bone disorders

what are the 2 main types of fibro-osseous lesions

• fibrous dysplasia

• cemento-osseous dysplasia (COD)

what is fibrous dysplasia

tumor-like condition, characterized by replacement of normal bone by fibrous connective tissue intermixed w abnormal bone

what does dysplasia in bone mean

disorganized growth, NOT malignant

fibrous dysplasia is a __________ condition resulting from a ___________ mutation

sporadic condition; postzygotic mutation

fibrous dysplasia may take place where depending on when and where the mutation takes place

• one bone → monostotic

• multiple bones → polyostotic

• skin

• endocrine system

is monostotic or polyostotic more common

monostotic

if you have a case of polyostotic, what may this be associated w

syndromes:

• McCune-Albright Syndrome

• Jaffe-Lichtenstein Syndrome

• Mazabraud Syndrome

what conditions are in combination in McCune-Albright Syndrome

• Polyostotic fibrous dysplasia

• cafe au lait spots (coast of Maine)

• multiple endocrinopathies

what endocrinopathies can be associated w McCune Albright Syndrome

• sexual precocity- early puberty

• pituitary adenoma

• hyperthyroidism

what gender is most associated w fibrous dysplasia monostotic

M = F

what age is most associated w fibrous dysplasia monostotic

teenage years (2nd or 3rd decade)

common location of fibrous dysplasia monostotic

maxilla > mandible

what is the common feature of the affected area in fibrous dysplasia monostotic

painless, slowly growing swelling of the affected area

how does fibrous dysplasia appear on a radiograph in

• ground glass opacification

• not well demarcated, blending

• narrow PDL

• ill-defined lamina dura

• Obliteration of the maxillary sinus

how does fibrous dysplasia progress from the early stage, then how does it progress

may be radiolucent but w time becomes radiopaque

what might you see clinically in fibrous dysplasia

expansion of both the buccal and lingual plates

dx

fibrous dysplasia

what is fibrous dysplasia- polyostotic

involvement of two or more bones → can involve up to 75% of skeleton

age most associated w fibrous dysplasia-polyostotic

before 10 yrs- children

how can fibrous dysplasia- polyostotic present

• if jaw involved, facial asymmetry may result

• pain, due to pathologic fracture of the long bones

• hockey stick deformity- leg length discrepancy

how do lesions of neurofibromatosis 1 (NF1) appear clinically

• cafe au lait spots are smaller and higher in number

• borders are smooth and ovoid shape→ “coast of california”

• cross the midline

how do lesions of McCune Albright Syndrome appear clinically

• cafe au lait spots are larger and fewer in number

• borders are jagged and irregular → “coast of Maine”

• found in midline and does NOT cross the midline

prognosis of fibrous dysplasia

• disease tends to stabilize and stop growing at skeletal maturity

• up to 50% recur

fibrous dysplasia tx

varies: medication, pain management, physical therapy, and in some cases- surgery

what is the most common fibro-osseous lesion encountered in clinical practice

cemento-osseous dysplasia (COD)

what is COD

abnormal bone mixed w soft tissue

location associated w COD

tooth-bearing areas of the jaw → apex

people most associated w COD

african american, middle-aged females

what are the three types of COD

• focal

• periapical

• florid

people most associated w periapical COD

• 90% are female

• 70% in african americans

• middle aged (40s)

location associated w periapical COD

periapical region of anterior mandible

how to teeth present in periapical COD

teeth are invariably vital and asymptomatic

how periapical COD present on a radiograph

• multiple foci are usually present

• early lesions are circumscribed areas of radiolucent involving the apex of a tooth- looks identical to periapical granuloma or cyst

what are the 3 stages of periapical

• early stage

• mixed stage

• late stage

how does the early stage of periapical COD stage present

radiolucent lesions

how does the mixed stage of periapical COD stage present

radiolucent-radiopaque appearance

how does the late stage of periapical COD stage present

densely radiopaque w a radiolucent rim

prognosis of periapical COD

lesion is typically non-expansile, self-limiting → will stop growing and expanding, biopsy not rlly recommended

people associated w focal COD

• 90% occur in african american females

• middle aged

location associated w focal COD

posterior mandible

how focal COD will appear radiographically

• single lesion

• radiolucent to radiopaque

• in tooth-bearing areas of the jaw

• well-defined rim during mixed stage

• smaller than 1.5 cm

would you expect pt to symptomatic or asymptomatic in focal COD

asymptomatic

how to differentiates COD and hypercementosis

• COD: not within PDL space

• hypercementosis: within PDL space

people associated w florid COD

• 90% are female and african american

• middle aged or older adults

location associated w florid COD

multiple focal involvement not limited to the anterior mandible

how does florid COD appear on a radiograph

• may have lesions in post jaws, some pts have lesions throughout

• bilateral and symmetrical

how does teeth vitality present in florid COD

vital and asymptomatic

how to dx COD

can be made from distinctive clinical and x-ray finding → do NOT need biopsy

if you biopsy COD, what can this lead to

necrosis due to hypovascularity

tx for COD

• focal COD: may require surgical investigation bc features are less specific

• follow up

• antibiotics if osteomyelitis/infection is present

what 5 things should be on your differential dx for a radiopaque lesion at the apex

