1. Cystic Lesions Of The Jaws Radiological Interpretation
Dr ASHRAF ABU KARAKY
Assistant Professor in Oral and Maxillofacial Surgery
The University of Jordan

2. Definition
A cyst is defined as a pathological cavity containing fluid, semi-fluid or gaseous material other than pus. It is frequently but not always lined by epithelium.

3. Classic radiographic appearance well defined round or oval arel of RL , circumscribed by a sharp RO margin
Variation in degree of bone distruction, expansion
Unilocular or multilocular

4. Diagnosis of Radiolucent Lesions of the Jaws
Step 1
Systematically describe the RL
. Site
. Size
. Shape
. Outline/ edge or periphery
. Relative radiodensity
. Effects on adjacent surrounding structures
. Time present

5. Decide whether or not the RL is: 1- A normal anatomical structure
Step 2
Decide whether or not the RL is:
1- A normal anatomical structure
2- Artefactual
3- Pathological:
a. Congenital.
b. Developmental
c. Acquired
1- mandible; mental foramen, id canal, developing tooth bud, maxilla; sinus, nasal fossa, nasopalatine fossa
2. overexposure, superimposition of airshadows

6. Step 3 IF acquired RL: - Infection; Localized to apical tissue
Spreading within the jaw
- Traumatic lesions
- Cysts
- Tumours
- Giant cell lesions
- Fibro-cemento-osseous lesions
- Idiopathic lesions

7. Step 4
Consider the classification and subdivision of cysts and other RL s within each of the other main disease categories

8. Step 5
Compare the radiological features of the unknown RL with the typical RG features of these possible conditions.
Construct a list showing in order of likelihood all the conditions that the lesion might be (radiological differential diagnosis)

9. Classification Browne 1975 and Main 1985
A- Odontogenic Cysts
1. Inflammatory Odontogenic Cysts
-Radicular
Residual
Lateral
- Paradental
2. Developmental Cysts
- Odontogenic Keratocyst
- Follicular cyst Dentigerous
Eruption
- Lateral Periodontal cyst
- Glandular Odonotogenic; Sialo odontogenic cyst
- Gingival cysts of adults
- Gingival Cysts of Infants (Epstein pearls)
B- Non-Odontogenic Cysts
1. Fissural Cysts
- Nasopalatine duct cyst
- Nasolabial cyst
- Median Madibular Cyst
- Median Palatine Cyst
- Globulo-Maxillary Cyst
2. Bone Cysts
- Solitary bone cyst
- Aneurysmal bone cyst
- Stafne Cyst ( Lingual Salivary Gland Inclusion Defect)
3. Soft tissue cyst
- Dermoid
- Branchial
- Thyroglossal duct cyst
- Salivary cyst

11. Inflammatory Odontogenic Cysts
Radicular
Residual
Lateral
Paradental

12. Radicular Cyst
Develops from the epithelial remnants of Hertwig s sheath- the cell rests of Malassez
Age usually adults, yrs
Frequency: most common of all jaw cysts (70%)

13. Typical radiographic features
Site: Apex of any non-vital tooth.
Size: Usually 1.5-3cm in diameter
Shape: Round
Monolocular
Outline: Smooth
Well defined
Well corticated if longstanding and continuous with the lamina dura of the associated tooth
Radiodensity: Uniformly radiolucent

14. Cont.// Radiographic Features
Effect: Adjacent teeth- displaced, rarely resorbed
Buccal expansion
Displacement of the antrum

15. Residual Cyst
This term refers to radicular (dental) cyst remaining after the causative tooth has been extracted
Age: Adults > 20yrs
Site: Apical regions of tooth bearing portion of the jaws

16. Typical radiographic features
Size: Variable, 2-3 cm in diameter
Shape: Round, Monolocular
Outline: Smooth, Well defined
Usually well corticated
Radiodensity: Uniformly radiolucent
Effects: -adjacent teeth displaced, rarely resorbed
-Buccal expansion
-Displacement of the antrum

17. Lateral Radicular Cyst
Form at the side of a non-vital tooth as a result of opening of a lateral branch of the root canal.

