DEFINITION OF CYST Cyst is defined as pathologic cavity, having fluid,semifluid, or gaseous contents and which is not created by accumulation of pus. It is frequently but not always lined by epithelium. cyst Lining epithelium lumen Wall of fibrous connective tissue
CLASSIFICATION OF CYST Cyst of the jaw Epithelial (true Non Epithelial (pseudo cyst) cyst) Odontogenic Non odontogenic Based on etiology Based on site of origin Inflammatory Developmental unclassified Reduced enamel epitelium Cell rest of Malassez Cell rest of Serre
ODONTOGENIC BASED ON SITE OF ORIGIN BASED ON ETIOLOGY 1)REDUCED ENAMEL EPITHELIUM DEVELOPMENTAL -dentigerous cyst CYST INFLAMMATORY -eruption cyst-gingival cyst of infants -periapical cyst 2)CELL REST OF SERRE -gingival cyst of adults -residual cyst -odontogenic keratocyst-odontogenic keratocyst -paradental cyst -gingival cyst of newborn -dentigerous cyst -gingival cyst of adults -eruption cyst -lateral periodontal cyst-lateral periodantal cyst -glandular odontogenic cyst-botryoid odontogenic cyst 3)CELL REST OF MALASSEZ-glandular odontogenic -periapical cyst cyst -residual cyst-calcifying odontogenic 4)UNCLASSIFIED cyst -calcified odontogenic cyst -paradental cyst
NON EPITHELIAL (PSEUDO CYST) -solitary bone cyst -aneurysm bone cyst
RADICULAR CYST synonyms:periapical cyst,apical periodontal cyst,dental cyst Definition: Cyst that results when cell rest of Malassez in periodontal ligament are stimulated to proliferate and undergo cystic degeneration by inflammatory products from NON VITAL tooth. Clinical Features: The most common type of cyst in the jaw Age:3rd-6th decade Sex:MALE predominance Arise from NON VITAL TOOTH ; -due to extensive caries,large restorations,trauma Asymptomatic Larger cyst may cause swelling
On palpation,the swelling may feel A)bony and hard if cortex is intact B)crepitant as the bone thins C)rubbery and fluactuant if the outer cortex is lost Radiographic Features; 1)location: -approximately at the apex of a non vital tooth, -60% are found in MAXILLA -Especially around INCISORS and CANINES -(mesial/distal surface of tooth root at the opening of accessory canal or in deep periodontal pocket) -because of distal inclination of the root,cyst that arise from the maxillary lateral incisor may invaginate the antrum -may associated with NONVITAL DECIDUOS MOLAR which is situated buccal to developing bicuspid.
Periphery and Shape: -well-defined cortical border -if the cyst is secondarily infected,the inflammatory reaction surrounding the bone may result in loss of this cortex or alteration lead to sclerotic border. -outline:curved or circular
Internal Structure: -radiolucent -in long standing cyst,dystrophic calcification may developed,appearing as sparsely distributed small particulate radiopacities. Effects on surrounding structures: -large cyst lead to displacement and resorption of adjacent teeth. -resorption patern have curved outline -the cyst may invaginate the antrum,but there should be evidence of cortical boundaries between the contents of the cyst and the internal structure of antrum. -cyst may displace mandibular alveolar canal in an inferior direction.
