3. contents
• Bone – introduction, classification, composition, functions , histology & bone cells
• Introduction of AB
• Development of AB
• Structure of AB
• Blood supply & nerve supply of AB
• Functions of AB
• Age changes of AB
• Clinical considerations of AB
• Therapeutic considerations of AB
• Summary
• References
4. Introduction
BONE – It is a living specialized
connective tissue with calcified inter
cellular substance, which makes up
the body skeleton and is one of the
hardest structures of human body.
10. •Immature(Woven) Bone •Mature (Lamellar )Bone
•Collagen fibers oriented in
many directions
•Fibers are orderly arranged
•Interfibrillar space is more •Interfibrillar space is less
•H&E- Matrix shows blue •H&E- Matrix shows Acidophilic
•Deposition & Mineralization
rates are fast.
•Deposition & Mineralization
rates are slow.
• Bone sialoprotein present •Osteocalcin present
Based on Maturity
11. Immature(Woven) Bone Mature (Lamellar )Bone
Mineral density is lower &water
content higher
Low water content
Entirely removed by osteo
clasts.
Portion of lamellar matrix
resorbed at one time
Matrix vesicles participate in
mineralization
Collagen mediated mechanism
is involved in calcification
16. :
• circumferential lamellae:
these lamellae are arranged in
parallel layers surrounding bone.
• concentric lamellae: these
lamellae are arranged in
concentric layers.
• Interstitial lamellae: these are
present in between osteons.
• TRABECULAE- spongy bone
consists of large slender
spicules
17. haversian canal
and concentric lamellae are together
called as osteon.
the vascular canal
present at the centre of concentric
lamellae.
adjacent haversian
systems are connected by volkmann’s
canals.Contain vascular network
19. this line has more regular
appearence which denotes period of rest
during formation of bone. Deliniates
haversion system
irregular lines which indicate
previous area of bone resorption.
20. Hemopoietic tissue
• Red marrow – young bone
Spongy bone of long and flat bones
Contain stem cells of fibroblasts and blood cells
• Yellow marrow – old bone
Seen in epiphysis of long bones
Loss of hemopoietic potential
Increased accumulation of fat cells
25. Bone lining cells
• The osteoblasts that have
completed their function and lie
on bony surface as bone lining
cells
• These cells contain few cell
organelles
26. osteocytes
• As the osteoblasts form bone matrix ,
they get entrapped within the matrix
they secrete are called osteocytes
• Number of osteoblasts that become
osteocytes , depends on rapidity of bone
formation
• Woven bone, repair bone shows more
osteocytes
• Osteocytes are 1o times more than
osteoblasts
• Half life
• Lacunae , canaliculi
27. osteoclasts
• It is a type of bone cell that
removes bone tissue by removing
mineralized matrix of bone
• Osteoclasts lie in resorption bays
• Multinucleated
• Exhibits 2 zones
• Acid phosphatase
28. Alveolar bone
Alveolar Bone (Process) is the part
of maxilla & mandible that forms &
supports the sockets (alveoli) of the
teeth
• Also known as Processes
Alveolaris
• Pars Alveolaris
29. Development of AB
• At the end of 2nd month of iu life, maxilla and
mandible forms a groove
• As tooth germs start to develop , bony septa form
gradually
• As root develop, alveolar process increases in height
• During rapid growth period, chondroid bone is
formed
30. alv. Process forms with development and eruption of teeth
Morphology of Alv. Bone depends on
Size
Shape
position of teeth
alv bone attains max thickness
Alv. bone undergoes atrophy
If teeth congenitally missing – Alv. Bone not developed
33. Structure of AB
Two Parts:
Alveolar Bone proper:
Thin lamellated bone that surrounds the
root of the tooth
Gives attachment to the PDL Fibres
Supporting alveolar Bone:
Surrounds the alveolar bone
Proper
Gives support to the socket
34. Alveolar bone proper
That lines the socket or alveolus
Forms the inner wall
Consists of two parts
0.1 – 0.4 mm thick
Otherwise called as cribriform plate
37. Lamellated bone
Lamellar bone consists of
osteons
Concentric lamellae along with
central blood vessel forms an
osteon
Continuous with supporting
alveolar bone
Mature bone
38. Bundle bone
Term bundle - Sharpey’s fibre
These fibers are inserted at 90 deg angle
into ABP
Consists of fibrils in the intercellular
substance and are arranged at right angles
to sharpey’s fibers
These fibrils are less in number compared
to lamellated bone and therefore it appears
dark in H&E
Silver stain
40. Alveolar Crest
alveolus
distance b/n CEJ and free border
of ABP
ABP meets cortical plates
Most cervical rim = alveolar crest
It is slightly apical to CEJ in
healthy patients
If neighburing teeth is inclined
Alveolus
Rim
Floor
Alv. crest
Fundus
42. Cortical Bone
Compact bone
Forms inner &outer plates of the
alveolar process
Variations:
Maxilla –thinner
Mandible -Thicker
Premolar, Molar region –Thicker
Anterior region -Thin
43. Buccal cortical plate – Thick
Lingual Cortical plate -Thinner
Relation to Local anaesthesia
maxilla
perforated by many
openings
Infiltration is sufficient
Mandible
Dense cortical plate
Nerve Blocks required
44. SpSpongiosaongiosa
Fills space b/n ABP and Cortical
bone
Variations;
Maxilla –More
Mandible -Less
In ant region –both jaws :
Spongiosa is absent
Cortical plate is fused with ABP
48. Nutrient Canals
Zuckerkandl & Hirschfeld
Interdental &Inter-radicular septum
Contain –BV, lymph vessels and nerves
Appear as radioluscent lines or shadows
Parallel to long axis of tooth
52. Functions of AB
• Houses the roots of teeth
• Anchorage
• Helps to move teeth
• Helps to absorb and distribute occlusal forces
• Supplies vessels to pdl
• Protects developing permanent teeth
• Organizes eruption of
53. Age changes
• Alveolar sockets appear jagged and
uneven
• Marrow spaces have fatty infiltration
• In Edentulous jaws
• Loss of maxillary bone
• Internal trabecular arrangement is
more open,
• Distance b/n alveolar crest and CEJ
54. • Brittleness
• Osteoporosis
• Alveolar crest slope distally due to mesial tilting of teeth
• With loss of teeth ,resorption of alveolar ridge
57. •Proximity of AB to sinus cavities or major nerves
•Dental implants
•Surgical procedures
•Periodontal disease
58. Therapeutic considerations
• Bone grafting – used to bone deposition in periodontal surgery
• Autografts, allografts , xenografts
• Guided tissue regeneration – collagen is used to support natural bone
formation
• Enamel matrix proteins – used as an adjunct to periodontal surgery