• Defination• Types Of Cysts• Parts Of A Cyst• Classification Of Jaw Cysts• Clinical, Radiological, Histological Features AndDifferential Diagnosis Of Important Jaw Cysts.OVERVIEW
• A Cyst is a pathological cavity having fluid,semifluid or gaseous contents and which isnot created by the accumulation of pus.Most cysts, but not all, are lined byepithelium. (KRAMER 1974).DEFINATION OF CYST
• TRUE CYSTS: that which is lined byepithelium e.g dentigerous cyst, radicularcyst etc.• PSEUDO CYSTS: not lined by epithelium, e.g.Solitary bone cyst, Aneurismal bone cyst etcTYPES OF CYSTS
Cyst has following parts:• WALL (made of connectivetissue)• EPITHELIAL LINING• LUMEN OF CYSTPARTS OF A CYST
1. Dermoid and epidermoid cysts2. Lymphoepithelial (branchial) cyst3. Thyroglossal duct cyst4. Anterior median lingual cyst (intralingual cyst of foregut origin)5. Oral cysts with gastric or intestinal epithelium (oral alimentary tract cyst)6. Cystic hygroma7. Nasopharyngeal cyst8. Thymic cyst9. Cysts of the salivary glands: mucous extravasation cyst; mucous retention cyst;ranula; polycystic (dysgenetic) disease of the parotid10. Parasitic cysts: hydatid cyst; Cysticercus cellulosae; trichinosisIII. CYSTS OF THE SOFT TISSUES OF THEMOUTH, FACE AND NECK
TWO STAGES1. Cyst initiation2. Cyst enlargement or expansionPATHOGENESISa. Initiationb. Formationc. Enlargement
• Initiation results in the proliferation of the epithelial cells and theformation of small cavity.a. Cell Rests of Malassez :Remanants of Hertwigs epithelial root sheath in the PDL after theroot formation is completed.b. Reduced Enamel Epithelium :Residual epithelial cells surrounds the crown of the tooth afterenamel formation is complete.c. Cell Rests of Serres (Dental Lamina) :Islands of epithelial cells that originate from the oral epithelium andremain in the tissue after inducing tooth development.CYST INITIATION
1. Increase in the volume of its contents.2. Increase in the surface area of the sac or epithelialproliferation.3. Resorption of surrounding bones.MECHANISM REGARDINGENLARGEMENT
FACTORS1. Secretions:Mucus secreting cyst – Lining secretes mucus – accumulation of mucus – increase in volume2. Transudation & exudation: Inflammatory cyst or Presence of infection.a. Inflammatory cells release cofactorsb. Lymphocytes release lymphokinec. Osteoclast activating factor (OAF) &d. Monocytes release interleukin- I3. Increased osmolarity:a. Raises internal hydrostatic pressure.b. Attracts fluid into the cavity.c. Retention of fluid within the cavityINCREASE IN THE VOLUME
• Toller suggested the role of osmolarity by the cyst fluid inenlargement of cyst. The Mean Osmolarity was 296 mosmolcompared with Serum Osmolarity of 282 mosmol.• The increase in the osmotic pressure is related to proteinspresent in the cyst fluid such as large molecules of albumin,globulin, fibrinogen.• Desquamated epithelial cells of cyst lining undergo autolysis &produce a larger number of molecules of lower molecular weight,raising the osmolarity of the fluid.RAISED INTERNALHYDROSTATIC PRESSURE
• DIALYSIS :It results from the higher osmolarity of cyst fluid than serum.• OSMOTIC PRESSURE :It’s related to the number of dissolved particles in a solution.• OSMOLARITY :It’s the number of these dissolved particles.• Fluid is attracted into the cyst cavity by products of epithelial cellautolysis.• Water from the tissue fluid (surrounding tissue) is attracted into thecyst to raise the internal pressure.• This hydrostatic pressure is transmitted to the adjacent bone.ATTRACTION OF FLUID INTOTHE CAVITY
• Semi permeable membrane –governs access into the cyst prevents the escape of certainsubstances from the contents.• Attracted fluid are unable to diffuse out of the cavity.• The products of epithelial autolysis could effect both osmoticattraction and retention within the cavity.RETENTION OF FLUID WITHINTHE CAVITY
Mural growth1) Peripheral cell division2) Accumulated contents• Presence of low grade infection -- stimulate cells – cell rests ofMalassez – to proliferate and form arcades of epithelium.• Collagenase activity – increased collagenolysis – in primordial &radicular cyst.• Proliferation of local group of epithelial cells – as in keratocysts• Unremitting growth – epithelial lining in keratocysts due to high mitoticvalue.EPITHELIAL PROLIFERATION
• Increased internal pressure – transmitted to the adjacent bone –bone undergoes resorption – bony cavity enlarged.• Due to the above changes, the surface area of cyst lining isincreased by cell multiplication.• Epithelial cells divide – cyst enlarges within bony cavity by therelease of bone resorbing factors from the capsule.• Stimulate osteoclast function – eg: prostaglandins like PGE2 &PGI2.BONE RESORPTION
52.30%18.10%11.60%8%5.60%4.20% SHEAR 2006 Radicular cystDentigerous cystOdontogenic keratocystResidual cystParadental cystUnclassified odontogeniccystsFREQUENCY OF EPITHELIALCYSTS OF JAWS
• The dentigerous cyst is defined as a cyst that originatesby the separat ion of the follicle from around the crownof an unerupted tooth• The dentigerous cyst encloses the crown of anunerupted tooth and is attached to the tooth at thecementoenamel junction• The pathogenesis of this cyst is uncertain, butapparently it develops by accumulation of fluidbetween the reduced enamel epithelium and the toothcrown.
