CYSTS OF THE JAWSdrg. SHANTY CHAIRANI, M. Si.

Definition A cyst is a pathologic cavity lled with uid, lined by epithelium, and surrounded by a denite connective tissue wall. The cystic uid either is secreted by the cells lining the cavity or derives from the surrounding tissue uid.

Classification Of The Main Cysts in the Jaw

Odontogenic cystsNon odontogenic cystCyst-like lesionsRadicular (dental) cystNasopalatine duct / incisive canal cystAneurysmal bone cystResidual radicular cystNasolabial cystSimple bone cystLateral periodontal cystStafnes bone cystDentigerous cystOdontogenic keratocyst (keratocystic odontogenic tumour)Glandular odontogenic cyst

Buccal bifurcation cyst Calcifying epithelial odontogenic cyst

Odontogenic cystis a developmental cysts arising in any cellular component of the enamel organ. It is make up approximately 90% of jaw cysts.Nonodontogenic cyst is a developmental cyst that arise from epithelial rests in lines of fusion between embryologic processes or that are remnants of embryologic oral or perioral structures. This account for some 6% of the cysts found in the jaws.The developmental of a cyst may be stimulated by inflammatory, developmental, traumatic or neoplastic causes.

Clinical Features Cysts occur more often in the jaws originate from the numerous rests of odontogenic epithelium that remain after tooth formation. The prevalent clinical features :are SwellingLack of pain (unless the cyst becomes secondarily infected or is related to a nonvital tooth)Association with unerupted teeth, especially third molars.

Radiographic FeaturesLocation Cysts may occur centrally (within bone) in any location in the maxilla or mandible but are rare in the condyle and coronoid process. Odontogenic cysts are found most often in the tooth-bearing region. In the mandible, they originate above the inferior alveolar nerve canal. A few cysts arise in the soft tissues of the orofacial region.

Radiographic FeaturesPeriphery Usually well dened and corticated (characterized by a fairly uniform, thin, radiopaque line). A secondary infection or a chronic state can change this appearance into a thicker, more sclerotic boundary or make the cortex less apparent.

Radiographic FeaturesPeriphery Usually well dened and corticated (characterized by a fairly uniform, thin, radiopaque line). A secondary infection or a chronic state can change this appearance into a thicker, more sclerotic boundary or make the cortex less apparent.

ShapeUsually are round or oval, resembling a uid-lled balloon. Some cysts may have a scalloped boundary.

Radiographic FeaturesInternal structureCysts often are totally radiolucent. Some cysts have septa, which produce multiple loculations separated by these bony walls or septa. Cysts that have a scalloped periphery may appear to have internal septa.

Radiographic FeaturesEffect on surrounding structureCysts grow slowly, sometimes causing displacement and resorption of teeth. Can expand the mandible, usually in a smooth, curved manner, and change the buccal or lingual cortical plate into a thin cortical boundary. May displace the inferior alveolar nerve canal in an inferior direction or invaginate into the maxillary antrum

ODONTOGENIC CYST

RADICULAR CYST Synonim : Periapical cyst, apical periodontal cyst, and dental cyst A cyst arising from the epithelial residues (rests of Malassez) on the periodontal ligament as a consequence of inflammation, usually following the death of the dental pulp It is the most common odontogenic cyst found in the jaw

Clinical Features:Associated with a non vital tooth, percussion (-) Size is variableOften has no symptoms unless secondary infection occurs. A large cyst may cause swelling. On palpation the swelling may feel bony and hard if the cortex is intact, crepitant as the bone thins, and rubbery and uctuant if the outer cortex is lost

Radiographic features :Location : approximately at the apex of a nonvital tooth Periphery : a well-dened cortical border, if the cyst becomes secondarily infected the border can be lost or alter into a more sclerotic border. Shape : usually a curved or circularEffects on surrounding structuresIf large displacement and resorption of the roots of adjacent teethMay invaginate the antrum and displace the mandibular alveolar nerve canal

Differential diagnosisGranulomaApical scarPeriapical semental displasiaOdontogenic keratocyst Lateral periodontal cyst

RESIDUAL CYSTA cyst that remains after incomplete removal of the original cyst. This term is used most often for a radicular cyst that may be left behind, most commonly after extraction of a tooth.Clinical Features:Asymptomatic Often is discovered on radiographic examination of an edentulous area. In the case of secondary infection some expansion of the jaw or pain

Radiographic Features: Location : occur in both jaws, more often in the mandible. The epicenter is positioned in the former periapical region of the involved and missing tooth. In the mandible the epicenter is always above the inferior alveolar nerve canalPeriphery : has a cortical margin unless it becomes secondarily infected. Shape : oval or circular. Internal Structure : typically radiolucent.

