BONE & ALVEOLAR BONE

1. GOOD MORNING…
GOOD MORNING…

2. ALVEOLAR
BONE
Presented by
DR NAVEEN PARVATHAREDDY
I MDS, NARAYANA DENTAL COLLEGE

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.

5. Based on
location
CLASSIFICATION OF BONES
Axial skeleton Appendicular skeleton
80 126+
206

6. Based on shape

7. Based on developmental origin
Intra-membranous Intracartilagenous / Endochondral

8. Based on cross section
 Compact bone
 Spongy bone
Based on Matrix arrangement
 Lamellar bone
 Woven bone

9. Woven bone

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

12. Composition

13. Non collagenous proteins
osteocalcin

sialoprotein

phosphoprotein

osteonectin

bone specific protein

bone morphogenic protein

14. functions
•Supportive
•Anchorage
•Protective
•Hematopoietic
•Storage
•Locomotive

15. Bone histology
: thin , delicate
connective tissue membrane

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

18. osteocytes are present in
the lacunae at the junctions of
lamellae.

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

21. Bone cells
Osteogenic cells:
1. Osteoprogenitor cells.
2. Osteoblasts.
3. bone lining cells
4. Osteocytes.
Osteoclasts

23.  these are
angular shaped cells with
centrally placed nuclei.
 these cells
differentiate in to
osteoblasts which form
bone.

24. osteoblasts
• Derivation
• Reservoir
• Morphology
• functions

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

31. Boundaries
No distinct boundary
Certain areas Alveolar bone fused with basal bone
Anterior maxillary region
Posterior Mandibular region.

32. Structure of AB
ALVEOLAR
BONE
ALVEOLAR
BONE
PROPER
LAMELLATED
BONE
BUNDLE BONE
SUPPORTING
ALVEOLAR
BONE
CORTICAL
PLATE
SPONGY
BONE

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

35. Cribriform plate
Anatomical name
Resembles a fine holed sieve
Perforated by – foramina
Transmit nerves &Vessels

36. Interdental septum
Inter –radicular septum

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

39. Lamina dura
Radiologic name
appears as radiopaque line
Is lost

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

41. Supporting alveolar bone
Two Parts
Cortical Bone
Spongiosa
Supporting alveolar bone

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

45. Spongy bone
Spongy bone

46. Two types –R/A
Type I
Trabeculae –
Regular
Horizontal
Thick
Ladderlike
Mandible
Trajectorial pattern
Along lines of stress

47. Type II
Irregular
Fine/Delicate
Maxila
No trajectory pattern , More
marrow space

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

49. Surface structures
Ju'ga alveolaria mandibulae
Ju'ga alveolaria maxillae

50. Blood supply
Nerve supply
Lymphatic drainage

51. Bony defects
• Fenestration
• Dehiscence
• Central buttressing
• Peripheral buttressing
• Osseous craters

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

55. Pattern of bone resorption
•Maxilla
•Mandible
•Alv crest

56. Clinical considerations
Maxillary teeth
Fractured tooth
 Abscess
loss of lamina dura
AB loss
Orthodontic Treatment
Effect of hormones

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

59. summary

60. References
 ORBAN'S ORAL HISTOLOGY : S.N. BHASKAR.
TENCATE’S ORAL HISTOLOGY
HISTOLOGY (ATEXT AND ATLAS), MICHEAL H. ROSS,WOJCIEH PAWLINA
HAM’S GENERAL HISTOLOGY
GLICKMANN'S CLINICAL PERIODONTOLOGY : CARRANZA.
BASIC HISTOLOGYTEXT AND ATLAS- LUIZ CARLOS JUNQUEIRA, JOSE CARNEIRO
ORAL STRUCTURAL BIOLOGY : H.E.SCHROEDER. .
 TEXT BOOK OF HISTOLOGY : ROSS & REITH.
INTERNET ACCESS

61. THANK YOU…