Dr.Neethu Kadar-alveolar bone

1. ALVEOLAR BONE
10/20/2022
1 Dr.Neethukadar
Dr. Neethu Kadar
Department of Oral Pathology and
Microbiology
Royal Dental College, Kerala

2. ALVEOLAR BONE
10/20/2022
2 Dr.Neethukadar

3. Alveolar bone
 Alveolar process of the jaws that forms and support the
sockets of the teeth.
 Hence one of the components of periodontium
 Develops during tooth formation and disappears as the tooth is
extracted or lost.
 The basic structure of alveolar bone is similar to the bone
found elsewhere in your body with few variations.
10/20/2022
3 Dr.Neethukadar

4. Alveolar process
10/20/2022
Dr.Neethukadar
4
1. Alveolar bone or alveolar bone proper – part which lines the socket of
tooth
2. Supporting alveolar bone
Outer bone – cortical plates – buccal and lingual
Inner bone – spongy bone.

5. Periodontium
10/20/2022
Dr.Neethukadar
5
Specialised fibrous joint – Gomphosis
Ectomesenchymal origin

6. 10/20/2022
Dr.Neethukadar
6
Develops during tooth formation and disappears
when the tooth is lost.

7. INTRODUCTION
DEFINITION – parts of maxilla &
mandible that forms & supports
the sockets of the teeth.
It forms when the tooth erupts to
provide the osseous attachment
to the forming periodontal
ligament; it disappears gradually
after the tooth is lost.
10/20/2022
7 Dr.Neethukadar

8. Functions
1. Houses the roots of the teeth.
2. Anchors the roots of teeth to the alveoli, which is achieved by insertion
of Sharpey’s fibres into the alveolar bone proper.
3. Helps to move the teeth for better occlusion.
4. Helps to absorb & distribute occlusal forces generated during tooth
contact.
5. Supplies vessels to periodontal ligament.
6. Houses & protects developing permanent teeth, while supporting
primary teeth.
7. Organizes eruption of primary & permanent teeth.
10/20/2022
8 Dr.Neethukadar

9. Development
1. Later stages of 2nd month of IUL, maxilla & mandible forms a
groove that opens towards oral cavity.
2. Within the groove the tooth germs develops & bony septa &
bridges separate the individual tooth from one another.
3. Even prior to the root formation tooth germs show bodily
movements to adjust jaw growth – bone remodeling
4. Once root formation begins, cells in DF different to form PDL
& cementum
5. Along side, cells of DF differentiate into osteoblasts & form
alveolar bone proper.
6. Major changes in AB development occurs during root
formation & eruption
7. So a root develops – AP increases in height.
8. Free border AP may have combined feature of cartilage &
bone – chondroid bone.
10/20/2022
9 Dr.Neethukadar

10. 10/20/2022
10 Dr.Neethukadar

11. Structure
 Adaptation to function
1. Alveolar bone proper
2. Supporting alveolar bone
10/20/2022
11 Dr.Neethukadar

12. 10/20/2022
12 Dr.Neethukadar

13. Alveolar bone proper
 Comprises partly of bundle
bone & lamellated bone
with gives attachment to the
periodontal fibers
 Lamellated bone
 Contains osteons
 Surrounded by concentric
lamellae
 Some lamellae arranged
parallel to surface of marrow
spaces
Bundle bone
 Bone on which principle fibers of
PDL ligaments are attached
 Bundles of fibers continue into bone
– Sharpey’s fibers.
 Represent areas of recent
apposition show lines of rest
 Contain fever fibrils than lamellar
bone – appear darker & less mature
than cementum
 Fibers are mineralized at periphery
 Fibrils in bundle bone is arranged
right angle to Sharpey’s Fibres
 Radiographically – Lamina dura –
increased radioopacity – thick bone
10/20/2022
13 Dr.Neethukadar

14. 10/20/2022
14 Dr.Neethukadar

15. 10/20/2022
15 Dr.Neethukadar

16. Radiographically – Lamina dura – increased radioopacity – thick
bone without trabaculae.
10/20/2022
16 Dr.Neethukadar

17.  Alveolar bone proper which forms
the inner wall of the socket is
perforated by small openings
that carry branches of nerves &
blood vessels into PDL –
Cribriform Plate
 bone between two teeth are
known as interdental septum
also comprise CP
 Interdental & interradicular
septa contain perforating nutirent
canals – Zuckerkandl &
Hirschfeld
10/20/2022
17 Dr.Neethukadar