Radiographic Features: Effects on Surrounding Structures : Tooth displacement or resorptionThe outer cortical plates of the jaws may expand. May invaginate into the maxillary antrum or depress the inferior alveolar nerve canal. Differential diagnosis :Odontogenic keratocystStafne bone cyst

DENTIGEROUS CYSTSynonim : follicular cyst.A cyst that forms around the crown of an unerupted tooth. It begins when uid accumulates in the layers of reduced enamel epithelium or between the epithelium and the crown of the unerupted tooth. Clinical feature :Develop around the crown of an unerupted or supernumerary tooth. The clinical examination reveals a missing tooth or teeth and possibly a hard swelling, occasionally resulting in facial asymmetry. The patient typically has no pain or discomfort.

Radiographic Features:Location : The epicenter of the cyst is just above the crown of the involved tooth, most commonly the mandibular or maxillary third molar or the maxillary canine . This cyst attaches at the cementoenamel junction. Some dentigerous cysts are eccentric, developing from the lateral aspect of the follicle so that they occupy an area beside the crown instead of above the crown Cysts related to maxillary third molars often grow into the maxillary antrum. Cysts attached to the crown of mandibular molars may extend a considerable distance into the ramus.

Radiographic Features:Periphery and Shape : typically have a well-dened cortex with a curved or circular outline. If infection is present, the cortex may be missing. Internal Structure : completely radiolucent, except for the crown of the involved tooth. Effects on Surrounding Structures : Tend to displace and resorb adjacent teeth It commonly displaces the associated tooth in an apical direction . The associated tooth may be displaced in most any direction and to any position.May displace the antrum and the inferior alveolar nerve canal in an inferior direction.Often expands the outer cortical boundary of the involved jaw (usually buccally)

Differential diagnosisFollicular space the size 2-3 mmOdontogenic keratocystAmeloblastic fibromaA cystic ameoblastomaAdenomatoid odontogenic tumors Calcied odontogenic cysts

ERUPTION CYSTThe soft tissue counterpart of a dentigerous cyst.Clinical Features: Common particularly with premature eruption of teethAny erupting tooth, molar and canines most frequentlyDirectly over the crown on an erupting toothSoft, fluctuant swelling of the alveolar ridgeBlue to dark red due to blood in the cystic fluid

Radiographic Features:The same appearance as dentigerous cyst except that they are associated with erupting teeth.

PARADENTAL CYSTSynonim = Inflammatory Paradental Cyst, Mandibular Infected Buccal Cyst, Buccal Bifurcation CystA cyst occurring near to the cervical margin of the lateral aspect of a root as a consequence of an inflammatory process in a periodontal pocket Its distinctive feature is its association with the buccal or distal aspects of an erupted mandibular molar tooth

Clinical Features:The lack of or a delay in eruption of a mandibular rst or second molar.Molar may be missing or the lingual cusp tips may be abnormally protruding through the mucosa. The rst molar is involved more frequently than is the second molar. The teeth are always vital. A hard swelling may occur buccal to the involved molar, and if it is secondarily infected, the patient has pain.

Radiographic featureLocation : M1 RB >>, followed by M2. The cyst occasionally is bilateral. It is always located in the buccal furcation of the affected molar Periphery and Shape : In some cases the periphery is not readily apparent, and the lesion may be a very subtle radiolucent region superimposed over the image of the roots of the molar. In other cases the lesion has a circular shape with a well-dened cortical border. Internal Structure : radiolucent

Effects on Surrounding StructuresThe tipping of the involved molar so that the root tips are pushed into the lingual cortical plate of the mandible and the occlusal surface is tipped toward the buccal aspect of the mandible If its large, it may displace and resorb the adjacent teeth and cause a considerable amount of smooth expansion of the buccal cortical plate. If its secondarily infected, periosteal new bone formation is seen on the buccal cortex adjacent to the involved tooth Differential diagnosis :Periodontal abcessDentigerous cyst

KERATOCYSTIC ODONTOGENIC TUMOR (KOT)Synonim : Odontogenic keratocyst and primordial cyst A benign uni- or multicystic intraosseous tumor of odontogenic origin, with a characteristic lining of parakeratinised stratified squamous epithelium and potentially aggressive, infiltrative behaviourClinical Features:Wide age range, peak occurance in 2nd and 3rd decades, with a slight male predominance. The cysts sometimes Typically asymptomatic, although mild swelling may occur. Pain may occur with secondary infection. Aspiration may reveal a thick, yellow, cheesy material (keratin).It can become very large. It extends along the body of the mandible, causing minimal mediolateral expansion.The cyst are multiple in 10% of cases basal cell nevus syndromeTendency for recurrence after inadequate surgery.

