Skip to main content
UploadLanguage (EN)Support
BusinessMobileSocial MediaMarketingTechnologyArt & PhotosCareerDesignEducationPresentations & Public SpeakingGovernment & NonprofitHealthcareInternetLawLeadership & ManagementAutomotiveEngineeringSoftwareRecruiting & HRRetailSalesServicesScienceSmall Business & EntrepreneurshipFoodEnvironmentEconomy & FinanceData & AnalyticsInvestor RelationsSportsSpiritualNews & PoliticsTravelSelf ImprovementReal EstateEntertainment & HumorHealth & MedicineDevices & HardwareLifestyle
DN
Uploaded byDr Monika Negi
PPTX, PDF3,728 views

Diseases Of Bone Manifested in Jaw

The document provides a comprehensive overview of fibro-osseous lesions (FOL), focusing on their classification, etiology, clinical presentation, and treatment options. It details types such as fibrous dysplasia, cemento-osseous dysplasias, and neoplastic lesions, highlighting the differences in their characteristics, symptoms, and radiographic features. The document also discusses the pathophysiology and management strategies associated with these lesions.

Health & Medicine◦
Downloaded 88 times
D R . M O N I K A N E G I M D S O R A L M A X I L L O F A C I A L P A T H O L O G Y A N D F O R E N S I C O D O N T O L O G Y FIBRO OSSEOUS LESIONS
Introduction The term fibro-osseous lesion (FOL) is a generic designation of a group of jaw disorders” characterized by the replacement of bone by a benign connective tissue matrix. (D.S Macdonald Jankowski, 2004) CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
CLASSIFICATION I CLASSIFICATION OF FIBRO-OSSEOUS LESIONS  Fibrous Dysplasia (FD)  Reactive lesions in the tooth bearing areas Periapical cemento-osseous dysplasia Focal cemento-osseous dysplasia Florid cemento-osseous dysplasia  Fibro-osseous neoplasms Cementifying fibroma, ossifying fibroma or cemento-ossifying fibroma ( REF: Charles A Waldron, 1985)
( REF: D S MacDonald- Jankowski, 2004 )
Benign fibro-osseous lesions of the craniofacial complex 1. Bone dysplasias a. Fibrous dysplasia  Monostotic  Polyostotic  Polyostotic with endocrinopathy (McCune-Albright)  Osteofibrous dysplasia b. Osteitis deformans c. Pagetoid heritable bone dysplasias of childhood d. Segmental odontomaxillary dysplasia 2. Cemento-osseous dysplasias a. Focal cemento-osseous dysplasia b. Florid cemento-osseous dysplasia ( Roy Eversole, 2008 ) 3. Inflammatory/reactive processes a. Focal sclerosing osteomyelitis b. Diffuse sclerosing osteomyelitis c. Proliferative periostitis 4. Metabolic Disease: hyperparathyroidism 5. Neoplastic lesions (Ossifying fibromas) a. Ossifying fibroma NOS b. Hyperparathyroidism jaw lesion syndrome c. Juvenile ossifying fibroma  Trabecular type  Psammomatoid type d. Gigantiform cementomas
FIBRO-OSSEOUS LESIONS OF MEDULLARY BONE ORIGIN
FIBROUS DYSPLASIA  Central lesions of bone which exhibit general histologic features of fibrosis with varying degrees of simultaneous resorption and repair have been reported for many years under uninformative terms  Term ~ by Lichtenstein in 1938  Skeletal developmental anomaly of the bone- forming mesenchyme that manifests as a defect in osteoblastic differentiation and maturation
Etiology : Mutation in GNAS I, a-stimulating activity polypeptide I gene ~ encodes Gs-alpha subunit > cAMP to hormone receptors GTPase perturbations > prolonged Gs alpha activation & stimulation of endocrine receptors Elevated intracellular cAMP in bone marrow osteoprogenitor cells > cell proliferation with differentiation defects
 Mutation Undiff. stem cells~ early embryologic life Osteoblasts, melanocytes, & endocrine cells ~ carry mutation C/F’s ~ multiple bone lesions, cut. pigmentation & endcrn. disturbances  Mutation ~ post natal life, Confined to one site, resulting in FD affecting single bone
 CLINICAL PRESENTATION Bone Pain  Localized pain associated with fractures in high- stress areas in dysplastic bone. Deformity  Unlike deformities in monostotic disease, deformities in patients with polyostotic disease may continue to progress after skeletal maturity.  Shepherd’s crook deformity of the proximal part of the femur (PFD) CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