-the outer cortical plates of maxilla or mandible may expand in curved or circular shape
Differential Diagnosis: 1)Apical granuloma -cyst characterized by round shape,well-defined cortical border,and size greater than 2cm in diameter. 2)early stage of periapical cemental dysplasia,an apical scar or surgical defect -patient’s history helps with the differentiation 3)Odontogenic keratocyst or Lateral Periodontal cyst -vitality of involved tooth should be test. -non vital tooth have large pulp chamber due to lack of secondary dentin. 4)Benign fibro-osseous lesion -a larger radicular cyst that invaginated maxillary antrum may collapse and start filling in with the new bone.with biopsy,the histologic analysis may result in ossifying fibroma or benign fibro-osseous lesion.Radiographically,the new bone will form first at the periphery of the cyst as the cyst shrinks and not in the center of cyst.(this is different pattern from benign lesion)
RESIDUAL CYSTDefinition:Cyst that remains after incomplete removal of the original cyst.Clinical Features:-Asymptomatic-associated with EDENTULOUS AREA
Radiographic Features:1)LocationSite:mandible-epicenter is positioned in the former periapical region of involved or missing tooth-in mandible,the epicenter is above the inferior alveolar nerve canal
2)Periphery and shape -cortical margin with oval or circular shape 3)Internal structure -radiolucent --dystrophic calcification in long standing cyst
4)Effect on surrounding structure:-tooth displacement or resorption-outer cortical plate of jaw may expand-cyst may invaginate maxillary antrum or depress the inferior alveolar canal.Differential Diagnosis:1)Odontogenic keratocyst-residual cyst has greater expansion than OKC2)Stafne developmental salivary gland defect-the defect is located below mandibular canal,thus is unlikely to be odontogenic in nature.Treatment:-surgical removal-marsupialization
DENTIGEROUS CYST Synonym:follicular cyst Definition: A cyst that forms around the crown of UNERUPTED tooth.It begins when fluid accumulates in the layers of REDUCED ENAMEL EPITHELIUM or between the epithelium and the crown of unerupted tooth. Clinical Features: -2nd most common cyst in the jaw -associated with UNERUPTED or SUPERNUMERARY TOOTH. (mesiodens in anterior maxilla) -no pain or discomfort -clinical examination shows: @>missing tooth with hard swelling resulting in facial asymmetry
Radiographic Features: 1)Location: -mandibular or maxillary THIRD MOLAR -MAXILLARY CANINE -this cyst attaches at CEMENTOENAMEL junction -types of radiographic presentation: a)central type
2)Periphery and shape -well defined cortex with a curved or circular outline 3)Internal structure -radiolucent except the crown of involved tooth 4)Effect of surrounding structure -displacement and resorption of adjacent tooth
-it displaces the associated tooth in apical direction -maxillary third molar or cuspid may be pushed to the floor of orbit -mandibular third molar may be moved to condylar or coronoid region or to the inferior cortex of mandible
-the floor of maxillary antrum may be displaced as the cyst invaginates the antrum -The cyst may displace the inferior alveolar nerve canal in an inferior direction Differential Diagnosis 1)hyperplastic follicle -size of normal follicle space is 2-3mm -If the folicular space exceed 5mm assaciated with tooth displacement and bone expansion,a dentigerous cyst is more likely. 2)odontogenic keratocyst -OKC does not expand the bone to the same degree as dentigerous cyst,less likely to resorb tooth,may attach further at apically on the root instead of CEJ.
3)ameloblastic fibroma or ameloblastoma -dentigerous cyst contain internal structure(tooth) 4)adenomatoid odontogenic tumor and calcified odontogenic cyst -evidence of a radiopaque internal structure in these two lesion. 5)radicular cyst at the apex of primary tooth -occasionally surrounds the crown of the developing permanent tooth positioned apical to it,giving false impression of dentigerous cyst associated with permanent tooth. -occur most often in MANDIBULAR DECIDUOUS MOLAR and the developing BICUSPIDS -thus,clinician should look for extensive caries or large restoration in primary tooth to indicate radicular cyst.
Management 1)surgical removal including the tooth 2)large cyst should be treated with marsupialization before surgical removal 3)cyst lining should be submitted for histologic examination because many lesion might be arise from cyst lining eg; a)AMELOBLASTOMA b)SQUAMOUS CELL CARCINOMA c)MUCOEPIDERMOID CARCINOMA
ODONTOGENIC KERATOCYSTSynonyms:-KERATOCYSTIC ODONTOGENIC TUMOR(KOT)-primordial cystDefinition:The WHO has reclassified this cystic lesion into a unicystic or multicystic odontogenic tumor on the basis of TUMORLIKE CHARACTERISTIC of the lining epithelium.The epithelium in the KOT appear to have innate growth potential,consistent with benign tumor.The epithelial lining is DISTINCTIVE because it is KERATINIZED (hence the name)and thin (4-8 cells thick).Occasionally,budlike proliferations of epithelium grow from the basal layer into the adjacent connective tissue wall.Islands of epithelium in the wall may give rise to SATELLITE MICROCYST.Inside the cyst contain a viscous or cheesy material derived from epithelial lining.
