1. Differential diagnosis of Multilocular Radiolucencies – Part 1
Specific learning objective
To know the criteria for defining a multilocular radiolucency.
To enumerate different diseases with multilocular appearance
To know the differentiating radiographic features among them.
DR.S.KARTHIGA KANNAN PROFESSOR ORAL MEDICINE & RADIOLOGY

2. Criteria for Multilocular
Radiolucencies

3. Periapical Radiolucency
Pericoronal Radiolucency

4. Inter-radicular Radiolucency

5. Introduction Multilocular radiolucency Pathogenesis
Multilocular radiolucency classification
Multiple, adjacent, frequently coalescing and overlapping pathologic compartments in bone
True multilocular lesions contains two or more pathologic chambers partially separated by septa of bone
More common in mandible
Multilocular cyst
Odontogenic keratocyst
Simple /Traumatic bone cyst
Aneurysmal bone cyst
Ameloblastoma
Odontogenic myxoma
Central giant cell granuloma
Cherubism
Giant cell lesion of hyperparathyroidism
Vascular malformations – central hemangioma

6. Different Multilocular Radiolucent Appearances
Soap Bubble Appearance –
Consisting of circular compartments of varying size and appear to somewhat overlap.
Honey comb appearance –
- Lesions whose compartments are small
and tend to be uniform in size
Tennis racket appearance –
Lesions composed of angular compartments
that result from development of more or
less straight septa.

7. Keratocystic Odontogenic Tumor Or Odontogenic keratocyst
Multilocular cyst
Keratocystic Odontogenic Tumor
Or Odontogenic keratocyst
The pathology appear unilocular or multilocular cyst clinically but it enlarge by the growth of lining epithelium showing tumor like character –Mural Growth
Commonly seen in mandible premolar and molar region
Age predilection – 2nd to 3rd decade
Sex predilection – Male > Female
Grows anterio-posterior initially and asymptomatic and may be noticed on routine examination
Later may cause swelling and facial asymmetry, but never causes paresthesia unless secondarily infected.

8. Radiographic appearence
Location
90% posterior body of mandible behind canine
Epicentre above inferior alveolar canal
Border – well defined, uniform or scalloped
Shape – Unilocular or multilocular, May occur in a pericoronal position mimicking like Dentigerous cyst
Size – In initial stage – Anterioposterior dimention is more than bucco-lingual direction
Internal structure-
Uniformly radiolucent, can have curved trabeculae or septa.
Effects on adjacent structure -may displace the root/tooth, inferior alveolar canal or cause root resorption, In maxilla encroches antrum.
Number – if multiple OKC are detected in Jaw ,should rule out Nevoid Basal cell carcinoma syndrome(NBCC)

9. Consistency: Depending on cortical plates thickness it may be bony hard, if thin – Tennis ball consistency, futher thinning results in egg shell crackling and if completely destroyed then soft and fluctuant cystic consistency.
Aspiration : straw colored fluid with flecks of keratin or thick yellow cheesy keration.
Differential Diagnosis
Ameloblastoma
Giant cell lesions of Hyperparathyroidism
Odontogenic myxoma
Management
Enucleation
Marsupialization with chemical cauterizing solution

10. Aneurysmal Bone Cyst
Definition – it’s a reactive bone lesion. It represents an exaggerated proliferative response of vascular tissue in bone.
It was separated as a distinct entity by Jaffe & Lichenstein in
Aneurysmal bone cysts (ABC) are expansile osteolytic lesions with thin wall cystic cavities without epithelial lining.
Age – In less than 30 yrs
Sex - common in female patient.
Seen as a fairly rapid bony swelling.
Pain is an occasional complaint & involved area is tender on palpation
Intra-operative finding – appear as blood soaked sponge with large pores representing cavernous spaces of lesion

11. Radiographic Features
Location -Mandibular molar and ramus is more involved
Periphery – well defined, circular in shape
Internal Structure – initial lesions are radiolucent – multilocular with internal septa.
Surrounding Structures – extreme expansion of outer cortical plate – displace and resorb teeth.
Differential Diagnosis
Traumatic bone cyst
Central giant cell granuloma – ocuur in anterior reion of mandible
Ameloblastoma – occurs in older age
Management
Surgical curettage – autogeneous bone graft.

12. Central Giant Cell Granuloma
Clinical features
Age - 2nd decade.
Male to Female ratio = 1: 2
Mandible > Maxilla
Anterior region > Posterior region
Painless – Rapid growing swelling – with tenderness on mild palpation
Overlying mucosa is bluish – brown in color
Synonyms – giant cell reparative granuloma, giant cell lesions & Giant cell tumor
Introduced by Waren – 1837
Described by Jaffe – 1953 – Giant Cell Reparative Granuloma
Definition – reactive lesion to unknown stimulus
not a true neoplastic lesion
Cane be associated with Hyperparathyroidism

14. Radiographic Features
Location – mandible – anterior to 1st molar or anterior to cuspids lesions cross midline.
Periphery – well defined lesions borders
Internal Structure – subtle granular pattern of calcification – ill defined wispy septa.
Surrounding Bone
- Causes expansion of cortical bone in maxilla cortical plate is destroyed more easily
– displace and resorb teeth, missing lamina dura, displaces inferior alveolar canal inferiorly.
Differential Diagnosis
Ameloblastoma
Odontogenic Myxoma
Aneurysmal Bone Cyst
Management
Medical Managment
Corticosteroid injections –
Exact mechanism is not known – inhibit bone resorption
Calcitonin – causes increased influx of Ca in bones – antagonist to parathyroid.
Synthetic Salmon Calcitonin – nasal spray (osteospray)
Interferon – differentiate mesenchymal stem cells into osteoblasts , thereby enhancing bone formation in CGCG.
Surgical excision with recurrence rate of 11 – 49%

15. Ameloblastoma Clinical Features
It is a true benign neoplasm of Odontogenic epithelium
Locally invasive
It is the most common odontogenic tumor
Arises from reminents of dental lamina or dental organ
Types
Solid / multicystic
Unicystic
Desmoplastic
Bone resorption is mediated by Interleukin 1 and Interleukin 6 mainly synthesized in stellate reticulum like cells
Clinical Features
More common in males
Age prdilection – 40 yrs
Grows slowly with expansion of jaw producing facial asymmetry
It can cause migration, tipping, mobility and root resorption.
Painless, No paresthesia
Initially bony hard in cosistency later may have egg shell crackiling and cystic consistency
In multi cystic variant aspiration may yield fluid.

16. Radiographic appearance
Effect on adjacent structure
Root resorption, displacement
Displacement of tooth, inferior alveolar canal
Cortical bone expansion is seen.
Maxilla is rarely involved but dangerous as the cortical plates are thin and mayextend to sinus, nasal walls and orbital floor
Differential Diagnosis –
Odontogenic keratocyst
Central giant cell granuloma
Treatment – enbloc surgical resection
Location –
80% in mandible Molar ramus area
Borders –
well defined with cortical border and may show scalloping
Shape –
Unilocular or multilocular
Soap bubble / honey comb
Pericoronal also.
Internal structure –
Uniformly radiolucent
Curved septa / trabeculae
Desmoplastic type shows irregular sclerotic raioopaque mass.

18. Thank you
Any questions???