 Structural deformation, with both expansion and weakness of the bone, can be caused by fibrous dysplasia Fatigue Fracture  common in areas of stress concentration within dysplastic lesions CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
 MONOSTOTIC FD OF JAWS:  Disease limited to single bone  80% to 85% of all cases,  Jaws ~ most common  Late 1st & early 2nd decades  Slow growing painless osseous expansion with facial asymmetry  Maxilla > mandible CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
•R / F ~ V A R Y •E A R L Y O N S E T ~ R / L • L A T E R C A L C I F Y > ‘ ‘ G R O U N D G L A S S ’ ’ O R M O T T L E D M I X E D P A T T E R N •C R I T I C A L T O D I A G N O S I S ~ F A I L S T O M A N I F E S T A N Y D I S C R E T E M A R G I N S •M A N D I B U L A R I N V O L V E . ~ E X P A N S I O N O F L I N G U A L & B U C C A L P L A T E S , B U L G I N G O F L O W E R B O R D E R B U C C A L E X P A N S I O N > L I N G U A L , D O E S N O T D I S P L A C E T H E A L V E O L A R C A N A L CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
•Narrowing ~ Pdl space, ill-defined lamina dura •Maxilla: lesion displaces sinus floor superiorly, obliterates sinus CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
Polyostotic fibrous dysplasia Craniofacial FD 2 or more bones, few to 75 % of entire skeleton 20-30 % of cases Pain, hockey stick deformity, pathologic fracture With cafe au lait pigmentation ~ Jaffe-Lichtenstein syndrome With cafe au lait pigmentation & multiple endocrinopathies ~ McCune-Albright syndrome CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
• Cafe au lait: • well-defined, unilateral tan macules, trunk & thighs • Oral mucosal macule also present, • Macule margins irregular, resembling a map of coastline of Maine  (neurofibromatosis has smooth borders like coast of California) CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
Craniofacial Fibrous Dysplasia  Fibrous Dysplasia extends to involve Maxillary Sinus ,Zygomatic Process ,Floor Of Orbit And Sometimes Base Of The Skull .  Results in :Severe Malocclusion And Marked Facial Deformity  Leads to Anosmia ,Deafness And Blindness  Proptosis of the affected eye .
 Radiographic Features  Radiolucent, with a “ground-glass” pattern, homogeneous, with no visible trabecular pattern. CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
Showing the pattern of disconnected, Irregularly shaped trabeculae of bone in ~ Chinese script writing, (hematoxylin and eosin,×100). CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
Mesenchymal stroma surrounding the trabeculae is relatively hypocellular , loosely arranged . & lack of osteoblastic rimming (H&E, ×200). CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
Malignant Transformation  Malignant transformation of fibrous dysplasia occurs very infrequently, with reported prevalences ranging from 0.4% to 4% Syndromes associated:  Mazabraud syndrome: FD+ intramuscular myxomas CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
 Differential Diagnosis  Simple bone cysts  Ossifying fibroma  Chronic diffuse sclerosing osteomyelitis  Osteosarcoma  Paget disease CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
Lab findings  Serum calcium, phosphorus and alkaline phosphate normal  In polyostotic: serum alkaline phosphatase raised in 50% cases. Treatment  Surgical procedures may be required for correction of a deformity, prevention of pathologic fracture, and/or eradication of symptomatic lesions  Simple curettage is associated with a high risk of recurrence  Curettage with use of autogenous cancellous bone graft. CONTENTS Introduction Classification Fibrous dysplasia Etiology and pathophysiology Epidemiological data Clinical presentation Monostotic type Polyostotic type Radiographic feature Histopathology Differential diagnosis Treatment
OSTEITIS DEFORMANS/ Paget disease of bone  Disease characterised by excessive and abnormal remodelling of bone, is a common disorder in middle aged & elderly  Involved bone warm to touch.