Gross specimen of a dentigerous cyst.Cyst encloses the crown of the tooth and is attached toits neckDENTIGEROUS CYST
AGE : 1st to 3rd decades.GENDER : more frequently in males than in females.SITE :• 2/3rd of follicular cyst associated with unerupted mandibularteeth, primarily III molar.• Maxillary canine• Mandibular premolar• Maxillary 3rd Molar• Supernumerary tooth also can be involvedCLINICAL FEATURES
• Most cysts grow to a large size before being discoveredaccidentally while observing a dental x ray to detectthe cause of an unerupted tooth.• Large lesions can cause cortical expansion, leading tofacial asymmetry, teeth displacement, rootresorption, even pain, if infected.SIGNS & SYMPTOMS
• Manifests as unilocular, well defined, ‘lucency withsclerotic margins, associated with crown of impacted /unerupted tooth.• A large DC may show persistence of boneytrabeculae, giving the appearance of multilocularity.RADIOLOGICAL FEATURES
• CENTRAL TYPE:• LATERAL TYPE :• CIRCUMFERENTIALTYPE :RADIOLOGICAL FEATURES
A central type of dentigerous cyst. Note resorption ofthe root of the first mandibular molarRADIOGRAPHIC FEATURES
Radiograph of two dentigerous cysts in the samepatient. The cyst on the right is a lateral type; that onthe left is a circumferential typeRADIOGRAPHIC FEATURES
CT scan of a maxillary dentigerous cyst extendingto, and impinging on, the floor of the nose.RADIOGRAPHIC FEATURES
HISTOLOGICAL FEATURESA. NON INFLAMMED TYPE:• Lining derived from reduced dental epithelium, consists of 2-4cell layers of non keratinized epithelium, without rete ridges.• Wall composed of thin fibrous connective tissue appearingimmature, as it is derived from the dental papilla.
NON INFLAMED dentigerous cyst shows a thin.nonkerat inized epithelial lining.NON INFLAMMED TYPE
HISTOLOGICAL FEATURESA. INFLAMED TYPE :• Lining shows varying degrees of hyperplasia with rete ridgesand occasionally even keratinization.• Wall is composed of mature connective tissue which showsinfiltration by chronic inflammatory cells.• Focal areas of mucous cells can be seen in the lining. Smallodontogenic epithelial islands can be seen in the wall.
INFLAMED DENTIGEROUS CYST shows a thickerepitheliallining with hyperplastic rete ridges. The fibrous cystcapsule shows a diffuse chronic inflammatory infiltrateINFLAMED TYPE
DIFFERENTIAL DIAGNOSISAlthough it presents a unique feature, yet some lesionsmust be considered in its differential diagnosis :1. Unicystic ameloblastoma2. Adenomatoid odontogenic tumor.
COMPLICATIONS1. Recurrence due to incomplete surgical removal.2. Development of ameloblastoma either from lining epitheliumor from odontogenic islands in the connective tissue wall.3. Development of squamous cell carcinoma from same twosources.4. Development of mucoepidermoid carcinoma from mucussecreting cells in the lining.
• The odontogenic keratocyst is a distinctive form of developmentalodontogenic cyst that deserves special consideration because of itsspecific histopathologic features and clinical behavior.• There is general agreement that the odontogenic keratocyst arisesfrom cell rests of the dental lamina.• This cyst shows a different growt h mechanism and biologic behaviorfrom themore common dentigerous cyst and radicular cyst.• odontogenic kerato cysts. and th eir growth may be related tounknown facto rs inherent in the epit helium itself or enzym aticactivity in the fibrous wall.• Several investigators suggest that odontogenic keratocysts beregarded as benign cystic neoplasms rather than cysts
AGE : occur over a wide age range and cases have beenrecorded as early as the first decade and as late asthe ninth.In most series there has been a pronounced peakfrequency in the second and third decades.GENDER : more frequently in males than in females.SITE : The mandible is involved far more frequently thanthe maxilla50% cases occur in angle region and extend toascending ramus and forwards to body ofmandible.CLINICAL FEATURES
Relative distribution ofodontogenic keratocysts in the jaws.SITE DISTRIBUTION
• Pain, swelling or discharge.• Occasionally, paraesthesia of the lower lip or teeth.• Some are unaware of the lesions until they developpathological fractures.• In many instances, patients are remarkably free ofsymptoms until the cysts have reached a large size, involvingthe maxillary sinus and the entire ascendingramus, including the condylar and coronoid processes.• occurs because the OKC tends to extend in the medullarycavity and clinically observable expansion of the boneoccurs late.CLINICAL FEATURES
• OKC demonstrate a well-defined radiolucent area withsmooth and often corticated margins.• Large lesions, particularly in the posterior body andascending ramus of the mandible, may appear multilocular• An unerupted tooth is involved in the lesion in 25% to 40%of cases; in such instances, the radiographic featuressuggest the diagnosis of dentigerous cystRADIOGRAPHIC FEATURES
Radiograph of a small odontogenic keratocyst.RADIOGRAPHIC FEATURES
Radiograph of an odontogenic keratocyst with scallopedmargins.RADIOGRAPHIC FEATURES
Radiograph of a multilocular odontogenic keratocyst.RADIOGRAPHIC FEATURES
Radiograph of an odontogenic keratocyst that hasenveloped an unerupted tooth to produce a‘dentigerous’ appearance.RADIOGRAPHIC FEATURES
• The epithelial lin ing is composed of a uniform layer of stratifiedsquamous epithelium,usually six to eight cells in thickness.• The epithelium and connective tissue interface is usually flat, andrete ridge formation is inconspicuous.• The basal cell layer has columnar / cuboidal cells with reverselypolarized nuclei, imparting a “picket fence” or “tombstone”appearance.• The luminal surface shows flattened parakeratotic epithelialcells, which exhibit a wavy or corrugated appearance.• Small satellite cysts, cords, or islands of odontogenic epitheliummay be seen within the fibrous wall .HISTOLOGIC FEATURES
Epithelial lining is 6 to 8 cells thick, with a hyperchromatic andpalisaded basal cell layer. Note the corrugated parakeratoticsurface.OKC
Satellite microcysts in the wall of an odontogenic keratocyst thatappear to be arising directly from an active dental lamina.SATELLITE MICROCYSTS
DIFFERENTIAL DIAGNOSIS• In case of unilocular ‘lucencies – Dentigerous cyst, Eruptioncyst, COC, AOT, Unicystic ameloblastoma etc.• In case of multilocular ‘lucencies – Conventionalameloblastoma, CEOT, Central giant cellgranuloma, Aneurysmal bone cyst etc.
