Keratocystic odontogenic tumors(KCOT) or Odontogenic Keratocyst(OKC)OKC

Keratocystic odontogenic tumors or KERATOCYSTIC ODONTOGENIC TUMOR is a distinctive form of developmental odontogenic cyst. in this presentation we will examine pathological , clinical and Especially it's radiographical features. at the end we will investigate a number of case reports from literature.

1. M. Lalegani Odontogenic Keratocyst Keratocystic Odontogenic Tumor

2. Epidemiology Male between 10 and 40 years of age 60% An unerupted tooth is involved in the lesion 25% -40% Female 60% 20%-40 % Slight predilection for male

3. Disease Mechanism 01

4. Derived from the dental lamina and is distinctive for its thin, keratinized epithelium ( four to eight cells thick ). Your Logo White and Pharoah's Oral Radiology E-Book: Principles and Interpretation Oral & Maxillofacial Pathology: Neville et al.

5. Your Logo V iscous or cheesy material inside (If Aspirate.) In contrast to most cysts, which are thought to enlarge solely by intraluminal osmotic pressure , the epithelium in the OKC appears to have some innate growth potential . Occasionally budlike proliferations of epithelium grow from the basal layer of the epithelium into the underlying connective tissue  Multilacularity Human homologue of Drosophila PTCH gene  non- cyctic behavior .

6. OKC Greater growth potential than most other odontogenic cysts Higher recurrence rate Possible association with the nevoid basal cell carcinoma syndrome Although there In the latest WHO monograph on head and neck tumors, this lesion has been given the name Keratocystic odontogenic tumor (KCOT). Molecular& genetic findings warrant reclassification of the OKC as a neoplasm (KCOT) KCOT

7. Clinical Features 02

8. KCOT OKCs can develop in association with an unerupted tooth or as solitary entities in bone . No symptoms / Mild swelling may occur Pain? Due to secondary infection Great propensity for recurrence  because of small satellite cysts or fragments of epithelium left behind after surgical removal

9. Imaging Features 03

10. Your Logo Location The epicenter is located superior to the inferior alveolar canal . Assassinated with unerupted teeth  difficult to distinguish from Dentigerous cysts . A change to the contour of the follicle coronal to the cementoenamel junction in an OKC. where the follicle enlarges smoothly and uniformly from the cementoenamel junction.

11. Periphery A well-defined and corticated periphery. Border may scallop a thick bone cortex.

12. Your Logo Most commonly radiolucent. Curved internal septa may be present, giving the lesion a multilocular appearance . Internal structure

13. An important characteristic of the OKC is its propensity to grow through the bone without significant bone expansion

14. Your Logo This “tunneling” type of growth  all body of the mandible Except for the ramus and coronoid process (where considerable expansion may be seen due to the very thin nature of the bone in these locations) Tunneling  Also in alveolar process of maxilla . Adjacent to an airspace such as the nasal fossa or maxillary sinus, OKCs expand in a concentric and hydraulic manner  As the cyst enlarges, it can reduce the volume of the adjacent airspace . The inferior alveolar nerve canal may be displaced inferiorly . Occasionally displace teeth and resorb tooth roots , but to a lesser degree than dentigerous cysts.

15. Axial (A) and buccal palatal (B) cone beam computed tomographic images of a maxillary odontogenic Keratocyst (OKC ). Note that the OKC is generally confined to the borders of the bone except superiorly , where there has been hydraulic expansion of the nasal floor

16. Differential Interpretation 04

17. Your Logo I n a pericoronal position  Dentigerous cyst The lesion is likely to be an OKC if the 1- cyst periphery is associated with the tooth at a point apical or coronal to the CEJ or 2- if little or no expansion of the bone has occurred. Internal structure Differential Diagnosis The scalloped margin or a multilocular appearance  ameloblastoma . Expansion. In maxilla  Large lateral periodontal cysts. Expansion. The mild expansion and multilocular appearance of the odontogenic myxoma. A simple bone cyst (SBC) often has a scalloped border and minimal bone expansion. The margins of an SBC usually are more delicate and often difficult to detect, and there is little or no effect on the teeth or the supporting structures .

18. Management 06

19. Your Logo OKC is suspected? Refer to OMFR. Cortical perforation? MDCT should be used to investigate the possibility of soft tissue extension . No Cortical perforation? CBCT Recurrence rate is high  precise extent required searching for soft tissue perforation using MDCT Resection/Curettage/Marsupialization (to reduce the size of large lesions before surgical excision) Important to complete removal of the cystic walls so as to reduce the chance of recurrence. After surgery  reexamine in regular intervals . Recurrence is common within first 5 years but can occur as much as 10 years .

20. CASE REPORTS

21. Case 1

22. Case 2

23. Case 3

24. Thank For Your Kind Attention.