o Phases Lytic Mixed lytic and blastic Sclerotic or burned out
Clinical and Radiographic Features:  Late adult onset  M ~ F  Rapid turnover of bone ~ osseous expansion, skeletal deformities  Tubular bones ~ bowing, spinal curvature ~ vertebral collapse in later stages  Resulting in Simian stance (monkey like)  All bones of craniofacial complex ~ affected to varying degrees  Cranial nerve neuropathies because of foramina narrowing ~ deafness  O/M  Maxilla > Mandible, 2.3:1, alv. Ridge ~ widened, Palate ~ flattened  Leontiasis ossea: lion like facial deformity  Teeth ~ loose, migrate, spacing  Prominent dental finding ~ hypercementosis , on PM & M teeth  Mouth remains open  Edentulous pt.s ~ appliances remade
 In early stages of disease, radiolucent ‘‘coin shaped’’ lesions appear in flat bones of skull ~ osteitis circumscripta  With progression, sclerosis is seen radiographically yielding the so-called ‘‘cotton wool’’ appearance
Histopathologic Features  Initial osteolytic phase ~ disordered areas of resorption, osteoclastic resorptive lacunae  Osteoblastic phase ~ haphazard woven bone  Resting & reversal lines  Mosaic pattern Jigsaw puzzle  Oseoblastic rimming is present.  Marrow spaces ~ loose vascularised tissue
Laboratory Findings  Serum calcium and phosphorus levels ~ within normal limits  Serum alkaline phosphatase level ~ elevated  Urinary hydroxyproline levels ~ elevated, N- telopeptide, alpha –C telopeptide TREATMENT AND PROGNOSIS  No specific treatment  Calcitonin, parathormone antagonist which suppresses bone resorption  Complications ~ pathological fractures, osteosarcoma
CHERUBISM  rare  inherited (AD)  (autosomal dominant)  limited to jaws, fullness like cherub  develops in early childhood
Clinical features  Starts after the age of 3yrs and growth starts to decrease when patient reaches 5yrs of age and stops at 12-15yrs of age  Sex: Males > Females  In case of maxillary swelling the pressure on the floor of orbit may result in upward looking pupil which is refereed to as “heaven ward look”, Eyes towards heaven look, the maxillary arch achieves a V shaped appearance bilateral involvement of mandible.  Cherubic look: chubby cheeks
 The main diagnostic features are related to Dental problems -  Premature exfoliation of deciduous teeth  Abnormal growth of permanent teeth due to displacement by cysts and lesions  Absence of 2nd and 3rd mandibular molars  Increased cheek fullness, expansion and widening of alveolar ridge, flattening of the palatal vault.  Bilaterally symmetrical enlargement of the jaw
 Grading of Cherubism: Grade I: Involvement of both mandibular ascending ramus. Grade II: Involvement of both maxillary tuberosities and the mandibular ascending ramus. Grade III: Involvement of whole maxilla and mandible.
Radiologic Features  bilateral radiolucent cyst-like lesions  begins in third molar-ramus area  extends posteriorly and anteriorly  occasionally into condyle  maxilla usually after mandible  causes enlargement of jaws  cortex remains intact  encroach upon maxillary sinuses  displacment of developing teeth  early exfoliation of deciduous teeth  Floating tooth
Cherubism
CEMENTO-OSSEOUS DYSPLASIAS (OSSEOUS DYSPLASIA)  Most common fibro-osseous lesion  Based on the clinical and radiographic features, it is separated into 3 groups: (1) focal, (2) periapical, and (3) florid  Occurs in tooth bearing areas of jaws  Arises in close proximity to PdL , H/F similarities with structure, some suggest ~ PdL origin  Others believe ~ defect in extraligamentary bone remodeling , triggered by local factors & possibly correlated to an underlying hormonal imbalance
Clinical and Radiographic Features  Focal cemento-osseous dysplasia: • Single site of involvement • Sex: 90% cases occur in females • Age: mean age of 38 (3rd to 6th decade) • Race: whites • Site: posterior mandible • Lesions occur in dentulous & edentulous areas, with many examples noted in extraction sites • S/S: typically asymptomatic • R/F: smaller than 1.5 cm, lesion varies from completely R/L to densely R/O with a thin peripheral R/L rim. Most commonly, however, there is a mixed R/L / R/O pattern, well defined with irregular borders
 Periapical cemento-osseous dysplasia (Osseous dysplasia; Cemental dysplasia; Cementomas) • Periapical region of the anterior mandible • Solitary lesions may occur, but multiple foci are present more frequently • Sex: female patients (ranging from 10:1 to 14:1) • Race: 70% of cases affect blacks • Age: 30 -50 Years • Teeth associated: are almost invariably vital & seldom have restorations • S/S: asymptomatic condition