Radiographic Features:Location : The posterior body of the mandible (90% occur posterior to the canines) and ramus (more than 50%). The epicenter is located superior to the inferior alveolar nerve canal. Occasionally has the same pericoronal position as, and is indistinguishable from, a dentigerous cystPeriphery and Shape : Theres cortical border unless they have become secondarily infected. The cyst may have a smooth round or oval, or it may have a scalloped outline (a series of contiguous arcs) Internal Structure : Most commonly radiolucent. In some cases curved internal septa may be present, giving the lesion a multilocular appearance

Radiographic Features:Effects on Surrounding Structures : Propensity to grow along the internal aspect of the jaws, causing minimal expansion. If expand, this occurs throughout the mandible except for the upper ramus and coronoid processCan displace and resorb teeth but to a slightly lesser degree than dentigerous cysts. May displace the inferior alveolar nerve canal inferiorly. In the maxilla this cyst can invaginate and occupy the entire maxillary antrum.

Differential diagnosisDentigerous cystAmeloblastomaOdontogenic myxomaSimple bone cyst

LATERAL PERIODONTAL CYSTA cyst occurring on the lateral aspect or between the roots of vital teeth and arising from odontogenic epithelial remnants, but not as a result of inflammatory stimuli . Clinical Features:50-70 years of ageCommon site: Along the lateral surface of the root of vital tooth. Usually in mandibular premolar/canine region. Slow growing, most often asymptomaticSmall size (less than 1 cm in diameter). Non-expansile

Radiographic Features:Location : mostly in the mandible, in a region extending from the lateral incisor to the second premolar. Occasionally these cysts appear in the maxilla, especially between the lateral incisor and the cuspid. Periphery and Shape : a well-dened radiolucency with a prominent cortical boundary and a round or oval shape. Rare large cysts have a more irregular shape. Internal Structure : usually radiolucent. Effects on Surrounding Structures. Small cysts may efface the lamina dura of the adjacent root. Large cysts can displace adjacent teeth and cause expansion.

Differential diagnosisSmall odontogenic keratocyst foramen mentaleRadicular cyst (lateral)

GLANDULAR ODONTOGENIC CYSTSynonym : Sialo-odontogenic cyst A rare cyst derived from odontogenic epithelium with a spectrum of characteristics including salivary gland features such as mucus-producing cellsClinical features :There is a slight female predominance with a mean age ranging from 46 to 50 years. This cyst has an aggressive behavior and a tendency to recur after surgery.

Radiographic Features Location : more commonly in the mandible and most often in the anterior mandible and in the maxilla, commonly the globulomaxillary region. Periphery and Shape : There is usually a cortical boundary that may be smooth or scalloped. Internal Structure : both unilocular and multilocular appearancesEffects on Surrounding Structures :Expansion of the outer cortical plates of the jaws with regions of perforation through the cortex Displacement of teethDifferential diagnosis : ameloblastoma

CALCIFYING ODONTOGENIC CYSTSynonyms : Calcifying cystic odontogenic tumor, calcifying epithelial odontogenic cyst, or Gorlin cystRare, well-circumscribed, solid or cystic lesion derived from odontogenic epithelium that resembles follicular ameloblastoma but contains "ghost cells" and spherical calcifications.Clinical Features:Any age but majority are below 40 years of ageEither jaw, usually in incisor-canine regionA slow growing, painless, non tender swelling of the jaw.Extraosseous lesions appear as focal localized swellingsIntraosseous lesions produce a generalized expansion of the jaw

Radiographic Features:Location : occur in both jaws. Most (75%) occur anterior to the rst molar, especially associated with cuspids and incisors, where the cyst sometimes manifests as a pericoronal radiolucency. Periphery and Shape : The periphery can vary from well dened and corticated with a curved, cystlike shape to ill dened and irregular.

