Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
MINERALS ESSENTIAL FOR CALCIFIED STRUCTURES CHAPTER 9 Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. Bone Mineralization and Growth Calcified structures include bones and teeth Collagen and bone undergo constant remodeling Organic matrix of bone is 90%–95% collagen fibers Formation of collagen requires protein, vitamin C, iron, copper, and zinc From Bath-Balogh M, Fehrenbach MJ: Illustrated Dental Embryology, Histology, and Anatomy, ed 3. St. Louis: Saunders, 2011. Once collagen is formed, mineralization begins Calcium, phosphorus, magnesium, sodium, potassium, and carbonate ions form mineral matrix Calcium reserve: 0.4%–10% of total bone calcium in shapeless (amorphous) form Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 2 Formation of Teeth Crystalline structure of enamel is one of the most insoluble and resistant proteins known Comparable to hardness of quartz Dentin contains the same constituents as bone, but its structure is more dense Cementum is another bone-like substance, but because it From Nanci A: Ten Cate’s Oral Histology, ed 8. St. Louis: Mosby, 2013. contains fewer minerals, it is softer than bone Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 3 Introduction to Minerals Minerals are inorganic elements that have many physiological functions Inorganic elements in body account for only about 4% of total body weight, or 6 lb for a 150-lb person Minerals subdivided into two categories Those required in larger amounts (major minerals) Those required in smaller amounts (micronutrients or trace elements) Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 4 Physiological Roles: Calcium Most abundant mineral in the body (~1200 g) 99% in teeth and bones Functions Bone health Blood clotting Transmit nerve impulses Muscle contraction and relaxation Membrane permeability Activate certain enzymes Salivary calcium acts as buffer From Fehrenbach MJ, Herring SW: Illustrated Anatomy of the Head and Neck, ed 4. St. Louis: Saunders, 2012. Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 5 Requirements: Calcium AI 9 to 13 y/o boys and girls 1300 mg/day 19 to 50 y/o men and women 1000 mg/day 51 to 70+ y/o men and women 1200 mg/day Only 1 in 4 Americans meets AI for calcium Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 6 Requirements: Calcium Current levels of intake Males ages 9 and older Average intake ~925 mg/day (71% of AI) Females ages 9 and older Average intake ~657 mg/day (51% of AI) AI for those with self-diagnosed lactose intolerance ~320 mg/day (25% of AI) At high risk of inadequate intakes to build peak bone mass and prevent osteoporosis Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 7 Calcium-to-Phosphorus Ratio Serum levels of calcium and phosphorus inversely related If calcium level goes up, phosphorus level goes down Ideal calcium/phosphorus ratio for adults is 1:1 Excessive intake of phosphorus compared with calcium reduces serum calcium concentration Calcium requirements are increased when dietary phosphate is high as in the typical American diet Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 8 Absorption: Calcium Absorption regulated by hormones (parathyroid, estrogen, glucocorticoids, thyroid) Best absorbed when consumed in smaller amounts and ingested several times during the day Factors decreasing absorption: Oxylates and phytates in grains, vegetables Reduced gastric acidity Excessive fiber Low-protein, low-phosphorus diets From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013. Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 9 Sources: Calcium Milk and dairy products Preferred sources of calcium because of high calcium, lactose, and other nutrient content that enhances calcium absorption Fortified soy and rice milk Other fortified foods (orange juice) Supplements Limited bioavailability Better absorbed when taken with food Calcium citrate malate, calcium lactate, calcium citrate, and calcium sulfate have high absorption rates Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 10 Hyperstates: Calcium Hypercalcemia-excess calcium levels in the blood Caused by: Hyperparathryoidism Overdoses of cholecalciferol Vitamin D poisoning Excessive calcium intake results in: Dizziness, flushing, nausea/vomiting, severe constipation, kidney stone formation, irregular heartbeat, tingling sensations, xerostomia, fatigue, and high blood pressure May inhibit iron and zinc absorption Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 11 Hypostates: Calcium Rickets Abnormal ossification from vitamin D, calcium deficiency Osteoporosis From Kumar V, Abbas AK, Fausto N: Robbins and Cotran Pathologic Basis of Disease, ed 8. Philadelphia: Saunders, 2010. “Osteoporosis is a disease of adolescence” 90% of peak bone mass is attained by age 16.9 + 1.3 yr and 99% by age 26.2 + 3.7 yr BMD associated with fractures in elder years, but also may predict fractures in children Inadequate calcium intake in early life accounts for as much as 50% of difference in hip fracture rates in postmenopausal years Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 12 Hypostates: Calcium Reduction in total skeletal mass is directly related to reduction in mandibular bone density in women with osteoporosis Postmenopausal women who lost teeth also lost bone mineral of the whole body and femoral neck at greater rates than those who retained their teeth Systemic bone loss appears to be a predictor of tooth loss in dentate postmenopausal women Inadequate calcium intake and periodontal disease Study of NHANES data suggests a 56% risk of periodontal disease with calcium intakes 500 mg/day 27% greater risk for those women consuming from 500 to 800 mg/day of calcium Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 13 Physiological Roles: Phosphorus Phosphorus: second-most abundant mineral in the body; about 85% in the skeleton and teeth Functions Formation of bones and teeth Muscle contraction and nerve activity Component of phospholipids in cell membranes, DNA, and RNA Energy metabolism (ADP) Buffer for the body Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 14 Requirement and Source: Phosphorus RDA Men and women: 700 mg/day Sources Abundant in foods—deficiency rare Best sources are milk products and meats Food additive in baked goods, cheese, processed meats, and soft drinks Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 15 Hyperstates: Phosphorus Hyperphosphatemia (serum level above 2.6 mg/dl) may occur in: Hypoparathyroidism Renal insufficiency Excessive amounts of phosphorus bind with calcium, resulting in tetany and convulsions From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013. Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 16 Hypostates: Phosphorus Long-term ingestion of aluminum hydroxide antacids Stress conditions in calcium-to-phosphorus balance Malabsorption conditions (sprue and celiac disease) During tooth development, phosphorus deficiency results in: Incomplete calcification of teeth Failure of dentin formation Increased susceptibility to caries Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 17 Physiological Roles: Magnesium Bones contain almost two thirds of body’s magnesium Role in bone and mineral physiology Cofactor for more than 300 enzymes Necessary for DNA and RNA synthesis Regulates transmission of nerve impulses and muscle contraction Associated with vitamin D conversion in the liver Facilitates blood clotting Facilitates PTH secretion Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 18 Requirements and Sources: Magnesium RDA (19 to 30 yr) Men: 400 mg/day Women: 310 mg/day UL 350 mg/day from nonfood sources Sources Dark green, leafy vegetables Whole grains and nuts Chocolate Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 19 Hyperstates: Magnesium No evidence of overconsumption of magnesium from food sources Kidney regulates magnesium, and toxicity may cause kidney failure Symptoms: Diarrhea Nausea Cramping Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 20 Hypostates: Magnesium Deficiency rare in healthy people Can occur w/prolonged vomiting, malabsorption, kidney disease, intestinal surgery, excessive use of OTC and medications (corticosteroids, diuretics) Present in nearly all chronic alcoholics Symptoms of deficiency: Fragility of alveolar bone and gingival hypertrophy Cardiac dysrhythmias Neuromuscular hyperexcitability Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 21 Nutritional Directions: Magnesium Evidence suggests that magnesium may play an important role in regulating blood pressure The DASH study (Dietary Approaches to Stop Hypertension) suggests HBP can be lowered by diet high in magnesium, potassium, and calcium, and low in sodium and fat The diet includes whole grains, fruits, vegetables, and low-fat dairy http://dashdiet.org Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 22 Overview: Fluoride In a strict nutritional sense, fluoride is not a nutrient essential for health because it has no known metabolic function However, because of benefits to dental and bone health, fluoride is considered a desirable element for humans Fluoride ions can replace hydroxyl ions in the hydroxyapatite crystal lattice, making it more resistant to caries Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 23 Physiological Roles: Fluoride Forms fluorapatite, which is more caries resistant Systemic fluoride results in changes to tooth morphology; increases tooth’s resistance to adherence of plaque biofilm Fluoride in saliva also interferes with demineralization Higher concentrations of fluoride From Bird DL, Robinson DS Modern Dental Assisting, ed 11. St. Louis: Saunders, 2015. inhibit Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus species Stimulates osteoblast proliferation and increases new mineral deposition in cancellous bone Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 24 Requirements: Fluoride Absorption occurs in the stomach AI 6 to 12 mo: 0.5 mg/day 1 to 3 yr: 0.7 mg/day 2 to 8 yr: 1.1 mg/day 9 to 13 yr: 2.0 mg/day 14 to 18 yr: 2.9–3.2 mg/day 19+ yr: 3.1–3.8 mg/day Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 25 Requirements: Fluoride UL 6 to 12 mo: 0.9 mg/day 1 to 3 yr: 1.3 mg/day 4 to 8 yr: 2.2 mg/day 9+ yr: 10 mg/day Sources Fluoridated water Brewed tea Ocean fish w/bones (salmon, herring, sardines) Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 26 Hyperstates: Fluoride Dental fluorosis (hypomineralization of enamel) directly related to fluoride exposure during tooth development Varies from white flecks, to white or brown staining, to brownish discoloration and varying degrees of enamel pitting Ingestion of large amounts of fluoride in adults can result in adverse effects on skeletal tissue and kidney function Courtesy Alton McWhorter, DDS, MS; Associate Professor Pediatric Dentistry; The Texas A&M University System; Baylor College of Dentistry; Dallas. Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 27 Nutritional Directions Encourage use of fluoridated water for those >6 months of age and topical fluorides for adults and children Encourage low-fat dairy, whole grains, and vegetables as calcium and magnesium sources Evaluate use of supplements and refer to a medical provider and/or registered dietitian as needed Stress need to minimize use of antacids and seek medical care for chronic heartburn Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 28 HEALTH APPLICATION Osteoporosis Discuss both overall & oral health impacts of patients developing osteoporosis Discuss demographic at risk for developing osteoporosis Discuss impacts of having osteoporosis on the oral cavity Discuss treatment options & adequate calcium intake for prevention of osteoporosis Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. 29