• R/F ~ • Early lesions ~ circumscribed R/L at apical area of a tooth (D/D: periapical granuloma or periapical cyst) • With time, adj. lesions fuse to form linear pattern of R/L that envelopes apices of several teeth • Lesion "mature' over time ~ mixed Rl –Ro appearance • End stage, circumscribed dense calcification surrounded by narrow Rl rim • PdL intact, fusion to tooth not seen • Lesion ~ self-limiting & doesn’t typically expand the cortex
 Florid cemento-osseous dysplasia: • Appears with multifocal involvement, • Synchronous involv. of ant. mandible • Bilateral symmetric involvement, all 4 quadrants • Sex & race: black women (> 90% ) • Age: middle-aged to elderly • S/S: asymptomatic to dull pain, & an alveolar sinus tract may be present, exposing yellowish, avascular bone to oral cavity • R/F : an identical pattern of maturation noted as in other two forms
Histopathologic Features  Fragments of cellular mesenchymal tissue composed of spindle- shaped fibroblasts & collagen fibers with numerous small b/v’s  Free hemorrhage ~ throughout lesion  CT: mixture of woven bone, lamellar bone & cementum like particles
 As lesions mature & become more sclerotic, ratio of fibrous CT to mineralized material decreases  With maturation, bone trabeculae become thick curvilinear structures that have been said to resemble the shape of ginger roots  With progression to final Ro stage, individual trabeculae fuse & form lobular masses composed of sheets or fused globules of relatively acellular & disorganized cemento- osseous material
Treatment and Prognosis  Generally do not require removal  For asymptomatic patient: regular recall examinations with prophylaxis & reinforcement of good home hygiene care to control Pdl disease & prevent tooth loss  Symptomatic patient: Antibiotics, Sequestration  A case of malignant fibrous histiocytoma arising within focus of florid has been observed
OSSIFYING FIBROMA (CEMENTIFYING FIBROMA; CEMENTO-OSSIFYING FIBROMA)  Demarcated & occasionally encapsulated lesion consisting of fibrous tissue containing variable amounts of mineralised material resembling bone or cementum  True neoplasm with significant growth potential  It has been suggested that origin is od. or from PdL., but microscopically identical neoplasms have been reported in orbital , frontal, ethmoid, sphenoid & temporal bone  Mutations in tumor suppressor gene, HRPT2
Clinical and Radiographical features:  Age: 3rd and 4th decades  Sex: female predilection  Site: Mand( premolar, molar area) > Max.  S/S: asymptomatic, painless swelling  R/F ~ well defined, unilocular, sclerotic border. Depending on amt. of calcified material produced : may be R/L or varying degrees of R/O  End stage COD: largely opaque with well defined R/L rim  Root divergence, resorption of roots  Large lesions: characteristic downward bowing of inferior cortex of mandible
Histopathologic Features:  Fibrous capsule  Fibrous tissue ~ varying degrees of cellularity , contains mineralized material  Hard tissue ~ trabeculae of osteoid & bone or basophilic & poorly cellular spherules resembling cementum  Trabeculae vary in size & frequently demonstrate mixture of woven & lamellar patterns  Peripheral osteoid & osteoblastic rimming present
 Spherules of cementum-like material often demonstrate peripheral brush borders that blend into adj. CT  Variation in types of mineralized material ~ helpful in distinguishing OF from FD, which has a more uniform pattern of osseous differentiation
Treatment and Prognosis  Enucleation  Surgical resection and bone grafting  Prognosis: very good  No evidence of malignant change
JUVENILE OSSIFYING FIBROMA (JUVENILE ACTIVE OSSIFYING FIBROMA; JUVENILE AGGRESSIVE OSSIFYING FIBROMA)  Two different neoplasms have been reported under the term, and demonstrate different histopathologic and clinical features (1) Trabecular and (2) Psammomatoid  Grow rapidly, well-circumscribed, and lack continuity with adj. normal bone  Age: < 6 months to over 70 years (11 years for first form, 22 yrs or second form)  Site: maxillary predominance
Radiographic Features:  The lesions are circumscribed radiolucencies that in some cases contain central radiopacities  Intracranial extension has been discovered in neoplasms arising adjacent to cribriform plates Aggressive Juvenile Ossifying Fibroma (a) Expansile maxillary mass
