Bone Diseases Flashcards
How common are tori?
2 - 10% of adults have them.
What are tori and exostoses?
Exophytic, hard, uninodular or multinodular bony masses covered by mucosa
What are the clinical features of tori and exostoses?
Torus palatinus and torus mandibularis on the
midline of palate and lingual mandible (usually
bilateral and symmetric)
Often site of bisphosphonate-associated
osteonecrosis
How common are exostoses?
27% of adults have them
Males have them more often than females 5:1 ratio
More than 90% having of people with exostoses have concurrent tori
What are exostoses?
Outgrowths of bone that are nodular or sessile
frequently on buccal aspects of mandible and
maxilla or ascending arch of the palate
What causes tori and exostoses?
Chronic irritation
Periosteal proliferation
Bone formation
Is a biopsy needed for tori and exostoses?
Only needed if there is radiographic change over time.
What are the differential diagnoses for tori and exostoses?
Condensing osteitis
True osteomas
What is condensing osteitis? (Not examinable)
Similar to idiopathic osteosclerosis but is found very close to the apices of teeth and is likely reactive to chronic occlusal trauma
or low-grade inflammation or odontogenic infection.
What are True osteomas? (Not examinable)
True osteomas are associated with Gardner syndrome
(autosomal dominant condition associated with
mutation in the APC gene and development of colonic
polyps and carcinoma, desmoid tumors, supernumerary
teeth, and skin cysts).
What is osteomyelitis?
inflammatory condition of the
bone, which begins as an infection of the
medullary cavity, rapidly involves the
haversian systems, and extends to involve
the periosteum of the affected area
How common is osteomyelitis?
Only 2 out of every 10,000 people get osteomyelitis
What are the predisposing factors to osteomyelitis?
Diabetes (most cases of osteomyelitis stem from diabetes)
Sickle cell disease
HIV or AIDS
Rheumatoid arthritis
Intravenous drug use
Alcoholism
Long-term use of steroids
Hemodialysis
Poor blood supply
Recent injury
What are potential sources of infection?
- Periapical infection
- Periodontal pocket’s
- Acute gingivitis
- Penetrating and contaminated injuries
- Tooth extraction
What are the signs and symptoms of osteomyelitis?
Fever, irritability, fatigue
Nausea
Tenderness, redness, and warmth in the area
of the infection
Swelling around the affected bone
Lost range of motion
How is osteomyelitis classified based on the Hjorting-Hansen E method?
Acute osteomyelitis is mainly in children
Chronic osteomyelitis is classified into primary and secondary osteomyelitis. Primary = non-suppurative, secondary = suppurative
When does osteomyelitis become chronic?
After 4 weeks.
What happens to the bone during osteomyelitis?
Inflammation causes thrombosis of vessels in the bone marrow and suppuration causes peri-osteal stripping due to pus accumulation. Bone and marrow undergo necrosis.
What is alveolar osteitis?
Localized inflammation of bone following either failure of blood clot to form in socket, or premature loss or disintegration of clot.
This is dry socket which is an unpredictable complication of tooth extraction.
What causes alveolar osteitis?
Failure of blood clot formation due to Poor blood supply as in: . Paget’s disease. . Osteopetrosis. . Following radiotherapy. . Excessive use of vasoconstrictor in local anesthesia.
Premature loss of blood clot may be due to: . Excessive mouth rinsing. . Fibrinolysis by proteolytic bacteria.
What are the clinical featurs of alveolar osteitis?
- Intense pain
- Most frequently seen in:
- 3rd molar extraction
- Difficult extraction with trauma
- Smoker . - tooth socket appears empty and dry
- jaw bone is visible in the tooth socket
- Bad breath and Unpleasant taste .
- Swollen of regional lymph node .
What are the histopathological features of alveolar osteitis?
Histological section of socket wall reveal formation of necrotic bone containing empty lacunae
What are the types of osteonecrosis?
Osteoradionecrosis
Osteochemonecrosis: Medication induced (bisphosphonates), phosphorous necrosis of the jaw (exposure to white phosphorus)
How does radiotherapy lead to osteonecrosis?
Radiation -> Hypoxia/hypocellular/hypovascular -> Superinfection/chronic nonhealing wound caused by trauma
Why are bisphosphonates used?
Can be for:
Osteoporosis
Multiple myeloma
Metastatic cancer
Why do bisphosphonates cause osteonecrosis?
Apoptosis -> Inhibition of release of BMP, ILG1, ILG2 (important for remodelling) -> Reduced bone turnover/resorption -> Reduced serum calcium -> Hypermineralization (sclerotic changes in lamina dura of alveolar bone)
Where is central giant cell granuloma most common?