• COMPLICATIONS IN OKC :1. Malignant transformation of cyst lining rare, but has beenreported.2. Recurrence – high rate of recurrence.• REASONS FOR RECURRENCE :1. Thin, fragile lining is very difficult to remove completely.2. New cysts develop from satellite cysts left behind.3. Some cysts may be left behind in cases of Gorlin – Gotzsyndrome.4. New cysts can also develop from basal cells of overlying oralepithelium, especially in ramus – 3rd molar region.
• Typical c/f of an eruption cyst. Note abluish colored, dome shaped swellingover the unerupted molar.• The dentigerous cyst develops aroundthe crown of an unerupted toothlying in the bone,• The eruption cyst occurs when atooth is impeded in its eruptionwithin the soft tissues overlying thebone.ERUPTION CYSTEruption cysts involving the maxillary permanentincisors.
The circumscribed cavity contains blood (dueto surface trauma on biting with oppositetooth )It imparts purple / deep blue colorHence known as• ERUPTION HEMATOMAPATHOGENESIS
CLINICAL FEATURESAGE : found in children of different ages, and occasionallyin adults if there is delayed eruptionSITE : most commonly associated with the first permanentmolars and the maxillary incisors
RADIOLOGICAL FEATURES• The cyst may throw a soft-tissue shadow, but there isusually no bone involvement except that the dilated andopen crypt may be seen on the radiograph.
• Show surface oral epithelium on thesuperior aspect. The underlyinglamina propria shows a variableinflammatory cell infiltrate.• The deep portion of thespecimen, which represents the roofof the cyst, shows a thin layer atnonkeratinizing squamous epitheliumHISTOLOGICAL FEATURESA cystic epithelial cavity can be seen belowthe mucosal surface.
PATHOGENESIS• A number of suggestions have been made aboutthepathogenesis of the gingival cyst in adults.• It was originallyproposed that they may arise fromodontogenicepithelial cell rests; or by traumaticimplantation ofsurface epithelium; or by cysticdegeneration of deep projectionsof surfaceepithelium
ORIGIN• Cystic transformation of dental lamina, traumaticimplantation of surface epi• Dome shaped soft, fluctuant swelling which is <1cm indiameter• Lesion is slow growing and painless• Adjacent teeth usually vital
Signs and symptoms:• Slowly enlarging, wellcircumscribed painless swelling.• Invariably occurs on facialaspect of free / attachedgingiva.• Surface of lesion is smooth andof normal color.• Fluctuant lesion, adjacent teethare vitalCLINICAL FEATURESClinical photograph of a gingival cyst of an adultAGE : 5th – 6th decade of lifeSITE : mand. canine and Pre Molararea; attached gingiva or I/D papilla
Radiograph of a gingival cyst in an adult. There is a faintradiographic shadow (marked with arrows) indicative of superficialbone erosion.RADIOLOGICAL FEATURES
• H/p features identical to Lateralperiodontal cyst.• Some cysts lined bythin, flattened stratifiedsquamous epithelium.• Sometimes, focal thickenings(Plaques) may be found withinthe lining.HISTOLOGYThe epithelial lining of a gingival cyst ofthe adult (G) lying contiguous to thejunctional epithelium (J) of an adjacenttooth.
• Uncommon, but well recognized type of odontogenic cyst.• The designation ‘lateral periodontal cyst’ is confined to thosecysts that occur in the lateral periodontal position and in whichan inflammatory etiology and a diagnosis of collateral OKC havebeen excluded on clinical and histological grounds(Shear and Pindborg, 1975).LATERAL PERIODONTAL CYST
• Age : 20 – 60 years, peak in 6th decade.• Sex : Male predilection.• Site : Lateral PDL regions of mandibular premolars,followed by anterior maxillaCLINICAL FEATURES
• Usually asymptomatic as it occurs on the lateral aspect ofroot of tooth.• Occasionally pain and swelling may occur.• Associated teeth are vital, unless otherwise affected.• Cysts rarely < 1cm in size, except for BOTRYOID VARIETYwhich is larger and also a multilocular lesion.SIGNS & SYMPTOMS
• Round to ovoid ‘lucency withsclerotic margins.• Cyst can be presentanywhere between cervicalmargin to root apex.• Radiographically, it can beconfused with collateral OKC.RADIOLOGICAL FEATURESRadiograph of a lateral periodontal cyst lying between themandibular premolar teeth. The margins are wellcorticated, indicative of slow enlargement.
RADIOLOGICAL FEATURESLateral periodontal cyst. Radiolucent lesionbetween the roots of a vital mandibular canine andfirst premolar.Lateral periodontal cyst. A larger lesion causingroot divergence.
