alveolar bone Flashcards
types of bone
Cortical (compact) bone
Trabecular (cancellous/ spongy) bone
what else is included in bone besides the actual bone
periosteum(outside)
endosteum (inside)
neurovascular supply
Marrow space
the secondary osteon
The haversion system (main functional unit of cortical bone)
the wall of the haversion system
concentric lamellae
the central canal of the haversion system
haversian canal with nerve and blood supply
main cell of the haversion system
osteocyte
separation between osteons
Interstitial lamellae
connection between osteons
Volkmann’s canals
the circular layers of each osteon
Concentric lamellae
lamellae that run parallel to the bone near its surface
Circumferential lamelae
fills the space between osteons
Interstitial lamella
where osteocytes reisde
lacunae
connect lacunae
canaliculi
inorganic matrix of bone
Hydroxyapaties (2/3 of bone)
organic matrix of bone
1/3 of bone
80% collagen
mucopolysaccharides
non-collagenous proteins
lineage for bone cells
Mesenchymal stem cells
dvelopement of bone cells
Mesenchymal stem cells Osteoprogenitor pre-osteoblasts osteoblast osteocyte and lining cell
what is the lineage for OSteoclasts
Haematopoietic stem cells
development of osteoclasts
Hematopoietic stem cells Multipotenet progenitor common myleoid progenior GMP monoctes Osteoclasts
other names for mesenchymal stem cells in the past
colony-forming firboblastss (CFU-F)
Marrow stromal cells
what can Mesenchyme stem cells become
Potential to differentiate into multiple cell types
Morphological features of mesenchymal stem cells
Small cell body
few cell processes
how can we get Mesenchymal stem cells
From bone marrow aspiration
then isolated to expansion
How can we confirm that its mesenchymal stem cells that we have
Expression of MSC markers (CD44, CD105) but not hematopoietic stem cell markers (CD45 and CD11b)
also: ability of osteogeneic, chondrogenic, and adiogenic differentiation
How can we tell a difference between mandibular and tibial bone marrow MSC’s
proliferarion (higher in mandible
Micro-array
real time PCR(higher fold change in Mandibule)
what is MSC’s important for mandibular bone regeneration
Mandibular sitraction osteogenesis leads is much smaller using Bone marrow stem cells than contol both verticle and horizontally
Classic mechanism for bone regrowth using mSC
Empower local bone regeneration by providing a large source of MSC and growth factors hense bossting or bypassing the slow MSC recruitment process
steps of Classical mech for MSC transplantation for bone formation
MSC transplantation Nutrients, O2, and others growth facros MSC survival and proliferation Cytokines growth factors and cells MSC differentiation into osteoblasts Cytolines, calcium and phosphorus new bone formation
location of osteoblasts
Bone surface
Morpholoy of osteoblasts
Cuboidal
Mononucleated
staining of osteoblasts
HE shows basophilic cytoplasm due to large quantity of RER
Major function of osteoblasts
Synth and secrete ECM
what does osteoblasts secrete
Collagen type I, III, V
Glycoproteins (Alkaline, phosphatase, Osteonectin)
Glycoaminoglycan-containing proteins ( Aggrecan, Versican, Decorin, Biglycan, Hyaluran)
Matrix extracellular phosphoglycoprotein (MEPE):
RGD-containing glycoproteins (Thrombospondis, Fibronectin, Vitronectin, Fibrillin 1 and 2)
Small insulin-binding N-linked glycoproteins (SIBLING): (Osteopontin, Bone sialoproteins)
gamma-Carboxy glutamic acid containing proteins:(Matrix Gla protein, Osteocalcin)
what features show the osteoblasts are very metabolically active
SIBLING
MEPE
what allows for matrix mineralization
TNAP NPP1 NTP ANK BSP
TNAP
Tissue non-specific alkaline phosphatas
NPP1
Nucleotide pyrophosphatase phosphodiesterase
NTP
nuceloside triphosphates
ANK
Ankylosis protein
BSP
Bone sialoprotein
what does NTP turn into
PC-1 gives PPi
TNAP gives Pi
what turns PP into Pi
TNAP
Calcium and Phosphorus reach what concentration in vesciles
Reach high concetrations without being saturated
what system regulates osteoclasts
The OPG/RANKL/ RANK system via Molecular interactions
Roll of RANKL
stimulate osteoblast differentation and maturation
roll of OPG
Binds to RANKL and indirctly inhibits osteoclast differentation
roll of osteocytes
Bone maintaining
how do osteocytes form
Derived from osteoblasts when buring in the matrix
location of osteocytes
In lacunae inside the matrix
commonness of osteocytes
Most abundant cel type in bone
morphology of osteocytes
Mononucleated
Multiple dentricitic processes
function of osteocytes
REgulate osteblasts and osteoclasts through cell process
Maintain bone vitality and function
what can OSteocytes sense
MEchanical loading via fluid flow leading to compression
what happens when osteocytes sense loading
regulate bone formation/resportpion mainly through the sclerostin OPG/RNAKL system
what is only expressed in osteocytes not in any other bone cells
