Alveolar bone is a specialized, mineralized connective tissue that supports the roots of the teeth Alveolar bone is the least stable of the periodontal tissues because the structure is in constant state of flux.

1. ALVEOLAR
BONE
Dr.Himanshu Tiwari
Senior Lecture
Dept. Of Prosthodontics
and Crown & Bridge

2. CONTENTS
 INTRODUCTION
 DEFINITION
 FUNCTIONS
 GROSS HISTOLOGY OF BONE
 BONE FORMATION
 BONE TURNOVER
 REMODELING
 PARTS OF ALVEOLAR BONE
 BUNDLE BONE
 OSSEOUS TOPOGRAPHY
 CLINICAL CONSIDERATIONS
 BONE LOSS AND PATTERNS OF BONE DESTRUCTION
 FACTORS AFFECTING BONE MORPHOLOGY IN PERIODONTAL
DISEASES

3. INTRODUCTION
 Specialized part that forms primary support
structure for teeth
 Constitutes alveolar process – tooth dependent
 Subjected to continual and rapid remodeling- for
positional adaptation
 Similar to basal bone histologically, but differ in
positional adaptation

4. DEFINITION
 Portion of maxilla and mandible that
forms and supports tooth sockets

5. FUNCTIONS
 Frame work
 Central axis
 Support and transmits weight
 Locomotion
 Protection
 Calcium storage
 Form blood
Of alveolar process in particular
 Socket formation
 Protection
 Esthetics
 Distribution of occlusal forces

6. GROSS HISTOLOGY
 Outer compact bone
 Inner medullary bone

8. Components of bone
components
matrix
cells
osteogenic osteoclastic organic inorganic
collagenous Non-collagenous

9. Cellular components
Osteoblasts:-
- Uninucleated
- Secretory cells
- Produce type I collagen, non-collagenous and plasma proteins
Osteocyte:-
- Occupy lacunae
- Number varies
- Continumm involving changes in extracellular environment and
cellular changes
- Osteocytic osteolysis
- Presence of cell process within canaliculi

10. Bone lining cells:-
- Represents final phenotypes of osteoblastic
lineage
- Transition involves a series of changes
Osteoclasts:-
ability to respond to biologically regulatory factors
and functional forces is because of osteoclasts
- Large multinucleated cells
- Haemopoetic origin
- Ruffled border
- Causes resorption in acidic extracellular
environment

11. Matrix
Forms a scaffold of interwoven collagen fibres
within and between which small uniform plate
like carbonated hydroxyapatite crystals are
deposited.
collagen:-
 Type I,III,V,XII
 Stabilized by cross links
 Orientation

12. Non-collageous:-
 Proteins- osteocalcin, bone sialoprotein,
osteonectin, osteopontin
 Proteoglycan- chondroitin sulphate, biglycan,
decorin
 Proteins from blood and tissue fluids- albumin,
immunoglobulin, matrix gla protein
Inorganic:-
 Calcium, phosphate
 Hydroxyl, citrate, carbonate
 Sodium, magnesium, fluoride

13. Bone formation
 Endocondral
 Intramembraneous
 Sutural

17. Mineralization
Two mechanisms involved-
 Matrix vesicles
 Heterogeous nucleation

18.  Factors regulating bone formation-
 Harmones- parathyroid, vitamin D3, glucocorticoids,
insulin, growth harmone, thyroid, estrogen.
 Growth factors- TGF-β, IGF-I &II, FGF, PDGF
 Factors regulating resorption
 PTH, Vit D, IL-1,6, TNF-α, TGF- α, lymphotoxin
 Factors that inhibit resorption
 Calcitonin, estrogen, TGF-β, IFN-G, PGE2.

19. Bone turnover
Replacement of old bone by new bone is called
bone turnover.
- formed on periosteal surface and removed from
endosteal surface.
- The leading edge of resorption is termed cutting cone
- Formation of cement/reversal line
- New bone deposited – filling cone

20. Bone remodeling
Important functional charecteristic of alveolar bone is its
capacity to undergo continuous remodeling in response to
functional demands.
Involves three phases
1. Resorption phase
2. Reversal phase (Baron)
3. Formation phase
Resting phase- follows until the functional condition locally activate a
new cycle.
Bone balance is negative.

21.  On appositional side
charecterised by the presence of continuous row of
osteoblast cells that lie between sharpey’s fibers over a
layer of osteoid tissue.
Bone balance is positive.
 Changes in external architecture accompanied by
changes in internal architecture.
 Remodeling never reach periodontal ligament space.

22. Cement lines
 Are hypomineralized lines with less calcium and
phosphate content and more sulphur content
 Provides striking mechanical properties
Cells responsible for remodeling:-
In mature periodontium, the renewal of the alveolar
wall is effected by the periodontal ligament cells.
Fewer data exist on the origin and location of
osteoclast precursor.

23. Parts of alveolar bone
The alveolar bone is divisible into
separate areas on the
anatomic basis, but it functions
as a unit, with all parts
interrelated in the support of
teeth.

24.  Interdental septum
separates two adjacent tooth sockets.
may contain cancellous bone surrounded by
cortical bone or may be made up of entirely of
cribriform plates.
mesiodistal angulation of the alveolar crest
parallels the line drawn between CEJ of
approximating teeth.

25. Bundle bone
 Consists of extrinsic and intrinsic components
 Thickness varies between 100-200µm
 Other names include cribriform plate, lamina dura,
alveolar bone proper
 All forms of bone histology is observed
Osseous topography:-
bone contour confirms to the prominence of roots,
alignment of the teeth, angulation of the root to the
bone and occlusal forces.

27. Clinical considerations
 Orthodontic movement of the teeth
 Qualitative and quantitative adaptation
 Healing of fractures and extractions
 Harmful change associated with periodontal diseases
 Tooth dependent- endodontic therapy
 Fenestrations and dehisence
 ankylosis

29. Bone loss patterns of bone destruction
 By extension of gingival inflamation
 By TFO
 By systemic disorders
Factors determining bone morphology in periodontal diseases
 Normal variations
 Exostoses
 TFO
 Buttressing bone formation
 Food impaction
 Juvenile periodontitis

30.  Patterns of bone loss
- horizontal bone loss
- vertical defects
- osseous craters
- bulbous bone contours
- ledges
- reversed architecture
-furcation involvement

31. Conclusion
Alveolar bone is a specialized, mineralized connective tissue
that supports the roots of the teeth
Alveolar bone is the least stable of the periodontal tissues
because the structure is in constant state of flux.

32. References
 Clinical periodontology- caranza 8th and 9th edition
 Clinical periodontics and implant dentistry- Jan lindhe
 Periodontics – Grant
 Oral histology and embryology –Ten cate
- orbans
 Periodontics 2000- 1995,1997