frequently in males than in females.
SITE : 2/3rd of follicular cyst associated with unerupted mandibular teeth, primarily III molar, Maxillary canine, Mandibular premolar, Maxillary 3rd Molar, Supernumerary tooth also can be involved
Dentigerous Cyst Clinical presentation:
Dentigerous cysts may grow to a large size before they are diagnosed. Most of them are discovered on radiographs when these are taken because a tooth has 1. Failed to erupt, or a tooth is missing, or 2. Because teeth are tilted or are
otherwise out of alignment.
Most common form of presentation: Slowly enlarging swelling. They are seldom painful unless infected.
Usually does not lead to paraesthesia
Dentigerous Cyst
Radiographically:
Well demarcated radiolucency asso with crown of unerupted tooth. Tooth may be displaced to the inferior border of mandible, even upto the level of condylar neck, nasal floor, maxillary sinus, approaching the orbit. Displace adjacent erupted teeth.
Root resorption in radiographs.
Dentigerous Cyst Types: a) Central b) Lateral c) Circumferential Aspirational biopsy gives:
Clear, pale straw colour fluid, Cholesterol crystals.
Total protein in excess 4 g/100ml. Resembles serum
Surgically managed by
enucleation with extraction,
Marsupialisation(risk of neoplastic transformation of cyst lining)
Done either when it will allow tooth to spontaneously erupt or guided orthodontically, or There is an identification of risk of damaging adjacent developing teeth or neurovascular bundles during enucleation
Lateral Periodontal Cyst
Usually diagnosed as an incidental radiographic finding. Round or tear-drop shaped unilocular radiographic appearance at mid-root level. Mostly in adults older than 21 and has a male prediliction. In both the jaws develops around the premolar and canine regions. D/D:
Botroid odontogenic cyst Squamous odontogenic tumor(occurs in premolar regions)
Lateral Periodontal Cyst
Botryoid Odontogenic Cyst • • •
• • •
•
Similar to lateral periodontal cyst in pathogenesis Differs radiographically, histologically and prognostically Differs in being multicysticgrape cluster appearance on radiograph Satellite or daughter cysts that pinch off the cystic lining High rates of recurrence Presents with: Swelling, Paresthesia, Pain, Discharge Complete surgical excision
Odontogenic Keratocyst- what’s the controversy about?
In 2005 the OKC was reclassified as a tumor based on “aggressive growth”, recurrence after treatment, the rare occurrence of a “solid” variant of OKC, and most importantly, mutations in the PTCH gene. 85% inherited mutated PTCH gene in NBCCS. 30% in non-NBCCS justified by somatic mutation to acquire the phenotype. So, mutated would be neoplasm and non-mutated would be cysts??? But classically a neoplasm should continue to grow after the stimulus which produced it is removed, should not regress spontaneously. OKCs are well documented to completely regress following decompression and the lining of many decompressed cysts appears more like oral mucosa than OKC histologically. Still lacking enough evidence to call it a tumor.
Odontogenic Keratocyst
Dental lamina remnants in the bony crypts.
Oral mucosa
Another variant that arises from the REE and is of dentigerous origin
Histopathology:
Parakeratinised stratified squamous epithelium which is 6-8 cells thick.
Absence of rete pegs.
Separation of epithelium from connective tissue due to metalloprotienases causing degradation of collagen at the juxta epithelial regions.
Epithelial dysplasia present.
Fibrous connective tissue wall.
In case of infection/inflammation of the cyst the epithelium becomes non-keratinised and may lead of an incorrect histopathological diagnosis.
Presense of daughter or satellite cysts in connective tissue.
Keratohyaline granules in the lumen.
Odontogenic Keratocyst
Presents as:
Aspirational biospy
Patients with OKCs complain of pain, swelling or discharge.
Dirty, creamy white viscoid suspension.
Occasionally, they experience paresthesia of the lower lip or teeth.
Total protein less than 4 g/00ml. Mostly albumin
Sometimes discovered fortuitously during dental examination when radiographs were taken. Extend in the medullary cavity and clinically observable expansion of the bone occurs late. Enlarging cyst may lead to displacement of tooth.
Keratin squames
COMPLICATIONS IN OKC : Malignant transformation of cyst lining rare, but has been reported. Recurrence – high rate of recurrence.
Odontogenic Keratocyst
Reasons for recurrence Tendency to multiply Satellite cyst Cystic lining is very thin and fragile, portions of which may left behind Epithelial lining of OKC has intrinsic growth potential Cyst can arise from basal cells of oral mucosa
Odontogenic Keratocyst Multiple OKC’s are seen in Gorlin’s syndrome or Gorlin-Goltz syndrome or Nevoid Basal Cell Carcinoma syndrome Multiple nevoid basal cell epitheliomas Multiple OKCs of the jaws Bifid ribs Plantar & palmar pits Occular hypertelorism Frontal bossing Ectopic calcifications
Odontogenic Keratocyst Surgical Management
Enucleation with curettage Enucleation with peripheral ostectomy Excision of attached mucosa with enucleation and carnoy’s solution for bony defect. Decompression with marsupialisation. Liquid nitrogen cryosurgery. Osseous resection (rim ostectomy or marginal resection) or with segmental resection(continuity defect) – Best – Zero recurrence rate.
Orthokeratinised Odontogenic Cyst
The cystic lining consists of a mature stratified squamous epithelium without rete ridge development which exhibits orthokeratosis and a prominent granular cell layer. The basal cells tend to be flattened to cuboidal but not palisaded and hyperchromatic.
In contradistinction to OKCs, orthokeratinized odontogenic cysts are
not particularly aggressive biologically,
do not have a significant recurrence rate after removal and
are typically not associated with the nevoid basal cell carcinoma syndrome.
Gingival Cyst • Arise from odontogenic epithelial cell rests; or by traumatic implantation of surface epithelium; or by cystic degeneration of deep projections of surface epithelium. • Clinically presents as dome shaped soft, fluctuant swelling which is <1cm in diameter • Slow growing and painless • Appears usually on facial aspect of gingiva, adjacent teeth usually vital • Surgical excision
Gingival Cyst of Newborn
This cyst occurs in infants a few hours to a few months old. Cysts appear as multiple, firm, white gingival nodules on the edentulous maxillary or mandibular ridges. They arise from proliferation of the dental lamina. They usually involute, and no treatment is required except parent reassurance.
Glandular Odontogenic Cyst
Rare lesion
Intrabony and multilocular radiologically
Could recur if not adequately excised
Multicystic, with the cystic spaces lined by a nonkeratinised epithelium akin to that of reduced enamel epithelium. Epithelial thickenings or plaques were present in the cyst linings and mucous and cylindrical cells formed an integral part of the epithelial component. Mucinous material within the cystic spaces was a prominent feature.
Eneucleation, peripheral ostectomy, marginal resection or partial jaw resection.
Calcifying odontogenic cyst
Presents as: Swelling, hard bony expansion that may be fairly extensive; Lingual expansion; Perforation of cortical plate; Displacement of teeth; Pink to red, circumscribed elevated masses measuring up to 4cm in diameter
As defined in the WHO classification of 1992, it is: ‘A cystic lesion in which the epithelial lining shows a well-defined basal layer of columnar cells, an overlying layer that is often many cells thick and that may resemble stellate reticulum, and masses of “ghost” epithelial cell that may be in in the epithelial lining or in the fibrous capsule. The “ghost” epithelial cells may become calcified. Dysplastic dentine may be laid down adjacent to the basal layer of the epithelium, and in some instances the cyst is associated with an area of more extensive dental hard tissue formation resembling that of a complex or compound odontoma.’
Calcifying odontogenic cyst • •
Radiographs show well-demarcated margin and calcifications suggestive of tooth material. Surgical enucleation
General Principles of Surgical Management
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Enucleation is the process by which the total removal of a cystic lesion is achieved. • Enucleation of cysts should be performed with care, in an attempt to remove the cyst in one piece without fragmentation, which reduces the chances of recurrence by increasing the likelihood of total removal. • However, maintenance of the cystic architecture is not always possible, and rupture of the cystic contents may occur during the procedure.
