diseases of bones of the jaw Flashcards
what 3 broad groups can bone diseases be divided into?
describe and give examples
- lesions of the jaw bones as part of a systemic bone disease
- most / or all bones affected
- e.g. osteogenesis imperfecta
- localised bone disease occuring in the jaws
- may affected almost any bone, including the jaws
- e.g. osteomyelitis
- lesions occuring only in the jaw bones
- e.g. dental cyst, ameloblastoma
Bone diseases can also be divided into groups depending on aetiology, what are the groups?
- developmental
- inflammatory
- cystic
- metabolic
- disorders of growth
give examples of developmental bone diseases
- torus palatainus
- torua mandibularis
- cleido-cranial dysostosis
- osteopetrosis
- osteogenesis imperfecta
- fibroud dysplasia
- monostotic
- poly stotis
- albright’s syndrome
- condylar hyperplasia
give examples of inflammatory bone diseases
- fracture
- healing extraction socket
- dry socket
- chronic periodontal disease
- osteomyelitis
- actinomycosis
- enostosis
- syphilis
- osteoradionecrosis
- increasingly common in patients treated with radiotherapy for head and neck cancer
give examples of cystic bone diseases
- odontogenic cysts
- developmental
- inflammatory
- non-odontogenic cysts
give examples of metabolic bone diseases
- vitamin deficiency
- vitamin D - rickets and ostemalacia
- vitamin C - scurvy
- endocrine
- acromegaly
- hyperparathyroidism
- steroid drug therapy
- osteoporosis
- functional atrophy - alveolar bone resorption following tooth extraction
- paaget’s disease
give examples of disorders of growth bone diseases
- dysplasia
- giant cell granuloma
- fibrous dysplasia
- neoplasia
- benign - osteoma, chondroma
- malignant primary bone tumours - osteosarcoma
- malignant bone marrow tumours - multiple myeloma, malignant lymphoma
- malignant secondary bone tumours - e.g. from primary breast, prostate and bronchus carcinoma
- odontogenic tumours
what is torus palatinus?
cause?
symptoms?
treatment?
- slow growing, sessile exostosis in the midline of the vault of the palate
- consists of normal lamellar bone
- cortical bone on the surface and lamellar bone in the centre
- strong genetic factor - simple autosomal dominance
- F:M 2:1
- symptomless - usually flat but may be lobular if large
- overlying mucosa may become ulcerated by trauma
- treatment:
- usually requires none but may be removed if it interferes with insertion of denture
what is this?
describe the symptoms you would expect and treatment
torus palatinus
- symptoms :
- symptomless
- treamtent :
- usually requires no treatment but may be removed if it interferes with insertion of denture
what is torus mandiularis?
cause?
symptoms?
treatment?
- exostosis on the lingual aspect of the mandible in the premolar region
- broad base with smooth or lobular surface
- consists of lamellar bone
- cortical bone on the surface and lamellar bone in the centre
- genetic basis
- autosomal dominance with 100% penetrance in females, 70% in males
- bilateral in 80% of cases
- no treatment but may be removed if interferes with insertion of denture
what is this?
symptoms expected?
treatment?
torus mandibularis
- no symptoms
- treatment not required unless interferes with denture insertion
aetiology of osteogenesis imperfecta
hereditary disease
- autosomal dominant most common but recessive forms and spontaneous cases occur
- heterogenous group of related disorders characteristed by defects in type I collagen synthesis
clinical features of osteogenesis imperfecta
- generalised osteoporosis with slender bones
- tendency for the bones to fracture on slight provocation
- slender long bones have narrow, poorly formed cortices composed of immature woven bone
- thin skull - may be wormian bones in the skull
- jaws rarely affected
- sclera may appear blue
- deafness due to distortion of ossicles
- joint hypermobility with lax ligaments
- translucent skin
- heart valve defects
what oral manifestations are associated with osteogenesis imperfecta
- often associated with dentinogenesis imperfecta
- esp. primary dentition
- increased tendency to class II occlusion and impactions of molar teeth
What is diagnosis? Why?
typical presentation of dentinogenesis imperfecta
- brown dentine shown through translucent enamel
- enamel has poor attachment
- defects at dentinal junction
- dentine exposed and slowly worn away
- on radiograph - short roots
what is osteopetrosis?
cause?
