Cysts of jaws and oral soft tissues, including developmental cysts. Markéta Hermanová Definition of a cyst nA pathological cavity, lined wholly or in part by epithelium, having fluid or semifluid contents n nBroader definition: a pathological cavity, having fluid or semifluid contents, which has not been created by the accumulation of pus n Classification of cysts of the jaws nOdontogenic cysts -developmenal -inflammatory nNon-odontogenic cysts nNon-epitheliazed primary bone cysts nCysts of the soft tissues Odontogenic cysts nDevelopmental -Odontogenic keratocysts -Dentigerous (follicular) cyst -Eruption cyst -Lateral periodontal cysts -Gingival cyst -Glandular odontogenic cyst nInflammatory -Radicular cyst n (a) apical n (b) lateral n (c) residual periapical -Paradental cyst n Non-odontogenic cysts nNasopalatine duct (incisive canal) cyst nNasolabial (nasoalveolar) cyst nMedian cysts nPalatal cyst of the newborn (Epstein perls; Bohn´s nodules) Non-epitheliazed primary bone cysts nSolitary bone cyst (simple, traumatic, haemorrhagic bone cyst) nAneurysmal bone cyst nStafne´s idiopathic bone cavity Incidence of cyst of the jaws Odontogenic cysts (90 %) Non-odontogenic c.(10%) Radicular cysts 60-75 % Nasopalatine cyst 5-10 % Dentigerous cyst 10-15 % Other non-odontogenic and primary bone cysts <1 % Keratocyst 5-10 % Paradental cyst 3-5 % Gingival cyst <1 % Lateral periodontal c. <1 % Origins of odontogenic cysts nDerived from epithelial residues of the tooth-forming organ nThe main cyst types derived from each residue are: -Dental lamina rests/gland of Serres n (a) odontogenic keratocysts n (b) some lateral periodontal and gingival cysts -Reduced enamel epithelium n (a) dentigerous cysts n (b) paradental cysts -Rests of Malassez n (a) radicular cysts Radicular cysts nApical, residual periapical, or lateral sub-types nApical most common nAssociated with non-vital tooth nApical radiolucency indistinguishable from a periapical granuloma nMay be symptomless nEnlargement of cyst leads to bone resorption Radicular cyst apikální laterální reziduální Radicular cyst radicular_cyst =Calcifying odontogenic tumour Radicular cyst-histology nArise from proliferation of the rests of Malassez within chronic periapical granulomas nLined by non-keratinizing squamous epithelium nSupported by a chronically inflammed capsule nCapsule may contain collections of cholesterols nHypertonic content: breakdown products, serum proteins, water and electrolytes, cholesterol crystals Expansion of radicular cyst nHydrostatic pressure of the cyst fluid increased due to hypertonic content nWater drawn into the cyst cavity along this osmotic gradient nCyst expansion nBone resorption Dentigerous (follicular) and eruption cyst nMost frequently involve impacted/late-erupting teeth nDevelop between reduced enamel epithelium and crown nSurround part or all of the involved crown nCysts attached to amelocemental junction nLined by thin, non-keratinizing squamous epithelium; often shows mucous cell metaplasia nNon-inflamed capsule; may contain odontogenic epithelial rests nEruption cyst = extraalveolar dentigerous cyst Odontogenic keratocysts nBimodal age distribution – 2nd-3rd decades and 5th decade nFew symptoms; cause little expansion; may reach large size nUnilocular/multilocular radiolucency; may mimic dentigerous cyst nMore common in mandibula than in maxilla nTendency to recur nMay be multiple; associated with nevoid basal cell carcinoma syndrome Naevoid basal cell carcinoma syndrome (Gorlin syndrome) nAD nMultiple naevoid BCC + multiple odontogenic keratocysts + skeletal abnormalities (rib abnormalitites, vertebral deformities, polydactyly, cleft lip/palate) + calcified falx cerebri + brain tumours nMutation in tumor supperssor gene PTCH (9q) nMutations of PTCH affect the normal function of Hedgehog signalling pathway nHedgehog signalling pathway controls transcription of the genes involved in the developlment, patterning, and growth of numerous tissues and organs n n Odontogenic keratocysts nThin, easily torn wall nLined by an even layer of parakeratinized squamous epithelium nPalisaded basal cell layer nSatellite cysts in capsule nTendency to recur due to difficulty of surgical removal -thin, easily ruptured wall -Projection into cancellous spaces easily torn -Satellite cysts in capsule nCyst enlargement involves -Focal areas of active growth of the cyst wall -Extension of proliferating areas along cancellous spaces -Production of bone resorbing factors nGingival cyst n- in neonates, arise from remnants of the dental lamina, disappear spontaneously nDevelopmental lateral periodontal cyst -Canine and premolar region of the mandibula, vital teeth -Non-keratinizing or cuboidal nGlandular odontogenic cyst -Anterior part of mandibula, potentially aggresive -Lining by cuboidal, columnar and mucous cells nParadental cyst -Alongside partly eruptive 3rd molar involved by pericoronitits -Histologically resemble radicular cysts-inflammatory Odontogenic keratocyst odontogenní cysta Non-odontogenic cysts nNasopalatine duct (incisive canal) cyst -Commonest of the non-odontogenic cysts -Derived from nasopalatine duct residues; midline anterior palate -Lining: stratified squamous epithelium, pseudostratified ciliated columnar epithelium, mucous cells, columnar or cuboidal epithelium nNasolabial cyst -In soft tissue of the upper lip; also bilateral -Lining: pseudostratified columnar epithelium, stratified squamous epithelium, mucous cell, ciliated cells -Derived from remnants of the lower part of the embryonic nasolacrimal duct nPalatal cyst of the newborn (Epstein perls; Bohn´s nodules) -1-3 mm papules, midline near the junction of soft and hard palate -Keratin filled, lined by stratified squamous epithelium nMedian cyst -Palate, mandibula -Displaced nasopalatine duct cyst??? -In mandibula odontogenic??? Non-epitheliazed primary bone cysts nSolitary bone cyst -Mainly molar region mandible; second decade -Empty cavity, no epithelial lining; loose fibrous tissue covering the bone -Pathogenesis: haemodynamic distrubance in medullary bone (trauma, haemorrhage) nAneurysmal bone cyst -Primary or secondary; uni- or multilocular -Blood filled spaces separated by cellular fibrous tissue -Pathogenesis: haemodynamic distrubance in medullary bone nStafne´s idiopathic bone cavity -Developmental anomaly of the mandible -Usually contains ectopic salivary tissue in continuity to submandibular salivary gland Aneurysmal bone cyst a bone cyst Cysts of the soft tissues nSalivary mucoceles -Mucous extravasation cyst n (lower lip, cheek, floor of the mouth; mucin-filled cystic cavity lined by inflammed granulation tissue, mucophages; ranula – clinical term, swelling of the floor of the mouth; usually mucous extravasation cyst) -Mucous retention cyst n (no in lower lip; cystic dilatation of the duct) nDermoid and epidermoid cysts -Dermoid cysts: Developmental lesions; lined by orthokeratinized stratified squamoud epithelium, with skin appendages in the wall -Epidermoid cysts: usually aquired, traumatic implantation of epithelium, cystic change and expansion nLymphoepithelial cyst -Also classified as branchial cyst -Lined by stratified squamous epithelium with well-organized lymphoid tissue in the wall nThyreoglossal cyst n- developmental, from the embryonic thareoglossal duct, localised in the midline of the tongue n Mucocele Mucocele_of_lower_lip_(2) Mucocele_of_lower_lip_(1) Thyreoglossal cyst end-6-obr3 Thank you for your attention …