Clinical Features:-KOT account for about one tenth (1/10) of all cystic lesion in jaws-age:20-30-sex:male predominance-may associated with UNERUPTED tooth-asymptomatic-aspiration reveal a thick yellow cheesy material(KERATIN)Have high properties of RECCURENCE ,because of small satellite cyst or epithelium fragments left behind after surgical removal of epithelium.Radiographic Features:1)Location-most common:POSTERIOR BODY OF MANDIBLE (90% occur posterior to canine) :RAMUS (more than 50%)-the epicenter located superior to inferior alveolar nerve canal
-has same pericoronal position as dentigerous cyst.2)Periphery and shape-well-defined cortical border-smooth round or oval shape-or might have scalloped outline
3)Internal Structure:-radiolucent-in some case curved internal septa may be present giving a multilocular apppearance.
4)Effect on surrounding structure:-a very characteristic feature that its PROPENSITY TO GROW ALONG THE INTERNAL ASPECT OF THE JAW CAUSING MINIMAL EXPANSION.-this occur throughout the mandible except for the upper ramus and coronoid process.
-the relatively slight expansion contributes to their late detection,which allow them to reach a large size. -KOT can displace and resorb teeth but to a slightly degree than dentigerous cyst. -the inferior alveolar nerve canal may be displaced inferiorly. -this may invaginate and occupy the maxillary antrum.
– RADIOGRAPHIC VARIETIES 1. REPLACEMENTAL – Cyst forms in place of normal tooth by degeneration of dental lamina. 2. EXTRANEOUS – OKC occurs in ascending ramus, away from tooth bearing areas
3. COLLATERAL –OKC occurs adjacent to root of tooth,mimicking a lateral periodontal cyst.4. ENVELOPMENTAL –This is an odontogenic keratocystwhich embraces or envelopes anadjacent unerupted tooth.
Differential Diagnosis:1)dentigerous cyst -it is KOT if the cystic outline is connected to the tooth at the point apical to CEJ,and if no expansion of the cortical plate. -although KOT can develop occlusal to developing tooth ,the follicle of involved tooth is not enlarged as dentigerous cyst.2)Ameloblastoma -scalloped margin and multilocular appearance of KOT may resemble ameloblastoma but ameloblastoma has greater propensity to expand.3)Odontogenic myxoma -have similar characteristic of mild expansion and multilocular appearance.4)Simple bone cyst -have similar characteristic of scalloped margin and minimal bone expansion -however the margins of simple bone cyst are more delicate and difficult to detect.5)4-5% of KOT cases may constitute part of BASAL CELL NEVUS SYNDROME.
Management:-referral to radiologist for a complete radiologic examination is advisable.-resection,curretage,or marsupialization to reduce the size of large lesion before surgical excision.-complete removal of the cystic walls to reduce the chance of recurrence-after surgical treatmant,it is important to make periodic posttreatment clinical and radiographic examination to detect any recurrence.-recurrent lesion usually develop within the first 5 years but may delayed as long as 10 years.
BASAL CELL NEVUS SYNDROME Synonyms:Nevoid basal cell carcinoma, GORLIN-GOLTZ syndrome Definition: Comprises a number of abnormalities as multiple nevoid basal cell carcinomas of the skin,skeletal abnormalities,central nervous system abnormalities,eyes abnormalities and multiple KOTs.it is inherited autosomal dominant trait with variable expressivity.
Clinical Features: age:5-30 years A) multiple KOTs-appearing in multiple quadrant -early in life -high RECURRENT RATE
B) skin lesion-small,flattened,flesh-colored or brown papules -prominent on face,neck, and trunk
4)temporal and temporoparietal bossing 5)minor hypertelorism- abnormally increased distance between two organs or bodily parts.
6) calcification of Falx cerebri Skull CT showing calcification of the falx
Radiographic features: 1) location:same as solitary KOTs,may develop bilaterally 2)other radiographic features: Radiopaque line of the calcified falx cerebri may be prominent on the posterior anterior skull projection
CALCIFYING CYSTIC ODONTOGENIC TUMORSynonyms:Calcifying odontogenic cyst,Calcifying epithelial odontogenic cyst, Gorlin cystDefinition : -uncommon slow growing,benign lesions.occupy a spectrum ranging from a cyst to an odontogenic tumor.It may manufacture calcified tissue (dysplastic dentin) or associated with an odontoma.when it contains a more solid component ,it gives appearance resembling ameloblastoma although it does not behave like one.