Histopathologic features:  Nonencapsulated but well demarcated  Cellular fibrous CT exhibits areas ~ loose & other zones ~ so cellular that cytoplasm of individual cells is hard to discern because of nuclear crowding  Myxomatous foci ~ not rare, ass. with pseudocystic degeneration  Mitotic figures, hemorrhage, MN giant cells seen
 The mineralized component in two patterns is very different: Trabecular: irregular strands of highly cellular osteoid encasing plump & irregular osteocytes, lined by plump osteoblasts & in other areas by MN osteoclasts
Psammomatoid: Concentric lamellated & spherical ossicles, vary in shape, Hv basophilic centers with peripheral eosinophilic osteoid rims Peripheral brush border blending into surr. Stroma noted in many of ossicles Occ., individual ossicles undergo remodeling & form crescentic shapes
Treatment and Prognosis:  For smaller lesions, complete local excision or thorough curettage appears adequate  For some rapidly growing lesions, wider resection required  Recurrence rates: 30% to 58%  Malignant transformation has not been documented
Other Lesions Of Bone
Osteoporosis  Often known as the Silent thief  Osteoporosis is a disease in which bones become fragile and are more likely to break  Characterized by a decrease in mass resulting in bones that are more porous and easily fractured.  These broken bones also termed fractures usually happen in the wrist, spine, and hips
Two types of osteoporosis  First type is termed type 1 which affect 5-20 % of women. This is the type associated with menopause as low estrogen levels cause a decrease in the amount of calcium absorbed. This type is characterized by vertebral fractures of the spine.  Second type is called type two with this type the process of re-absorption and formation of bone are no longer coordinated meaning your osteoblast and osteoclast cells are not balanced leading to a state where bone breakdown overcomes bone building. This type happens in both men and women.
Causes  Caused by decreased osteoblast function  Change in parathyroid activity  Menopause is # 1 cause in women due to the decrease in estrogen levels  Insufficient dietary intake of vitamin C and D
 Height loss  Curving spine or stooped posture  Broken bones or fractures in the wrists and hips and spine  Protruding abdomen- this is the most unrecognized symptom of osteoporosis as most don’t realize curvature of the spine cause less abdomen space so intestines have no where else to go so lean forward.  Kyphosis- caused by vertebral compression fractures and factures are disfiguring . This is the symptom most recognized in patients.  A chest x-ray that shows osteopenia which is a condition where women’s bone mass is smaller than usual. Symptoms
Risk Factors  Race – if you are white or of Southern Asian descent.  Age – Older you get the more you chances of getting osteoporosis increases.  Family History – greater risk if there is a history of it in your family  Frame Size – people who are exceptionally thin and have a small body  Sedentary lifestyle  Low body mass < 19 kg/m2  Had an eating disorder like anorexia nervosa or bulimia. This cause high risk of lower bone density on back and hips  Chronic alcoholism  Excessive smoking
Risk factors continued  Never been pregnant  Had an early menopause  Abnormal absence of menstrual cycle or periods of amenorrhea causing low estrogen levels  Low testosterone in men  Taking certain medications like corticosteroids and anti convulsants  Women who have had surgery to remove an ovary as this accelerates bone loss  People who have had an overactive thyroid
Clinical Features  Age –congenital or infantile  Fracture – typically affect Forearm (Colle’s Fracture ) ,spine (vertebral fracture ) and Hip (Femur )  Congenita form inhereted as an autosomal recessive disorder  Percussion –painful  Symptoms –loss of height due to shortening of trunk  Osteomyelitis
Oral Manifestations  Osteomyelitis  Fracture of Jaw  Enamel Hypoplasia  Arrested root development ,retardation of tooth eruption .
Radiographic Features
How it is detected  A bone density test should be done on women who have reached menopause as bone mass rapidly decreases each year.  A complete survey of dietary intake, drug history, and lifestyle can determine your risks of this condition.