Advantages: • pathologic examination of the entire cyst can be undertaken • the initial excisional biopsy (i.e., enucleation) has also appropriately treated the lesion. • The patient does not have to care for a marsupial cavity with constant irrigations. Disadvantages: • Normal tissue may be jeopardized • Fracture of the jaw • Devitalization of associated teeth • Impacted teeth that the clinician may wish to save could be removed.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Enucleation of a cyst. A, Mild swelling in area of periapical cyst. B, A mucoperiosteal flap is elevated from around the necks of teeth, and a bur is used to remove thinned cortical bone overlying the cyst. Care is taken to prevent rupturing of cystic contents during this and the following steps. C and D, A spoon-type curette is used to strip the cyst from bone. Note that the concave side of the curette is kept in contact with bone. The convex surface is the working end of the instrument. E, Closure.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Apical cystectomy performed at time of tooth removal. A to C, Removal of a cyst with curette via a tooth socket is visualized. An apical cystectomy must be performed with care because of the proximity of the apices of teeth to other structures such as the maxillary sinus and the inferior alveolar canal. D to J, Removal of an apical cyst by flap reflection and creation of osseous window is demonstrated at the time of tooth removal.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage. Photographs of a clinical case of apical cystectomy performed at time of tooth extraction. A, Pretreatment panoramic radiograph showing large radiolucent lesion at the apices of teeth No. 18 and 20. B, Appearance of lesion after buccal flap elevated. Note that the lesion has eroded the bone. C, Curette used to elevate the lesion from the bony walls. D, Cyst being removed. E, Note the inferior alveolar neurovascular bundle passing along the inferior aspect of the bony cavity. F, Surgical specimen. G, When opened, the specimen appeared to be cystic. H, Postoperative panoramic radiograph showing defect. The patient should be monitored with periodic radiographs to ensure bone fill and no recurrence of the lesion.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Marsupialization, decompression, and the Partsch operation all refer to creating a surgical window in the wall of the cyst, evacuating the contents of the cyst, and maintaining continuity between the cyst and the oral cavity, maxillary sinus, or nasal cavity. • The only portion of the cyst that is removed is the piece removed to produce the window. The remaining cystic lining is left in situ. • This process decreases intracystic pressure and promotes shrinkage of the cyst and bone fill. Marsupialization can be used as the sole therapy for a cyst or as a preliminary step in management, with enucleation deferred until later.
INDICATIONS: 1. Amount of tissue injury : Proximity of a cyst to vital structures can mean unnecessary sacrifice of tissue if enucleation is used. 2. Surgical access : If access to all portions of the cyst is difficult, portions of the cystic wall may be left behind, which could result in recurrence. 3. Assistance in eruption of teeth : If an unerupted tooth that is needed in the dental arch is involved with the cyst (i.e., a dentigerous cyst), marsupialization may allow its continued eruption into the oral cavity 4. Extent of surgery : Marsupialization is a reasonable alternative to enucleation, because it is simple and may be less stressful for the patient 5. Size of cyst : In very large cysts, a risk of jaw fracture during enucleation is possible. It may be better to marsupialize the cyst and defer enucleation until after considerable bone fill has occurred.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Advantages: • It is a simple procedure to perform. Marsupialization also spare vital structures from damage should immediate enucleation be attempted. Disadvantages: • Pathologic tissue is left in situ, without thorough histologic examination. • Patient is inconvenienced in several respects • The cystic cavity must be kept clean to prevent infection, because the cavity frequently traps food debris. • In most instances this means that the patient must irrigate the cavity several times every day with a syringe
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Marsupialization technique. A, Cyst within maxilla. B, Incision through oral mucosa and cystic wall into center of cyst. C, Scissors used to complete excision of window of mucosa and cystic wall. D, Oral mucosa and mucosa of cystic wall sutured together around periphery of opening.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Marsupialization of cyst in right mandible associated with unerupted teeth. A, Photograph showing swelling around right second deciduous molar. B, Radiographic appearance before marsupialization. Note the large radiolucent lesion and displacement of the second right premolar toward the inferior border (compare with the opposite side). Cystectomy would probably injure or necessitate the removal of premolars, so it was decided to perform marsupialization of the cyst instead. C, Aspiration performed to determine whether the lesion was fluid filled (cystic). D, The lower right deciduous second molar was removed, and the cyst was opened through the socket (decompressed). E, Panoramic radiograph taken 5 months after surgery showing bone fill and eruption of the premolars.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Marsupialization of an odontogenic keratocyst in right mandible associated with an impacted third molar. A, Panoramic radiograph showing large multilocular radiolucent lesion associated with tooth No. 32. B, Aspiration of the lesion reveals a creamy liquid (keratin). C, Exposure and removal of bone behind the second molar reveals the impacted third molar crown. D, The impacted tooth was removed, and additional bone was removed to provide a large window into the lesion. A portion of the lining was excised and sent for pathologic examination. The cavity was inspected through the opening to ensure there was no solid mass that might indicate tumor. E, Holes were drilled around the periphery of the bony opening to pass sutures from the oral mucosa, through the holes in the bone, and through the cyst lining. This provided a stable opening from the oral cavity into the cyst.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
INDICATIONS • When bone has covered the adjacent vital structures. • Adequate bone fill. Prevents fracture during enucleation. • When patients find it difficult to cleanse the cavity. • To detect any occult pathological condition. ADVANTAGES • Spares adjacent vital structures • Accelerates healing process • Development of thick cystic lining – enucleation easier • Allows histopathological examination of residual tissue. • Combined approach reduces morbidity DISADVANTAGES • Patient has under go second surgery and any possible complicatton associated with surgery.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Enucleation with curettage means that after enucleation a curette or bur is used to remove 1 to 2 mm of bone around the entire periphery of the cystic cavity • Any remaining epithelial cells that may be present in the periphery of the cystic wall or bony cavity must be removed. • These cells could proliferate into a recurrence of the cyst.
Indications : • In this case the more aggressive approach of enucleation with curettage should be used. • Daughter, or satellite, cysts found in the periphery of the main cystic lesion may be incompletely removed • The second instance in which enucleation with curettage is indicated is with any cyst that recurs after what was deemed a thorough removal. Advantages : • If enucleation leaves epithelial remnants, curettage may remove them, thereby decreasing the likelihood of recurrence.
Enucleation with Peripheral Ostectomy
A peripheral ostectomy with rotary instruments enables the surgeon to remove as much bone as necessary to ensure that all residual lining is gone. One of the inherent problems with a peripheral ostectomy, just like curettage, is the ‘‘immeasurability’’ of the amount of osseous resection. Use of methylene blue to identify dysplastic tissue.
Enucleation and use of Carnoy’s solution
• •
The first use of Carnoy’s solution in surgery was reported by Cutler and Zollinger in 1933. They used it as a fixative, haemostatic and cauterising agent and mentioned its action in penetrating cancellous spaces of bone, devitalising tissue and fixing tumor cells. Carnoy’s solution otherwise was being used otherwise in fixing lymph nodes in cadavers and as fixative in histopathological fields. Success of the application of this medicament after enucleation of OKC is thought to be due to both penetration and fixation action. The application of Carnoy's solution promotes a superficial chemical necrosis and is intended to reduce recurrence rates of jaw cysts and tumors.
Cutler EC, Zollinger R. Sclerosing solutionin the treatment of cysts and fistulae. Am JSurg;19:411, (1933). Lau SL, Samman N. Recurrence related to treatment modalities of unicystic amelo-blastoma: a systematic review.Int. J. Oral Maxillofac. Surg. 2006; 35: 681–690
Carnoy’s Solution Composition:
•
Carnoy’s solution II (Recommended by Cutler and Zollinger - 1933):
This led to the reformulated carnoy’s solution without chloroform and is now being accepted.