• The lateral periodontal cysts were lined by a thin, non-keratinising layerof squamous or cuboidal epithelium usually ranging from 1 to 5 celllayers wide, which resembled the reduced enamel epithelium• The epithelial cells were sometimes separated by intercellular fluid.Their nuclei were small and pyknotic.• An interesting feature seen in many of the lateral periodontal cysts wasthe presence of what appear to be localised plaques or thickenings ofthe epithelial lining• Small epithelial nests may be seen in connective tissue wall, which mayshow signs of mild inflammation.HISTOLOGICAL FEATURES
HISTOLOGICAL FEATURESLateral periodontal cyst which in part has a thin, nonkeratinisedstratified squamous epithelial lining resembling reduced enamelepithelium. Two epithelial plaques are seen. The one on the right isconvoluted
Diagram illustrating the possible mode of formation of epithelial plaques by localised proliferation of cells.(a) Cyst lined by thin epithelium resembling reduced enamel epithelium. (b) Early epithelial thickening by basal cellproliferation. (c) Basal cells continue to proliferate. Superficial cells swell by accumulation of intracellular fluid. (d) and (e)Basal proliferation ceases or slows down. Superficial cells are waterlogged and swollen. Plaque protrudes into cyst cavityand cyst wall where it can undermine and raise adjacent cyst lining. (f) Epithelial plaque can form convolutions. Protrusionsinto cyst wall as in (c–f) may be ‘pinched off’ and develop into daughter cysts, leading to the formation of the botryoidvariety of lateral periodontal cyst.
• Also called as Odontogenic ghost cell cyst or Gorlin cyst.• It Has many features of odontogenic tumor, therefore it isplaced in the category of tumors in the latest WHOclassification of odontogenic cysts and tumors.• In the latest WHO publication on odontogenic tumours(Prætorius and Ledesma-Montes, 2005) it was classified as abenign odontogenic tumour and was renamed calcifyingcystic odontogenic tumour (CCOT).CALCIFYING ODONTOGENICCYST
• Age : Wide range, peak in 2nd decade.• Sex : Equal.• Site : Anterior segment of both jawsCLINICAL FEATURES
• COC is a unicystic process and develops from thereduced dental epithelium or remnants of dentallamina.• The cyst lining has the potential to induceformation of dentinoid or even odontoma inadjacent CT wall.PATHOGENESIS
• Group 1 : ‘Simple’ cysts Calcifying odontogenic cyst (COC)• Group 2 : Cysts associated with odontogenic hamartomas or benignneoplasms: calcifying cystic odontogenic tumours (CCOT).• Group 3 : Solid benign odontogenic neoplasms with similar cellmorphology to that in the COC, and with dentinoid Formation• Group 4 : Malignant odontogenic neoplasms with features similar tothose of the dentinogenic ghost cell tumour Ghost cellodontogenic carcinomaCLASSIFICATION OF THE ODONTOGENIC GHOSTCELL LESIONS
• Swelling is the commonest complaint, seldomassociated with pain.• Intraosseous lesions can cause hard bony expansionand resulting facial asymmetry.• Displacement of teeth can also occur.SIGNS & SYMPTOMS
• Intraosseous lesions producewell defined lucency whichis usually unilocular.• Irregular calcified masses ofvarying sizes may be seenwithin the lucency.• Displacement of root/rootswith or without rootresorption and expansion ofcortical plates also seenRADIOLOGICAL FEATURESRadiograph of a calcifying odontogenic cyst of the maxilla.There is a well-demarcated margin and calcificationssuggestive of tooth material.
Radiograph of a calcifying odontogenic cyst with well-demarcatedmargins extending from the right to the left premolar regions of themandible. Numerous calcifications are present, some suggestive ofsmall denticles.RADIOLOGICAL FEATURES
• Lining is usually thin about 6 – 8 cell thick, may be thickened in otherareas.• Lining shows characteristic odontogenic features with reverselypolarized basal cell layer.• TYPICALLY – GHOST CELLS may be seen in thicker areas of lining.• Ghost cells are enlarged, ballooned, ovoid, eosinophilic cells with welldefined cell boundaries.• Some times many cells may fuse.• They represent abnormal keratinization and frequently calcify.• Tubular dentinoid and even complex odontome may be found inconnective tissue wall close to epithelial lining.HISTOLOGICAL FEATURES
Histological features of a calcifying odontogenic cyst with clustersof fusiform ghost cells and focal calcifications, lying in a stratifiedsquamous epithelium.HISTOLOGICAL FEATURES
In this calcifying odontogenic cyst, there are sheets of ghost cellsand a focal area in which there has been induction of a strip ofdysplastic dentine (dentinoid).HISTOLOGICAL FEATURES
• Based on radiographic appearance, followinglesions must be included in the provisionaldiagnosis –• Ameloblastoma• CEOT• AOT• Ameloblastic fibro odontomaDIFFERENTIAL DIAGNOSIS
• Also classified as “FISSURAL CYSTS”.• Believed to be derived from epithelial remnants includedduring closure of embryonic facial processes.• Controversy – actual “closure” of embryonic processes doesnot occur. Grooves between processes is smoothed byproliferation of underlying mesenchyme.• Usually occurs within the nasopalatine canal or in soft tissueof palate at the opening of canal.NASOPALATINE DUCT(INCISIVE CANAL) CYST
• Age : 4th, 5th & 6th decades.• Sex : More in females• Frequency: Commonest non odontogenicdevelopmental cystCLINICAL FEATURES
• In lower animals, the NP duct concerned with olfactorysensation – in humans only vestigial remnants persist inincisive canal in form of epithelial islands, ducts, cords etc.• These nests can show central degenration to form cysts.Etiology for cyst transformation is yet unclear.• Some believe, it may arise spontaneously like an OKC.PATHOGENESIS
• Commonest symptom isswelling, usually in anteriorregion of mid palate.• Swelling can also occur inmidline on labial aspect ofalveolar ridge.• If pressure on NP nerves – pain• Exclude possibility of periapicalcyst by testing vitality ofincisors.SIGNS & SYMPTOMS
NASOPALATINE DUCT(INCISIVE CANAL) CYSTSmall nasopalatine cyst presenting as a soft ovoidswelling in the midline of the maxilla, posterior tothe central incisor teeth.Large nasopalatine duct cyst extending laterally andposteriorly to involve much of the hard palate.