Prevention continued  Basic prevention Model
Treatment  Calcitionin- naturally occurring hormone that increases bone mass in the spine and may lessen the pain of fractures already there.  Raloxifene – It is a selective estrogen receptor modulator that prevents bone loss and spine fractures.  Alendronate and risedronate - these are biphosphates that slow down the breakdown of bone and increase bone density  Calcium – keeps the bones strong  Vitamin D – helps you absorb calcium
Osteopetrosis  (Albers - Schönberg Disease, Marble bone disease) Rare hereditary bone disorder characterized by increase in bone density due to defect in bone remodeling caused by failure of normal osteoclast function.  Clinical types – infantile, intermediate and adult osteopetrosis.
 PATHOGENESIS: -  Osteoclasts fail to function normally.  As a result, bone remodeling is affected.  Defective bone resorption combined with continued bone deposition results in thickening of cortical bone and sclerosis of cancellous bone.  The exact mechanism is unknown. However, deficiency of carbonic anhydrase in osteoclasts is noted. Hence, bone resorption fails while its formation persists. Excessive bone is formed.
I. INFANTILE OSTEOPETROSIS  Autosomal recessive trait- severe form.  Diffusely sclerotic skeleton, marrow failure and signs of cranial nerve compression present.  Initial signs – normocytic normochromic anemia and hepatosplenomegaly, due to compensatory extramedullary heamatopoiesis.  Increased susceptibility to infections due to granulocytopenia.
II. Intermediate Osteopetrosis  Affected patients have a short stature and are often asymptomatic at birth, but frequently exhibit fractures by the end of their first decade of life.  Marrow failure and hepatosplenomegaly are rare.  Some present with cranial nerve deficits, macrocephaly, mild or moderately severe anemia and ankylosed teeth that may predispose them to osteomyelitis of the jaws.
III. ADULT OSTEOPETROSIS  Discovered late in life – milder symptoms. Autosomal dominant trait.  About 40% cases are asymptomatic.  Axial skeleton shows sclerosis, while long bones show little or no defects.  Bone pain is seen  10% shows osteomyelitis of mandible
ORAL MANIFESTATIONS  Facial deformity leading to hypertelorism, snub nose, frontal bossing etc.  Delayed tooth eruption and osteomyelitis of jaws.  Sclerosis of skull bones leads to narrowing of foramina which causes compression of various cranial nerves – blindness, deafness, facial paralysis etc.  The medullary spaces of the jaws are reduced.  Fracture of jaws during extraction procedure can occur without undue force, due to fragility of the bone.
HISTOLOGICAL FEATURES:  A failure of osteoclasts to resorb skeletal tissue, with remnants of mineralized primary spongiosa that persist as islands of calcified cartilage within mature bone, is characteristic of osteopetrosis. Several patterns of abnormal endosteal bone formation may be seen  tortuous lamellar trabeculae replacing the cancellous portion of bone  globular amorphous bone deposition in marrow spaces  osteophytic bone formation. The number of osteoclasts may be increased, normal or decreased, but there is no evidence of functional osteoclast as Howship’s lacunae are not visible.
RADIOGRAPHIC FEATURES  Wide spread increase in bone density.  • Distinction between cortical and cancellous bone is lost.  • Dental X rays – difficult to distinguish roots
Osteogenesis Imprefecta/Brittle Bone Disease  Most common type of developmental, inherited bone disorder, showing both autosomal dominant and recessive pattern.  Comprises heterogeneous group of heritable CT disorder in which bone fragility is the primary feature.  It is a condition resulting from abnormality in the type I collagen.  It is characterized by impairment of collagen maturation.  Collagen forms a major portion of bone, dentine, sclerae, ligaments, and skin, OI demonstrate a variety of changes that involves these sites.
 Abnormal collagenous maturation results in bone with thin cortex, fine trabeculation, and diffused osteoporosis.  The chief clinical feature is the extreme fragility and porosity of the bones, with an attended proneness to fracture.  Upon fracture, healing will occurs but may be associated with exuberant callus formation.  Several different forms of OI have been reported and they represent the most common type of inherited bone disease.
Clinical Features  The other characteristic feature of OI is the occurrence of blue sclera.  The sclera is abnormally thin, and for this reason the pigmented choroid shows through and produces the bluish colour.
Other condition in which blue sclera can be seen  Osteopetrosis  Fetal rickets  Turner syndrome  Pagets disease  Marfan syndrome &  Ehlers-Danlos syndrome.  Some times in normal infants.