Ferric chloride - 1gram
Ferric chloride - 1 gram
Glacial acetic acid - 1ml
Chloroform - 3ml
Absolute alocohol - 6ml
Glacial acetic acid - 1ml
Absolute alocohol - 6ml
Extensive studies have proved that exposure to chloroform has been associated with cancer and reproductive toxicity thus banning the use of the medicament in many parts of the world.
Frerich B, Cornelius CP, Wietholter H. Critical time of exposure of the rabbit inferior alveolar nerve to Carnoy’s solution. J Oral Maxillofac Surg 1994: 52: 599–606.
Carnoy’s Solution
Mechanism of action:
Absolute alcohol hardens the tissue by shrinking it, glacial acetic acid swells tissue and prevents over-hardening, chloroform increases the speed of fixation and ferric chloride acts as a dehydrating agent.
Uses in Maxillofacial Surgery:
Used to fix the tissue after enucleation of the OKC Used to fix the tissue after enucleation of few types of ameloblastoma
• Carnoy’s solution as a surgical medicament in the Treatment of keratocystic odontogenic tumour. Dr. Madhulaxmi. M, Dr. P.U. Abdul Wahab. Int J Pharm Bio Sci 2014 Jan; 5(1): (B) 492 – 495
Carnoy’s Solution
The usual practice is the application of Carnoy's solution after enucleation and peripheral ostectomy with application of methylene blue. Carnoy’s solution with cotton applicators or ribbon gauze for 3– 5 min, rinse the bony cavity and pack the wound open for healing by secondary intention. Primary closure is likely to precipitate infection of necrotic debris.
It is assumed that carnoy’s solution eradicates epithelial rests from the bony cyst wall. Its average depth of penetration is 1.54mm after 5 mins of application. However, FRERICH et al. suggested the application of Carnoy’s solution should not exceed 3 min. They showed that the critical time to nerve impairment of the inferior alveolar nerve was 3 min, and that Carnoy’s solution should not be applied directly over the nerve. Though this still remains a matter of study.
Carnoy’s Solution
Adverse effects
Among all the ingredients of carnoys solution, chloroform is considered to be very hazardous and should be used in a ventilated hood by wearing masks. Exposure to chloroform has been associated with cancer and reproductive toxicity. Alteration in the neural conductivity after direct application of carnoys solution over 2 minutes. Carnoy’s solution does not maintain the osseous structure where as cryotherapy maintains bony architecture and facilitates new bone formation.
It lowers the recurrence rate after enucleation of Keratocystic odontogenic tumour. To overweigh the risks, reformulated carnoy’s solution can be used and avoid using the carnoy’s solution in close vicinity to the nerve.
• Surgical treatment of keratocystic odontogenic tumour: A review article; The Saudi Dental Journal (2011) 23, 61–65 • Carnoy’s in Aggressive Lesions: Our Experience; J. Maxillofac. Oral Surg. (Jan-Mar 2013) 12(1):42–47
Enucleation and liquid nitrogen cryotherapy Liquid nitrogen has the ability to devitalize bone in situ while leaving the inorganic framework untouched, as a result of this, cryotherapy has been used for a number of locally aggressive jaw lesions, including OKC, ameloblastoma and ossifying fibroma. Principles of cryosurgery The mechanism of cell and tissue death with cryosurgery involves the following mechanisms: intracellular and extracellular ice crystal formation, osmotic and electrolyte disturbances, denaturation of proteins complexed with lipids, and vascular stasis.
•
The use of liquid nitrogen cryotherapy in the management of the odontogenic keratocyst. Brian L. Schmidt. Oral Maxillofacial Surg Clin N Am 15 (2003) 393–405
Cryotherapy
Tissues freeze at approximately -2.2C; temperatures below -20C are believed to cause cell death on a consistent basis. Liquid nitrogen cryotherapy can weaken the bone significantly with resultant pathologic fractures. Synchronous grafting with cancellous bone can be accomplished after cryotherapy. Sensory nerves within the field may show paresthesia; however, the majority recover within 3 to 6 months.
Cryotherapy
Indications for management cysts with cryotherapy
Recurrent OKC Large complex mandibular lesions Conventional treatment might involve vital structures Noncompliant patient
Oral cryosurgical techniques
Protection of extraoral soft tissues Enucleation Exposure and retraction of intraoral soft tissues Cryosurgical technique
Cryoprobe with water soluble jelly Liquid nitrogen spray
Cryotherapy Technique
Advantages
Disadvantag es
Cryoprobe with watersoluble jelly
Able to freeze irregular, gravity dependent portions of the cavity
Non-uniform freezing
Liquid Nitrogen Spray
Potent, thorough freezing
Damage to surrounding tissues
BIPP
BIPP is a bright yellow paste of sub nitrate 250mg/g, iodoform 500mg/g and liquid paraffin 250 mg/g. This paste is usually placed in cavities and left in place till the cavities heals or a graft is taken. Bismuth has topical antiseptic properties and can be used as an astringent. This property contributes to the antibacterial properties of BIPP by releasing dilute nitric acid on hydrolysis. Iodoform decomposes to release iodine which is an antiseptic. Paraffin is added into BIPP as a lubricant which aids in atraumatic placement and removal of pack.
Int J Dent Med Res | JULY-AUGUST 2014 | VOL 1 | ISSUE 2; Agrawal R et al: Bismuth Iodoform and Paraffin Paste in Keratocystic Odontogenic Tumor
Jaw Resection Block resection, with or without preservation of the continuity of the jaw Resection refers to either segmental resection (surgical removal of a segment of the mandible or maxilla without maintaining the continuity of the bone) or marginal resection (surgical removal of a lesion intact, with a rim of uninvolved bone, maintaining the continuity of the bone). Extreme technique, that results in considerable morbidity, particularly because reconstructive measures are necessary to restore jaw function and aesthetics.
Methods of mandibular resection
Two basic methods: In
the marginal or rim resection, the integrity of the lower or upper border of the mandible is kept intact. In the full or segmental resection of the mandible, both the upper and lower border are included in the resection so that there is a loss of continuity of the mandible.
MARGINAL OR RIM RESECTION
Infective or osteonecrotic disorders- general debridement.
Odontogenic tumors- resection with wider margins.
Segmental Resection
Indicated for
Infiltrative lesions
Lesions involving lower and posterior border
Recurrent lesions
Complete segment from alveolus to inferior border is resected. Deviation of mandible to resected side, occlusion derranged, marked facial deformity. Need for reconstruction.
Resecting the Maxilla
Maxillary resection is guided by the extent of cyst. Pre-operative imaging will include an orthopantomogram (opg) and a CT scan and often an additional MRI will be useful to assess the skull base. The main issues in maxillary resection involve the removal of the orbit and the extent of the disease into the infratemporal fossa.
Class 1 (alveolectomy)
Class 2 (low level maxillectomy)
Class 3 (high level maxillectomy maintaining the orbit) Class 4 (radical maxillectomy with orbital exenteration)
Conclusion
Cysts are a common clinical condition and frequently encountered in practice. They can be a window to the diagnosis of underlying symptoms in a subject. The initial surgical treatment and the subsequent follow-up of cysts of the oral and maxillofacial region depend on several factors:
The patient’s age and overall health condition Size and location of the cyst Histologic diagnosis of the lesion gained by excisional, incisional, or FNA biopsies.
