BONE DISEASES

BONEone of the hardest tissues of body Ch. Ch. By high elasticity

Bone is a calcified collagenous matrix with some cells entrapped in-between

TYPES OF BONE3 types have been recognized

1- Lamellar bone = Mature bone

2- NON-Lamellar bone = Immature bone = WOVEN BONE

3- Bundle bone

Classification of bone diseases

HORMONALBONE DISEASES

= Osteitis Fibrosa Cystica = Von Recklinghausen's disease of bone

Hyperparathyrodism

= PTH

?In 2ry hyperparathyroidism, high levels of PTH do not cause hypocalcaemia

2 Types (1ry, 2ry hyperparathyroidism) are harmful to bone????!!!

Clinical features

DevelopmentalBONE DISEASES

Fibrous Dysplasia of boneBone is replaced by Fibrous C.T

Fibrous Dysplasia of boneFibrous Dysplasia of boneFibrous Dysplasia of boneBone is replaced by Fibrous C.T

proliferating gritty

Bone resorption Fibrous replacement Ossous metaplasiaWoven Bone

Fibrous Dysplasia of boneEtiology ??!!

1. Non- Neoplastic growth2. Abnormal reaction to traumatic episode.3. Endocrinal disturbances.

TYPES

Monostotic Fibrous Dysplasia= fibrous dysplasia confined to a single bone, 6 times as polyostotic

Age 1st or 2nd decade of life (4-18 years) Sex ♀ = ♂

Siteaffects only one bone particularly the jaws.Max. > Mand.

S&S

Slowly growing painless swelling…. not well circumscribed (diffuse)smooth and covered e normal mucosa.Disfiguring

stabilization and expansion stops with skeletal maturation.

Age 1st or 2nd decade of life (4-18 years) Sex ♀ = ♂Site affects only one bone particularly the jaws.

Max. > Mand.

S&S

Slowly growing painless swelling…. not well circumscribed (diffuse)smooth and covered e normal mucosa.Disfiguring

stabilization and expansion stops with skeletal maturation.

Polystotic Fibrous Dysplasia =fibrous dysplasia involve multiple bones, up to 75% of skeleton

Age 1st or 2nd decadeSex ♀>♂Site involves several bones including long bones, skull and jaws.

S&S

Slowly growing painless swelling…. not well circumscribed (diffuse)smooth and covered e normal mucosa.Disfiguring

stabilization and expansion stops with skeletal maturation.

Jaffe 's syndrome Albright’s syndrome

Polystotic fibrous dysplaisa

Café au lait skin pigmentation

Endocrinal disturbances

Polystotic fibrous dysplaisa

Café au lait skin pigmentation

Oral manifestation

Radiographic features

1. Mottled or Mixed

2. Radio-opaque.

Lesions merge with normal bone at the margins (= ill defined)

Lesion differ radiographoically according degree of osseous metaplasia

Histopathological features

Treatment

Self limiting

Cosmotic surgery may be needed

DystrophicBONE DISEASES

Paget’s disease of bonePaget’s disease of bone2nd most common osteodystrophic condition after osteopetrosis

1. Inflammatory disease (Paget's original believe).2. Autoimmune disease.3. Endocrine abnormality related to hyperthyroid

disease.4. vascular disorder.5. Bone remodling disturbance.6. viral infection (paramyxo v. + measles + RSV)

Etiology ??!!Phases

Age uncommon before age 40 (= 40 years)

Sex ♂> (2:1)♀

Site

vertebral column (1st most common site) - Sacrum > Lumbar > Thoracic > Cervical vertebrae. - mechanical stress i.e bearing most wt. being most affectedSkull (next most frequently affected) - mand. & max. about 17% of cases. - Max.> Mand. - functional stress + traction of neck muscles + stresses of mastication

S&S

severe pain.Bones become larger…. flat bones become thicker. round bones in circumference hats and dentures may no longer fit. Weight bearing bones…… bend under pressure crippling + bowing deformities. break easily.Deafness and Blindness , d.t. narrowing of cranial foramina.High cardiac output failure may occur due to arteriovenous shunt.

Clinical features

Clinical features

Clinical features

Clinical features

Clinical features

Clinical features

Radiographical features

Histopathological features

HereditaryBONE DISEASES

A) Affects membranous bone

B) Affects endochondral bone

C) Affects both types of bone

OI , cherubism , osteopetrosis

achondroplasia

Cleido-cranial dysplasia

Cherubism= familial fibrous dysplasia = familial multilocular cystic disease of jaws

Age early childhood bn (2-4 years)Sex ♂ > ♀Site Mand.> Max.

S&SBilateral ,Firm, painless swelling at angles of mand.

Clinical features

Pathogenesis