Additional signs & symptoms  Deafness- due to osteosclerosis.  Abnormalities of teeth.  Laxity of ligaments.  A peculiar shape of the skull.  Abnormal electrical reaction of the muscles. Tendency towards capillary bleeding.
Types of OI  TYPE I Osteogenesis imperfecta:  Commonest type – autosomal dominant.  Mild to moderate bone fragility – onset is highly variable – may be present at birth also.  Hearing loss develops before 30 years.  Some patients may show dentinogenesis imperfecta sub type B.  Blue sclera is seen.  Kyphoscoliosis  Easy bruising  Short stature
 Deformity of long bones Dentinogenesis imperfecta
 TYPE II Osteogenesis imperfecta:  Extreme bone fragility with frequent fractures. Many patients stillborn – 90% die before 4 weeks of age.  Blue sclera present.  Dentinogenesis imperfecta present.  Hearing loss present.  Micrognathia  Short trunk.
 TYPE III Osteogenesis imperfecta:  Moderate to severe bone fragility.  Blue sclera present in infants but fades by adulthood.  Mortality rate higher in older children.  Death from cardiopulmonary complications caused by kyphoscoliosis (backward & lateral curvature of spine).  Dentinogenesis imperfecta.  Short limbs.  Triangular face, with frontal bossing
 TYPE IV Osteogenesis imperfecta: -  Mild to moderate bone fragility.  Sclera pale in early life, but fades in later life.  Fractures present in 50 % case – frequency of fractures decreases after puberty.  Some patients may have dentinogenesis imperfecta, some may not.
Oral Manifestation  Both the dentitions are affected, and demonstrate blue to brown translucency.  •Radiographically reveals premature obliteration of pulp. •Although the altered teeth closely resemble dentinogenesis imperfecta , the two disease are the result of different mutations and should be considered as separate processes.  •Head size is large.  •Frontal and temporal bossing is seen.  •Class III malocclusion is seen due to maxillary hypoplasia rather than mandibular hyperplasia.  •Anterior and posterior cross bite and open bites can be seen. •Large numbers of impacted and ectopic teeth can be reported.  •Unerupted 1st and 2nd molar is very common feature.
Radiographic Features  Hallmarks of OI includes:  Osteopenia  Bowing  Angulation  Deformity of long bones  Multiple fratures
Histologic Features  Anomaly due to abnormal collagen synthesis by abnormal osteoblasts.  Mass of cortical and cancellous bone is abnormal and greatly reduced.  Cortical bone is extremely thin while the cancellous bone is delicate and shows micro fractures.  Osteoblasts are present but bone matrix synthesis is reduced, for this reason the thickness of long bone is deficient.  Bone architecture remains immature throughout life.
Treatment  No known treatment.  Only treatment of the infection when they occur.
 Key features:-  Thin fragile bones due to inadequate type I collagen.  Inherited as an autosomal dominant trait. Multiple features typically lead to gross deformities.  Jaw fractures are uncommon.
CLEIDOCRANIAL DYSPLASIA  Bone defects primarily involve skull and clavicle – defects seen in other bone also.  Inherited as autosomal dominant trait, but almost 40% cases show spontaneous mutation.
Clinical Features  Age incidence: Children  Sex incidence: Nil  Site predilection: Skull, clavicles and jaw bones.  Signs & symptoms:  Short height with large heads showing pronounced frontal and parietal bossing.  Nose is broad with depressed nasal bridge.  Shoulders narrow and droop excessively.  Sagittal suture is sunken giving the skull a flat appearance.  Paranasal sinuses are underdeveloped  Patients show unusual mobility of shoulders due to absence / hypoplasia of clavicles.
Oral Manifestation  Narrow, high arched palate.  Increased prevalence of cleft palate.  Maxilla is underdeveloped and smaller than mandible.  Prolonged retention of deciduous teeth and delay / complete failure of eruption of permanent teeth.  OPG and dental radiographs show multiple impacted and supernumerary teeth.  The roots of the teeth are short and thinner than usual, and might be deformed.
Treatment  No treatment exists for the skull, clavicular, and other bone anomalies associated with CCD.  Most patient function well with out any significant problem.
Key features:-  Rare genetic disorder causing defective formation of clavicle, delayed closure of fontanells and other defects.  Many or most permanent teeth typically remains embedded in the jaw.  Many additional unerupted teeth also present. Sometimes many dentigerous cysts