Periodontium Flashcards
periodontium has three principle components
- alveolar process
- cementum
- periodontal ligament
perio develops during a series of complex interaction of
mesenchyme, HERS, and dentel follicle
gomphosis
fibrous peg-in-socket joint
origin of osteoblast
surrounding mesenchymal tissue
origin of cemtoblast: HERS/follicle cells
ectomesenchyme cells
origin of PDL fibroblast
follicle cells/ectomesenchymecells
origin of odontoblast:
formdentinpart of the cemento-dentaljunction, dental pailla
the perioduntium contains ___ types of mineralized tissues found in the oral cavity
3 of 4
alveolar process: formed by
intramembranous ossification
alveolar process: begins during
8th week of uterine life
alveolar bone proper is
compact bone, lines the socket
supporting alveolar bone is
compact and trabecular
cortical plates:
compact bone component, central
Spongiosa
trabecular bone componet
cribrum=
sieve, it has volksmann’s canals running through it
lamina dura is
radiographic term :area of PDL attachment
bundle bone
histological term: sharpey’s fibers (PDL) embedded in bone
alveolar bone proper: inner
constantly being remolded, smooth in young/rougher with age
cortical plate inner
lingual and palatal surface
cortical plate outer
labial and buccal surface
central spongiosa
- trabecular (spongy/cancellous) bone supporting alveolar bone proper and cortical plate
- Marrow- red (hemopoietic) in young, yellow with aged
maxilla, spongiosa ___ prevalent than mandible
more
often abesent/diminished in ____ region of bothjaws
anterior
interradicular septum is
bony septum between roots of a single tooth
interalveolar septum
bony septum between adjacent teeth
function of alveolar bone
- protect/stucture of socket for tooth to rest in
- attachment of sharpy’s fibers of PDL(embedded in bone)
- support of tooth roots, especially facial/lingual
- distribution of loading from the tooth and PDL to surrounding bone
PDL composed of
fibroblast, mesenchymal, epithelial cells and macrophages
associated with PDL
osteo blats/clast and cementoblast
PDL ranges between
.15 mm to .38, decreases with age
PDL is primarily
collagen fibers( I, III, XII)
individual fibers can or cannot be remodeled while the overall bundle isnot changed
can
main elastic fiber of PDL is
oxytalan
Alveolar crest group
attach just at the CEJ and run outward to attach into the alveoar socket rim
Horizontal Group
run from cementum at right angle to the tooth into the alveolar socket
oblique group
most numerous, run atoblique from cementum most of the way down the root
apical group
from root apex to the underlying bone
interradicular group
only on multi-root teeth, attach to the interradicular spetum
dentogingival group
most numerous, runs from cervical cementum to lamina propria
alveologingival group
run from alveolar crest (bone) to lamina propia of free/attach gingivae
circular group
circular band around neck of the tooth, attaches to other fiber and free gingiva
dentoperiosteal group
run apically from cementum to the periosteum of the outer cortical plate
transeptal fibers
run from cementum justunder the junctional epithelium, over the alveolar crest and into the cementum of an adjacent tooth. sig cause of orthodontic relapse