- excessive density of all bones
- with obliteration of marrow cavities and development of secondary anaemia
- defect in osteoclastic activity leading to failure of bone remodelling
- excessive formation of mechanically weak bone
- fractures common
- autosomal recessive form severe and progressive - usually death before puberty
- autosomal dominant less severe
what can be seen on a radiograph of someone with osteopetrosis
- bones very dense
- increased thickness and dentistry of lamina dura of tooth sockets
what is cleidocranial dysplasia (cleidocranial dysostosis)?
abnormalities of many bones - particularly skull, jaws and clavicle
- widened cranium
- fontanels and sutures remain open
- skull appears flat
- prominent frontal, parietal and occipital bones
- partial or complete abscence of clavicles
- super numerary and unerupted teeth
describe the steps of a tooth socket healing
- socket fills with extravasated blood which clots
- blood clot is organised to form granulation tissue
- macrophages begin to remove clot at periphery
- fibroblasts in remnants of PDL divide and migrate into clot
- endothelial cells in remnents of PDL divide and produce new thin walled vessels
- osteoclast resorption of crestal bone and spicules of bone detacted during extraction
- gingival epithelial proliferation and migration across defect
- migration between bloot clot and granulation tissue
- osteoblasts appear in granulation tissue at base of socket
- produce unmineralised osteoid
- granulation tissue is replaced by woven bone
- remodelling of woven bone and removal of lamina dura of tooth socket
- radiologically socket usually obliterated 20-30 weeks after extraction
at what times after extraction do the steps of tooth socket healing occur?
when is a patient with dry socket expected to present?
Either
- Immediately after LA has worn off
- Same day as tooth extraction or day after
- Blood clot has failed to form
- 4-6 days after extraction
- Blood clot has disintegrated prematurely before granulation tissue can form on the surface of the tooth socket
in what cases is dry socket more common?
- more in
- molar teeth than anteriors
- mandible than maxilla
- LA than GA
- difficult extraction than simple extraction
- most commin with lower third molar extraction
how does dry socket occur?
aka alveolar osteitis
- localised inflammation of bone following either failure of blood clot to form or premature loss of disintegration of clot
- loss of clot exposes alveolar bone to saliva, food debris and bacteria
- bone becomes necrotic with inflammation in adjacent bone
- healing slow, dead bone separated by osteoclasts, granulation tissue extends from surrounding bone
what are the types of osteomyelitis?
- suppurative osteomyelitis
- chronic sclerosing osteomyelitis
- special
- they are uncommon in the jaws
what suppurative osteomyelitis is there?
acute and chronic suppurative osteomyelitis
- may become chronic if too much dead bone
- continuing pus formation and pus escaping through sinuses
what is chronic sclerosing ostemyelitis?
what types of chronic sclerosing osteomyelitis are there?
- increased bone formation
- focal sclerosing ostemyelitis
- diffuse sclerosing ostemyelitis
- over a large area
- chronic sclerosing ostemyelitis with proliferative periostitis
- if periosteium is raised then new bone is formed under the periosteum
what are the special types osteomyelitis?
- radiation osteomyelitis
- chemical osteomyelitis
- ostemyelitis of newborn infacts
- esp. affecting maxilla
describe acute suppurative osteomyelitis
cause? predisposing factors?
- usually due to spread of local infection
- e.g. periapical infection
- very occasionally due to haematogenous spread
- infection brought from the long bones
- surprisingly rare
- predisposing factors
- reduced host resistance, either local or systemic
- virulent bacteria
- more common mandible than maxilla
- thicker bone trabeculae and cortical plates
- blood supply from central end artery more earily compromised
what would expect to see on a radiograph of someone with osteomyelitis?