• Seen as lucency usually in incisivecanal – DIFFICULT TODISTINGUISH FROM A NATURALLYLARGE INCISIVE CANAL.• Lucency with AP dimension upto10 mm considered as enlargedincisive canal, but if lucency < 14mm, then NP duct cyst.• The lucency appears well definedwith sclerotic borders, in midlineof palate between roots ofincisors.RADIOLOGICAL FEATURES
Radiograph of a nasopalatine duct cyst showing a pear-shaped radiolucency in the anterior maxilla. The laminadura on the left is intact although the apex appears to bein the cyst.RADIOLOGICAL FEATURES
Shows a large round radiolucency. The roots of themaxillary incisor teeth are displaced laterally.RADIOLOGICAL FEATURES
• Lining epithelium extremelyvariable, consisting of stratifiedsquamous, pseudo stratifiedcolumnar, simple columnar orcuboidal epithelium.• Most commonly lining isstratified squamous followed bypseudo stratified columnar.• A useful diagnostic aid –presence of large nerve andvascular bundles in connectivetissue wall.HISTOLOGICAL FEATURES
HISTOLOGICAL FEATURESNeurovascular bundle in the wall of anasopalatineduct cyst.
• Radicular cyst, if it is associated with a pulpallyinvolved tooth.• Large incisive canal.DIFFERENTIAL DIAGNOSIS
• The nasolabial cyst occurs outside the bone in thenasolabial folds below the alae nasi.• It is traditionally regarded as a jaw cyst althoughstrictly speaking it should be classified as a softtissue cyst.NASOLABIAL CYST
• Age : Peak incidence in 4th & 5th decades.• Sex : More in females.• Frequency: Rare in occurrence.CLINICAL FEATURES
• Commonest complaint – slowlygrowing swelling andoccasionally, pain and difficultyin nasal breathing.• Extra orally – filling out ofnasolabial fold and may lift alanasi.• Intra orally – bulge in labialsulcus.• Fluctuant lesion.SIGNS & SYMPTOMSNasolabial cyst producing a swelling of the rightupper lip, forming a bulge in the labial sulcus.
• Believed to develop from lower anterior portion of nasolacrimalduct.• When margins of lateral and maxillary processes fuse, ectodermalong boundary between them gives rise to solid cellular rod whichfirst develops as a linear surface elevation (Nasolacrimal ridge) andthen sinks into underlying mesenchyme.• This solid rod canalizes to form NL duct.• The NL cysts are located such that it is possible that they developfrom embryonic remnants of NL duct.• Importantly, a mature NL duct is lined by pseudo stratified columnarepithelium, which is also the lining of NL cyst.PATHOGENESIS
• Difficult to interpret onradiograph.• May be seen as localizedincreased lucency of alveolarprocess above apices of incisors.• Lucency results from pressureresorption on labial surface ofmaxilla.RADIOLOGICAL FEATURESStandard occlusal radiograph of a patient with a nasolabialcyst. There is a posterior convexity of the left half of theradiopaque line that forms the bony border of the nasalaperture.
• Cyst lined by non ciliatedpseudo stratified columnarepithelium.• Goblet cells also seen in somecases.• Occasionally, part of lining maybe cuboidal / flat squamous.• Conncetive tissue wall isfibrous, relatively acellular withfibers arranged loosely orcompactly.HISTOLOGICAL FEATURESNasolabial cyst lined by a pseudostratifiedcolumnar epithelium containing many goblet cells.In the example illustrated here, mucous glands arepresent in the wall.
• Also called APICAL PERIODONTAL CYST• Radicular cysts are the most common inflammatory cystsand arise from the epithelial residues in the periodontalligament as a result of periapical periodontitis followingdeath and necrosis of the pulp.• Quite often a radicular cyst remains behind in the jaws afterremoval of the offending tooth and this is referred to as aresidual cyst.RADICULAR CYST
1. PHASE OF INITIATION:• Accepted generally that rests of Malassez included within adeveloping periapical granuloma proliferates to form the liningof radicular cyst.• How these cells are stimulated is not clear.• Some product of non vital pulp can be responsible whichsimultaneously evokes an inflammatory response in CT.• Immune factors also held responsible as plenty of plasma cellsare seen in a periapical granuloma.PATHOGENESIS
2. PHASE OF CYST FORMATION:• Can occur in two possible ways.• One theory states that epithelium proliferates and coversthe bare connective tissue surface of the abscess cavity.• Another theory – cyst cavity forms within proliferatingepithelium as the cells in center move away from theirnutrient source.PATHOGENESIS
3. PHASE OF ENLARGEMENT:• Enlargement occurs by collection of fluid withinthe lumen of the cyst.• Osmosis plays an important role here as the cystwall appears to have the properties of a semipermeable membrane.PATHOGENESIS
• Age : peak in 3rd, 4th and 5th decades.• Sex : Slightly more in males.• Site : Maxillary anterior region.• Frequency: Commonest cystic lesion of jaws.CLINICAL FEATURES
• Primarily symptom less.• Discovered accidentally during routine dental X rayexam.• Slowly enlarging hard bony swelling initially. Later, ifcysts breaks through cortical plates, lesion becomesfluctuant.• Diagnostic criteria – associated teeth are non vital• Rare in deciduous teeth.SIGNS & SYMPTOMS
• Classically presents asround / ovoid lucency withsclerotic borders andassociated with pulpallyaffected tooth / teeth.• If infection supervenes, themargins becomeindistinct, making itimpossible to distinguish itfrom a peripaicalgranuloma.RADIOLOGICAL FEATURESRadiograph of a radicular cyst. The lesion is a welldefined radiolucency associated with the apex of a non-vital root filled tooth.