Sclerostin
how does Sclerostin work
inhibits the WNT pathway leading to decreased bone formation (less Sclerostin leads to increased bone)
morphology of osteoclasts
LArgest of all bone cell types
multinucleated
lots of mitochondria
vesicles of acid phosphatase
LOcation of Osteoclasts
Located on bone surface (Howship’s lacunae)
what does the cytoplasm of OSteoclasts possitive to
Tartrate restistant acid phosphatas
zones of osteoclasts
Sealing zone
Ruffled border
Roll of the sealing zone of osteoclasts
attachment and sealing
Roll of the ruffled border of osteoclasts
Pump H+ for demineralization release enzymes (for organic matrix degratdation)
function of osteoclasts
Demineralizes bone
Degrade organic matrix
endocytosis of degraded products
what are bone lining cells
Inactive osteoblasts
morpholgy of bone lining cells
Flattened spindle shape
ovoid mono-nucleus
Few organelles
location of bone lining cells
on bone surface
function of bone lining cells
uncertain
Induced to proliferate and differentiate into osteoblasts
involved in smooothening osteoclasts lacunae
2 processes from bone formation
Endochondral ossification
Intramembranous ossification
when bone forms from cartialge first
Endochondral ossification
when bone forms directly from periosteum
Intramembranous ossification
what is sutural bone formation
special intramembranous process through a sutural matrix
Modeling
change of overall bone size, shape
bone formation and resorption at different location
Remodeling
replacment of existing bone
bone formation and resporption at the same location but at different times
Typical remodeling cycle
activation resorption reversal formation resting activation
what kind of osteon is important for cortical bone remodelling
Secondary osteons
where does ttraceular bone remodelling start
at bone surfaces
cycle dduration length of formation vs resorption for bone remodeling
Formation greater than resorption
remodeling rate of children vs adults
greater in children
remodeling rate in trbecular vs crotical bone
greater in trabecular
what leads to osteoporosis
Unbalanced formation and resorption leading to a net bone loss
REgulation of bone remodling
Multiple factors (gene, hormone, mech loading, metabolism…)
how are alveolar and basal bones separate
are continous
where is trabecular bone in the alveolar bone
only presented in the apical 1/3 of the alveolar processor under the alveolar crest in the interdental area
layers of the interdental septum froma mesial distal section
2 layers (bundle bone and supporting bone
what layer does sharpey’s fibers insert into
Bundle bone
what is the cement line
Bundle bone supporting bone borderline
CElls between sharpey’s fibers
Fibroblasts
Mesenchymal stem cells and osteoprogenitors
Vascular cells
Cells on the bone surface
Osteoblasts
Bone lining cells
tissue orgin of long bones and craniofacial bones
Embryonically differny
What does JAw bone mesenchym come from
Neural crest (1st branchial arch) and mesoderm
IMportance of tooth eruption and the alveolar process
Postnatal growth needs the teeth
when does modeling of the alveolar bone take place
furing bone growth
how does bone formation occur in the alveolar bone
vertically at crests along with tooth eruption
transversely at buccal surface and lingual bundle bone along with buccal expansion
how does Bone resportion occur in the alveolar bone
Lingual surface and buccal bundle bone
risk factors for alveolar bone loss
Periodontal disease Tooth loss Pathology systemic disease side efect of med trauma, parafunction, excessive orthodontic force
techniques for alveolar bone preservation/augmentation
guided one regenration with bioabsorbable membranes bovide derived bone graft mineralized human allograft bioactive glass material synthetic alloplast autogenous bone graft decoronation and submergence of roots immediate implants ortho tooth movement distraction osteogenesis stem cell assisted treatment
what does tooth movement do to the alveolar bone
a modeling process of the alveolar bone
what happens to the intedetnal septum duing tooth movemnt
Due to resorption on one side and formation on the other, not removed
what happens to PDL fibers during ortho tooth movement
PDL fiber attachment adpats to bone modeling
what happens to the PDL fibers on the bone resorption side
detachment with eventual attachment reconstituation
what happens to the PDL fibers on the bone formation side
Thickening of bundle bone
remodeling of bundle bone from the endosteum (opposite die of the PDL
source of OSteoclast on the resorption side of the boe during tooth movement
Normally not present in the pDL
recruited from blood flow (light pressure) or bone marrow of the adhacent alveolar prcess (heavy pressure)
sources of osteoblasts on the formation side of tooth movement
OSteblasts already present atbone surface
MSCs in the PDL
MSCs in the bone marrow
bone lining cells