References
4th Edition of the World Health Organization Classification of Head and Neck Tumours: Odontogenic and Maxillofacial Bone Tumors, 2017
Cysts of the Oral and Maxillofacial Regions Fourth edition Mervyn Shear, Paul Speight
Oral And Maxillofacial Surgery Volume II Trauma, Surgical Pathology, Temporomandibular Disorders - Eric R. Carlson, Raymond J. Fonseca, Gregory M. Ness - 3rd Edition (2017)
DIFFERENTIAL DIAGNOSIS of ORAL and MAXILLOFACIAL LESIONS; NORMAN K. WOOD, PAUL W. GOAZ
Odontogenic Cysts and Tumors Brad W. Neville, Douglas D. Damm, Carl M. Allen, and Angela C. Chi; Oral and Maxillofacial Pathology, 15, 632-689
THE PATHOGENESIS OF DENTAL CYSTS MALCOLM HARRIS; Br.Med.BuU. 1975; Vol. 31 No. 2
The pathogenesis of odontogenic cysts: a review; R. M. BROWNE Jottrtial of Oral Pathology 1975: 4: 31-46
Controversies in Oral and Maxillofacial Pathology Zachary S. Peacock, DMD, MD; Oral Maxillofacial Surg Clin N Am 29 (2017) 475–486
Odontogenic cysts; Lisette Martin, Paul M Speight; DIAGNOSTIC HISTOPATHOLOGY 21:9; MINI-SYMPOSIUM: PATHOLOGY OF THE JAWS
Surgical treatment of keratocystic odontogenic tumour: A review article Walid Ahmed Abdullah; The Saudi Dental Journal (2011) 23, 61–65
An analysis of the clinical and histopathologic parameters of the odontogenic keratocyst Thomas P. Pay, Atlanta, DEPARTMENT OF ORAL PATHOLOGY, EMORY UNIVERSITY SCHOOL OF DENTISTRY
The use of liquid nitrogen cryotherapy in the management of the odontogenic keratocyst; Brian L. Schmidt; Oral Maxillofacial Surg Clin N Am 15 (2003) 393–405
JAW CYSTS: DIAGNOSIS AND TREATMENT GORDON W. SUMMERS; HEAD & NECK SURGERY 1:243-256 1979
Surgical treatment of keratocystic odontogenic tumour: A review article; The Saudi Dental Journal (2011) 23, 61–65
Carnoy’s in Aggressive Lesions: Our Experience; J. Maxillofac. Oral Surg. (Jan-Mar 2013) 12(1):42–47
What is a cyst?
A cyst is defined as a pathologic cavity lined by epithelium.
Cyst is an entity that constitutes an epithelium lined sac filled with fluid or semi-fluid material. Killey & Kay (1966) A cyst is an abnormal cavity in hard or soft tissues which contains fluid, semi-fluid, or gas and is often encapsulated and lined by epithelium. Killey & Kay (1966) A cyst is a pathologic cavity having fluid, semifluid or gaseous contents that are not created by the accumulation of pus; frequently, but not always, is lined by epithelium. Kramer (1974)
Connective tissue
Lumen
Epithelial lining
Classification, WHO 2017 I. Cysts of the jaws
A. Epithelial lined B. Not epithelial lined
II. Cysts associated with the maxillary antrum III. Cysts of the soft tissues of the mouth, face, neck and salivary glands i. ii. iii. iv. v. vi. vii.
Dentigerous cyst Odontogenic keratocyst Lateral periodontal and botryoid odontogenic cyst Gingival cyst Glandular odontogenic cyst Calcifying odontogenic cyst Orthokeratinized odontogenic cyst
(a) Odontogenic (b) Non-odontogenic 1. Developmental origin 2. Inflammatory origin
i. ii. iii.
Radicular cyst Residual cyst Collateral inflammatory cyst
4th Edition of the World Health Organization Classification of Head and Neck Tumours: Odontogenic and Maxillofacial Bone Tumors
What changes?
Reincorporation of odontogenic keratocyst and calcifying odontogenic cyst in the cyst classification when they had been classified in 2005 as neoplasms. Under inflammatory cysts, inflammatory collateral cysts are included. Primordial cysts have been dropped and are no longer used synonymously for odontogenic keratocysts.
What changes?
Orthokeratinized odontogenic cysts are now recognized as an odontogenic cyst distinct from OKC. New diagnostic criteria for glandular odontogenic cysts (GOC) are presented, and the histologic overlap between GOC and cystic mucoepidermoid carcinomas acknowledged. No MAML2 gene in GOC.
Histogenic Classification The epithelial lining origins of odontogenic cysts Epithelial residue
Origin of Epithelium
Cyst
Rests of Serres
Dental lamina
OKC, Glandular odontogenic cyst, Gingival cyst of infants and adults
Reduced Enamel Epithelium
Enamel organ
Dentigerous cyst, Eruption cyst, Botryoid odontogenic cyst, Paradental cyst
Rests of Malassez
Hertwig’s root sheath
Radicular cyst, Residual cyst
Distribution of odontogenic cysts according to diagnosis. From Jones et al. (2006), Sheffield. Cysts
Number
%
Radicular cyst
3724
52.3
Dentigerous cyst Odontogenic keratocyst Residual cyst
1292 828 573
18.1 11.6 8.0
Paradental cyst
402
5.6
Unclassified odontogenic cysts Lateral periodontal cyst
210 28
2.9 0.4
Calcifying odontogenic cyst Gingival cyst Eruption cyst
21 16 15
0.3 0.2 0.2
Glandular odontogenic cyst Epstein pearl Total
11 1 7121
0.2 0.0 100.00
Pathophysiology “A Surgeon must be a pathologist who does operations.” Eric Carlson
How does a cyst develop and grow? Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity for bone resorption and cyst growth.
Odontogenic epithelium derived from the basal epithelium of the stomatodeum. • Remnants of the dental lamina(rests of Serres),
• Reduced enamel epithelium, • Hertwig’s epithelial rooth sheath(rests of Malassez)
Cyst Initiation Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity for bone resorption and cyst growth.
From the Cell Rests of Mallasez (Hertwig’s Epithelial Root Sheath):
From within apical granuloma(round/ovoid cellular islands) > extension of proliferating epithelium strands > the arcades and rings surround the inflamed necrotic part. > a hollow sponge-like structure which consolidates to form a continuous epithelium lining to the cavity > forms barrier to pulpal irritants from surrounding tissues. Eg: Radicular Cyst, Residual Cyst
Cyst Initiation Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity for bone resorption and cyst growth.
From Reduced Enamel Epithelium (Enamel organ): Clefts arise from within layers of REE > enlarges and encloses tooth crown
> impaired tooth eruption, or a disturbance in the mucosal epithelial component of the eruption process, could lead to continued enlargement of this programmed crevicular cleft arising from proliferation of the outer layers of the reduced enamel epithelium, and hence to the formation of a follicular cyst.
Eg: Dentigerous cyst, paradental cyst, Lateral periodontal cyst, eruption cyst, botryoid odontogenic cyst
Cyst Initiation Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity for bone resorption and cyst growth.
From Cells Rests of Serre (Dental lamina): Develops from remnants of dental lamina rather than from aborted primordial tooth germs as it was believed before. The abundance of these lamina remnants in the third molar region correlates well with the high frequency of occurrence of keratocysts in this area. Impacted or absent wisdom teeth would predispose to the preservation of these rests and to cyst formation. Eg: OKC, Glandular odontogenic cyst, gingival cyst
Cyst Enlargement Cyst formation in the jaws requires three elements: a source of epithelium,
a stimulus for epithelial proliferation and the capacity of cyst enlargement and bone resorption.
The mechanisms concerned with their enlargement can be divided roughly into three groups: a. Mural growth i. Peripheral cell division ii. Accumulation of cellular contents
b. Hydrostatic enlargement i. Secretion ii. Transudation and exudation iii. Dialysis
c. Bone-resorbing factor
Mural Growth
Hydrostatic Enlargement i. Secretion: Goblet cells have intracystic secretions ii. Transudation and exudation: owing to the protein content of cystic fluids iii. Dialysis: accumulation of low-molecular weight protein forms a gradient with net inflow of fluid from capillaries into cystic lumen.
