Osteoporosis

OsteoporosisA Review for dentists

DefinitionThe internationally agreed description of osteoporosis is:A systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue with a consequent increase in bone fragility and susceptibility to fracture

The Silent DiseaseOsteoporosis can weaken bones and cause them to break easily, especially those in the wrist, spine, or hip. It is often called the silent disease because bone loss occurs without symptoms. Many people may not know that they have osteoporosis until they experience a fracture due to weak bones.

2- Epidemiology of OsteoporosisOsteoporosis is a major public health threat in the United States. 10 million Americans have osteoporosis 34 million have low bone mass, (high risk) One out of every two women & one in four men over the age of 50 will have an osteoporosis related fracture in their lifetime. Each year, osteoporosis is responsible for:300,000 hip fractures700,000 vertebral fractures250,000 wrist fracturesMore than 300,000 other types of fractures. Expenses for these fractures are estimated to be approximately $14 billion each year.

Relative OccuranceThe lifetime risk for hip, vertebral and forearm (wrist) fractures have been estimated to be approximately 40%, similar to that for coronary heart disease.Following hip fracture in women520% mortality within 1 year20% severely impaired mobility after 12 months, requiring long-term nursing care 50% do not regain previous mobility

Repartition of the Participants (total 18000) according to their BMD statusNormalOsteopenicOsteoporotic%%%Femoral Neck277215.4%966653.7%556230.9%Lumbar Spine712839.6%689438.3%397822.1%Both Sites10896.05%1117862.1%572431.8%

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3- PathogenesisThroughout your lifetime, new bone is added to the skeleton and old bone is removed.New bone is added faster during childhood and teenage years, resulting in larger, heavier, and denser bones. Bone continues to be added until around age 30, when peak bone mass is reached.After age 30, bone loss slowly begins to exceed bone formation. Osteoporosis develops when bone loss exceeds bone replacement.

Bone RemodellingBalance

4- ClassificationsCauses

I- CAUSES OF OSTEOPOROSIS:2ry to Disease/ 1ry OP

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II - Risk FactorsRisk factors that you cannot change:AgeThe older you are, the greater your risk of developing osteoporosis.GenderYou have a greater chance of developing osteoporosis if you are female. Women do not have as much bone tissue as men and lose it more rapidly because of menopause.Body sizeSmall, thin-boned women are at greater risk for developing osteoporosis. Family HistoryIf you have a family history of fractures, you have a greater risk. Osteoporosis may be hereditary. EthnicityCaucasian and Asian women have the highest risk for developing osteoporosis. African-American and Latino women have a risk, but not as significant.

II- Risk FactorsRisk factors that you can change:DietPeople with a lifetime diet that is low in calcium and vitamin D have a higher risk for developing osteoporosis.AlcoholExcessive use of alcohol puts you at higher risk for osteoporosis.Cigarette smokingSmoking increases your risk.Physical activityAn inactive lifestyle increases your risk of developing osteoporosis.HormonesLow estrogen levels in women and low testosterone levels in men have been linked to an increased risk for osteoporosis.MedicationsCertain medications, such as glucocorticoids or some anticonvulsants, increase the risk of osteoporosis.

III - According to IncidenceFrequent Types:Postmenopausal OP (Type I)Senile OP (Type II)Immobilization OPNeoplastic OPInfrequent Types:Osteogenesis ImperfectaChromosomal AbnormalitiesMigratory Cushing SyndromeHyperthyroidismIron Storage DiseasesDisappearing Bones

5- DiagnosisA- Clinical DiagnosisB- Radiographic DiagnosisC-Laboratory DiagnosisD- Bone DensitometryE- Bone Biopsy

1- CLINICAL DIAGNOSISHistory of positive risk factors.Clinical presentation:Loss of height. Diffuse kyphosis.Pains.Fractures.Worry and psychic effects.

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A- LOSS OF HEIGHTVERTEBRAL COMPRESSION.VERTEBRAL WEDGING.LOWER LIMB BONES BOWING.

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KYPHOSISDIFFUSE.DORSAL.DORSO-LUMBAR.SLOWLY PROGRESSIVE.