A non-neoplastic, reactive lesion seen in all age groups.
Affecting females more than males
In the anerior mandible (70%)
What are the symptoms of a central giant cell granuloma?
Painless expansion
Radiograph: Unilocular to multilocular radiolucency and can be between 0.5 - 10cm large
What are the histological features of a central giant cell granuloma?
Multinucleated giant
cells
Spindled stroma
Erythrocyte extravasation
Hemosiderin deposits
Fibrosis
Osteoid formation
How is Central Giant Cell Granuloma treated?
Curettage
intra-lesional steroids
Calcitonin
Interferon alpha 2a
Resection
What are the differential diagnoses of a central giant cell granuloma?
Central giant cell granuloma
Brown tumor –hyperparathyroidism
Aneurysmal bone cyst
Cherubism
Giant cell tumor
Benign fibro-osseous lesion
What are the potential prognoses of a central giant cell granuloma?
It can be aggressive or non aggressive
What is the recurrence rate of a central giant cell granuloma?
15 - 20%
What is a cyst?
A cyst is a pathological cavity filled with fluid, semi-fluid or gaseous contents and is
not created by an accumulation of pus.
What causes a cyst?
Epithelial proliferation + hydrostatic/osmotic factors
Keratin formation
Bone resorption (Prostaglandins and collagenase)
What are the typical clinical features of a cyst?
Noticeable swelling
Discharge into the mouth
Pain due to a secondary infection
How is a cyst diagnosed?
Combination of adequate history, clinical examination, and selected investigations need to be completed.
Which odontogenic cysts are most common?
Odontogenic cysts are more common than non-odontogenic cysts and are divided into:
Radicular (60 - 75%)
Dentigerous (10 - 15%)
Keratocyst (5 - 10%)
Paradental (3 - 5%)
gingival and lateral periodontal cysts form <1% of all cysts
What are the types of radicular cysts?
Periapical
Lateral
Residual
What are the clinical features of radicular cysts?
Affects non-vital teeth
Upper lateral incisor most commonly affected
Rare in deciduous teeth
Asymptomatic on expansion -> springy -> egg shell crackling -> fluctuation
Infection results in pain
Which patients most commonly get radicular cysts?
Peak in 4th and 5th decades
Most common radicular cysts and makes up 60 -75% of all jaw cysts
What do radicular cysts look like on radiograph?
Often monolocular
Well defined out line and well corticated.
Has uniform radiolucency
How do radicular cysts occur?
Initiated by cell rest of malassez being activated by the products of necrotic pulps.
The central cells degenerate and die and this leads to cavitation and cyst formation.
The cysts then enlarge due to osmolality of the inside of the cyst increasing as the breakdown products get smaller and more osmotically active and this leads to the wall becoming a semi-permeable membrane
What is contained within a radicular cyst?
Breakdown products of cells
Serum proteins
Water and electrolytes
Cholesterol crystals
What are the histological features of a radicular cyst?
Periapical granuloma with epithelial proliferation -
polymorphs in epithelium
Cyst lined by irregular, non-keratinised stratified
squamous epithelium
Foam cells, lymphocytes, plasma cells, cholesterol
clefts, surrounding fibrosis
Lining becomes thinner and less inflamed
10% contain hyaline (Rushton) bodies
What kind of cyst is a dentigerous cyst?
It is an odontogenic, developmental cyst
What is a dentigerous cyst?
A cyst enclosing the crown of an unerupted tooth it is a cyst of the follicle and is usually attached to the cementoenamel junction
What causes a dentigerous cyst?
Intrafollicular fluid begins to accumulate between the enamel and the reduced enamel epithelium. Pressure of the tooth on the impacted follicle leads to obstruction of venous outflow, serum transudation, and exudation)
Who is most commonly affected by dentigerous cysts?
Children and young adults (permanent teeth are usually affected)
M:F 1.6:1
Which teeth are most commonly affected by a dentigerous cyst?
Permanent teeth; upper canine and lower 3rd molars
What are the clinical features of a dentigerous cyst?
Painless enlargement
Tilting of tooth
Root resorption
What are the histopathological features of dentigerous cysts?
Clear yellow fluid
Purulent if infected
Lined by flattened, non-keratinized stratified squamous epithelium
Continuous with the reduced enamel epithelium
Mucous and ciliated columnar metaplasia
Fibrous wall with variable inflammation
What is an eruption cyst?
An extra-alveolar dentigerous cyst affecting deciduous teeth and permanent molar
What do eruption cysts look like?
