alveolar bone and cementum Flashcards
what is the alveolar bone AKA? what is it?
Alveolar Bone {AB}:Also called the Alveolar Process
Def: That part of the bone that support the teeth.
what does the AB depend on for it’s existence?
AB depends on the ROOT for it’s existence!
what are the two parts of the alveolar bone and what part has like 4 names?
supporting bone
inner socket wall, AKA - alveolar bone proper, cribriform plate, lamina dura.
CRIBRIFORM PLATE MEANS POCK MARKED. IT HAS HOLES.
Alveolar bone proper is that part of the bone that surrounds the root leaving only a small space between occupied by the periodontal membrane.
the alveolar bone proper consists of 2 layers of bone which are?
Consist of 2 layers of bone
Compact dense LAMELLAR bone
Bundle Bone – found adjacent to the PL and contains Sharpy’s fibers.
[Bundle bone is also seen where ligaments/bone meet.]
what are the parts of the supporting AB?
Inner and Outer Cortical Plate
Cancellous Trabecula
what is the inter dental septum?
Inter dental Septum: This is the AB found between the socket of one tooth and the socket of the adjacent tooth. composed entirely of cribriform plate/AB bone proper/LD.
what is the inter radicular septum?
Inter Radicular Septum: The AB found between the roots of multi rooted teeth.
what is the gross appearance and the external appearance of the alveolar bone?
Gross Appearance: Though separated anatomically, they function as ONE unit.
External Appearance:
Varies from pt to pt.
Follows contour of the CEJ.
Conforms to the shape of the root.
when does the development occur and how of the alveolar bone? what is the composition?
Development: Occurs mostly during tooth eruptionThe matrix laid down by the Osteoblast is at first NOT mineralized – PRE-BONE /OSTEOIDWhen new pre bone is being deposited, older pre bone beneath gets calcified
Composition:
INORG: Ca, PO4, (OH), CO3, CITRATES
ORG: Collagen
what is on the surface of the alveolar bone? what is the height and thickness of AB affected?
On the Surface there is a thin layer of osteoid + collagen + Osteoblasts, Osteoclasts etc. – known as PERIOSTEUM
The Height and thickness of AB is affected by; Alignment of teeth Angulation of root to bone Periodontal disease Occlusal forces
Covers the outer surface of a bone in all places except at joints.
The periosteum also contains attachments sites for muscles, ligaments, and tendons. In adults, the periosteum is responsible for forming new bone as a result of injury or infection.
what is the alveolar crest?
Is usually around 1-2 mm apical to the CEJ.
Is used to as an indicator to assess past evidence of Periodontitis.
Is normally rounded or pointed evenly.
As you get further back it becomes more flat.
For occlusal forces and alveolar bone how do these relate?
AB exists to support the teeth during function.
Depends on some stimulation from occlusal forces for the preservation of it’s structure.
how do occlusal forces stimulate things?
OF –> tooth is displaced against a resilient PD –> socket wall —> B/lingual plates —> plates stretch —> When force is released they spring back!
what happens when occlusal forces is excessive or too long? what about no force at all?
Injury – trauma from occlusion.
DISUSE or Afunctional Atrophy.
what is the least stable of the perio tissues?
AB is the least stable of the perio tissues!!!
Bone is resorbed at the same time bone is formed. Sensitive Balance!
Bone is the calcium reservoir of the body.
Which fibers are responsible for retention of the free gingivae against forces of tongue and masticatory muscle? DENTO GINGIVAL FIBERS.
Persistence of which fibers can cause disappointing results in orthodontic treatment? TRANSSEPTAL FIBERS.