• COD

• condensing osteitis

• idiopathic osteosclerosis

• hypercementosis

• cementoblastoma

how does focal COD appear in the mixed phase on a radiograph

rim is prominent

what is cementoblastoma

benign neoplasm of cementum

how does cementoblastoma present on a radiograph

radiolucent rim is contiguous w PDL and PDL is NOT in tact at involved portion of the root, effacement of root

what is condensing osteitis also called

focal sclerosing osteomyelitis

how does condensing osteitis present on a radiograph

no radiolucent rim, borders blend w surrounding trabeculae; is due to pulpal involvement

how does idiopathic osteosclerosis dense bone, enostosis, bone scar present on a radiograph

no radiolucent rim, borders blend w surrounding trabeculae

what are the 4 hereditary bone disorders

• osteogenesis imperfecta (OI)

• osteopetrosis

• cleidocranial dysplasia

• cherubism

osteogenesis imperfecta is also called…

brittle bone disease

in osteogenesis imperfecta, there is a mutation in…

type collagen 1

osteogenesis imperfecta mode of inheritance

• AD: 90%

• AR: 10%

• some are sporadic

gender associated w osteogenesis imperfecta

M = F

age associated w osteogenesis imperfecta

infant, young children

location associated w osteogenesis imperfecta

bone, teeth, ligament, skin, sclera

what is the most common inherited bone disorder, even though it is uncommon

osteogenesis imperfecta

main clinical features of osteogenesis imperfecta

• low bone density- osteopenia

• blue sclera

dental features of osteogenesis imperfecta

• blue/grey translucent teeth

• obliterated pulp chamber/ shell teeth

osteogenesis imperfecta presents similarly to…

dentinogenesis imperfecta; diff is they have diff mutations

management of osteogenesis imperfecta

restorations

osteopetrosis is also called…

• albers-schonberg disease

• marble bone disease

what cells are affected in osteopetrosis

decreased osteoclastic activity

in osteopetrosis, there is an _____ (inc/dec) in bone density

inc

mode of inheritance of osteopetrosis

AD or AR-fatal

gender associated w osteopetrosis

M = F

age associated w osteopetrosis

infancy except adult form

location associated w osteopetrosis

anywhere

clinical features of osteopetrosis

anemia, pathologic fractures, infection, deafness, and blindness

facial features of osteopetrosis

• delayed tooth eruption

• osteomyelitis

• frontal bossing

• hypertelorism

• broad face

• snub nose

tx for osteopetrosis

• bone marrow transplant

• palliative

prognosis of osteopetrosis

good for AD but fatal for AR

cleidocranial dysplasia is also called…

cleidocranial dysostosis

how is cleidocranial dysplasia characterized

by dental and clavicle abnormalities

mode of inheritance for cleidocranial dysplasia

AD

bone defects of cleidocranial dysplasia chiefly affect what bones

skull and clavicles- hypoplasia

dental features associated w cleidocranial dysplasia

• prolonged retention of teeth

• delay or failure of eruption of permanent teeth

• supernumerary teeth

• numerous unerupted permanent and supernumerary teeth

supernumerary teeth can be associated w what two conditions

• gardeners syndrome

• cleidocranial dysplasia

mode of inheritance in cherubism

AD

mutation in cherubism

SH3BP2 chromosome #4p16

gender associated w cherubism

M = F

age associated w cherubism

2-5 → children

location associated w cherubism

bilateral posterior mandible (MOST COMMON), maxilla

clinical manifestations of cherubism

• mandibular lesions are painless, bilateral, posterior, and expansile

• distortion of alveolar ridge

• may lead to failure of tooth eruption

microscopic findings of cherubism are identical to those found in…

central giant cell granulomas (CGCG)

x-ray features that can be seen in cherubism

multilocular, radiolucent, expansile

prognosis of cherubism

• unpredictable

• varying degrees of remission and involution after puberty

tx of cherubism

• early surgical intervention w curettage has lead to both good results or rapid regrowth w worsening deformity → optimal therapy hasn’t been determined

• radiation therapy is contraindicated due to risk of postirradiation sarcoma

paget disease of bone is also called…

osteitis deformans

what is paget disease

a metabolic bone disease characterized by abnormal resorption and deposition of bone of unknown cause- mainly osteoclast

what are the possible causes of paget disease

• 30% hereditary

• AD

• sporadic

• paramyxovirus

gender associated w paget disease of bone

M caucasians > F