18. Paradental Cyst
Results from inflammation around partially erupted teeth, particularly mandibular third molars.
Age: 20-25yrs
Teeth Vital- Pericorinitis

19. - Odontogenic Keratocyst - Follicular cyst Dentigerous cyst
Developmental Cysts
- Odontogenic Keratocyst
- Follicular cyst Dentigerous cyst
Eruption Cyst
- Lateral Periodontal cyst
- Glandular Odontogenic Cyst
- Gingival Cyst of Adults
- Gingival Cyst of Newborn (Epstein Pearls)

20. Dentigerous (follicular cyst)
Develop from the remnants of the reduced dental epithelium
Age: Usually adolescents or young adults (20-40yrs), occasionally the elderly.
Frequency: About 20% of all Cysts

21. Typical radiographic features
Site: Associated with the crown of an unerupted and displaced tooth, typically teeth where eruption is impeded, e.g. upper 3, lower 8
Size: Very variable, cyst suspected if follicular space exceeds 3 mm but may grow to several cms in diameter and extend up into the ramus
Shape: - Round or oval, typically enveloping the crown symmetrically
- Monolocular
- 3 varieties are described depending on the cyst – crown relationship; central,lateral circumferential

22. Cont.// Radiographic Features
Outline: - Smooth
- Well defined
- Often Well Corticated
RD: Uniformly RL
Effects: - Associated tooth; unerupted and displaced
- Adjacent teeth: Displaced Rarely resorbed
- Buccal or medial expansion, can be extensive with large cysts causing facial asymmetry and displacement of the antrum

23. Eruption Cyst
dentigerous cyst in the soft tissue

24. Odontogenic Keratocyst
Develop from the epithelium of the dental lamina (the cell rests of Serres)
Age: Very variable, 2nd and 4th decade
Frequency : less than 5% of all odontogenic cysts

25. Radiographic Features
Site: Posterior body / angle of the mandible extending to the ramus
Anterior maxilla in canine region
Size: Variable, but often large in the mandible
Shape: - Oval, extending along the body of the mandible with little mediolateral expansion
- Pseudolocular or multilocular
Outline: -Smooth
- Well defined
- Often well corticated

26. Cont// Radiographic Features
Radiodensity: Uniformly radiolucent
Effects: - Adjacent teeth- minimal displacement, rarely resorbed
- Extensive expansion
within cancellous bone typically out of the proportion to the minimal degree of medio-lateral expansion.

27. Gorlin s Syndrome (nevoid basal cell carcinoma syndrome)
Multiple Odontogenic Keratocysts
Multiple Basal Cell Carcinomas
Skeletal Anomalies, e.g. bifid ribs and calcification of the flax cerebri.

28. Developmental Lateral Periodontal Cyst
Uncommon developmental intraosseous cysts form beside a vital tooth.
Age: Variable
Frequency: Uncommon

29. Radiographic Features
Site: Between roots of lateral incisor and canine
Size: Usually small in size
Shape: Round
Outline: Well- demarcated
RD: RL
Effect: Adjacent teeth- May be displaced
May erode through the bone to extend into the gingiva

30. Glandular Odontogenic Cyst
Very rare
Age: Middle- aged adults 49yrs
Site: 89% Mandible, anterior region
many cross the midline
Size: vary up to several cms
RD: Uniformly RL
Shape: multilocular st unilocular
Outline: Well demarcated
Effects: Expansion
Paresthesia
Aggressive, glandular or salivary behavior an indication of multipotential odontogenic epth

31. Gingival Cyst
Dental lamina cysts of the newborn, (Bohns nodules;Epsteins pearls)
Gingival cysts of adults: st erode the underlying bone
Up to 80% of newborn infants, due to profileration of the epithelial rests of Serres
Epsteins may arrise from nonodontogenic epithelium along the midpalatine raphae
Resolve spontaneously
Adults >40, unlike to occur after enucleation

33. Non-Odontogenic Cysts
Developmental Cysts
Nasopalatine duct cyst
Nasolabial cyst
Median Palatine Cyst
Globulo-Maxillary Cyst
Median Mandibular Cyst

34. Nasopalatine Duct / Incisive Canal Cyst
Develop from epithelial remnants of Nasopalatine Duct or Incisive Canal.
Age: Variable, but most frequently detected in middle age (40-60 yrs olds).
Frequency: Most Common of all non-odontogenic cysts, 1% of total population

35. Radiographic Features
Site: Midline, anterior maxilla just posterior to the upper central incisors
Size: Variable, but usually from 6mm to several cm s in diameter.
Shape: Round or Oval
Monolocular
Outline: Smooth
Well defined
Well corticated
RD: Uniformly RL but RO shadows st superimposed
Effects: -Adjacent teeth- distal displacement, rarely resorbed
-Palatal expansion
Superimposition of the nasal septum or anterior nasal spine may cause he cyst to appear heart-shaped or resemble an inverted tear drop

36. Differentiation between Nasopalatine Duct Cyst and a large normal Naopalatine foramen?
. Size
. Outline
. Relative RD
. Shape?
> 6mm cyst
Foramina usually defined laterally but not all the way arround
Cyst more RL having resorbed the surrounding bone
Foramina are usually round or oval!

