IN THE NAME OF GOD

Dr.kheirandish DDS,MSCOral and maxillofacial pathology

Bone PathologyChapter 14

Osteogenesis Imperfecta Osteopetrosis Cleidocranial Dysplasia Focal Osteoporotic Marrow Defect Idiopathic Osteosclerosis Massive Osteolysis Paget's Disease of Bone

OSTEOGENESIS IMPERFECTA

o Most common type of inherited bone diseaseo Collagen maturationo Type I collageno COL1A1 gene on chromosome 17o COL1A2 gene on chromosome 7

Collagen forms :• Major portion of bone• Dentin• Sclerae• Ligaments• Skin

Autosomal dominant Autosomal recessive Sporadic

Bone Thin cortex Fine trabeculation Diffuse osteoporosis Fracture Long bone and spine deformities

Blue sclera

Altered teeth

Hypoacusis (hearing loss)

Joint hyperextensibility

Radiographic hallmarks o Osteopeniao Bowingo Angulationo Deformity of the long boneso Multiple fractureso Wormian bones in the skull (not specific)

Wormian bones10 or more sutural bones that are 6 x 4 mm in diameter or larger and arranged in a mosaic pattern.

Oral cavity

o Both dentitions o Blue to brown translucenceo Reveal premature pulpal obliterationo Dentinogenesis imperfectao Class III malocclusion (maxillary hypoplasia)

TYPE I OSTEOGENESIS IMPERFECTA Most common and mildest form Mild to moderately severe bone fragility Hearing loss commonly develops before age 30 Hypermobile joints and easy bruising Opalescent dentin Blue sclerae Autosomal dominant

TYPE II OSTEOGENESIS IMPERFECTA Most severe form Extreme bone fragility Many patients are stillborn, and 90% die before 4 weeks of

age Blue sclerae Opalescent teeth Both autosomal recessive and dominant

TYPE III OSTEOGENESIS IMPERFECTA Most severe form noted in individuals beyond the perinatal

period Severe bone fragility Sclerae (fades as the child grows older) Hearing loss Die during childhood(cardiopulmonary complications

caused by kyphoscoliosis) Opalescent dentin/normal teeth Both autosomal dominant and recessive

TYPE IV OSTEOGENESIS IMPERFECTA Mild to moderate bone fragility (decreases after puberty) Sclerae (blue color fades later in life) Opalescent dentin/normal teeth. Autosomal dominant

Osteoblasts are present Bone matrix Failure of woven bone to become transformed

to lamellar bone

o No cure o Symptomatic improvement Intravenous (IV) or oral bisphosphonates : decreased

pain, reduced risk of fracture Opalescent dentin : severe attrition of their teeth,

leading to tooth loss

OSTEOPETROSIS

MARBLE BONE DISEASE Increase in bone density Failure of normal osteoclast function (Number of

osteoclasts … Bone is not resorbed)

Key elements necessary for osteoclast function :

I. Proton pumpII. Chloride channelIII. Carbonic anhydrase II

Two major clinical patterns:1)Infantile osteopetrosis2)adult osteopetrosis

INFANTILE OSTEOPETROSIS Malignant osteopetrosis Autosomal recessive Marrow failure Frequent fractures Cranial nerve compression Initial signs Normocytic anemia Hepatosplenomegaly(resulting from compensatory

extramedullary hematopoiesis) Granulocytopenia : Increased susceptibility to

infection

Facial deformity Broad face Hypertelorism Snub nose Frontal bossing Tooth eruption : delayed Narrowing skull foramina Press on the cranial nerves Optic nerve atrophy and blindness Deafness Facial paralysis Pathologic fractures : common Osteomyelitis : common complication of tooth

extraction Increase in skeletal density (distinction between

cortical and cancellous bone is lost)

Intermediate osteopetrosiso Less severe variants o Asymptomatic at birth o Marrow failureo Hepatosplenomegaly

Transient osteopetrosiso Radiographic evidence of diffuse sclerosis o Marrow failure BUTo Resolve without specific therapyo Return to normalcy

ADULT OSTEOPETROSIS Benign osteopetrosis Discovered later in life Autosomal dominant Long bones Asymptomatic Marrow failure

Two major variants I. Cranial nerve compression … common / Fractures

rareII. Frequent fractures / Nerve compression …

uncommon

Mandible is involved, fracture and osteomyelitis after tooth extraction

Abnormal endosteal bone formation Numerous osteoclasts

Adult osteopetrosis : long-term survival Infantile osteopetrosis : bone marrow

transplantation

Interferon gamma-1b + calcitriol :Reduce bone mass Decrease infectionsLower nerve compression

