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
Mechanism01

4. o 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
 Viscous 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
1. Greater growth potential than most other
odontogenic cysts
2. Higher recurrence rate
3. 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.

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

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

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

15. 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.

16. • 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

17. Differential
Interpretation04

18. Your
Logo
 In 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.

19. Management 06

20. 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.

21. CASE
REPORTS

22. Case1

23. Case2

24. Case3

25. Thank For Your Kind Attention.