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Dentigerous Cyst.ppt

  1. DENTIGEROUS CYST Presented by Dr. Rahul Srivastava Professor Rama Dental College Hospital & Research Centre, Kanpur
  2. Dentigerous Cyst (DC) The term dentigerous means “containing tooth,” and this is the characteristic description of the cyst. A dentigerous cyst surrounds the crown of an unerupted tooth, expands the follicle and is characteristically attached to the cemento- enamel junction of the unerupted tooth.
  3. It is caused by alteration of reduced enamel epithelium after the completion of amelogenesis, which results in fluid accumulation between epithelium and tooth crown.
  4. Etiology of Dentigerous Cyst  The pathogenesis of dentigerous cyst is still controversial.  Three feasible mechanisms have been proposed for histogenesis of the cyst by Benn and Altini: A- They proposed that developmental dentigerous cyst might form a dental follicle and might become secondarily inflamd, a source of inflammation being a non-vital tooth.
  5. B- The second mechanism they proposed was formation of a radicular cyst at an apex of a non- vital deciduous tooth followed by eruption of its permanent sucessor into the radicular cyst resulting in a dentigerous cyst of extrafollicular origin. C- Follicle of permanent successor might get secondarily infected from either periapical inflammation of a non-vital predecessor or other source leading to a dentigerous cyst formation.
  6. Clinical features  Dentigerous cysts accounts for one of the most common odontogenic cysts, frequently seen with embedded unerupted teeth, supernumerary teeth, and odontomes.  Occurrence of dentigerous cysts with deciduous teeth is a rare phenomenon.
  7.  They are more frequent in the second and third decades of life, with a male preference and the mandible being the most influenced region.  Males are more affected with an incidence rate of 1.6:1.  These cysts can lead to cortical bone expansion, swelling, tooth mobility and displacement.
  8.  Cystic involvement of an unerupted mandibular third molar may result in a ‘hollowing-out’ of the entire ramus extending up to the coronoid process and condyle as well as in expansion of the cortical plate due to the pressure exerted by the lesion.  Cyst associated with a maxillary cuspid, expansion of the anterior maxilla often occurs and may superficially resemble an acute sinusitis or cellulitis.
  9.  Dentigerous cyst occuring in association with supernumerary tooth and mesiodens has been occasionally seen.  About 5% of all dentigerous cysts are attributed by the dentigerous cysts with supernumerary teeth. They usually occur in the maxillary anterior region in association with mesiodens.
  10.  Dentigerous cysts usually are solitary, however, bilateral and multiple cysts may be seen with syndromes such as :  Gardner's syndrome.  Mucopolysaccharidosis.  Maroteaux-Lamy syndrome.  Basal cell nevus syndrome.  Cleidocranial dysplasia.
  11.  Enamel hypoplasia seen when a dentigerous cyst commences at an early stage of development of the involved tooth whereas in cases where the cyst originating after the completion of tooth development, enamel hypoplasia is not a significant factor.
  12. Radiographic Features: While a normal follicular space is 3–4 mm, a dentigerous cyst can be suspected when the space is more than 5 mm. Radiographically, the dentigerous cyst usually occurs as a well-defined unilocular radiolucency, often with a sclerotic border.
  13. As the epithelial lining is derived from the reduced enamel epithelium, this radiolucency, typically and characterstically surrounds the crown of the tooth. A large dentigerous cyst may sometimes resemble a multilocular process, as bone trabeculae may be seen within the radiolucency. However, mostly dentigerous cysts are grossly and histopathologically unilocular processes and probably are never truly multilocular lesions.
  14. A B C A dentigerous cyst (a) unilocular and crown side type; (b) multilocular type; (c) whole-tooth type.
  15. Three types of dentigerous cyst have been described radiographically: (a) The central variety in which the tooth crown is enclosed by the radiolucency, and the crown protrudes into the cystic lumen. (a) The lateral variety in which the cyst occurs laterally along the tooth root, thus, partially surrounding the crown.
  16. (c) The circumferential variety exists when the cyst not only surrounds the crown, but also extends down along the root surface, thus, giving the impression of the tooth within the cyst.
  17. CT is useful to evaluate large lesions and can show the origin, size, and internal contents of the cyst and evaluate the integrity of the cortical plate and its relationship to the adjacent anatomic structures. Significant cortical expansion or thinning of the buccal and lingual cortical plates may be seen with larger lesions.