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B- PAINSMICROFRACTURES.LONG STANDING KYPHOSIS.ASSOCIATED OSTEOMALACIA.OSTEOPOROTIC FRACTURES.MUSCULAR.FIBROMYOSITIS.

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C- FRACTURESFRAGILITY FRACTURES.MINOR TRAUMA.COMMON SITES:Spine.Proximal end of femur.Distal end of radius.Proximal end of humerus.

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2- Radiographic findings in osteoporosis

AB + CD >/= medullaAB+CD/XY >/= 1/2In ostepenia < 1/2Midshaft of index finger is used for measurement

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Assessment of FracturesRadiologically performed

Primary axial osteoporosis

65 year-old female with a few years history of pain in the back

Fracture Neck of Femur

75 year-old female with a frail constitution, hospitalized in an institution for chronic diseases; fractures of the right neck of femur at the age of 68, intertrochanteric fracture at 72, in both instances due to a slight fall.

3- Laboratory diagnosis and Biochemical assessment of osteoporosisSerum and urine calcium.Alkaline phosphatase.Hydroxyproline.Ostecalcin.Hydroxylysine glycosides.Procollagen I extension peptidesCrosslink assaysAlpha2 HS glycoproteinAcid phosphataseBiochemical estimation of bone loss.

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4- Bone Densitometry(why is it used?)Conventional radiograph:not sensitive (needs 30% reduction in mineral content)not accurateImplications in Orthopaedic practice:evaluation and management of bone-loss syndromesevaluation of periprosthetic bone-remodeling

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At present, the assessment of bone mineral is the only aspect that can be readily measured in clinical practice, and it now forms the cornerstone for the general management of osteoporosis. Bone mineral density is the amount of bone mass per unit volume (volumetric density, g/cm3), or per unit area (areal density, g/cm2), and both can be measured in vivo by densitometric techniques.A wide variety of techniques is available to assess bone mineral that are reviewed elsewhere

Assessment of Osteoporosis byBone Mineral Density

Based on X-ray absorptiometry in bone, since the absorption of X-rays is very sensitive to the calcium content of tissue, of which bone is the most important source. Particularly DXA (= dual-energy X-ray absorptiometry). The most widely used bone densitometric technique. It can be used to assess bone mineral content of :the whole skeleton Specific sites, including those most vulnerable to fracture.Other techniques:Quantitative ultrasound (QUS).Quantitative computed tomography (QCT) applied both to the spine and hip and to the appendicular skeleton (pQCT).Digital X-ray radiogrammetry.Radiographic absorptiometry.Techniques to detect BMD

DEXA Scan

Osteoporosis of the Lumbar Spine

T-score -4

Osteoporosis of the Femur Neck

T-score -2.7

Quantitative Ultrasound (QUS)

E- Bone Biopsy

Bone Biopsy

Red-stained osteoid seams lined with OB (osteblasts) and OC (osteoclasts) versus poor osteoid seams and little osteoblasts and osteclasts in bone resorptionTetracycline labeling on fluorescent microscopy showing normal bone with yellow lines at mineralization front versus absence of bone formation. T= bone trabecula M= marrow

6- Treatment & PreventionA- DietB- Physical ActivityC- Medications

A- DietTreatment of osteoporosis focuses on diet, physical activity, fall prevention, medication, and changing behaviors that are linked to the development of the disease.DietCalcium and vitamin D are necessary for :Developing strong bones. Regulating heart, muscle, and nerve functioning. As you age, your body becomes less efficient at absorbing calcium and other nutrients; The recommended daily intake of calcium for adults age 51 and older is 1,200 mg. Dietary calcium is found in:Low-fat dairy products, such as cheese, yogurt, and milk. Nondairy sources of calcium include canned salmon and sardines with bones, dark-green leafy vegetables, such as broccoli, orange juice, and breads made with fortified calcium.

A- DietVitamin D is necessary for calcium absorption.Our bodies manufacture vitamin D when exposed to sunlight. Vitamin D production decreases in the winter for those who are housebound and not able to get enough light. Vitamin D supplements may be necessary to ensure daily intake of 400 to 800 Ius.