Bone Resorption Vital cyst tissue(capsule and its leukocyte content, contribution from vascular structures) prostaglandin E2 (PGEj) and prostaglandin E3(PGE3) That production takes place in the capsule under the influence of epithelial proliferation, lysosomal phospholipases from fibroblasts and polymorphonuclear leucocytes breaking down phospholipid cell membranes to produce arachidonic acid, which is converted by the ubiquitous enzyme prostaglandin synthetase to prostaglandin. Keratocysts contain matrix-solubilizing enzyme, collagenase, in their walls contributing to cyst growth.
Diagnosis
Clinical Presentation Symptoms:
Completely symptomless, chance finding, swelling intraoral discharge- tasteless, salty or sweet, acute abscess of infected cysts, dull throbbing pain in less severe infections,
impaired sensation of lower lip in mandibular cysts, discomfort or difficulty in wearing dentures in edentulous patients,
tilted or shifted teeth in the mouth.
On Examination Signs:
Swelling, frankly fluctuant or bony hard on palpation,
egg-shell crackling effect, springy in consistency,
bluish tinge or dark red colour of soft tissues,
infected cysts tender on touch,
rarely lingual plate involvement in mandible,
sinus opening,
glairy cholesterol containing fluid or yellow purulent discharge,
vitality of teeth may be compromised.
Investigations
RADIOLOGY CT SCAN MRI RADIOPAQUE DYES
ASPIRATION BIOPSY
Radiographic Appearances
Area of radiolucency surrounded by radioopaque line of condensed bone. Confirm with aspiration of cystic fluid, diagnostic biopsy.
Is it a cyst?
Periapical Radiolucency
Periapical granuloma Scar Chronic or acute dentoalveolar abcess Osteomyelitis Hyperplasia of maxillary sinus lining Periapical Cementoosseous Dysplasia in its lytic or fibroblastic stage Traumatic bone cyst Periodontal disease
Wide array of odontogenic cysts and tumors including carcinomas and fibroosseous diseases can begin and develop radiolucencies that may appear periapically.
Is it a cyst?
Pericoronal radiolucencies: Follicular
space Dentigerous cyst Unicystic Ameloblastoma(mural type) Adenomatoid odontogenic tumor Calcifying odontogenic cyst or tumor(early stage) Ameloblastic fibroma
Is it a cyst?
Solitray radiolucencies not contacting teeth Anatomic patterns Post extraction socket Residual cyst Traumatic bone cyst OKC Ameloblastoma Focal Osteoporotic defect of the jaws
Surgical defect Central Giant call granuloma Giant cell lesion Focal cemento osseous dysplasia Early stage of cementifying and ossifying fibroma Benign non-odontogenic tumors
Aspiration and Biopsy
Aspiration
Inability to aspirate, vacuum on suction indicates a solid mass within
Excisional biopsy for smaller cysts Incisional biopsy if cyst is bigger
Cyst
Aspirate
Features
Dentigerous cyst
Clear, straw colour fluid
Total protein more than 4mg/dl. Resembles serum.
OKC
Dirty, creamy white, viscoid suspension
Keratin squames Total protein less than 4mg/dl. Albumin in excess.
Periodontal cyst
Clear, pale, straw colour fluid
Cholesterol crystals Total protein 5-11mg/dl
Infected cyst
Pus, brownish fluid, foul smelling
PMNs, cholesterol clefts
Vascular lesion Needle in vessel
Blood
Traumatic bone cyst Antrum
Air
Inflammatory Odontogenic Cysts
Radicular Cyst
The most common odontogenic cyst
Usually symptomless, the most common cause of slow growing swellings in the jaw.
Pain and infection, Sinus opening
Inflammatory origin
A sine qua non for the diagnosis of a radicular cyst is the related presence of a tooth with a non-vital pulp. Radiographically only apical radiolucency. Rarely any bony expansion until secondary infection is there. Sclerotic bone lining d/d from periapical granuloma. Usually 0.5 to 1.5 cm but can become 5cm or larger. Infected radicular cysts will show resorption of adjacent tooth root.
Radicular Cyst
D/D:
periapical granuloma
In the anterior mandible, early osteolytic phase of periapical cementoosseous dysplasia
Aspiration: Soft brown material with glistening oily yellow flecks. Nodules of cholesterol.
Histopathology:
Proliferative nonkeratinising stratum squamous epithelium with plexiform arrangement.
Dense rich inflammatory infiltrate
Most odontogenic cysts that become infected can show similar features.
Residual Cyst
Refers to a radicular cyst that fails to involute after endodontic therapy or tooth removal. Failed endodontic treatment, residual periapical infection, tooth removal without radicular cyst enucleation. D/d:
Radicular cyst of another tooth OKC and Ameloblastoma or myxoma to be considered in case where it is present even after tooth removal.
Collateral Inflammatory Cyst
The inflammatory collateral cyst has previously been described as the inflammatory paradental cyst, the inflammatory lateral periodontal cyst, the paradental cyst, or the mandibular infected buccal cyst. It is an inflammatory odontogenic cyst which occurs in association with the root surface of partially or fully erupted vital tooth. Origin:
Rests of malassez Reduced enamel epithelium
Etiology: Inflammation due to periodontitis Pathogenesis: Occurs due to unilateral enlargement of dental follicle due to inflammatory destruction of periodontium and alveolar bone. The consistent finding of a hyperplastic, nonkeratinized stratified squamous epithelium with an intense inflammation in the connective tissue is in accordance with the hypothesis that inflammation is important for the development of these cysts.
Developmental Odontogenic Cysts
Dentigerous Cyst
A dentigerous cyst is one that encloses the crown of an unerupted tooth by expansion of its follicle, and is attached to its neck. The dentigerous cyst is attached to the tooth at the cementoenamel junction. Clinical Features:
AGE : 1st to 3rd decades.
GENDER : More frequently in males than in females.
SITE : 2/3rd of follicular cyst associated with unerupted mandibular teeth, primarily III molar, Maxillary canine, Mandibular premolar, Maxillary 3rd Molar, Supernumerary tooth also can be involved
Dentigerous Cyst Clinical presentation:
Dentigerous cysts may grow to a large size before they are diagnosed. Most of them are discovered on radiographs when these are taken because a tooth has 1. Failed to erupt, or a tooth is missing, or 2. Because teeth are tilted or are
otherwise out of alignment.
Most common form of presentation: Slowly enlarging swelling. They are seldom painful unless infected.
Usually does not lead to paraesthesia
Dentigerous Cyst
Radiographically:
Well demarcated radiolucency asso with crown of unerupted tooth. Tooth may be displaced to the inferior border of mandible, even upto the level of condylar neck, nasal floor, maxillary sinus, approaching the orbit. Displace adjacent erupted teeth.
Root resorption in radiographs.
Dentigerous Cyst Types: a) Central b) Lateral c) Circumferential Aspirational biopsy gives:
Clear, pale straw colour fluid, Cholesterol crystals.
Total protein in excess 4 g/100ml. Resembles serum
Surgically managed by
enucleation with extraction,
Marsupialisation(risk of neoplastic transformation of cyst lining)
Done either when it will allow tooth to spontaneously erupt or guided orthodontically, or There is an identification of risk of damaging adjacent developing teeth or neurovascular bundles during enucleation
Lateral Periodontal Cyst
Usually diagnosed as an incidental radiographic finding. Round or tear-drop shaped unilocular radiographic appearance at mid-root level. Mostly in adults older than 21 and has a male prediliction. In both the jaws develops around the premolar and canine regions. D/D:
Botroid odontogenic cyst Squamous odontogenic tumor(occurs in premolar regions)
Lateral Periodontal Cyst
Botryoid Odontogenic Cyst • • •
• • •
•
Similar to lateral periodontal cyst in pathogenesis Differs radiographically, histologically and prognostically Differs in being multicysticgrape cluster appearance on radiograph Satellite or daughter cysts that pinch off the cystic lining High rates of recurrence Presents with: Swelling, Paresthesia, Pain, Discharge Complete surgical excision
Odontogenic Keratocyst- what’s the controversy about?