• Lined partly / completely by non keratinized epithelium ofvarying thickness.• Epithelium usually shows arcading around the connectivetissue.• The connective tissue wall shows inflammatory infiltratemainly in the form of lymphocytes and plasma cells.• Hyaline / Rushton bodies are found in epithelium and rarelyin connective tissue wall.• These are curved or linear structure with eosinophilicstaining propertiesHISTOLOGICAL FEATURES
• Cholesterol crystals in from of clefts are often seen in theconnective tissue wall, inciting a foreign body giant cellreaction.• Originate from disintegrating RBC’s in presence ofinflammation.• Different types of dystrophic calcification are also seen inconnective tissue wall.• Mucus cell metaplasia as well as respiratory cells may be seenin the epithelial lining.• Keratinization if found is due to metaplasia and must not beconfused with an OKC.HISTOLOGICAL FEATURES
HISTOLOGICAL FEATURESQuiescent epithelium lining a mature, long-standingradicular cyst (H & E).Mucous cells in the surface layer of the stratifiedsquamous epithelial lining of a radicular cyst (H & E).
HISTOLOGICAL FEATURESHyaline bodies in the epithelial lining of a radicularcyst (H & E).Mural nodule of cholesterol-containing granulationtissue fungating into the cavity of a radicular cyst(H & E).
Radiographic appearance of a large residualcyst left behind after extraction of 1stmandibular molar.• The histopathological features of theresidual cyst are similar to thosedescribed above for conventionalradicular cysts. However, becausethe cause of the cyst has beenremoved, residual cysts mayprogressively become less inflamedso that eventually the cyst wall iscomposed of uninflamed• The epithelial lining may be thin andregular and indistinguishable from adevelopmental cyst such as adentigerous cyst or lateralperiodontal cyst. collagenous fibroustissue.RESIDUAL CYSTS
Following lesions must be distinguished from other periapicalradiolucencies–1. Periapical granuloma2. Peripaical cemento – osseous dysplasia (early lesions)DIFFERENTIAL DIAGNOSIS:
• A cyst of inflammatory origin-occurring on lateral aspect of rootof partially erupted mandibular3rd molar with an associatedhistory of pericoronitis• Age : 20-40 years• Tooth is vital• Facial swelling• Facial sinus in some casesPARADENTAL CYSTS
• Affected tooth is tilted Welldemarcated RadioLucency Distalto partially erupted tooth• Lamina Dura is intact• New bone may be laid downRADIOGRAPHIC FEATURES(a,b) Two cases of bilateral paradental cysts associated with eruptingmandibular third molar teeth. The cysts are distal and buccal to theinvolved teeth. Note that the periodontal ligament space is not widenedand that the distal part of the cyst is separate from the distinct distalfollicular space.
• The cysts are lined by ahyperplastic, non-keratinised, stratified squamousepithelium which may be spongioticand of varying thickness.• An intense inflammatory cellinfiltrate was present associatedwith the hyperplastic epitheliumand in the adjacent• fibrous capsule is the seat of anintense chronic or mixedinflammatory cell infiltrate. fibrouscapsuleHISTOLOGICAL FEATURESParadental cyst adjacent to the root of an impactedmandibular third molar. The cyst is lined by non-keratinisedstratified squamous epithelium of variable thickness andshowing areas of proliferation (H & E).
• Uncommon cyst, found mostly in long bones and spine.• CLINICAL FEATURES: -1. Age : First 3 decades.2. Sex : Mainly females.3. Site : molar regions of mandible & maxilla.• Signs & symptoms:Hard, rapidly growing swelling which can cause malocclusion.If lesion perforates cortical plates, can cause “egg shellcrackling”.ANEURYSMAL BONE CYST
• Controversy whether lesion arises de novo or froma vascular disturbance in the form of suddenvenous occlusion or development of an AV shuntoccurring secondarily in a pre existing lesion likecentral giant cell granuloma, Osteosarcoma etc.• Due to the malformation, change in hemodynamicforces occurs which can lead to ABC.PATHOGENESIS
• Classically seen as a unilocular, ovoid / fusiform lucencywhich balloons the cortical plates.• Teeth displacement and root resorption also observed.• Lesions are usually unilocular but longer-standing lesionsmay show a ‘soap-bubble’ appearance and may becomeprogressively calcifiedRADIOLOGICAL FEATURES
Radiograph of an aneurysmal bone cyst involving the angle andascending ramus of the mandible. There is a ballooning expansionof the cortex.