B- Physical ActivityPhysical ActivityBones respond to physical activity that involves weight-bearing exercise, such as walking or jogging. These activities help improve bone health and increase muscle strength, resulting in fewer fractures from falls. Fall PreventionFalls increase the chance of a bone fracture in the wrist, hip, or spine and other parts of the skeleton. It is important that individuals with osteoporosis discuss with their physician physical changes that may affect their sense of balance and ability to walk.

C- MedicationsAim: To stop or slow bone loss and increase bone density, resulting in reduced risk of fractures. bisphosphonates that can help in the prevention and treatment of osteoporosis. Reduces bone loss and increases bone density in both the spine and the hip. Calcitonin is a naturally occurring non-sex hormone involved in calcium regulation and bone metabolism. It is currently available as an injection or nasal spray. Estrogen/Hormone Replacement therapy (HRT) It is most commonly administered in the form of a pill or skin patch.

PreventionThe best way to prevent osteoporosis is to live a healthy lifestyle and practice behaviors that promote positive bone health. As we age, it is important to be aware of the risks associated with osteoporosis and to talk with a physician if you think you might be at risk for osteoporosis to determine if testing is necessary.

Optimal Treatment of Osteoporosis in Postmenopausal Women

7- Dental RelationsA- Oral Radiographs as a way of DiagnosisB- Effect of Osteoporosis on Dental Bone.C- Osteoradionecrosis of Jaw (ONJ) due to Bisphosphanates.

A- Dental Radiograph as a low costed screening methodMany Authors recommended screening all women older than 65 years.In many countries, bone assessment methods are:Not widely available.Costing high fees, larger than Panoramic Views in most of places.Dental screening of patients at high risk of OP among the population would be practical and cost effective in such countries.Thus Dentists may be able to help detect the first stages of osteoporosis.

Mandibular Inferior CortexPanoramic Radiographs are used to detect osteoporosis from assessment of the Mandibular inferior cortex (MIC), which was detected to be 0.54 mm thinner in subjects with OP fracture, in relation to controls. Devlin & Horner in 2002, reported a diagnostic threshold of 3 mm or less, for referral for Bone densitometry in women.

Osteoporosis . Cropped panoramics images shows a relative radiolucency of both jaws with reduced definition and mandibular inferior cortex moderately eroded, evidence of lacunar resorption (right-D) or cortex severely eroded (left-E).

Regular CheckupsPeriodic dental checkups using dental radiographs shows the amount of jaw bone loss.This is dependent on:The experience of the dentistExposure and film processing variations.The problem of this idea in Egypt, that the least of patients, are those who go to the dentist regularly for checkups, and from those the minority are having regular dental Radiographs. More and more, the reserved radiographs are missed in clinics, a problem which will be solved by electronic registration and digital radiography and photography.

B- Effect of Osteoporosis on Dental Hygiene.Early Signs of Osteoporosis may include:More severe gingivitis,Bone loss around the teeth represented as periodontitis and teeth loss. Dentures become ill-fitted leading to mouth sores.

Alveolar Bone Mass, structure and thickness:Local Functional factors mainly influence Mandibular Bone Mass (MABM) and alveolar thickness in molar region, whereas BMD influences the trabecular structure. In Lower Premolar Region, Longitudinal Alterations in BMD are related to:Longitudinal changes in grey-level value.Bone textureAlveolar thickness: Decrease in BL (buccolingual) alveolar thickness may be due to periosteal resorption related to skeletal bone loss.

C- Osteonecrosis of Jaw (ONJ) due to Osteoporosis Therapy: Bisphosphanates.

A potential side effect associated with bisphosphonates, treating osteoporosis, Paget's disease and metastatic bone disease, The incidence of ONJ in the general population is unknown. Case reports have discussed ONJ development in patients with: Multiple myeloma or metastatic breast cancer receiving bisphosphonates as palliation for bone metastases. These patients are also receiving chemotherapeutic agents that might impair the immune system and affect angiogenesis.

ONJ due to BisphosphanatesThe incidence or prevalence of ONJ in patients taking bisphosphonates for osteoporosis seems to be very rare. No causative relationship has been demonstrated between ONJ and bisphosphonate therapy. A majority of ONJ occurs after tooth extraction. Furthermore, the underlying risk of developing ONJ may be increased in osteoporotic patients by other overlying diseases. Treatment for ONJ is generally conservative.