alveolar bone ppt sjmdch chitradurga dental topic

1. GOOD MORNING

2. DEPARTMENT OF PERIODONTICS
ALVEOLAR BONE
CHENNABASAV M G
III BDS
SJMDC&H
CHITRADURGA

3. • Introduction
• Definition of Alveolar bone
• Development of Alveolar bone
• Composition
• Parts of Alveolar bone
• Functions of Alveolar bone
• Remodeling and Repair
• Blood supply and Nerve supply
• Age Changes
• Clinical Considerations
• conclusion
• References

4. INTRODUCTION
BONE :-
Bone is a specialized connective
tissue that is mainly characterized
by its mineralized organic matrix.

5. Alveolar process
 The alveolar process is the
portion of maxilla and
mandible that forms and
support the tooth socket.
 It forms when tooth erupts to provide
the osseous attachment to the
forming periodontal ligament; it
disappears gradually after the tooth
is lost.

6. Maxilla Mandible

7. ALVEOLR BONE HISTOLOGY
• All mature bones have a dense outer
sheet of compact bone and a central
medullary cavity
• The cavity is filled with red or yellow
bone marrow
• Cavity shows a network of bone
trabeculae. (Trabecular, spongy or
cancellous bone are the terms used to
describe this network)

9. These are tooth
dependent bony
structures therefore
the size, shape,
location and function
of the teeth
determines their
morphology.

10.  The alveolar process is defined as that part of the maxilla and
the mandible that forms and supports the sockets of the teeth.
–Orbans
 The alveolar process is the portion of the maxilla and mandible
that forms and supports the tooth sockets (alveoli)
–Carranza

11. DEVELOPMENT OF ALVEOLAR PROCESS
At the end of 2nd month of fetal life, the maxilla
as well as mandible forms a groove that open to
surface of oral cavity Tooth germs contained in
these groove (alveolar vessels & nerve) .
Alveolar process consists of bone
which is formed both by cells from the
dental follicle (alveolar bone proper) &
cells which are independent of tooth
development

12. Permanent tooth moves into place, developing its own alveolar bone from
its own follicle

13. With the onset of root formation - interradicular bone develops in
multirooted teeth.
When a deciduous tooth is shed, its alveolar bone is resorbed.
Alveolar process gradually incorporated into maxillary or mandibular
body.
Permanent tooth moves into place, developing its own alveolar bone
from its own follicle

14. BONE
Inorganic (67%) Organic (33%) CELLS
(Hydroxyapatite )
Collagen (28%) 1.Osteoblasts
Non collagenous 2.Osteoclasts
Proteins (5%) 3.Osteocytes
4.Bone lining cells

15. collagenous proteins Noncollagenous
proteins-
-Type I collagen sialoproteins,
osteocalcin,
osteonectin,
osteopontin,
proteoglycans,

16. Parts & Structure of Alveolar process
1. Inner socket wall of thin compact bone called alveolar
bone proper
2.Supporting alveolar bone
a) Cortical plates
b) Spongy bone

17. 1.
2. Supporting alveolar bone
o Cortical plates
o Spongy bone

18. ALVEOLAR BONE PROPER
•Cribriform plate (anatomic term)
•Lamina dura (radiographic term)
•Bundle bone (histologic term, coined by Stein and Weinmann, 1925)
Consists partly of lamellated & bundle bone
About 0.1–0.4 mm thick.
•It is that bone in which the principal fibers of the periodontal
ligament are anchored. (Sharpey’s fibers).
•This type of bone contains several layers of bone deposited in
orientation parallel to the tooth

20. • It is characterized by the scarcity of the fibrils in the intercellular
substance.
• It contains fewer fibrils than lamellated bone.
• Since bundle bone contains more calcium salts per unit area than
other type of bone tissues, they appear as dense radioopacities in
x-rays.