• It consist of many capillaries and blood-filled spaces of varying size lined byflat spindle cells and separated by delicate loose-textured fibrous tissue• Most lesions contain small multinucleate cells and scattered trabeculae ofosteoid and woven bone.• In some of the solid areas, sheets of vascular tissue, containing largenumbers of multinucleate giant cells, fibroblasts, haemorrhage andhaemosiderin, look very much like giant cell granuloma of the jaws• The diagnosis is made primarily on the basis of the clinical and radiologicalfeatures because histologically such solid lesions may be indistinguishablefrom giant cell granuloma.HISTOLOGICAL FEATURES
HISTOLOGICAL FEATURESAneurysmal bone cyst in which the solid areas havehistological features identical to those of the centralgiant cell granuloma of the jaws (H & E).Aneurysmal bone cyst of the mandible. The solidareas show the features of cemento-ossifyingfibroma and a portion of one of the many cysticspaces is present at the top of the photomicrograph(H & E).
• Conventional ameloblastoma• CEOT• Central giant cell granulomaDIFFERENTIAL DIAGNOSIS
• Also called as Hemorrhagic bone cyst, or Traumaticbone cyst.• Commonly seen in mandible, rare in maxilla.• Identical to solitary bone cyst of humerus inchildren and adolescents.SOLITARY BONE CYST
• Age : Young individuals• Sex : Equal• Site : Body and symphysismenti of mandible.CLINICAL FEATURES
• None of the theories are certain about exact cause.• First theory – cyst may follow trauma to bone which causesintra medullary hemorrhage which fails to organize. This clotsubsequently liquefies - CYST.• Recent theory osteogenic cells fail to differentiate locallyand thus instead of bone, the undifferentiated cells formsynovial tissue.PATHOGENESIS
• Asymptomatic.• Rarely, swelling and pain may be seen.• Half of all patients give a history of trauma to thearea.SIGNS & SYMPTOMS
• Appears as a lucency withirregular but well definededges and slightcortication.• On occlusal view the‘lucency is seen to extendalong cancellous bone.RADIOLOGICAL FEATURESRadiograph of a solitary bone cyst involving anextensive area in the right body of the mandible. Thisexample has a well-defined margin with cortication.Interradicular scalloping is a prominent feature.
• Lumen not lined by anyepithelium (Pseudo cyst).• Wall shows loose fibro vascularconnective tissue.• Hemorrhage and hemosiderinpigment usually present.• Multinucleated giant cellsscattered within the connectivetissue.• Adjacent bone showsosteoclastic resorption on innersurface.HISTOLOGICAL FEATURESA solitary bone cyst of the jaw. The lining iscomposed of loose vascular fibrous tissue withosteoclastic activity on the surface of the adjacentbone (H & E).
REASONS• Cysts tend to increase in size.• Cysts tend to get infected.• Cysts weaken the jaw. ( pathological fracture)• Some cysts undergo changes. Eg:Ameloblastoma, Mucoepidermoid carcinoma ( histological studyto be done)• Cysts prevent eruption of teeth. (dentigerous cyst)• Involvement of neighboring structures.( maxillarysinus, nose, adjacent tooth)PRINCIPLES OF TREATMENT
1. To remove the lining totally or to remove a part of lining toenable the body to rearrange the position of abnormaltissue so that it is eliminated from within the jaws.2. To preserve important adjacent structures such as nervesand healthy tissues.3. To achieve rapid healing of the operation site.4. To restore the part to a near normal form and to restorenormal function.1. AIMS OF TREATMENT
1. Marsupialization (Partch 1 Operation) (Cystotomy)Combined Decompression & enucleationMarupialization through nose or antrum2) Enucleation (Partch 2 Operation) (Cystectomy))a) Enucleation & packingb) Enucleation & primary closurec) Enucleation & primary closure with reconstruction / bone graftingTREATMENT
VARIOUS ASPIRATESPATHOLOGY ASPIRATE Other Findings of AspiratesDentigerous Cyst Clear, pale straw colourfluidCholesterol crystals.Total protein in excess4 g / 100ml. Resembles serumOdontogenic Keratocyst Dirty, creamy whiteviscoid suspensionPara keratinized squames.Total protein less than4 g /100ml. Mostly albuminPeriodontal Cyst Clear, pale yellow strawcolour fluidCholesterol crystals.Total protein 5 — 11g / 100mlInfected Cyst Pus, brownish fluid Polymorphonuclear leukocytes,,Cholesterol cleftsMucocele, Ranula Mucus -----Gingival Cysts Clear fluid -----
VARIOUS ASPIRATESPATHOLOGY ASPIRATE Other Findings ofAspiratesSolitary Bone Cyst Serous fluid, blood orempty cavityNecrotic blood clotStafne’s Bone Cyst Empty cavity – yield air ---Dermoid Cyst Thick sebaceous material ---Fissural Cyst Mucoid fluid ----
Cysts of the jaws are treated in one of the following four basic methods:(1) Enucleation,(2) Marsupialization,(3) A staged combination of the two procedures, and(4) Enucleation with curettage.TREATMENT
• Enucleation is the process by which the total removal of a cystic lesionis achieved.• By definition, it means a shelling- out of the entire cystic lesion withoutrupture.• Enucleation of cysts should be performed with care, in an attempt toremove the cyst in one piece without frag-mentation, which reducesthe chances of recurrence by increasing the likelihood of total removal.• However, maintenance of the cystic architecture is not alwayspossible, and rupture of the cystic contents may occur duringmanipulation.1. ENUCLEATION
Indications :• Enucleation is the treatment of choiceAdvantages :• pathologic examination of the entire cyst can be undertaken• the initial excisional biopsy (i.e., enucleation) has also appropriately treatedthe lesion.• The patient does not have to care for a marsupial cavity with constantirrigations.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.ENUCLEATION
TECHNIQUE :• Aspiration Biopsy of Radiolucent Lesions• Mucoperiosteal Flaps• Osseous Window• Removal of SpecimenENUCLEATION
