Alveolar bone is a specialized bone structure that contains the sockets for teeth and supports the teeth. It is composed of alveolar bone proper and supporting bone. Alveolar bone develops from the dental follicle during tooth development and eruption. It functions to protect tooth sockets, provide attachment for periodontal ligament fibers, and support the teeth. The structure of alveolar bone includes an outer cortical plate, inner alveolar bone proper, and central spongy bone. It receives its blood supply from alveolar arteries. Periodontal disease can affect the tissues that support teeth, including the alveolar bone.

1. Alveolar bone1

2. Part I2BONE

3. Bone Tissue2 Types of bone tissue:Compact (Cortical) boneSpongy (Cancellous) boneBone tissueis 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.http://en.wikipedia.org/wiki/Bone_tissue3

4. Functions of Bonehttp://en.wikipedia.org/wiki/HaematopoiesisSupport: provides framework that supports and anchors all soft organs.Protection: skull and vertebrae surround soft tissue of the nervous system, and the rib cage protects vital thoracic organs.Movement: skeletal muscles use the bones as levers to move the body.Storage: fat stored in the interior of the bones. Bone matrix serves as a storehouse for various minerals.Blood Cell Formation: hematopoiesis occurs within the marrow cavities of the bones.4

5. Classification of BoneBone may be classified in several ways:5

6. endochondralboneWhere bone is preceded by a cartilagenous model that is eventually replaced by bone In a process termed endochondral ossification.intramembranous boneWhere bone forms directly w/in a vascular, fibrous membrane.6

7. CHEMICAL PROPERTIES of Bone“Oral Anatomy, Histology, and Embryology”60 % Inorganic materialis formed from carbonated hydroxyapatite. 25 % Organic materialmainly composed of Type I collagen.The organic part is also composed of various growth factors:glycosaminoglycans, osteocalcin, osteonectin, bone sialo protein, osteopontin and Cell Attachment Factor.715% WaterOrganic Matrix of the bone8

8. Structural Elements of BoneBone CellsOdontoblasts – are mononucleatecells that are responsible for bone formationOsteocytes – When osteoblasts become trapped in the matrix they secrete, they become osteocytes.Osteoclasts – is a type of bone cell that removes bone tissue by removing its mineralized matrix and breaking up the organic boneBone Matrixis the intercelluar substance of bone consisting of collagenous fibers ground substances & inorganic saltsSharpey’s FibersAre a matrix of connective tissue consisting of bundles of collagenous fibers connecting periosteum to bone Blood vessels, nerves, lymph vessels9

9. Sharpey’s fibers10

10. Cell types in boneOsteoblastsare mononucleatecells that are responsible for bone formationOsteocytesWhen osteoblasts become trapped in the matrix they secrete, they become osteocytes.Bone-lining cellsAre inactive osteoblasts that cover all of the available bone surface and function as a barrier for certain ionsOsteoprogenitor cellsrelatively undifferentiated cells found on or near all of the free surfaces of bone, which, under certain circumstances, undergo division and transform into osteoblasts or coalesce to give rise to osteoclasts.Osteoclastsis a type of bone cell that removes bone tissue by removing its mineralized matrix and breaking up the organic bone11

11. RESORPTION AND FORMATION OF BONE DURING REMODELLINGResorptionReversalFormationResting12

12. OssificationAlso called Osteogenesisis the natural process of bone formationThere are two processes resulting in the formation of normal, healthy bone tissue:Endochondral (Intracartilaginous) Bone OssificationThe formation of bone in which a cartilage template is gradually replaced by a bone matrix, as in the formation of long bones or in osteoarthritic ossification of synovial cartilage.Intramembranous Bone Ossificationthe development of bone from tissue or membrane, as in the formation of the skull.http://en.wikipedia.org/wiki/Ossification13

13. SuturalBone Growthvariable and irregularly shaped bones in the sutures between the bones of the skull. 14

14. Alveolar Bone

15. ALVEOLAR BONEhttp://www.answers.com/topic/alveolar-bone#ixzz12ko9kyTQAlso called as alveolar processThe specialized bone structure that contains the alveoli or sockets of the teeth and supports the teeth.If the teeth are lost the alveolar process disappearsIt is composed mainly of two parts:alveolar bone properSupporting bone

16. Alveolar Bone

17. Development of Alveolar Bone

18. Development of Alveolar BoneAlveolar bone develops from the dental follicleThe ectomesenchymal cells of the dental follicle differentiate into osteoblasts and lay down the matrix called osteoidSome osteoblasts become embedded in the matrix and are called osteocytes

19. Near the end of the 2nd month of fetal life, mandible and maxilla form a groove that is opened toward the surface of the oral cavityAs tooth germs start to develop, bony septa form gradually. The alveolar process starts developing strictly during tooth eruption.