  18. MRI plays a key role in the diagnostic process by providing new information which enabled us to determine a consistent presumptive diagnosis and consequently a more coherent surgical approach. The T1-weighted image of the lesion showed an intermediate signal, thus not being useful for determination of the content of the lesion.
  19. Nevertheless, T2-weighted image enabled to observe an intense brightness inside the lesion, which contributed significantly to the interpretation of a probable cystic lesion rather than tumoural.
  20. CBCT is similar to panoramic radiography, however, this exam provides more precise information on the size, position, and relationship of the lesion to the surrounding structures. In classical helical computed tomography, the content of a DC typically appears as low density on CBCT (liquid-like).
  21. Dentigerous cyst Aspirate: Aspirate is Clear, pale, straw colored fluid which contains “Cholesterol crystals” and the protein content is in excess of 4.0 gm per 100 ml. Histologic Features  Composed of a thin connective tissue wall with a thin layer of stratified squamous epithelium lining the lumen.  Rete peg formation is generally absent except in cases that are secondarily infected.
  22.  The connective tissue wall is frequently quite thickened and composed of a very loose fibrous connective tissue or of a sparsely collagenized myxomatous tissue. An additional finding, especially in cysts which exhibit inflammation, is the presence of Rushton bodies within the lining epithelium.
  23. Differential diagnosis : Hyperplastic follicle. Odontogenic keratocyst. Ameloblastic fibroma. Cystic ameloblastoma. Treatment Various treatment plans proposed for dentigerous cysts are: (a) Surgically removing the cyst. Consideration should be taken not to damage the associated permanent tooth.
  24. (b) Cyst enucleation along with extraction of the involved tooth. (c) Marsupialization technique - involves removal of the cyst, however, the developing tooth is preserved. The offending tooth playa a major role in deciding the type of surgical intervention required for the dentigerous cyst.
  25. Isolated lesions in young patients, where preservation of the teeth is desirable, marsupialization is the recommended treatment option. Potential Complications The development of an ameloblastoma either from the lining epithelium or from rests of odontogenic epithelium in the wall of the cyst.
  26. The development of epidermoid carcinoma from the same two sources of epithelium. The development of a mucoepidermoid carcinoma, basically a malignant salivary gland tumor, from the lining epithelium of the dentigerous cyst which contains mucussecreting cells, or at least cells with this potential, most commonly seen in dentigerous cysts associated with impacted mandibular third molars.
  27. References Shear M, Speight P. Cysts of the Oral and Maxillofacial Regions. 4th ed. Oxford Blackwell Publishing Ltd.; 2007. p. 5978. Al-Talabani NG, Smith CJ. Experimental dentigerous cysts and enamel hypoplasia: their possible significance in explaining the pathogenesis of human dentigerous cysts. J Oral Pathol. 1980 Mar;9(2):82–91.
  28. Boyczuk MP, Berger JR, Lazow SK. Identifying a deciduous dentigerous cyst. J Am Dent Assoc. 1995;126:643–4. Roberts MW, Barton NW, Constantopoulos G, Butler DP, Donahue AH. Occurrence of multiple dentigerous cysts in a patient with the Maroteaux-Lamy syndrome (mucopolysaccharidosis, type VI) Oral Surg Oral Med Oral Pathol. 1984;58:169–75.
  29. Benn A, Altini M. Dentigerous cysts of inflammatory origin. A clinicopathologic study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1996;81:203–9. Hasan S, Ahmed SA, Reddy LB. Dentigerous cyst in association with impacted inverted mesiodens: Report of a rare case with a brief review of literature. Int J Appl Basic Med Res. 2014 Sep;4(Suppl 1):S61-4. doi: 10.4103/2229-516X.140748.
  30. Terauchi et al An Analysis of Dentigerous Cysts Developed around a Mandibular Third Molar by Panoramic Radiographs. Dentistry Journal 2019;7:1-9. Regezi AJ, Sciubba JJ, Jordan RC. Oral Pathology: Clinical-Pathologic Correlations. 5th ed. St. Louis: Saunders; 2008. pp. 242–4.
  31. Zerrin E, Husniye DK, Peruze C. Dentigerous cysts of the jaws: Clinical and radiological findings of 18 cases . J Oral Maxillofac Radiol 2014;2:77-81
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