07/01/2012 Lecture Objectives CYSTS OF At the end of this lecture you should be able to: THE JAWS & • Define & classify cysts of the jaws & oral cavity • Describe pathogenesis, features, differential THE ORAL diagnosis and management of cysts in general CAVITY • Explain the following of common cysts – Aetiopathogenesis – Clinical features – Radiographic appearance (if present) – Histopathology r v subramanyam – Management [email protected] 2 18 Aug 2009 Definitions Definitions • Etymology: Derived • True cysts from Greek “Kystis” – Radicular cyst for sac, bladder, pouch, bag from – Dentigerous cyst “Kyso” I hold – Keratocyst • Pathological cavity or • Pseudocysts pouch, containing – Aneurysmal bone fluid or semi-fluid cyst material, and which may or may not be – Solitary bone cyst lined by epithelium. – Mucus escape phenomenon 3 4 18 Aug 2009 18 Aug 2009 CLASSIFICATION CLASSIFICATION Developmental I. Cysts of the jaws b) INFLAMMATORY A. Epithelial-lined cysts i. Radicular cyst, apical and SINUS lateral Odontogenic 1. ODONTOGENIC ii. Residual cyst Inflammatory a) DEVELOPMENTAL iii. Paradental cyst and juvenile Epithelial‐ i. Dentigerous cyst paradental cyst lined ii. Odontogenic keratocyst iv. Inflammatory collateral cyst Non‐ iii. Eruption cyst 2. NON-ODONTOGENIC CYSTS JAWS odontogenic iv. Gingival cyst of infants (Developmental) i. Midpalatal raphé cyst of infants So‐called v. Gingival cyst of adults Non‐Epithelial‐ vi. Developmental lateral ii. Nasopalatine duct cyst Fissural cysts periodontal cyst lined iii. Nasolabial cyst vii. Botryoid odontogenic cyst B. Non-Epithelial-lined cysts SOFT viii. Glandular odontogenic cyst 1. Aneurysmal bone cyst TISSUES ix. Calcifying odontogenic cyst 2. Solitary bone cyst 5 6 18 Aug 2009 18 Aug 2009 1 07/01/2012 CLASSIFICATION Frequency of occurrence II. Cysts associated Maxillary 5. Oral cysts with gastric or 1. Radicular cyst Antrum intestinal epithelium 2. Dentigerous cyst 1. Mucocele 6. Cystic hygroma 3. Odontogenic keratocyst 2. Retention cyst 7. Nasopharyngeal cyst 4. Nasopalatine duct cyst 3. Pseudocyst 8. Thymic cyst 4. Postoperative maxillary 9. Cysts of the salivary glands: 5. Paradental cyst cyst Developmental origin mucous extravasation cyst; 6. Solitary bone cyst III. Cysts of the soft tissues of mucous retention cyst; ranula; 7. Calcifying cystic odontogenic tumour the mouth, face and neck polycystic (dysgenetic) 1. Dermoid & epidermoid cysts disease of the parotid 8. Eruption cyst 2. Lymphoepithelial 10. Parasitic cysts: hydatid cyst; 9. Developmental lateral periodontal cyst (branchial) cyst Cysticercus cellulosae; 10. Nasolabial cyst 3. Thyroglossal duct cyst trichinosis 11. Gingival cyst of adults 4. Anterior median lingual cyst 12. Aneurysmal bone cyst 7 8 18 Aug 2009 18 Aug 2009 Pathogenesis of true cysts Sources of epithelial cells Dental lamina Cell rests of Serres 9 10 18 Aug 2009 18 Aug 2009 Sources of epithelial cells Sources of epithelial cells Tooth primordium Cell rests of Malassez Cell rests at the line of Sinus lining fusion 11 12 18 Aug 2009 18 Aug 2009 2 07/01/2012 Aetiopathogenesis of Odontogenic Cysts Aetiopathogenesis of true cysts CYST OE DL DO COM REE PHASE OF INITIATION . Genetic ODONTOGENIC KERATOCYST . Immunological DENTIGEROUS CYST & ERUPTION CYST . Inflammatory . Local factors – O & GINGIVAL CYST OF INFANTS 2 CO2 tension GINGIVAL CYST OF ADULTS PHASE OF CYST FORMATION LATERAL PERIODONTAL CYST (Dev) . Death & degeneration RADICULAR CYST / RESIDUAL CYST of central cells due to vascularity KEY: OE –ODONTOGENIC EPITHELIUM; DL –DENTAL LAMINA; DO –DENTAL ORGAN; COM –CELL RESTS OF MALASSEZ; REE – REDUCED ENAMEL EPITHELIUM PHASE OF CYST ENLARGEMENT 13 14 18 Aug 2009 18 Aug 2009 Aetiopathogenesis of true cysts Factors involved in the growth of the cysts • Attraction of fluid into the cyst cavity Retention of fluid within the cavity Raised internal hydrostatic pressure • Bone resorption with increased size of bone cavity – MMPs 1, 2, 3 and Prostaglandins E2 & E3 • Epithelial proliferation 15 16 18 Aug 2009 18 Aug 2009 General Features of Jaw Cysts General Features of Jaw Cysts • Slowly enlarging swelling. • Usually painless, unless secondarily infected or impinging on a nerve. • Normally only buccal cortical plate expansion, and not lingual. • "Eggshell crackling" on palpation of large cysts. • Occasionally pathological fracture. • Displacement of adjacent teeth may occur. • Sometimes resorption of roots of adjacent teeth. • Well-circumscribed radioloucency, unilocular (occasionally multilocular) with a radiopaque border. 