20. Gross Morphology of BoneMorphology -is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural

22. Alveolar SocketAlso called Dental alveolusare 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.

23. Interdental Septa“Septa” – in Latin, it means “fence” or “wall”Are plates of bone that separate each individual sockets from one another.Interradicular SeptaAre thin plates of bone that separate the roots of multi-rooted teeth

24. Cribriform Platealso called as bundle boneIs the compact layer of bone lining the tooth socket (alveolar socket)Reflects the sieve-like appearance produced by numerous Volkmann’s canals passing from the alveolar bone to the PDL (periodontal ligament).Numerous Sharpey’s Fiber pass through it.

25. Alveolar processis 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 MandibleAre the tooth-bearing bones

26. Lamina Durathis part which is attached to the cementum of the roots by the periodontal ligament.Is the bone lining the alveolusIn clinical radiographs, it commonly appears as a dense white line.Lamina DuraRadiographic appearance of alveolar bone proper as ‘Lamina Dura’

27. Functions of the bone

28. Functions of Alveolar boneProtectionAlveolar bone forms and protects the sockets for the teeth.AttachmentIt gives the attachment to the periodontal ligament fibers, which are the principle fibers. These fibers which enter the bone are regarded as Sharpey’s fibers.SupportIt supports the tooth roots on the facial and on the palatal/lingual sides.Shock-absorberIt helps absorb the forces placed upon the tooth by disseminating the force to underlying tissues.

29. Structure of the Alveolar BoneCortical Plate – outermost partAlveolar bone proper or laminaSpongiosa – spongy bone

30. a) outer cortical platesb) a central spongiosac) bone lining the alveolus (bundle bone)

31. Cortical PlateOuter bony plate of varying thickness, which is the outside wall of the maxilla and mandible, covered with periosteumContinuous with the lamina cribriformis at the orifice of the alveoli – alveolar crestConsists of haversian systems (osteons) and interstitial lamellaeThicker in the mandible than maxillaGenerally greater on the lingual than on the buccal/facial

32. Alveolar Bone Proper or LaminaAn inner, heavily perforated bony lamellae, forming the alveolar wallIn radiograph, appears as radioopaque line distinct from the adjacent spongiosa – Lamina DuraContains osteons like other cortical bone, but is distinguished by the presence of Bundle Bone

33. SpongiosaAre spongy (or cancellous/trabecullar) bone between the 2 bony plates and between the lamina cribriformis of adjacent teeth or rootsConsists of delicate trabeculae, between which are marrow spaces, filled mostly with fatty marrowRegions of maxillary tuberosity and the angle of mandible, erythropoietic …

34. VascuLAR Supply of ALVEOLAR BONE

35. Vascular Supply of Alveolar ProcessAlveolar process of the maxillaAnterior and posterior alveolar arteries (branch from the maxilla and infraorbital arteries)Alveolar process of the mandibleInferior alveolar arteries (internal)Periosteal branches of submental and buccal arteries (external)

36. Periodontal disease

37. PeriodonTal diseasehttp://en.wikipedia.org/wiki/Periodontal_diseasePeriodontal disease is a type of disease that affects one or more of the periodontal tissues:Alveolar bonePeriodontal ligamentCementumgingivaWhile many different diseases affect the tooth-supporting structures, plaque-induced inflammatory lesions make up the vast majority of periodontal diseases and have traditionally been divided into two categories:gingivitis orperiodontitis.

38. Histological Arrangement of Mature BoneMature bone is composed of:Compact boneSpongy Bonehttp://www.physioweb.org/skeletal/bone_tissue.html39

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40. Compact BoneAlso called as Cortical boneAs its name implies. . .“cortical” bone forms the cortex or outer shell of most bones.“compact” bone is much denser than cancellous bone. Furthermore, it is harder, stronger and stiffer than cancellous bone. The primary anatomical and functional unit of cortical bone is the osteon.3Distinct Layering of Compact Bone:Circumferential lamellaConcentric lamellaInterstitial lamellaFunctions:facilitates to support the whole bodyprotect organsprovide levers for movementstore and release chemical elements, mainly calcium.http://en.wikipedia.org/wiki/Bone_tissue41

41. 3 Distinct Layering of Compact Bone:Circumferential Lamellaeenclose the entire adult bone, forming its outer perimeterConcentric Lamellaemake up the bulk of compact bone and form the basic metabolic unit of bone, the osteonInterstitial Lamellaeinterspersed between adjacent concentric lamellae and fill the spaces between them42

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43. Spongy BoneAlso called Cancellous bone orTrabecular boneCompared to compact bone, cancellous bone has a higher surface area but is less dense, softer, weaker, and less stiff.Cancellous bone is highly vascular and frequently contains red red bone marrow where hematopoeisis occurs.The primary anatomical and functional unit of cancellous bone is the trabecula.44