Clinical features: Mean age:36 years first peak:10-19 years second peak:seventh decade Appearance:slow –growing,painless swelling in jaw Radiographic features: 1) location: - 75% occur in bone anterior to first molar especially associated with cuspids and incisors
2) periphery and shape: -vary from well-defined and corticated with a curved, cystlike shape to ill- defined and regular 3) Internal structure: -a)completely radiolucent -b)evidence of small foci or calcified material that appear as white flecks or small smooth pebbles -c)larger,solid,amorphus masses -d)multilocular
4) effect on surrounding structure: -20-50% of cases is associated with tooth(cuspid) and impedes it eruption -displacement of teeth and root resorptions -perforation of cortical plate may be seen with enlarging lesion. Management: Enucleation and curettage.
NASOPALATINE DUCT CYST Synonyms:Nasopalatine canal cyst, Incisive canal cyst, Nasopalatine cyst, Median palatine cyst, Median anterior maxillary cyst. Definition: Nasopalatine canal usually contains remnants of the nasopalatine duct, a primitive organ of smell, and the nasopalatine vessels and nerves. Occasionally, a cyst forms in the nasopalatine canal when these embryonic epithelial remnants of the nasopalatine duct undergo proliferation and cystic degeneration.
Clinical Features: 10% of jaw cysts Age:4th-6th decades Sex:male predilection Asymptomatic Small,well-defined swelling just posterior to palatine papilla Fluactuant and blue swelling if near the surface. May penetrate labial plate and produce swelling below maxillary labial frenum. May bulge into nasal cavity and distort nasal septum Pressure of cyst on adjacent nasopalatine nerve may cause burning sensation or numbness over palatal mucosa.
Radiographic Features: 1) location -a) found in the nasopalatine foramen or canal -b) If extends posteriorly involving hard palate MEDIAN PALATAL CYST -c)if expands anteriorly between central incisors,destroying or expanding labial plate of bone and causing teeth to diverge MEDIAN ANTERIOR MAXILLARY CYST
2) Periphery and shape: -well-defined and corticated circular or oval in shape -HEART SHAPE is due to shadow of nasal spine superimposed on the cyst
Internal structure: -radiolucent Effects on Surrounding structures: -roots of central incisors diverge -root resorption -expansion of labial cortex and palatal cortex -floor of nasal fossa may be displaced in superior direction
Differential Diagnosis: 1) large incisive foramen -cyst is presumed when the width of foramen exceeds 1cm and cause tooth displacement. 2) a radicular cyst or granuloma -absence of lamina dura and enlargement of periodontal ligament space around apex of central incisors indicate an inflammatory lesion. -vitality test -a second periapical view taken at different horizontal angulation should show altered position of a nasopalatine duct cyst, whereas radicular cyst should remain centered about the apex of central incisors. Management: -enucleation -marsupialize indicated for large cyst
NASOLABIAL CYST Synonyms:Nasoalveolar cyst Definition -exact origin is unknown, may be fissural cyst arising from epithelial rests in fusion lines of globular,lateral nasal and maxillary process.
Clinical Features: Age:12-75 years Sex:female predilection Usually UNILATERAL a)small lesion -very subtle,unilateral swelling of nasolabial fold associated with pain or discomfort. b) large lesion -it may bulge into floor of nasal cavity causing obstruction,flaring of alae,distortion of nostrils and fullness of upper lip.
Radiographic Features: 1) location: -located adjacent to alveolar process above apices of incisors -because this is soft tissue lession, investigation should be done using CT or MRI(magnetic resonance imaging. 2)Periphery and shape: -CT images shows circular or oval lesion with slight tissue enhancement on periphery 3)Internal structure: -CT images shows homogenous & relatively radiolucent compared with surrounding structure.
4)Effects on surrounding structures: -erosion on underlying bone -usual outline of inferior border of nasal fossa become distorted resulting posterior bowing of this margin. Management: -excision through an intraoral approach.