In 2005 the OKC was reclassified as a tumor based on “aggressive growth”, recurrence after treatment, the rare occurrence of a “solid” variant of OKC, and most importantly, mutations in the PTCH gene. 85% inherited mutated PTCH gene in NBCCS. 30% in non-NBCCS justified by somatic mutation to acquire the phenotype. So, mutated would be neoplasm and non-mutated would be cysts??? But classically a neoplasm should continue to grow after the stimulus which produced it is removed, should not regress spontaneously. OKCs are well documented to completely regress following decompression and the lining of many decompressed cysts appears more like oral mucosa than OKC histologically. Still lacking enough evidence to call it a tumor.
Odontogenic Keratocyst
Dental lamina remnants in the bony crypts.
Oral mucosa
Another variant that arises from the REE and is of dentigerous origin
Histopathology:
Parakeratinised stratified squamous epithelium which is 6-8 cells thick.
Absence of rete pegs.
Separation of epithelium from connective tissue due to metalloprotienases causing degradation of collagen at the juxta epithelial regions.
Epithelial dysplasia present.
Fibrous connective tissue wall.
In case of infection/inflammation of the cyst the epithelium becomes non-keratinised and may lead of an incorrect histopathological diagnosis.
Presense of daughter or satellite cysts in connective tissue.
Keratohyaline granules in the lumen.
Odontogenic Keratocyst
Presents as:
Aspirational biospy
Patients with OKCs complain of pain, swelling or discharge.
Dirty, creamy white viscoid suspension.
Occasionally, they experience paresthesia of the lower lip or teeth.
Total protein less than 4 g/00ml. Mostly albumin
Sometimes discovered fortuitously during dental examination when radiographs were taken. Extend in the medullary cavity and clinically observable expansion of the bone occurs late. Enlarging cyst may lead to displacement of tooth.
Keratin squames
COMPLICATIONS IN OKC : Malignant transformation of cyst lining rare, but has been reported. Recurrence – high rate of recurrence.
Odontogenic Keratocyst
Reasons for recurrence Tendency to multiply Satellite cyst Cystic lining is very thin and fragile, portions of which may left behind Epithelial lining of OKC has intrinsic growth potential Cyst can arise from basal cells of oral mucosa
Odontogenic Keratocyst Multiple OKC’s are seen in Gorlin’s syndrome or Gorlin-Goltz syndrome or Nevoid Basal Cell Carcinoma syndrome Multiple nevoid basal cell epitheliomas Multiple OKCs of the jaws Bifid ribs Plantar & palmar pits Occular hypertelorism Frontal bossing Ectopic calcifications
Odontogenic Keratocyst Surgical Management
Enucleation with curettage Enucleation with peripheral ostectomy Excision of attached mucosa with enucleation and carnoy’s solution for bony defect. Decompression with marsupialisation. Liquid nitrogen cryosurgery. Osseous resection (rim ostectomy or marginal resection) or with segmental resection(continuity defect) – Best – Zero recurrence rate.
Orthokeratinised Odontogenic Cyst
The cystic lining consists of a mature stratified squamous epithelium without rete ridge development which exhibits orthokeratosis and a prominent granular cell layer. The basal cells tend to be flattened to cuboidal but not palisaded and hyperchromatic.
In contradistinction to OKCs, orthokeratinized odontogenic cysts are
not particularly aggressive biologically,
do not have a significant recurrence rate after removal and
are typically not associated with the nevoid basal cell carcinoma syndrome.
Gingival Cyst • Arise from odontogenic epithelial cell rests; or by traumatic implantation of surface epithelium; or by cystic degeneration of deep projections of surface epithelium. • Clinically presents as dome shaped soft, fluctuant swelling which is <1cm in diameter • Slow growing and painless • Appears usually on facial aspect of gingiva, adjacent teeth usually vital • Surgical excision
Gingival Cyst of Newborn
This cyst occurs in infants a few hours to a few months old. Cysts appear as multiple, firm, white gingival nodules on the edentulous maxillary or mandibular ridges. They arise from proliferation of the dental lamina. They usually involute, and no treatment is required except parent reassurance.
Glandular Odontogenic Cyst
Rare lesion
Intrabony and multilocular radiologically
Could recur if not adequately excised
Multicystic, with the cystic spaces lined by a nonkeratinised epithelium akin to that of reduced enamel epithelium. Epithelial thickenings or plaques were present in the cyst linings and mucous and cylindrical cells formed an integral part of the epithelial component. Mucinous material within the cystic spaces was a prominent feature.
Eneucleation, peripheral ostectomy, marginal resection or partial jaw resection.
Calcifying odontogenic cyst
Presents as: Swelling, hard bony expansion that may be fairly extensive; Lingual expansion; Perforation of cortical plate; Displacement of teeth; Pink to red, circumscribed elevated masses measuring up to 4cm in diameter
As defined in the WHO classification of 1992, it is: ‘A cystic lesion in which the epithelial lining shows a well-defined basal layer of columnar cells, an overlying layer that is often many cells thick and that may resemble stellate reticulum, and masses of “ghost” epithelial cell that may be in in the epithelial lining or in the fibrous capsule. The “ghost” epithelial cells may become calcified. Dysplastic dentine may be laid down adjacent to the basal layer of the epithelium, and in some instances the cyst is associated with an area of more extensive dental hard tissue formation resembling that of a complex or compound odontoma.’
Calcifying odontogenic cyst • •
Radiographs show well-demarcated margin and calcifications suggestive of tooth material. Surgical enucleation
General Principles of Surgical Management
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Enucleation is the process by which the total removal of a cystic lesion is achieved. • Enucleation of cysts should be performed with care, in an attempt to remove the cyst in one piece without fragmentation, which reduces the chances of recurrence by increasing the likelihood of total removal. • However, maintenance of the cystic architecture is not always possible, and rupture of the cystic contents may occur during the procedure.
Advantages: • pathologic examination of the entire cyst can be undertaken • the initial excisional biopsy (i.e., enucleation) has also appropriately treated the lesion. • The patient does not have to care for a marsupial cavity with constant irrigations. Disadvantages: • Normal tissue may be jeopardized • Fracture of the jaw • Devitalization of associated teeth • Impacted teeth that the clinician may wish to save could be removed.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Enucleation of a cyst. A, Mild swelling in area of periapical cyst. B, A mucoperiosteal flap is elevated from around the necks of teeth, and a bur is used to remove thinned cortical bone overlying the cyst. Care is taken to prevent rupturing of cystic contents during this and the following steps. C and D, A spoon-type curette is used to strip the cyst from bone. Note that the concave side of the curette is kept in contact with bone. The convex surface is the working end of the instrument. E, Closure.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Apical cystectomy performed at time of tooth removal. A to C, Removal of a cyst with curette via a tooth socket is visualized. An apical cystectomy must be performed with care because of the proximity of the apices of teeth to other structures such as the maxillary sinus and the inferior alveolar canal. D to J, Removal of an apical cyst by flap reflection and creation of osseous window is demonstrated at the time of tooth removal.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage. Photographs of a clinical case of apical cystectomy performed at time of tooth extraction. A, Pretreatment panoramic radiograph showing large radiolucent lesion at the apices of teeth No. 18 and 20. B, Appearance of lesion after buccal flap elevated. Note that the lesion has eroded the bone. C, Curette used to elevate the lesion from the bony walls. D, Cyst being removed. E, Note the inferior alveolar neurovascular bundle passing along the inferior aspect of the bony cavity. F, Surgical specimen. G, When opened, the specimen appeared to be cystic. H, Postoperative panoramic radiograph showing defect. The patient should be monitored with periodic radiographs to ensure bone fill and no recurrence of the lesion.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Marsupialization, decompression, and the Partsch operation all refer to creating a surgical window in the wall of the cyst, evacuating the contents of the cyst, and maintaining continuity between the cyst and the oral cavity, maxillary sinus, or nasal cavity. • The only portion of the cyst that is removed is the piece removed to produce the window. The remaining cystic lining is left in situ. • This process decreases intracystic pressure and promotes shrinkage of the cyst and bone fill. Marsupialization can be used as the sole therapy for a cyst or as a preliminary step in management, with enucleation deferred until later.