37. Median mandibular cyst
Develop from embryonic epithelial remnants in the symphyseal region of the mandible
Epithelial remnants in this area during embryonic development is not possible, cysts that develop in this region are certainly odontogenic, lateral periodontal or keratocyst

38. Median Palatine Cyst

39. Globulo-Maxillary Cyst
Have been traditionally ascribed as proliferation of sequestrated epithelium along the line of fusion of embryonic processes
No evidence of epithelium being buried this fasion
Odontogenic cysts of variant types

40. Nasolabial Cyst
Rare fissural cyst, arise at the junction of the globular process, the lateral nasal process and the maxillary process as a result of proliferation of entrapped epithelium along the fusion line.
X-ray findings are negative
Produce swelling at the attachment of the ala of the nose may encroach the nasal cavity

42. 2. Bone Cysts - Solitary bone cyst - Aneurysmal bone cyst
- Stafne Cyst ( Lingual Salivary Gland Inclusion Defect)

43. Solitary (simple) bone cyst
Unknown aetiology, may be associated with trauma.
Age: Children and young adults < 20yrs

44. Radiographic Features
Site: Premolar and Molar region of the Mandible
Rarely, anterior Maxilla
Size: Variable, up to several cms
Shape: Monolocular
Irregular, upper border arches between the roots of the teeth
Outline: - Smooth and undulating
- Moderately well defined
- Moderately well or poorly corticated
RD: uniformly RL
Effects: - Adjacent Teeth- minimal or no displacement, v rarely resorbed
- Minimal or no expansion of the jaw

45. Aneurysmal Bone Cyst More accurately classified as Giant Cell Lesion
Localized non-neoplastic proliferative lesion of vascular tissue, containing Giant Cells.
Age: Usually < 20yrs old
Frequency: Rare.

46. Radiographic Features
Site: Body/ posterior mandible
Maxilla occasionally
Size: Variable, up to several cms
Shape: - Mono or Multilocular
- Faint internal trabeculation, may produce a soap-bubble appearance.
Outline: - Smooth
- Moderately well defined
- Peripheral cortex even when large
RD: RL with evidence of faint, random internal trabeculations
Effects: - Adjacent teeth- displaced, rarely resorbed
- Buccal and lingual expansion of the cortex, often marked and described as Ballooning or Blow-Out

47. Stafne Cyst ( Lingual Salivary Gland Inclusion Defect)
Well defined depression in the lingual surface of the posterior body of the mandible
Usually asymptomatic and are incidental RG finding
At surgical exploration an aberrant lobe of the submandibular g or occasionally fat is found to extend into the depression

48. Radiographic Features
Site: usually near the angle of the mandible, above the inferior border, inferior to the mandibular canal and posterior to the third molar
Size: can penetrate the mandible to depths extending from the lingual to the buccal cortex
Shape: Ovoid or Rectangular
Outline: - Well defined
RD: Uniformly RL
Effects : Incidental

49. - Thyroglossal duct cyst - Salivary cyst
3. Soft tissue cyst
- Dermoid
- Branchial
- Thyroglossal duct cyst
- Salivary cyst
Dermoid cystic teratoma derived from embryonic germinal epithelium
Branchial: remnants of branchial arches

50. Dermoid Cyst

51. Branchial Cyst

52. Thyroglossal Duct Cyst

53. Salivary Cysts

54. Calcifying Odontogenic Cyst (Gorlin Cyst)
Classified by WHO as odontogenic tumour
Presents typically as radiolucency resembling other odontogenic cysts
As it develops, a variable amount of calcified material becomes evident, scattered throughout the RL. The RO can range from small flecks to large masses.
Age: Variable, usually adults < 40 yrs old

55. Radiographic Features
Frequency: rare
Site: Usually mandible (70%)- anterior or premolar regions, occasionaly associated with an odontome or errupted tooth.
Size: Usually small, 1-3 cm in diameter but can become very large, involving much of the mandible.
Shape: Variable, but usually monolocular
Outline: Smooth, well defined
Often corticated
RD: initially RL, in advanced lesions – variable amount of calcified RO material
Effects: - Adjacent teeth usually displaced and / or resobed
- Bony expansion

86. calcifying

87. Thank you