The document discusses the structure and types of bone, including alveolar bone. It notes that bone is composed of osteoprogenitor cells, bone cells, and intercellular substance. There are two types of bone: compact bone and spongy bone. Compact bone is dense and found in shafts, while spongy bone is porous and found in flat bones. Alveolar bone lines the tooth socket and is composed of bundle bone, with Sharpey's fibers inserting into it. It includes the alveolar bone proper and supporting alveolar bone made of cortical and trabecular plates.
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4. 1. Support and protect the skeletal functions.
2. Bone stores minerals, especially calcium and
phosphorous, which are mobilized according to the body
needs.
3. Bone protects the internal organs.
4. Bone marrow manufactures the blood elements.
5. Bone remodeling is responsible for the development,
growth, movements, fracture and repair.
Functions of bone
6. Osteoprogenitor cell
Location: Present in the deepest layer of periosteum
and lining the vascular canals of compact bone.
Origin: It is mesenchymal in origin.
Function: According to the function needed they
divide by mitosis to give any type of bone cells
Morphology: It resembles mesenchymal cell with pale
stained nucleus and little esinophilic cytoplasm.
8. Bone cells
All types of bone cells are from the same type, the alters
there appearance according to there function: this is what
is called cell modulation.
11. Lamellar bone
a. Compact bone (ivory bone):
It forms the main part of the shafts of the long bone and
covers the cancellous bone e.g. ribs and flat bones
of the skull.
Its lamellae are arranged in 3 patterns:
Circumferential lamellae
Havarsian lamellae
Interstitial lamellae
14. Lamellar bone
Havarsian lamellae:
It is the unite structure of the compact bone and is
called the Haversian system or osteon.
The Haversian system if formed of Haversian canal
which is surrounded by (4-20) concentrically
arranged lamellae.
The Haversian canal contains B.Vs., nerves, C.T.
and lined by osteoprogenitor cells.
15. Lamellar bone
Osteocytes are arranged concentrically in
the osteons (they anastomose with each
others by their process).
Haversian canals connected to each
others or to the outer surface or to the
bone marrow spaces with Volkmann's
canal.
16. Lamellar bone
Interstitial lamellae:
The Haversian systems are separated from each
others by the interstitial lamellae.
They represent the remnants of an old resorbed
and remodeled bone.
20. Spongy bone
It is present in the central part of the flat bone.
It is formed of connected bone trabeculae in the
form of network to give maximum rigidity.
In between the bone trabeculae, there are bone
marrow spaces
The bone trabeculae have osteocytes.
21.
22. Woven bone
This type of bone is characterized by:
Irregular arrangement of the collagen fibers.
Great number, large size and irregular arrangement of
the osteocytes.
Increase in the organic substance and decrease in the
inorganic contents so; it appears radiolucent in X-ray.
This type of bone is resorbed completely and is
replaced by lamellar bone.
23. It is referred to the bundles of principal fibers of
either the periosteum or PDL continue into the
bone as sharpeys fibers.
3. Bundle Bone
24. Bundle bone
It is found adjacent to the periosteum and periodontal
ligament (areas of tension).
It is characterized by the presence of the Sharpey's
fibers.
It has less number of cells than Woven bone; but more
calcium salts than lamellar bone. So it appears more
radio-opaque and called lamina dura.
Its fibers are arranged parallel to the socket wall.
26. The alveolar process is that bone containing the alveoli.
It consists of:
an outer (lingual and buccal) cortical plate (compact
bone)
A central spongiosa (spongous bone) and
Alveolar bone (bone lining the alveolus), (bundle
bone)
The alveolar bone and the cortical plate meet at the alveolar
crest (1.5 to 2 mm below the level of CEJ).
Alveolar bone
29. divided into the:
a. alveolar bone proper
lining of the tooth socket or alveolus
bone is also called the cribriform plate because
of the many holes through which Volkmann’s canals
pass (from the alveolar bone into the PDL)
Alveolar bone
30. also called bundle bone because Sharpey’s fibers
insert into this bone (Sharpey’s fibers = portion of
the fibers of the PDL)
these fibers are inserted at a 90 angle into the ABP –
but are fewer in number than those found at the
cemental surface
consists of plates of compact bone that surround the
tooth
Alveolar bone
31. varies in thickness from 0.1 to 0.5mm
can see a portion of the ABP on radiographs lamina
dura
most cervical rim = alveolar crest – slightly apical to the
CEJ in healthy patients
Alveolar bone
32. b. supporting alveolar bone
has the same components as ABP
but is considered to be cortical and trabecular bone –
different arrangement of bony plates
cortical bone is made up of cortical plates of compact bone
found on the facial and lingual surfaces
plates are usually 1.5 to 3mm thick over the posterior teeth
and can vary over the anterior teeth
Alveolar bone
33. trabecular bone is located between the ABP and the plates
of the cortical bone (cross section of mandible)
Alveolar bone
34. alveolar bone can be resorbed with age (edentulous)
the underlying basal bone is less affected with age –
because it does not need the presence of teeth to
remain viable
loss of teeth + alveolar bone can results in loss in the
vertical dimension of the face – “Popeye” facial
appearance
Alveolar bone
35. after tooth extraction the clot is replaced with immature
bone
later remodelled as mature secondary bone, very
similar process to fracture repair in skeletal bone
Alveolar bone
39. The alveolar bone is
perforated by many
foramina to allow blood
and nerve supply to the
teeth, so it is referred to
cribriform plate
Alveolar bone
Hirschfeld
canal
