1. Alveolar bone 1

2. BONE Part I 2

3. Bone Tissue Bone tissue is a specialized form of connective tissue and is the main element of the skeletal tissues. is composed of cells and an extracellular matrix in which fibers are embedded. is unlike other connective tissues in that the extracellular matrix becomes calcified. 3

4. Functions of Bone Skeletal function of support, protection, locomotion and attachment of muscles Bone constitutes an important reservoir of minerals Bone is for hemopoiesis 4

5. Compositionof Bone 65% Inorganic (Hydroxyapatite) Mostly Calcium and inorganic orthophosphate deposited between collagen 35% Organic 28% collagen 5% Osteocalcin Sialoprotein Phosphoprotein Osteonectin Bone specific protein 5

6. Structural Elements of Bone Bone Cells Odontoblasts – forms bone Osteocytes – maintains bone Osteoclasts – resorbsbone Bone Matrix is the intercelluar substance of bone consisting of collagenous fibers ground substances & inorganic salts Sharpey’s Fibers Are a matrix of connective tissue consisting of bundles of collagenous fibers connecting periosteum to bone Blood vessels, nerves, lymph vessels 6

7. Histological Arrangement of Mature Bone Compact Bone Spongy Bone 7

8. Compact Bone are dense outer sheet that are closely packed 3 Distinct Layering: Circumferential lamella Concentric lamella Interstitial lamella 8

9. 3 Distinct Layering of Compact Bone: Circumferential Lamellae - enclose the entire adult bone, forming its outer perimeter Concentric Lamellae- make up the bulk of compact bone and form the basic metabolic unit of bone, the osteon Interstitial Lamellae - interspersed between adjacent concentric lamellae and fill the spaces between them 9

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11. Spongy Bone Also called Cancellous bone flattened spicules surrounding the spaces known as marrow spaces containing the bone marrow 11

12. Osteon - basic metabolic unit of bone generally oriented in the long axis of bone Haversian Canal - canal lined by a single layer of bone cells at the outer of an osteon; each cana; houses a capillary Volkman’s Canal - channels that connect adjacent haversian canal;contains blood vessels 12

13. Periosteum – osteogenic connective tissue membrane that surrounds every compact bone; consists of 2 layers Inner layer – consists of bone cells; their precursors and a rich microvascular supply Outer layer – more fibrous, gives rise to… 13

14. Bone Formation (Ossification) Endochondral(Intracartilaginous) Bone Ossification Has a precatilaginous stage Intramembranous Bone Ossification Mandible and maxilla Sutural Bone Growth 14

15. Alveolar Socket Part II: 15

16. Alveolar Socket Also called Dental alveolus are sockets in the jaws in which the roots of teeth are held in the alveolar process with the periodontal ligament. Alveolar socket of the second premolar tooth in a bovine maxillary bone. http://en.wikipedia.org/wiki/Dental_alveolus 16

17. Alveolar Process Part II: 17

18. Alveolar process is the thickened ridge of bone that contains the tooth sockets on bones that bear teeth. The alveolar process contains a region of compact bone adjacent to the periodontal ligament called Lamina dura. Maxilla and Mandible Are the tooth-bearing bones http://en.wikipedia.org/wiki/Alveolar_process_of_maxilla 18

19. Lamina Dura is this part which is attached to the cementum of the roots by the periodontal ligament. http://en.wikipedia.org/wiki/Lamina_dura 19

20. Functions of Alveolar bone Acts as the anchoring of teeth within the alveoli Absorption and distribution of occlusal pressures produced by intermittent tooth contacts during chewing, swallowing, speech and parafunctional activities such as grinding and chewing 20

21. Structure of the Alveolar Bone Cortical Plate – outermost part Alveolar bone proper or lamina Spongiosa – spongy bone 21

22. Cortical Plate Outer bony plate of varying thickness, which is the outside wall of the maxilla and mandible, covered with periosteum Continuous with the lamina cribriformis at the orifice of the alveoli – alveolar crest Consists of haversian systems (osteons) and interstitial lamellae Thicker in the mandible than maxilla Generally greater on the lingual than on the buccal/facial 22

23. Alveolar Bone Proper or Lamina An inner, heavily perforated bony lamellae, forming the alveolar wall In radiograph, appears as radioopaque line distinct from the adjacent spongiosa – Lamina Dura Contains osteons like other cortical bone, but is distinguished by the presence of Bundle Bone 23

24. Bundle Bone Multiple layers of bone parallel to surface of alveolar wall which are penetrated by bundles of Sharpey’s Fibers embedded nearly right angle… 24

25. Spongiosa Are spongy (or cancellous/trabecullar) bone between the 2 bony plates and between the lamina cribriformis of adjacent teeth or roots Consists of delicate trabeculae, between which are marrow spaces, filled mostly with fatty marrow Regions of maxillary tuberosity and the angle of mandible, erythropoietic … 25

26. Vascular Supply of Alveolar Process Alveolar process of the maxilla Anterior and posterior alveolar arteries (branch from the maxilla and infraorbital arteries) Alveolar process of the mandible Inferior alveolar arteries (internal) Periosteal branches of submental and buccal arteries (external) 26