18. 10/20/2022
18 Dr.Neethukadar

19. 10/20/2022
19 Dr.Neethukadar

20. Supporting alveolar bone
 Cortical plates
 Forms outer & inner plates of
AB
 Continuous with cortex of
max & mandible
 Thinner in maxilla
 Thickest in PM & M region of
mandible
 Anterior region- thin bone,
with no spongy bone; PDL
may attach to gingiva.
Cribriform plate & cortical plate
separated by SB
 Contain osteons and
lamellae
10/20/2022
20 Dr.Neethukadar

21.  Spongy bone
 Type I- the interdental &
interradicular trabeculae are
regular & horizontal in a
ladderlike arrangement.
Seen most often in mandible
 Type II- shows irregularly
arranged, numerous,
delicate interdental &
interradicular trabeculae.
Seen most often in maxilla.
10/20/2022
21 Dr.Neethukadar

22.  Crest of alveolar
septa
10/20/2022
22 Dr.Neethukadar

23. Internal reconstruction of bone
 Tooth movement does not end when active eruption is
completed and the tooth is in functional occlusion.
 With time and wear, the proximal contact areas of the
teeth are flattened and the teeth tend to move
mesially.
 This is referred to as physiologic mesial migration
(mesial drift)
 During this process – bone is apposed on distal side & resorbed
from mesial
 Distal wall is made entirely of bundle bone
 How ever, the osteoclast remove some of bundle bone near
adjacent marrow space& lamellated bone is deposited in its
place.
10/20/2022
23 Dr.Neethukadar

24. 10/20/2022
24 Dr.Neethukadar

25. 10/20/2022
25 Dr.Neethukadar

26.  On mesial wall of the drifting tooth, the sign of active
resorption – osteoclasts
 Here, mere thinning of bundle bone is seen - because
drifting doesn’t occur altogether – alternate resting
periods with detaching & securing of PDL
 During these changes, compact bone may be
replaced by spongy bone & vice versa
 Interdental septum show apposition on one side &
resorption on other
 If the alveolar bone proper is thickened by the
apposition of bundle bone; interdental marrow spaces
widen & advances in the direction of apposition and
converse happens during resoption of ABP were
deposition occurs surface facing marrow space.
10/20/2022
26 Dr.Neethukadar

27. 10/20/2022
27 Dr.Neethukadar

28. Clinical considerations
1. biologically highly plastic – helps in orthodontic movement
 Sensitive to pressure
 Bone is resorbed at the side of pressure and
 Bone is deposited at the side of tension.
2. Adaptation of bone: increased functional demand cause deposition
whereas decreased function causes reduction in bone volume.
3. Healing of fractures or extraction wounds
4. Periodontal disease – lead to alveolar bone resorption. Resorption can be
in vertical or horizontal pattern.
Pattern of Resorption- after tooth lose, labial aspect of alveolar crest reduces
first in width and height.
 Mandible – alveolar ridge resorb downward and outward.
 Maxilla – upward and inward 10/20/2022
28 Dr.Neethukadar

29. Therapeutic considerations
 Bone grafts or synthetic materials are used to fill defect in the bone
and to provide structural support.
 Bone grafting – stimulate bone deposition. Important in treatment of
periodontal bone lose.
 Procedure involves surgical placement of bone or bone substitute
material into the defect that can cause new bone formation and
regeneration pdl ligament and cementum.
 Types of Bone grafts
1. Autograft – from the host
2. Allograft – from a human donor
3. Xenograft – from an animal donor
4. Alloplast – synthetic material - natural or synthetic hydroxyapetite
crystals, ceramics, calcium carbonate, silicon containing glasses, and
synthetic polymers.
10/20/2022
29 Dr.Neethukadar

30.  Guided tissue regeneration (GTR) – is a dental surgical procedure that use barrier
membranes to direct the growth of new bone and gingival tissue at the sites where
there is insufficient volumes or dimensions of bone or gingival for proper function,
esthetics or prosthetic restoration. Eg: expanded polytetrafluoroethylene (ePTFE).
 Biologically mediated strategies – contains materials that can be premixed
with vehicle solution used as an adjunct to periodontal surgeries to speed up
periodontal regeneration.
 Enamel matrix proteins – used as a topical applicant on to exposed root
surfaces or bone to treat intrabony defects and furcations due to moderate or
severe periodontitis.
 Bone tissue engineering –promote bone healing, regenerate and
repair bone by using various combinations of polymeric scaffolds, calls
or inductive factors.
 Osteoconductive and osteoinductive scaffolds 10/20/2022
30 Dr.Neethukadar

31. Thank you
10/20/2022
31 Dr.Neethukadar