21. Lamellated bone
• Contains osteons each of which has a
blood Vessel in a haversian canal.
• Blood vessel is surrounded by concentric
Lamellae to form osteon.
• Some lamellae of the lamellated Bone are
arranged roughly parallel to the surface of
the Adjacent marrow spaces, whereas
others form haversian systems.

22. Bundle bone
• Bone in which the principal fibers of the periodontal ligament are
anchored
• The term ‘bundle’ because, the bundles of the principal fibers
continue into the bone as Sharpey’s fibers
• Characterized by the scarcity of the fibrils in the
• intercellular substance and arranged at right angles to Sharpey’s
fibers
• Contains fewer fibrils than does lamellated bone

23. Sharpey’s fibers
• Sharpey’s fibers are
mineralized at the periphery
and have a larger diameter.
• These fibers are less
numerous than the
corresponding fiber bundles in
the cementum

24. Radiographically
it is also referred to as the lamina
dura, because, of increased
radiopacity, which is due to the
presence of thick bone without
trabeculations

25. Supporting alveolar bone
Consists of two parts
1. Cortical plates
2. Spongy bone

26. Cortical plates
• It makes upto 80% of the body of the mandible
Consist of compact bone and form the outer and inner plates of the
alveolar processes Continuous with the compact layers of the
maxillary and mandibular body Thinner in the maxilla, than in the
mandible Thickest in the premolar and molar region on buccal side
of the lower jaw
• The supporting bone usually very thin in anterior teeth region of
both jaws – no spongy bone

28. CANCELLOUS BONE
• Spongy bone (anatomic term)
• Trabecular bone (radiographic term)
• Cancellous bone (histologic term)
• Presence of trabeculae enclosing irregular marrow spaces lined
with a layer of thin, flattened endosteal cells.
• Variation in trabeculae pattern depending upon occlusal forces
and genetically.

29. INTERDENTAL SEPTA
• The interdental septa are bony partitions that separate adjacent
alveoli.
• Coronally, the inner & outer cortical plates fuse 1mm apical to the
Cemento-enamel junction.
• The mesiodistal angulation of crest of the interdental septum
usually parallels a line drawn between the CEJ of the
approximating teeth.

30. • The mesiodistal and faciolingual
dimensions and shape of the
interdental septum are governed
by the size and convexity of the
crowns of the two approximating
teeth,as well as by the position of
the teeth in the jaw and their
degree of eruption.

31. Osseous topography
• Normally conforms to the prominence of the roots
• The height and thickness of the facial and lingual bony plates are
affected by the alignment of the teeth, by the angulation of the
root to the bone, and by occlusal forces

33. PERIOSTEUM & ENDOSTEUM
• The outer aspect of cortical bone is surrounded by a connective
tissue membrane which has two layers.
1. The outer fibrous layer – Periosteum
2. The inner cellular layer -

36. FUNCTIONS OF ALVEOLAR BONE
1.Houses -root of teeth. (sockets)
2. Anchors - root of teeth to Alveoli.(support)
3. Helps to move teeth for better occlusion.
4.Helps to absorb and distribute occlusal forces generated
during tooth contact.
5. Supplies vessels to Periodontal ligament.

37. 6. Houses and protects developing permanent teeth,
while supporting primary teeth.
7. Organizes eruption of permanent and primary teeth.
8. Provide attachment to muscles.

38. BONE RESORPTION
Sequence of events in resorptive process
Attachment of osteoclasts to mineralized surface of bone
Creation of a sealed acidic environment through action of the proton
pump which demineralizes bone and expose organic matrix.
Degradation of the exposed organic matrix to its constituents amino
acids by action of released enzymes such as acid phosphatase and
cathepsin
Sequestering of mineral ions and amino acids within the osteoclast

39. Various bone resorbing factors
A. Systemic factors:
(a) Parathyroid hormone (b) Parathyroid related peptide (c) Vitamin D3
(d) Thyroid hormone
B. Local factors:
(a) Prostanoids (b) Lipoxygenase metabolites (c) Cytokines: IL – 1, IL – 4,
TNF – α, TNF – β, IL – 6
C. Bacterial factors:
• (a) Lipopolysaccharides (b) Capsular material
• (c) Peptidoglycans (d) Lipoteichoic acids.