Aspiration Biopsy of Radiolucent Lesions :• Any radiolucent lesion should be aspirated before surgical exploration.• This provides the dentist with valuable diagnostic information regardingthe nature of the lesionMucoperiosteal Flaps :• Several varieties of mucoperiosteal flaps are available; the choicedepends chiefly on the size and location of the lesion.• Access may necessitate extension of the irmcoperiosteal flap. Thelocation of the lesion dictates where the flap incisions are to be made.• the flap design should provide 4 to 5 mm of sound bone around theanticipated surgical margins• mucoperiosteal flaps for biopsies in or on the jaws she be full thicknessand incised through mucosa, submucosa, and periosteumENUCLEATION
Osseous Window :• once the flap has been elevated, a rotating bur should be used toremove an osseous window• The size of the window depends on the size of the lesion and theproximity of the window to normal anatomic structures such as rootsand neurovascular bundles.ENUCLEATION
Technique :• A dental curette is used to peel the connective tissues wall of thespecimen from surrounding bone.• The concave surface of the instrument should always be kept in contactwith the osseous surfaces of the bone cavity• The bony cavity is inspected after irrigation with sterile saline• Any residual fragments of soft tissue within the cavity should beremoved with curettes.• Once the cavity is devoid of residual pathologic tissue, it is irrigated andthe flap is replaced and sutured in its proper location.ENUCLEATION
• Marsupialization, decompression, and the Partsch operation all refer tocreating a surgical window in the wall of the cyst, evacuating thecontents of the cyst, and maintaining continuity between the cyst andthe oral cavity, maxillary sinus, or nasal cavity.• The only portion of the cyst that is removed is the piece removed toproduce the window. The remaining cystic lining is left in situ.• This process decreases intracystic pressure and promotes shrinkage ofthe cyst and bone fill. Marsupialtzatron can be used as the sole therapyfor a cyst or as a preliminary step in management, with enucleationdeferred until later.2. MARSUPIAIIZATION
1. Amount of tissue injury : Proximity of a cyst to vital structures can meanunnecessary sacrifice of tissue if enucleation is used.2. Surgical access : If access to all portions of the cyst is difficult, portions of thecystic wall may be left behind, which could result in recurrence.3. Assistance in eruption of teeth : If an unerupted tooth that is needed in thedental arch is involved with the cyst (i.e., a dentigerous cyst), marsupializationmay allow its continued eruption into the oral cavity4. Extent of surgery : Marsupialization is a reasonable alternative toenucleation, because it is simple and may be less stressful for the patient5. Size of cyst : In very large cysts, a risk of jaw fracture during enucleation ispossible. It may be better to marsupialize the cyst and defer enucleation untilafter considerable bone fill has occurred.INDICATION
Advantages :• It is a simple procedure to perform. Marsupiaiization also spare vitalstructures from damage should immediate enucleation be attempted.Disadvantages :• Pathologic tissue is left in situ, without thorough histologicexamination.• Patient is inconvenienced in several respects• The cystic cavity must be kept clean to prevent infection, because thecavity frequently traps food debris.• In most instances this means that the patient must irrigate the cavityseveral times every day with a syringeMARSUPIAIIZATION
1) Anaesthesia2) Aspiration3) IncisionCircular, oval or elliptic. Inverted U shaped incision with broad baseto the buccal sulcus. Mucoperioteum is reflected in this case.4) Removal of bone5) Removal of cystic lining specimen6) Visual examination of residual cystic lining7) Irrigation of cystic cavity8) SuturingCystic lining sutured with the edge of oral mucosa.In U shaped incision the mucoperiosteal flap can be turned into cysticcavity covering the margin. The remaining is sutured to oral mucosa.TECHNIQUE OF MARSUPIAIIZATION
9) Packing-- Prevents food contamination & covers wound margins.Done with ribbon gauze soaked with WHITEHEAD VARNISH.COMPOSTION:Benzoin – 10gIodoform – 10gStorax - 7.5gBalsam of Tolu – 5gSolvent ether to 100mlPack removed after 2 weeks.10) Maintenance of cystic cavityInstruct the patient to clean and irrigate the cavity regularly with oralantiseptic rinse with a disposable syringe.CONTINUE…
11) Use of plugPrevents contamination. Preserves patency of cyst orifice.Plug should be stable, retentive and safe design.Should be made of resilient material ( avoid irritation) like acrylic.12) HealingCavity may or may not obliterate totally. Depression remains in thealveolar process.CONTINUE…
3. ENUCLEATION AFTERMARSUPIALIZATIONINDICATIONS• 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 morbidityDISADVANTAGES• Patient has under go second surgery and any possible complicattonassociated with surgery.
4. ENUCLEATION WITHCURETTAGE• Enucleation with curettage means that after enucleation a curette orbur is used to remove 1 to 2 mm of bone around the entire periphery ofthe cystic cavity• Any remaining epithelial cells that may be present in the periphery ofthe 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 curettageshould be used.• Daughter, or satellite, cysts found in the periphery of the main cysticlesion may be incompletely removed• The second instance in which enucleation with curettage is indicated iswith any cyst that recurs after what was deemed a thorough removal.Advantages :• If enucleation leaves epithelial remnants, curettage may removethem, thereby decreasing the likelihood of recurrence.ENUCLEATION WITHCURETTAGE
Disadvantages :• Curettage is more destructive of adjacent bone and other tissues• The dental pulps may be stripped of their neurovascular supply whencurettage is performed close to the root tips• Adjacent neurovascular bundles can be similarly damagedENUCLEATION WITHCURETTAGE