Fibro-osseous Bone Disorders Flashcards
What is Fibrous dysplasia?
Skeletal anomaly in which normal bone is replaced by poorly organised immature bone and fibrous tissue
Non-neoplastic
What age group is most affected by fibrous dysplasia?
Children & adolescents (as affects actively growing bone & progression ceases with age)
What is the cause of fibrous dysplasia?
Mutation in GNAS gene
What are the two classifications of fibrous dysplsia?
1) Monostotic (affects single bone) – More common
2) Polyostotic (multiple bones)
What is the presentation of fibrous dysplasia?
Asymmetrical, painless swelling – often in children & adolescents
May be associated with Albright syndrome
What are the most common sites of fibrous dysplasia?
Craniofacial bones (Maxilla > Mandible) & femur
What can be seen on this radiograph?
Fibrous dysplasia
Ill-defined border & loss of lamina dura
Early stage = More fibrous (radiolucent)
What are some histological features to look out for in fibrous dysplasia?
Islands of fibrous tissue embedded within bone
Immature woven bone with lack of osteoblasts
What are Ossifying/Cemento-ossifying Fibromas?
Benign, fibro-osseous NEOPLASM that affects jaws & craniofacial skeleton
(continue to enlarge, not self-limiting as with Fibrous Dysplasia)
What are the different pathological variants of ossifying/cemento-ossifying fibromas?
Cemento-Ossifying Fibroma (COF)
Juvenile Trabecular Ossifying Fibroma (JTOF)
Juvenile Psammomatoid Ossifying Fibroma (JPOF)
At what age groups do the different variants of ossifying/cemento-ossifying fibromas present?
Peak incidence in 3rd-4th decade (F>M 5:1) Cemento-Ossifying Fibroma (COF)
Children & Adolescents
Juvenile Trabecular Ossifying Fibroma (JTOF)
Juvenile Psammomatoid Ossifying Fibroma (JPOF)
NB: JTOF/JPOF multiple recurrence
Describe the expansion of lesions for ossifying/cemento-ossifying fibromas
Painless expansion of buccal & lingual plates of affected bone
Larger lesions: Expansion of lower border of mandible or maxillary antrum floor
Radiographically what would you see for a ossifying/cemento-ossifying fibroma?
Well-circumscribed & clearly demarcated lesion from surrounding normal bone*
Early lesions = Radiolucent
Later = Progressively more radiopaque
*distinguishing feature from Fibrous Dysplasia
Radiographically how can you distinguish between a cemento-ossifying fibroma and a cemento-blastoma?
No connection with roots of teeth for a cemento-ossifying fibroma
What is the managment for Ossifying/cemento-ossifying fibromas
Surgical excision
NB: JTOF/JPOF multiple recurrence
What is Cemento-osseous Dysplasia?
NON-Neoplastic, fibro-osseous condition affecting tooth-bearing regions (alveolar bone) of mandible & maxilla
What are the different classifications of cemento-osseouf dysplasia and what do they mean?
1) Periapical (typically anterior mandibular teeth)
2) Focal (single tooth)
3) Florid (multiple)
4) Familial Gigantiform Cementoma (genetic)
Comment on the vitality of teeth affected by cemento-osseous dysplasia
Teeth remain vital
What may you see radiographically for a cemento-osseous dysplasia lesion?
Well-circumscribed & surrounded by a thin radiolucent rim
Radiolucent, mixed or radiopaque – Increased density as lesions mature
What is the managment for Focal Cemento-Ossifying dysplasia?
No tx & monitor
What is the managment for Florid Cemento-Ossifying dysplasia?
Monitor closely (osteomyelitis complications)
What is Paget’s disease?
Paget’s disease of bone disrupts the normal cycle of bone renewal, causing bones to become weakened and possibly deformed
What genetic and environmental factors could potentially cause paget’s disease?
Genetic links = Chromosome 18q
Environmental links = Paramyxoviridae viral infection
What age group is most affected by Pagets disease?
Patients over 40 years old
What are some manifestations of Pagets disease?
Susceptibility to fracture and deformity of weight bearing bones
Cranial nerve disorders, deafness, vertigo and tinnitus occur as a consequence of nerve compression in foramina
What occurs during the Osteolytic stage of Pagets disease?
What may you also see on a radiograph?
Excessive bone resorption with replacement by fibrous and vascular tissue
Ill-defined radiolucent areas
What occurs during the Osteolytic and osteogenesis stage of Pagets disease?
What may you also see on a radiograph?
New bone formation within the fibrous tissue with simultaneous osteoclastic and osteoblastic
activity
Mixed radiolucent and opacity on radiograph
What occurs during the Osteosclerosis stage of Pagets disease?
What may you also see on a radiograph?
Late phase in which the irregular haphazardly arranged bone coalesces to form dense
sclerotic bone
The bone exhibits a dense radiopaque appearance
During the early stages of Pagets disease there is prominent resorption what are the dental implications of this?
Bone replaced by vascular stroma therefore there is an increased bleeding risk with XLA
During the late stages of Pagets disease there is prominent bone apposition what are the dental implications of this?
Irregular bone with minimal vascularity therefore there is an increased infection risk (Osteomyelitis)
During the late stages of Pagets disease there is prominent bone apposition what are the dental implications of this?
Irregular bone with minimal vascularity therefore there is an increased infection risk (Osteomyelitis)
Why may Pagets disease make extractions more difficult?
Hyper-cementosis which leads to bulbous roots which in turn leads to difficulty extracting
What medication will patients with Pagets disease be on?
Bisphosphontates