40. Bone modeling
• Bone modeling is defined as a change in the shape and
architecture of the bone
• It extends from embryonic bone development to the pre-adult
period of human growth, which is continuous and covers a large
surface
• The ability of bone to adapt to mechanical loads is brought about
by continuous bone resorption and bone formation

41. Bone remodeling
• Bone remodeling is defined as a change without concomitant
change in the shape and architecture of the bone
• In a homeostatic equilibrium resorption and formation are
balanced In that case old bone is continuously replaced by new
tissue
• This ensures that the mechanical integrity of the bone is
maintained but it causes no global changes in morphology

42. • Major pathway of bony changes in shape, resistance to forces,
repair of wounds and calcium-phosphate homeostasis
• Involves the co-ordination of activities of cells from two distinct
lineages, the osteoblasts and the osteoclasts
• A complex process involving hormone and local factors acting in
autocrine and paracrine manner on generation and activity of
differentiated bone cells

44. BLOOD SUPPLY
• It receive blood supply from inferior alveolar arteries
and superior alveolar arteries for mandible and maxilla
,respectively .
• they are reaches Periodontal ligaments from three
sources; apical vessels, penetrating vessels from the
alveolar bone and anastomosing vessels from gingiva.

45. VENOUS DRAINAGE
• The venous drainage of periodontal ligament
accompanies the arterial supply.
• Venules recives the blood via the abundant capillary
network.
• arteririovenous anastomoses that byapass the capillaries.

46. Nerve Supply
• Labial aspect of maxillary incisors, canines & premolars
is innervated - superior labial branches from the infraorbital nerve.
• Buccal aspect of maxillary molar regions innervated branches from
the posterior superior alveolar nerve
• Palatal aspect by greater palatine nerve, except for
incisor which is innervated by long sphenopalatine nerve.

48. • Lingual aspect in mandible - lingual nerve
• Labial aspect of mandibular incisors & canines - mental nerve.
• Buccal aspect of the molars - buccal nerve.
• The nerve enters the periodontal ligament through Volkmann's
canal of alveolar bone.

49. AGE CHANGES
• Similar to those occurring in remainder of skeletal system like
fracture progressing
• Osteoporosis with ageing
• Decreased vascularity
• Reduction in metabolic rate and healing capacity
• Bone resorption may increase or decrease
• More irregular periodontal surface

50. FENESTRATION : Isolated areas in which the root is
denuded of bone and root surface is covered only by
periosteum and overlying gingiva is termed as fenestration.
DEHISCENCE : When the denuded areas extend through
the marginal bone,defect is called dehiscence.
Fenestration and dehiscence are important, because they
may complicate the outcome of periodontal surgery.

52. Several treatment modalities includes:
• Root planning along with chlorhexidene mouth rinsing,
• Full thickness mucogingival flap with primary closure,
• Free gingival grafting,
• Guided tissue regeneration and
• Combination of bone grafting and free mucosal graft.

53. CONCLUSION
• Bone is a mineralized connective tissue with a relatively
flexible character and compressive strength.
• In order to maintain stability and integrity of bone, it constantly
undergoes remodeling.
• Thus knowledge of alveolar bone anatomy, histology and
physiology, will help the clinician in and treatment
planning, and lead to a favorable outcome of surgical
procedures performed.

54. BIBILOGRAPHY
• Clinical Periodontology - 8th edition , Carranza Newman
• Oral Histology and Embryology -12th edition , Orban's
• PICTURES
• http://myforgottencoast.com/wp-content/uploads/2018/06/bone-
connective-tissue-diagram-awesome-alveolar-bone-foundations-
of-periodontics-alveolar-bone-grafting-ppt-of-bone connective-
tissue-diagram.jpg

55. THANK YOU !!!