periodontium II - alveolar process Flashcards
3 steps of ortho
- Compression and Tension of the PDL
- Inflammation and lag period:
- Tooth movement phase: Bone resorption and Bone deposition
T/F: facial bones DO NOT follow growth of body
FALSE. they do!
when is the peak rate of facial skeleton growth
14-18
T/F
Mandible and maxilla grow simultaneously but stop differentially
true!
what are the 2 regions of the jaw bone
basal bone and alveolar process
body of the mandible or maxilla is called
basal bone
portion of jaw that contains the tooth:
o requires the presence of the tooth and masticatory force to maintain bone density, height, thickness
o Atrophy with loss of tooth
alveolar process
what are the 2 regions of the alveolar process
supportive region and alveolar bone proper (ABP)
what is found in the supportive region of the alveolar process
outer cortical plate and cancellous (central)
T/F: F is thinner than L
true!
where can we find the THICKEST cortical bone in jaw
POST and L on MAND
does max or mand have THINNER cortical bone
MAX has thinner!
what is the ABP
tooth socket that surrounds tooth
what is the ABP comprised of
compact bone
what is the ABP also called
lamina dura (radiograph); bundle bone, or cribriform
site of insertion for PDL via sharpeys
ABP
what are the 3 regions of ABP
- Interdental septum – area between each tooth- forms mesial/distal wall of tooth socket
- Inter-radicular septum- tooth socket between roots
- Alveolar crest - cortical plate and alveolar socket meet
what is lamellar bone
MATURE compact and spongey
what is cribriform plate
term used to describe openings to allow passage of neurovascular structures into alveolar bone
can alveolar bone repair and remodel
yes!
what happens to the alveolar bone as we age
-Increase in resorption
* Increase in adipose in marrow cavity
* Thinning of alveolar bone
* Atrophy if loss of tooth occlusion or tooth
when does jaw movements start and end
occurs during 14-18 yrs /stops when growth ceases 18-25yr
histological features of post-eruptive jaw growth
- increase in bone at alveolar crest
- increase in root length by deposition of
secondary cementum - Increase in bone density
do movements to compensate for occlusal wear occur throughout life?
yes!
Outcome of occlusal wear and histological features
- Apical increase in secondary cementum deposition
- PDL remodeling and functional adaptation of increased
width - Increase in bone height at alveolar crest; change in
bone density
does bone have intrinsic AND extrinsic fibers?
yes!! collagen (intrinsic) and sharpeys (extrinsic)
3 categories of post eruptive movements
- accommodate jaw growth
- accommodate occlusal wear (2º cementum deposition)
- accommodate interproximal wear (mesial drift)
what are the 2 axial movements post-erup
due to adolescent jaw growth
due to compensation of occlusal wear
mesial drift is due to
interproximal wear
what is happening during the inflam and laggin period in ortho
no movement of tooth!
When the PDL is compressed, there is a decrease in blood flow and necrosis of some PDL fibers and subsequent inflammation.
The process of inflammation leads to the recruitment of osteoclasts from the bone marrow and transient narrowing of the PDL
forces that cause mesial drift
- Generation of Anterior directed force
- Contraction of trans-septal ligament (PDL)
- Soft tissue Pressure- influence (tongue, muscles)
will bone RESORPTION be occurring on the M or D wall of the ALVEOLUS during mesial drift
MESIAL
will bone APPOSITION be occurring on the M or D wall of the ALVEOLUS during mesial drift
DISTAL