Corticosteroids Limiting calcium intake Antibiotics

CLEIDOCRANIAL DYSPLASIA

Dental and clavicular abnormalities

CBFA1 gene (RUNX2) OdontogenesisOdontoblast differentiationEnamel organ formation Dental lamina proliferation

Clavicles o Absent(unilaterally or bilaterally)…10%o Hypoplasia o Muscles : underdeveloped

o Neck : longo Shoulders : narrow / unusual mobility o Short statureo Large heads with pronounced frontal and parietal

bossingo Hypertelorismo Broad base nose o Depressed nasal bridge o Wormian bones

Dental and jaw manifestations

Small or absent maxillary sinuses Mandibular prognathism Narrow, high-arched palate Cleft palate Prolonged retention of deciduous teeth Delay or complete failure of eruption of permanent

teeth Numerous unerupted permanent and supernumerary

teeth (more than 60)

Unerupted permanent teeth Lack secondary cementum

Insufficient alveolar bone resorption is the reason for impaired tooth eruption

FOCAL OSTEOPOROTIC

MARROW DEFECT

Area of hematopoietic marrow that is sufficient in size

May be confused with an intraosseous neoplasm

I. Aberrant bone regeneration after tooth extraction

II. Persistence of fetal marrowIII. Marrow hyperplasia in response to increased

demand for erythrocytes

o Asymptomatic o Radiographic examinationo Radiolucent lesiono Varying in size o More than 75% : adult womeno 70% : posterior mandible (edentulous

areas)o No expansion

o Hematopoietic and/or fatty marrow

o Incisional biopsyo Treatment : no

IDIOPATHIC OSTEOSCLEROSIS

Dense bone island Bone scar Enostosis Focal periapical osteopetrosis

Focal area of increased radiodensity Unknown cause Other bonesNonvital teeth or significantly inflamed

pulps :Condensing osteitis or focal chronic sclerosing osteomyelitis

Blacks and asians Late first or early second decade Slow increase in size Asymptomatic Cortical expansion : no Routine radiographic examination Mandible : 90% (first molar / second

premolar / second molar )

o Well-definedo Roundedo Radiodense mass (uniformly radiopaque OR

nonhomogeneous)o Radiolucent rim : noo Associated with a root apex

MASSIVE OSTEOLYSIS

GORHAM DISEASEVANISHING BONE DISEASEPHANTOM BONE DISEASE

o Rare diseaseo Spontaneous and usually progressive

destruction of one or more boneso Replaced by a vascular proliferation…

dense fibrous tissueo Cause … unknowno Proliferation of blood or lymphatic vessels

that is occasionally multicentric

o Children and young adults (50% report of trauma)

o Maxillofacial : 30% o Mandible o Mobile teetho Paino Malocclusiono Deviation of the mandibleo Deformityo Obstructive sleep apnea syndrome

o Radiolucent foci of varying size with indistinct margins…become larger

o Loss of the lamina dura o Thinning of the cortical plates o Mimc periodontitis or periapical

inflammatory disease

Early stages : Nonspecific vascular proliferation intermixed

with fibrous connective and a chronic inflammatory infiltrate

Later stages : More collagenized Repair by new bone formation is not seen

Spontaneous arrest Mortality : Uncommon Bone grafRadiation therapy is the most

successful Postirradiation sarcoma

PAGET'S DISEASE OF BONE

o Abnormal resorption and deposition of bone

o Distortion and weakening of the affected bones

o Cause … unknown InflammatoryGeneticEndocrine factors Mutations sqstml (p62) / VCP geneVirus infection

o Commono Geographic varianceo Britaino Men : whites o Older than 45 y/o

o Asymptomatic disease : o Radiography o Elevation in serum alkaline phosphatase

o Most cases : polyostotic o Bone pain : common complaint

o Most commonly affected bones : lumbar vertebrae, pelvis, skull, and femur

o Simian (monkeylike) stance

Skull Increase in the circumference of the head Maxilla : more common / enlargement of

the 1/3 face Lionlike facial deformity Alveolar ridges : symmetrical enlarged Spacing of the teeth Dentures no longer fit

Radiographically

I. Osteolytic : radiolucentII. Osteoblastic : radiopaque (patchy /"cotton

wool")

Hypercementosis Bone scintigraphy : entire mandible from

condyle to condyle, a black beard or Lincoln's sign

Resorption and formation of boneOsteoclasts activityOsteoblastic activity

Characteristic microscopic feature :Basophilic reversal lines "jigsaw puzzle" or "mosaic" appearance

o Serum alkaline phosphataseo Blood calcium and phosphoruso Urinary hydroxyprolineo Alkaline phosphatase is more than 25%

to 50%o Osteosarcoma