Diseases of the Jaw II

Question 1

What are fibro-osseous lesions?

Answer 1

Lesions where normal bone is replaced by fibrous tissue in which abnormal bone is laid down

Question 2

Radiographic features of fibro-osseous lesions?

Answer 2

Initially radiolucent bcos of bone loss
Later more mixed radiodensity lesion as the abnormal bone is laid down

Extent of this varies with the lesion, some lesions are almost always radio-opaque or radiolucent

Question 3

Types of fibro-osseous lesions?

Answer 3

Neoplastic: (Cemento) ossifying fibroma
Developmental: fibrous dysplasia
Reactive: (Cemento) osseous dysplasia

Osteodystrophy
- Ideopathic - paget’s disease

Question 4

What is an ossifying fibroma?

Answer 4

Benign neoplasm composed of fibrous tissue which forms spicules, islands of cementicles of bone

20-50yrs old, average 35yrs 
- Children may be affected 
Females>Males (3:1)
Mandible most common site (65%)
- Premolar or molar region
- May be in craniofacial bones

Question 5

Ossifying fibroma histology and radiographic appearance>

Answer 5

Lesion has well defined margin and is separated from cortical bone

Early stage
- Well defined, radiolucent, not corticated, root resorption, expansion of mandible
Mature
- Increased amount of bone being laid down
- Cotton wool like

Question 6

Patient management of ossifying fibroma?

Answer 6

Conservative enucleation
Resection
Low recurrence rate

Question 7

Fibrous dysplasia features?

Answer 7

Developmental disorder of bone
- Mutations in GNAS1, not inherited
25% affect head and neck 
15-30yrs old
Males = females
Painless smooth enlargements/swellings
Maxilla most frequent site in H&N
Poorly demarcated radiopacity

Histology:

• Fibrous tissue replacing bone (fibroblasts)
• Alteration of normal bone and marrow spaces
• Retraction artefacts around bone (white areas around bone) and the stroma is less cellular than ossifying fibroma

Question 8

Radiographic appearance of fibrous dysplasia?

Answer 8

Stippled orange peel appearance

Merges with surrounding bone

Question 9

Clinical variants of fibrous dysplasia?

Answer 9

Monostotic (single bone invovled):
• Single skeletal lesions
• Ribs and femur most common site
• 25% of lesions in head and neck
• Age 15-30 (average 25)
• Males = females

Polyostotic (multiple bones involved):
• Multiple lesions
• Head & neck involved in 50%
• Age: <15
• 75% in females
• May be part of McCune-Albright’s syndrome

Question 10

Patient management of fibrous dysplasia?

Answer 10

Growth stabilises over time (skeletal maturity)
Debulking and contouring of bone
- Recurrence if during growth phase
- Can reactivate in pregnancy

Surgical removal
Orthodontics and orthognathic surgery

V low risk of malignant transformation

Question 11

Differences of fibrous dysplasia and ossifying fibroma?

Answer 11

Fibrous dysplasia

• Poorly defined lesion
• No margin
• Males = females
• Often maxilla

Ossifying fibroma

• Well defined lesion
• Clear margin
• Females > Males
• Often mandible

Question 12

(Cemento)osseous dysplasias features?

Answer 12

A clinicopathological spectrum of reactive lesions
Age 30-50
Often females
Often multiple radiopacities in the tooth bearing areas of the jaws
Composed of irregular trabeculae of woven bone and cementum in fibrous stroma

Question 13

Classification of osseous dysplasias?

Answer 13

• Focal -  Single lesions
• Periapical - Multiple lesions at apex of the
teeth
• Florid - Multiple lesions throughout
the jaws

Question 14

Periapical osseous dysplasia features?

Answer 14

Multiple mixed radiodensity lesions

Question 15

Florid osseous dysplasia: familial gigantiform cementoma features?

Answer 15

Usually described as a variant of Florid OD
• Appears to be a different entity to Florid OD
• Autosomal dominant inheritance pattern
• M=F
• Found in white patients

Question 16

What is Paget’s disease?

Answer 16

Rare disorder affecting bones
Bone turnover increased and no longer related to functional demands
Early stages: bone becomes very vascular, may result in heart failure
Later stages: bone becomes sclerotic and shows numerous resting and reversal lines

Question 17

Clinical features of paget’s disease?

Answer 17

Legs become bowed
Enlargement of the skull causing constriction of foramen: deafness, hats do not fit
Jaws become enlarged: tooth spacing and dentures do not fit

Question 18

Dental implications of paget’s disease?

Answer 18

Bone sclerotic: difficulty with extractions and prone to infections
Hypercementosis: difficulty with extractions
Bisphosphonates may complicate matters
Increased incidence of osteosarcomas and other bone malignancy

Question 19

Giant cell lesions of the jaws - what characterises them?

Answer 19

Characterised by replacement of bone by fibrous tissue containing numerous multi-nucleate giant cells (osteoclasts)

Cherubism
Central giant cell granuloma
Hyperparathyroidism

Question 20

What is cherubism?

Answer 20

Developmental condition
• Autosomal dominant inheritance
• Bilateral expansion of posterior mandible
• May regress after puberty

Histology - vascular multinucleated giant cell lesions

Question 21

Giant cell lesions of the jaws: features?

Answer 21

Reactive or hyperplastic lesions
• Benign but may be locally destructive
• Age: 10-30
• 60% in females
• Usually mandible
• Characterised by osteoclasts

• Giant cell granuloma (central or peripheral)
• Hyperparathyroidism (Brown tumour)

Question 22

Central giant cell granuloma

Answer 22

Well demarcated radiolucency
Composed of giant cells - osteoclasts
May be destructive - root resorption

Question 23

Pt management of giant cell lesions of jaws?

Answer 23

Blood biochemistry (serum calcium initially)
Curettage
Resection
20% recurrence rate

Question 24

Types of hyperparathyroidism?

Answer 24

Primary: parathyroid adenoma (90%)
Secondary: renal failure, malabsorption
Hereditary: autosomal dominant

Radiolucent lesion - demin of sinus outline and inferior border of mandible
Brown tumour identical to central giant cell granuloma

Question 25

Blood biochemistry of hyperparathyroidism?

Answer 25

Raised serum calcium, phosphate

Parthyroid hormone

Question 26

Management of hyperparathyroidism?

Answer 26

Surgery