- acute osteomyelitis
- ragged moth-eaten radiolucency
- Fragments of bone separated throughout the radiolucent area
- may be sequestra
- subperiosteal bone formation
- chronic osteomyelitis
- moth eaten ragged radiolucency
- sclerosis of the surrounding bone
- increased dentistry of the bone surrounding the radiolucent area
- sequestra
- involucrum formation
pathogenesis of acute suppurative osteomyelitis
- infection of marrow produces acute inflammatory reaction
- tissue necrosis and pus formation (suppuration) follow
- thrombosis may produce widespread necrosis of osteogenic tissues
- inflmmation, necrosis and suppuration extends through marrow spaces which are filled with pus
- pus reached periosteum
- periosteum is elevated
- blood supply is reduced
- pus may discharged through sinuses to mouth and skin
- granulation tissue seen in marrow spaces beyond areas of necrosis
- osteoclasts differentiate and separate off necrotic bone from vital bone - forms sequestrum
- new bone (involucrum) may be formed beneath elevated periosteum
what would you expect to see histologically in osteomyelitis?
bone with empty osteocyte lacunae
necrotic bone
necrotic fatty marrow - filled with granulation tissue with dense inflammatory cell infiltrate
describe radiation osteomyelitis & osteoradionecrosis
- radiotherapy involving jaw bone causes ischaemia
- reduced blood flow
- ischaemia due to proliferation of intima blood vessels - may occlude vessels
- mandibular central artery may be occluded - may produce ischaemic and necrotic bone
- bone now very susceptible to infection from teeth, periodontium, tooth extraction, mucosa
- extensive and painful necrosis of bone with sloughing of overlying mucosa exposing more bone to infection
what is BRONJ
Bisphosphonate Related Osteo Necrosis of the Jaw
- AKA medication related osteonecrosis of the jaw
- localised osteonecrosis
- associated with bisphosphonate therapy
- inhibits osteoclast function - inhibits bone turnover
- used for osteoporosis, paget’s, myeloma
- related to drug used, IV or oral, length of treatment
- exposed bone, localised pain, failure of extraction socket to heal
- tooth extraction should be avoided in these patients
- management
- prevention
- daily irrigation and antimicrobial rinses
- antibiotics to control infection
- surgical treatment to remove the necrotic bone may be advisable in more advanced cases
what diagnosis can you make from this clinical presentation and radiographs
BRONJ
describe multiple myeloma
- age
- site
- size
- radiographically
- shape
- outline
- radiodensity
- effect on adjacent structures
- malignancy of plasma cells
- age = middle aged
- site = multiple sites including skull vault and mandible
- size = variable
- radiographically
- shape = round
- outline = punched out
- radiodensity = uniformly radiolucent
- effect on adjacent structures = if large may lead to pathological fracture
what is a likely diagnosis
langerhans cell disease
the roots are embedded in soft tissue and appear to be floating
what features are shown in this radiograph
which bone diseases have these typical characteristics
the bone has a ground blast appearance
the lamina dura is absent
typical of : hyperparathyroidism, fibrous dysplasia, paget’s bone disease
what features are shown here?
what are these characteristics typical of?
enlarged pituitary fossa
enlarged prognathic mandible
acromegaly
what is this?
what features are present?
- multilocular lesion
- displaces teeth
- lightly corticated
-> brown tumour
what is this?
what features are present?
fibrous dysplasia
- swelling with smooth surface
- bucally pronounced
- tooth displacement
what is this?
what radiographic features are present?
- localised lesion
- on left side of lesion - able to see the contrast between normal and abnormal
- loss of lamina dura
- ground glass appearance
what is this?
what radiographic features are present?
late stages of pagets disease of bone
- cotton wool patches
- hypercementation of the bone