Radiographic Features:Internal Structure : vary in appearance. It may be completely radiolucent; it may show evidence of small foci of calcied material that appear as white ecks or small smooth pebbles; or it may show even larger, solid, amorphous masses. In rare cases the lesion may appear multilocular. Effects on Surrounding Structures : Occasionally (20% to 50% of cases) this tumor is associated with a tooth (most commonly a cuspid) and impedes its eruption. Displacement of teeth and resorption of roots may occur. Perforation of the cortical plate may be seen radiographically with enlarging lesions.

Differential diagnosisDentigerous cystAdenomatoid odontogenic tumor

NON ODONTOGENIC CYST

Synonim : Nasopalatine canal cyst, incisive canal cyst, nasopalatine cyst, median palatine cyst, and median anterior maxillary cyst An intraosseous developmental cyst of the midline of the anterior palate, derived from the islands of epithelium remaining after closure of the embryonic nasopalatine duct.Clinical Features:Arises from embryologic remnants of the nasopalatine ductUsually present in the midline of the anterior maxilla near the incisive foramenUsually asymptomatic but pain, pressure, drainage and swelling can occurIt may cause palatal expansions. NASOPALATINE DUCT CYST

Radiographic Features: Unilocular, well-circumscribed oval or heart-shaped radiolucency of the midline of the anterior maxilla superior to and between the roots of the central incisorsSmooth cortical borderAdjacent teeth: displaced, rarely resorbed.

NASOLABIAL CYSTSynonim : naso alveolar cystA developmental cyst of the soft tissue of the anterior muco-buccal fold beneath the ala of the nose, most likely derived from remnants of the inferior portion of the nasolacrimal duct.Clinical Features:4th and 5th decades of lifeUsually unilateralAsymptomatic soft tissue swellingMost are less than 1.5 cmOccurs in the region of the maxillary lip and alar base, lateral to the midline

Radiographic Features:May not be apparent on a radiograph because it is a soft tissue lesion.Occasionally the cyst may causes erosion of the underlying bone by virtue of its presence and pressure and make an increased radiolucency of the alveolar process beneath the cyst and above the apices of the incisors. Injection of a radiopague dye into the lumen will help to define the cyst outline

PSEUDO CYST

Synonim : Traumatic Bone Cyst, Hemorrhagic Bone Cyst, Solitary Bone Cyst, Idiopathic Bone Cavity, Progressive Bone Cyst and Extravasation CystAsymptomatic intraosseous empty cavity of young patients located primarily within the mandible, lined by a thin loose connective tissue membrane (not lined by epithelium).Unknown etiology and pathogenesis. SIMPLE BONE CYST

Clinical Features:Children and adolescents, usually before the age of 20Usually asymptomaticPrimarily seen in mandible, premolar/molar region Associated with vital teeth, no displaced teethRadiographic Features:Well demarcated unilocular or multilocular radiolucency with scalloping around roots of the adjacent teeth Commonly found in posterior mandibleRarely cause cortical expansion, but when this occur, it is mostly buccal-lingual expansionAny resorption or displacement of teeth is uncommon

ANEURYSMAL BONE CYSTAn uncommon lesion (not a true cystic lesion) located primarily in the posterior mandible and maxilla; it contains many large blood-filled spaces separated by connective tissue septa containing giant cell tissue.This cyst is primarily an abnormality of the long tubular bone. Although rare, it may found in the jawClinical Features: Rare, localized, non-neoplastic, proliferative lesion of vascular tissue, containing giant cells Mostly found in young people, 2nd or 3rd decade of lifePain varies and firm, diffuse swellingFacial asymmetry due to outward expansion of the bony cortex Most occur in the posterior mandible and often extend into the ramus

Radiographic Features:Unilocular (early stages), multilocular (soap-bubble or honey comb appearance) Generally a well defined, expansive osteolytic unilocular radiolucent Cortex is thin or erodedIt can causes marked bony expansion and displacement of the adjacent teeth (resorption is rare).

LINGUAL MANDIBULAR SALIVARY GLAND DEPRESSIONSynonim : Stafne Cyst, Stafnes Bone Defect, Static Bone Cyst and Latent Bone CystA developmental concavity of the lingual cortex of the mandible, usually in the third molar area, caused by overextension of an accessory lateral lobe of the submandibular gland.Clinical Features:Anatomic indentation of the posterior lingual mandibleThe appearance and location are characteristic. Mostly, it is situated in the angle region of the mandible, between the mandibular canal and lower border. AsymptomaticMost often adult malesOccasionally bilateral

Radiographic Features:Resembles a cystRound or oval radiolucency beneath the level of the inferior alveolar canalDiscrete corticated marginVary in size from 1-3 cm in diameter.

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