Downloaded 1,055 times
Uploaded byMuhammad Awadine
Alveolar bone
The document discusses alveolar bone, which forms the primary support structure for teeth. It defines alveolar bone and discusses its classification, composition, function, histology, cells, development, remodeling, and age-related changes. Alveolar bone holds teeth firmly in position, supplies vessels to periodontal ligaments and cementum, and houses developing permanent teeth. It is a specialized part of the maxilla and mandible composed of lamellar and bundle bone that surrounds tooth roots and provides attachment for periodontal ligament fibers. Alveolar bone is constantly remodeled through formation and resorption to adapt to functional forces.
More Related Content
Alveolar bone
- 1. ALVEOLAR BONE By MuhammadAwadine
- 2. Defining alveolarbone Classification of alveolar bone Composition of alveolar bone Function Gross histology of bone Bone Cells Alveolar Process Development of bone Bone remodeling and resorption Age changes in alveolar bone OBJECTIVES
- 3. DEFINITION Bone isspecialized C.T with calcified intercellular substance Alveolar bone is specialized part of maxillary and mandibular bone that forms the primary support structure for teeth
- 4. CLASSIFICATION OF BONE Shape : Long Short Flat Irregular bone Development: endochondral intramembranous Microscopic structure: Embryonic or woven bone lamellar bone Macroscopic structure: + Compact bone + Sponge (cancellous ) bone
- 5.
- 6. FUNCTION OF BONE Give shape and support of the body Insertion for muscles and ligaments of the body Bone marrow is a site for blood cells production Alveolar bone holds the teeth firmly in position to masticate Supplies vessels to periodontal ligaments and cementum Houses and protects developing permanent teeth while supporting primary teeth
- 8. GROSS HISTOLOGY OFTHE BONE
- 13. CELLS OF THEBONE Osteoblasts: these are mononucleated cells which synthesise and secrete the bone matrix Osteocytes: inactive osteoblasts which get entrapped within the bone are called as osteocytes. Osteoclasts: cells responsible for resorption of bone. These are large cells having 15-20 nuclei. Derived from monocytes – macrophages Contain acid phosphatase enzyme Has a ruffled border on the cell surface, more mitochondria and less rough endoplasmic reticulum. Always found in concave areas know as “Howships lacunae”
- 16.
- 17. ALVEOLAR BONE (PROCESS) Definition: alveolar process is that part of maxilla and mandible that forms and supports the sockets of teeth. Development: it starts in the second month of fetal life Maxilla and mandible forms a groove that is open towards the surface of the oral cavity. Developing tooth buds are enclosed in these grooves. Major portion of the alveolar process begins with root formation and eruption of the teeth. During rapid growth alveolar crest shows characteristics of cartilage and bone - CHONDROID BONE
- 18. STRUCTURE OF ALVEOLARBONE ALVEOLAR BONE ALVEOLAR BONE PROPER LAMELLATED BONE BUNDLE BONE SUPPORTING ALVEOLAR BONE CORTICAL PLATE SPONGY BONE
- 19. ALVEOLAR BONE PROPER It surrounds the root of the tooth and gives attachment to the periodontal ligament fibres. It consists of Lamellated bone Bundle bone Lamellated bone consists of osteons. Concentric lamellae along with a central blood vessel form an osteon.
- 21. BUNDLE BONE Partof the alveolar bone where periodontal ligament fibres are inserted (attached). Bundle – bundles of fibres Sharpeys fibres – principal fibres of the periodontal ligament that are embedded in the bone or cementum. Sharpeys fibres are seen perpendicular to the bundle bone. Other fibrils are less and are arranged parallel to the bundle bone surface Radiographically is more radiodense due to presence of thick bone without trabeculations and is called as “lamina dura” Alveolar bone proper has many openings for blood vessels and nerves – is perforated and is called as “cribriform plate” Interdental and interradicular septa have canals known as canals of “ zukerkandl and hirschfeld”
- 22. CRIBRIFORM PLATE VSLAMINA DURA
- 23. SUPPORTING ALVEOLAR BONE It consists of two parts – Cortical plates (Outer and inner) Spongy bone Cortical plates: these are made up of compact bone & form the outer and inner plates of alveolar bone. Cortical bone varies in thickness in different areas – it is thicker in the mandible than in the maxilla and thicker in the premolar-molar region than in the anteriors.
- 24. Spongy bone:it fills the area between the cortical plates and the alveolar bone proper. It contains trabaculae of bone and marrow spaces. Types of spongy bone (spongiosa) :- Type I: the trabaculae are regular and horizontal like a ladder. This is seen most commonly in the mandible. Type II: irregularly arranged delicate and numerous trabaculae. This is seen most commonly in the maxilla. The spongy bone is very thin or absent in the anterior regions of both the jaws.
- 25.
- 26. ALVEOLAR CREST (CRESTOF ALVEOLAR SEPTA): alveolar bone proper meets cortical plates at the alveolar crest In healthy mouths the alveolar crest is around 1.5 to 2 mm below the cementoenamel junction.
- 27. DEVELOPMENT OF BONE Endochondral bone formation
- 28. Intramembranous boneformation
- 29. BONE REMODELING ANDRESORPTION Bone is a dynamic tissue and is always undergoing changes to adapt for functional forces, mesial drift, and eruption of teeth. There is constant formation and resorption of bone. Periods of resorption alternate with periods of rest and repair. Lines seen in bone: Resting line: these lines correspond to the resting period in the process of continous bone formation. Reversal line: when a period of bone resorption is followed by bone formation, a dark line is seen which seperates the new bone from old bone, this resembles the shape of howships lacunae.
- 30.
- 31. AGE CHANGES INALVEOLAR BONE Brittleness due to decreased water content Sponge bone become thin trabecula , wide marrow spaces Red bone marrow become fatty Osteoporosis Alveolar crest slope distally due to mesial tilting of teeth With loss of teeth and resorption of alveolar ridge mental foramen become very close also maxillary sinus in upper jaw Thank you!!