Seminar on : - Vitamin-D-Resistant Rickets. - Renal Rickets. - Hypophosphatasia.

Seminar on-- Vitamin-D-Resistant Rickets.- Renal Rickets.1References

Textbook of Oral Pathology Shafers Textbook of General Pathology Harsh Mohan Harrisons Textbook of Internal Medicine Google ImagesIntroductionTypes of RicketsClinical FeaturesRadiographic Features Oral manifestationsHistopathologyTreatment and PrognosisCONTENTS3Rickets : It is a disorder primarily canned by lack of vitamin D or abnormal metabolism.The term Rickets is derieved from the English word Wricken which mean to bend.It is found in children prior to closure of growth plates.

Introduction 4Vitamin - D deficient rickets.Vitamin D resistant rickets.Renal rickets. Osteomalasia [adult rickets].

Types of Rickets5Synonyms : Familial hypophosphatemia, phosphate diabetes, refractory rickets.

Definition : Vitamin D resistant rickets is an X-linked dominant inherited kidney disorder characterized by hypophosphatemia and hyperphosphaturia.Vitamin D Resistant Rickets 6Hypophosphatemia and hyperphosphaturia associated with decreased renal tubular reabsorption of inorganic phosphates.Familial occurrence, being inherited as an X-linked dominant trait.Does not respond to the usual doses of vitamin D.Normocalcemia with high noraml parathyroid hormone levels.Diminished intestinal calcium and phosphate absorption.

Characteristics features7Decreased growth with short stature.Normal vitamin D metabolism.The absence of other related abnormalities.

Since these characteristic features of rickets do not respond to the therapeutic doses of vitamin D, hence it is known as vitamin D resistant rickets.

8Occurs in childhoodMale > Female.Widened joint spaces and flaring at kneesBowing of long bones When child begins to walkClinical features9In adults because of rickets in childhood leads to more serious disturbance such as,Bowing of legs.Shortening of stature.Continuing osteomalacia.Presence of pseudofracture.

10The history or X-ray examination reveals abnormalities such asSkull deformities.Retardation of eruption of teeth.Sitting deformities of legs. Radiographic Features11

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There is histologic evidence of widespread formation of globular, hypocalcified dentine with clefts and tubular defects occuring in the region of pulp horns.Pulp horns are elongated and extend high, reaching nearly to the DEJ.Large pulp chambers.Because of these defects there is commonly invasion of pulp by micro organisms which leads to presence of multiple dental abscess.Oral Manifestations145. Periapical involvement of grossly normal appealing deciduous or permanent teeth.6. Followed by development of multiple fistulas.7. Abnormal cementum 8. Lamina dura absent or poorly defined on xray9. Abnormal alveolar bone pattern.10. Width of predentin is increased.11. Recently formed dentin is incompletely calcified.12. Taurodontism was found in permanent molars as a feature of the condition in the more severly affected male subjects.

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Fistula

Dental abscess16Lamina dura absent or poorly defined.Abnormal cementum.Larger pulp chamber.Abnormal alveolar pattern. Radiographic features17

18Alternation found primarily in the cartilage plate and shaft of long bone.Failure of bone salts to deposit in the cartilage matrix between the rows of hypertrophic cells.Histologic picture characterized by a broad zone between the multiplying cartilage cells and the shaft, hence called Rachitic Metaphysis.Broad zone is composed of tongues of cartilage which extends towards the shaft and separates from one another by collection of capillaries.

Histologic features19Broad zone contains trabeculae made of uncalcified cartilage matrix upon which osteoid bone has deposited.Osteoid is found deposited on pre existing bony trabeculae because osteoblastic activity is not affected, but calcification is interfered so the osteoid does not calcified and not remodeled.

Biochemical findings :

Serum calcium : NormalSerum PTH : Normal or slightly increasedCalcitriol level : LowSerum 25 [OH] cholecalciferol : NormalUrinary loss of phosphate : High

20Highly individualized.Massive dose of vitamin D is given = Risk of hypervitaminosis.Success was reported with 25 [OH] cholecalciferol in lower dosage i.e., 10,000 25,000 IU/day.Healing initiated by methods like Immobilization + administration of large amount of phosphate.Low dosage of vitamin D i.e., 15,000 50,000 IU/day + supplemental oral phosphate.Endodontic treatment to the non vital teeth.

Treatment 21Synonym : Renal osteodystrophy.

Definition : Renal rickets is a painful crippling bone disease commonly found in patient with chronic renal failure where there is a inability of diseased kidney to synthesize 1- alpha hydroxylase enzyme and convert 25 [OH] cholecalciferol to active form of vitamin D.

Renal Rickets22 Failure of kidney

No activation of vitamin D

Calcium absorption in intestine is impaired

Fecal calcium excretion [negative calcium balance]

Increased in serum phosphate level[phosphatemia]Pathogenesis23Secondary reduction in serum calcium level to maintain stable calcium/phosphate solubility products.

Compensatory increase in PTH production [secondary hyperparathyrodism].

Superimposed osteitis fibrosis cystica.24Serious in children, in which legs bend inward towards each other or outwards away from each other.In adult bone changes begins years before symptoms appear with kidney disease, so called silent crippler.Older patient and women in menopausal age are at greater risk.Increased risk for bone fracture.Clinical features25

26If renal failure begins at young age enamel hypoplasia occur on developing teeth.Tooth mobility.Malocclusion.Development of pulp stone.Oral manifestation27

28Radiographic alteration of jaw bones are common in patient undergoing dialysis.Bone resorption results inLoss of lamina duraThinning of cortical plateBlurring of anatomic landmarks like mental foramen, inferior alveolar canal and floor of maxillary sinus.Radiographic features29Dihydrotachysterol [vitamin D analogue]1-alpha hydroxycholecalciferol.Renal transplantation.Dietry changes should be done like milk, cheese, dried beans, peas, nuts should be consumed.Should decrease the consumption of drinks such as cocoa, beer.Prognosis of bone disease is difficult because of inability to cure underlying renal disease.Treatment and Prognosis30