INDICATIONS: 1. Amount of tissue injury : Proximity of a cyst to vital structures can mean unnecessary sacrifice of tissue if enucleation is used. 2. Surgical access : If access to all portions of the cyst is difficult, portions of the cystic wall may be left behind, which could result in recurrence. 3. Assistance in eruption of teeth : If an unerupted tooth that is needed in the dental arch is involved with the cyst (i.e., a dentigerous cyst), marsupialization may allow its continued eruption into the oral cavity 4. Extent of surgery : Marsupialization is a reasonable alternative to enucleation, because it is simple and may be less stressful for the patient 5. Size of cyst : In very large cysts, a risk of jaw fracture during enucleation is possible. It may be better to marsupialize the cyst and defer enucleation until after considerable bone fill has occurred.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Advantages: • It is a simple procedure to perform. Marsupialization also spare vital structures from damage should immediate enucleation be attempted. Disadvantages: • Pathologic tissue is left in situ, without thorough histologic examination. • Patient is inconvenienced in several respects • The cystic cavity must be kept clean to prevent infection, because the cavity frequently traps food debris. • In most instances this means that the patient must irrigate the cavity several times every day with a syringe
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Marsupialization technique. A, Cyst within maxilla. B, Incision through oral mucosa and cystic wall into center of cyst. C, Scissors used to complete excision of window of mucosa and cystic wall. D, Oral mucosa and mucosa of cystic wall sutured together around periphery of opening.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Marsupialization of cyst in right mandible associated with unerupted teeth. A, Photograph showing swelling around right second deciduous molar. B, Radiographic appearance before marsupialization. Note the large radiolucent lesion and displacement of the second right premolar toward the inferior border (compare with the opposite side). Cystectomy would probably injure or necessitate the removal of premolars, so it was decided to perform marsupialization of the cyst instead. C, Aspiration performed to determine whether the lesion was fluid filled (cystic). D, The lower right deciduous second molar was removed, and the cyst was opened through the socket (decompressed). E, Panoramic radiograph taken 5 months after surgery showing bone fill and eruption of the premolars.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Marsupialization of an odontogenic keratocyst in right mandible associated with an impacted third molar. A, Panoramic radiograph showing large multilocular radiolucent lesion associated with tooth No. 32. B, Aspiration of the lesion reveals a creamy liquid (keratin). C, Exposure and removal of bone behind the second molar reveals the impacted third molar crown. D, The impacted tooth was removed, and additional bone was removed to provide a large window into the lesion. A portion of the lining was excised and sent for pathologic examination. The cavity was inspected through the opening to ensure there was no solid mass that might indicate tumor. E, Holes were drilled around the periphery of the bony opening to pass sutures from the oral mucosa, through the holes in the bone, and through the cyst lining. This provided a stable opening from the oral cavity into the cyst.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
INDICATIONS • When bone has covered the adjacent vital structures. • Adequate bone fill. Prevents fracture during enucleation. • When patients find it difficult to cleanse the cavity. • To detect any occult pathological condition. ADVANTAGES • Spares adjacent vital structures • Accelerates healing process • Development of thick cystic lining – enucleation easier • Allows histopathological examination of residual tissue. • Combined approach reduces morbidity DISADVANTAGES • Patient has under go second surgery and any possible complicatton associated with surgery.
Surgical Management 1.
Enucleation
2.
Marsupialization
3.
A staged combination of the two procedures
4.
Enucleation with curettage.
Enucleation with curettage means that after enucleation a curette or bur is used to remove 1 to 2 mm of bone around the entire periphery of the cystic cavity • Any remaining epithelial cells that may be present in the periphery of the cystic wall or bony cavity must be removed. • These cells could proliferate into a recurrence of the cyst.
Indications : • In this case the more aggressive approach of enucleation with curettage should be used. • Daughter, or satellite, cysts found in the periphery of the main cystic lesion may be incompletely removed • The second instance in which enucleation with curettage is indicated is with any cyst that recurs after what was deemed a thorough removal. Advantages : • If enucleation leaves epithelial remnants, curettage may remove them, thereby decreasing the likelihood of recurrence.
Enucleation with Peripheral Ostectomy
A peripheral ostectomy with rotary instruments enables the surgeon to remove as much bone as necessary to ensure that all residual lining is gone. One of the inherent problems with a peripheral ostectomy, just like curettage, is the ‘‘immeasurability’’ of the amount of osseous resection. Use of methylene blue to identify dysplastic tissue.
Enucleation and use of Carnoy’s solution
• •
The first use of Carnoy’s solution in surgery was reported by Cutler and Zollinger in 1933. They used it as a fixative, haemostatic and cauterising agent and mentioned its action in penetrating cancellous spaces of bone, devitalising tissue and fixing tumor cells. Carnoy’s solution otherwise was being used otherwise in fixing lymph nodes in cadavers and as fixative in histopathological fields. Success of the application of this medicament after enucleation of OKC is thought to be due to both penetration and fixation action. The application of Carnoy's solution promotes a superficial chemical necrosis and is intended to reduce recurrence rates of jaw cysts and tumors.
Cutler EC, Zollinger R. Sclerosing solutionin the treatment of cysts and fistulae. Am JSurg;19:411, (1933). Lau SL, Samman N. Recurrence related to treatment modalities of unicystic amelo-blastoma: a systematic review.Int. J. Oral Maxillofac. Surg. 2006; 35: 681–690
Carnoy’s Solution Composition:
•
Carnoy’s solution II (Recommended by Cutler and Zollinger - 1933):
This led to the reformulated carnoy’s solution without chloroform and is now being accepted.
Ferric chloride - 1gram
Ferric chloride - 1 gram
Glacial acetic acid - 1ml
Chloroform - 3ml
Absolute alocohol - 6ml
Glacial acetic acid - 1ml
Absolute alocohol - 6ml
Extensive studies have proved that exposure to chloroform has been associated with cancer and reproductive toxicity thus banning the use of the medicament in many parts of the world.
Frerich B, Cornelius CP, Wietholter H. Critical time of exposure of the rabbit inferior alveolar nerve to Carnoy’s solution. J Oral Maxillofac Surg 1994: 52: 599–606.
Carnoy’s Solution
Mechanism of action:
Absolute alcohol hardens the tissue by shrinking it, glacial acetic acid swells tissue and prevents over-hardening, chloroform increases the speed of fixation and ferric chloride acts as a dehydrating agent.
Uses in Maxillofacial Surgery:
Used to fix the tissue after enucleation of the OKC Used to fix the tissue after enucleation of few types of ameloblastoma
• Carnoy’s solution as a surgical medicament in the Treatment of keratocystic odontogenic tumour. Dr. Madhulaxmi. M, Dr. P.U. Abdul Wahab. Int J Pharm Bio Sci 2014 Jan; 5(1): (B) 492 – 495
Carnoy’s Solution
The usual practice is the application of Carnoy's solution after enucleation and peripheral ostectomy with application of methylene blue. Carnoy’s solution with cotton applicators or ribbon gauze for 3– 5 min, rinse the bony cavity and pack the wound open for healing by secondary intention. Primary closure is likely to precipitate infection of necrotic debris.
It is assumed that carnoy’s solution eradicates epithelial rests from the bony cyst wall. Its average depth of penetration is 1.54mm after 5 mins of application. However, FRERICH et al. suggested the application of Carnoy’s solution should not exceed 3 min. They showed that the critical time to nerve impairment of the inferior alveolar nerve was 3 min, and that Carnoy’s solution should not be applied directly over the nerve. Though this still remains a matter of study.