17 18 18 Aug 2009 18 Aug 2009 3 07/01/2012 General Features of Soft Tissue Cysts General Features of Cysts • Slowly enlarging swelling • All true cysts show • Painless usually – a lumen – an epithelial lining, • Fluctuant on palpation and – a connective tissue wall 19 20 18 Aug 2009 18 Aug 2009 ASPIRATION Differential Diagnosis CONTENT CYST Radiolucent cyst-like features can be seen in Whitish, pale, cheesy material – keratin • Odontogenic tumours Keratocyst flakes; protein level < 4 mg/100 ml • Non-odontogenic tumours Light straw coloured fluid Dentigerous cyst • Giant cell granuloma Shimmering straw colour – cholesterol • Hyperparathyroidism Radicular cyst crystals; protein level > 5 mg/100 ml • Cherubism Serosanguinous - pus Infected cyst • Stafne bone cavity Red - blood Aneurysmal bone cyst • Normal anatomic structures (antrum, incisive canal fossa) Nothing on aspiration Solitary bone cyst 21 22 18 Aug 2009 18 Aug 2009 Management of Cysts Cysts that will be discussed… 1. Enucleation 1. Radicular Cyst Separation of the lesion from the bone, with preservation of bone continuity 2. Dentigerous Cyst 2. Curettage 3. Odontogenic keratocyst (Kerato- Removal by scraping or morcellation odontogenic tumour) 3. Marsupialization 4. Gorlin Cyst Surgical removal of overlying tissue, creating a window in the wall of the cyst decompresses cyst & s intra-cystic 5. Gingival cyst of infants / Epstein’s Pearls pressure promotes cyst shrinkage & bone fill 6. Mucocoeles 4. Resection without continuity defect 7. Fissural Cysts 5. Resection with continuity defect 6. Disarticulation 8. Aneurysmal Bone Cyst 7. Recontouring 9. Solitary Bone Cyst 23 24 18 Aug 2009 18 Aug 2009 4 07/01/2012 RADICULAR CYST Radicular Cyst: Demographics • Synonyms: Dental Cyst, Apical Cyst, Periapical Cyst • Most common jaw cyst – nearly 60% of all jaw • Most common cyst of the jaws, which is of inflammatory origin cysts and arises from the epithelial cell rests of Malassez, as a result of • Age predilection – 3rd to 5th decade periapical periodontitis following death and necrosis of the pulp. • Residual Cyst: Radicular cyst that remains behind in the jaws after • Gender predilection – more in males removal of the offending tooth. – Girls less likely to neglect their teeth • Inflammatory Collateral Cyst: Inflammatory cysts that occur at the – Boys more likely to sustain trauma cervical margin of the lateral aspect of a root as a consequence of an inflammatory process in a periodontal pocket. Main (1970) • Site predilection – more in maxillary anterior • Paradental Cyst: Cyst of inflammatory origin occurring on the region lateral aspects of the roots of partially erupted mandibular third – high prevalence of palatal invaginations in the molars with an associated history of pericoronitis. Craig (1976) maxillary lateral incisors • Mandibular Infected Buccal Cyst: Cyst of inflammatory origin – >> placement of silicate restorations occurring on the buccal aspects of mandibular molars in young – teeth are more prone to traumatic injuries children. Stoneman and Worth (1983) 25 26 18 Aug 2009 18 Aug 2009 Radicular Cyst: Clinical features Radicular Cyst: Radiographic features • Usually asymptomatic Radicular cyst DD from Periapical • Discovered when periapical radiographs are Granuloma taken for swelling associated with non-vital teeth • < 5 mm more likely to be • slowly enlarging swellings PA granuloma – Maxilla – buccal or palatal • > 2 cm more likely to be – Mandible – buccal or labial, but rarely lingual PA cyst • Large cysts – may show egg shell crackling Due to infection many • Pain ± cysts have diffuse margin & lack circumscribed • Aspiration or sinus formation: straw coloured appearance usually fluid that is rich in cholesterol crystals ascribed to radicular cysts 27 28 18 Aug 2009 18 Aug 2009 Periapical Inflammation – Radiographic appearances Other radiographic appearances A –Normal Bay Cyst Radicular cyst in dens in B – widening of PDL dente space – acute apical periodontitis C – Loss of Lamina dura – Early apical abscess D – Diffuse ill- defined margins – Apical abscess E-Diffuse radiopaque area – condensing osteitis F- Apical granuloma or cyst 29 30 18 Aug 2009 18 Aug 2009 5 07/01/2012 Radicular Cyst: Radiographic features Radicular Cyst: Aetiopathogenesis Residual cyst Residual cyst Dental Caries Trauma + pulp • The lesion is at the site exposure Pulp Necrosis of a previously Deep extracted tooth. periodontal • DD: The lesion must be pocket differentiated from a Periapical granuloma / keratocyst abscess PERIAPICAL CYST Residual cyst Lateral cyst 31 32 18 Aug 2009 18 Aug 2009 Radicular Cyst: Pathogenesis Radicular cyst: Phase of Initiation • Phase of Initiation Possible factors that cause proliferation of – sources of epithelium epithelial cells • Cell rests of Malassez • Bacterial endotoxins from the dead pulp • Maxillary sinus lining • inflammatory cytokines – IL-1 & IL-6, • Fistulous tract • Reduced O2 tension • Periodontal pocket • Increased CO2 tension • Phase