Causes fluctuant bluish swelling
Haemorrhage into the cyst is common
What is the prognosis if an eruption cyst?
Most spontaneously resolve especially if marsupialized
Where are odontogenic keratocysts typically located?
Usually present on the mandible (70 - 80%) on the ramus/angle of the mandible (50%)
How common are odontogenic keratocysts? Who most commonly gets them?
5 - 10% of all cysts
M>F
What are the clinical features of an odontogenic keratocyst?
Mostly on the mandible especially on the ramus/angle
Often asymptomatic
Can cause swelling, discharge, pain, pathological fracture, tooth displacement, and rarely can lead to buccal expansion.
Has a high recurrence rate
What are the developmental origins of the odontogenic keratocyst?
Derived from the dental lamina or it’s remnants (cell rests of Serres)
Originates from the enamel organ (tooth primordium) of a tooth before hard tissues develop (normal tooth or supernumerary teeth can cause this)
What are the radiographic features of an odontogenic keratocyst?
Well demarcated radiolucency
Pseudolocular or multilocular, often with scalloped periphery
Root or tooth displacement
What are the histopathological features of an odontogenic keratocyst?
Regular stratified squamous epithelium
Thin epithelial later (5 - 8 cells thick)
Palisaded basal layer
Corrugated surface which can be parakeratnised or orthokeratinised
Thin, friable fibrous capsule - little inflammation
Satellite (daughter) cysts
How do odontogenic keratocysts enlarge?
Cancellous enlargement antero-posteriorly
Little or no bucco-lingual expansion -> Large, especially in angle and ramus of the mandible
How common is recurrence in odontogenic keratocysts?
Up to 60% recurrence rate
How do odontogenic keratocysts recur?
They have a large size and an infiltrative nature
They tend to form multiple minicysts and satellite cysts
Why do odontogenic keratocysts recur so often?
They have intinsic growth potential, form multiples of themselves, and satellite cysts.
In people with Gorlin-Goltz they recur spontaneously
What are the features of Gorlin-Goltz syndrome?
Multiple keratocysts
Multiple basal cell naevi (carcinomas)
Skeletal abnormalities (bifid ribs, spine defects)
Frontal bossing (large forehead growth) and hypertelorism (Large distance between the eyes)
Calcification of the falx cerebri
What are the types of non-odontogenic developmental cysts?
Nasopalatine duct cysts
Nasolabial cyst
What is a naso-palatine cyst?
An incisive canal cyst formed by the remnants of the nasopalatine duct
Who most commonly gets a naso-palatine duct cyst?
M:F 4:1
30 - 60 years of age
What are the clinical features of a naso-palatine duct cyst?
Swilling of the midline of the palate
Pain and discharge (mucoid and salty)
What is a nasolabial cyst?
Bilateral swelling in the nasolabial fold below alae and leading to loss of the fold
What do nasolabial cysts result in?
Swelling, pain, and difficulty with nasal breathing
What does a simple bone cyst look like clinically?
Empty intra-osseus bone cavity
Usually asymptomatic (painless swelling)
What causes simple bone cysts?
Uncertain, thought to be caused by trauma which leads to intra-medullary haemorrhage
Which people most commonly have simple bone cysts?
10 - 20 years of age
Male > females
Where are simple bone cysts seen on the face?
Mandibular body (molar-premolar)
What does a simple bone cyst look like on radiology?
Often seen incidentally.
1 - 10cm radiolucency that can be well or ill defined.
Scalloping seen between tooth roots of vital teeth
No root resorption often seen
What are the typical surgical findings of a simple bone cyst?
Aspiration - serosanguinous fluid
Empty bone cavity
Smooth bone walls
Scant fibrous tissue
What are the histological findings of a simple bone cyst?
Cortical bone cap
Bone resorption - remodeling
Membranous fibrovascular tissue
Fibrin - hemorrhage
No epithelial lining
How is a simple bone cyst treated?
Surgical exploration
Stimulate haemorrhage into the defect to stimulate rapid spontaneous healing.
What is the prognosis of a simple bone cyst?
Prognosis is excellent and recurrence is rare.
Following up the patient is important.
Associated with fibro-osseus lesions
What is stafne’s bone defect?
Static bone cavity of the mandible or lingual salivary gland inclusion defect
How common and who commonly gets stafne’s cysts?
Middle-aged men typically. Prevalence of this condition is estimated to be around 0.1 - 0.48%
What is the differential diagnosis of stafne’s cyst?
Other radiolucent lesions of the jaws