Carnoy’s Solution
Adverse effects
Among all the ingredients of carnoys solution, chloroform is considered to be very hazardous and should be used in a ventilated hood by wearing masks. Exposure to chloroform has been associated with cancer and reproductive toxicity. Alteration in the neural conductivity after direct application of carnoys solution over 2 minutes. Carnoy’s solution does not maintain the osseous structure where as cryotherapy maintains bony architecture and facilitates new bone formation.
It lowers the recurrence rate after enucleation of Keratocystic odontogenic tumour. To overweigh the risks, reformulated carnoy’s solution can be used and avoid using the carnoy’s solution in close vicinity to the nerve.
• Surgical treatment of keratocystic odontogenic tumour: A review article; The Saudi Dental Journal (2011) 23, 61–65 • Carnoy’s in Aggressive Lesions: Our Experience; J. Maxillofac. Oral Surg. (Jan-Mar 2013) 12(1):42–47
Enucleation and liquid nitrogen cryotherapy Liquid nitrogen has the ability to devitalize bone in situ while leaving the inorganic framework untouched, as a result of this, cryotherapy has been used for a number of locally aggressive jaw lesions, including OKC, ameloblastoma and ossifying fibroma. Principles of cryosurgery The mechanism of cell and tissue death with cryosurgery involves the following mechanisms: intracellular and extracellular ice crystal formation, osmotic and electrolyte disturbances, denaturation of proteins complexed with lipids, and vascular stasis.
•
The use of liquid nitrogen cryotherapy in the management of the odontogenic keratocyst. Brian L. Schmidt. Oral Maxillofacial Surg Clin N Am 15 (2003) 393–405
Cryotherapy
Tissues freeze at approximately -2.2C; temperatures below -20C are believed to cause cell death on a consistent basis. Liquid nitrogen cryotherapy can weaken the bone significantly with resultant pathologic fractures. Synchronous grafting with cancellous bone can be accomplished after cryotherapy. Sensory nerves within the field may show paresthesia; however, the majority recover within 3 to 6 months.
Cryotherapy
Indications for management cysts with cryotherapy
Recurrent OKC Large complex mandibular lesions Conventional treatment might involve vital structures Noncompliant patient
Oral cryosurgical techniques
Protection of extraoral soft tissues Enucleation Exposure and retraction of intraoral soft tissues Cryosurgical technique
Cryoprobe with water soluble jelly Liquid nitrogen spray
Cryotherapy Technique
Advantages
Disadvantag es
Cryoprobe with watersoluble jelly
Able to freeze irregular, gravity dependent portions of the cavity
Non-uniform freezing
Liquid Nitrogen Spray
Potent, thorough freezing
Damage to surrounding tissues
BIPP
BIPP is a bright yellow paste of sub nitrate 250mg/g, iodoform 500mg/g and liquid paraffin 250 mg/g. This paste is usually placed in cavities and left in place till the cavities heals or a graft is taken. Bismuth has topical antiseptic properties and can be used as an astringent. This property contributes to the antibacterial properties of BIPP by releasing dilute nitric acid on hydrolysis. Iodoform decomposes to release iodine which is an antiseptic. Paraffin is added into BIPP as a lubricant which aids in atraumatic placement and removal of pack.
Int J Dent Med Res | JULY-AUGUST 2014 | VOL 1 | ISSUE 2; Agrawal R et al: Bismuth Iodoform and Paraffin Paste in Keratocystic Odontogenic Tumor
Jaw Resection Block resection, with or without preservation of the continuity of the jaw Resection refers to either segmental resection (surgical removal of a segment of the mandible or maxilla without maintaining the continuity of the bone) or marginal resection (surgical removal of a lesion intact, with a rim of uninvolved bone, maintaining the continuity of the bone). Extreme technique, that results in considerable morbidity, particularly because reconstructive measures are necessary to restore jaw function and aesthetics.
Methods of mandibular resection
Two basic methods: In
the marginal or rim resection, the integrity of the lower or upper border of the mandible is kept intact. In the full or segmental resection of the mandible, both the upper and lower border are included in the resection so that there is a loss of continuity of the mandible.
MARGINAL OR RIM RESECTION
Infective or osteonecrotic disorders- general debridement.
Odontogenic tumors- resection with wider margins.
Segmental Resection
Indicated for
Infiltrative lesions
Lesions involving lower and posterior border
Recurrent lesions
Complete segment from alveolus to inferior border is resected. Deviation of mandible to resected side, occlusion derranged, marked facial deformity. Need for reconstruction.
Resecting the Maxilla
Maxillary resection is guided by the extent of cyst. Pre-operative imaging will include an orthopantomogram (opg) and a CT scan and often an additional MRI will be useful to assess the skull base. The main issues in maxillary resection involve the removal of the orbit and the extent of the disease into the infratemporal fossa.
Class 1 (alveolectomy)
Class 2 (low level maxillectomy)
Class 3 (high level maxillectomy maintaining the orbit) Class 4 (radical maxillectomy with orbital exenteration)
Conclusion
Cysts are a common clinical condition and frequently encountered in practice. They can be a window to the diagnosis of underlying symptoms in a subject. The initial surgical treatment and the subsequent follow-up of cysts of the oral and maxillofacial region depend on several factors:
The patient’s age and overall health condition Size and location of the cyst Histologic diagnosis of the lesion gained by excisional, incisional, or FNA biopsies.
References
4th Edition of the World Health Organization Classification of Head and Neck Tumours: Odontogenic and Maxillofacial Bone Tumors, 2017
Cysts of the Oral and Maxillofacial Regions Fourth edition Mervyn Shear, Paul Speight
Oral And Maxillofacial Surgery Volume II Trauma, Surgical Pathology, Temporomandibular Disorders - Eric R. Carlson, Raymond J. Fonseca, Gregory M. Ness - 3rd Edition (2017)
DIFFERENTIAL DIAGNOSIS of ORAL and MAXILLOFACIAL LESIONS; NORMAN K. WOOD, PAUL W. GOAZ
Odontogenic Cysts and Tumors Brad W. Neville, Douglas D. Damm, Carl M. Allen, and Angela C. Chi; Oral and Maxillofacial Pathology, 15, 632-689
THE PATHOGENESIS OF DENTAL CYSTS MALCOLM HARRIS; Br.Med.BuU. 1975; Vol. 31 No. 2
The pathogenesis of odontogenic cysts: a review; R. M. BROWNE Jottrtial of Oral Pathology 1975: 4: 31-46
Controversies in Oral and Maxillofacial Pathology Zachary S. Peacock, DMD, MD; Oral Maxillofacial Surg Clin N Am 29 (2017) 475–486
Odontogenic cysts; Lisette Martin, Paul M Speight; DIAGNOSTIC HISTOPATHOLOGY 21:9; MINI-SYMPOSIUM: PATHOLOGY OF THE JAWS
Surgical treatment of keratocystic odontogenic tumour: A review article Walid Ahmed Abdullah; The Saudi Dental Journal (2011) 23, 61–65
An analysis of the clinical and histopathologic parameters of the odontogenic keratocyst Thomas P. Pay, Atlanta, DEPARTMENT OF ORAL PATHOLOGY, EMORY UNIVERSITY SCHOOL OF DENTISTRY
The use of liquid nitrogen cryotherapy in the management of the odontogenic keratocyst; Brian L. Schmidt; Oral Maxillofacial Surg Clin N Am 15 (2003) 393–405
JAW CYSTS: DIAGNOSIS AND TREATMENT GORDON W. SUMMERS; HEAD & NECK SURGERY 1:243-256 1979
Surgical treatment of keratocystic odontogenic tumour: A review article; The Saudi Dental Journal (2011) 23, 61–65
Carnoy’s in Aggressive Lesions: Our Experience; J. Maxillofac. Oral Surg. (Jan-Mar 2013) 12(1):42–47
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