anatomy of the periodontium Flashcards
specialized connective tissue that provides support needed to maintain teeth in function
periodontium
periodontium 4 structures
gingiva
cementum
periodontal ligaments
alveolar bone
oral mucosa consists of 3 zones
- gingiva and covering of the hard palate (masticatory mucosa)
- dorsum of the tongue (specialized mucosa)
- oral mucous membrane lining remainder of oral cavity
masticatory mucosa that covers alveolar bone and tooth root coronal to the cementoenamel junction (CEJ)
gingiva
the gingiva is divided into 3 parts
- marginal gingiva
- attached gingiva
- interdental areas
free, collar-like tissue surrounding the teeth on facial, lingual, and interproximal surfaces
marginal gingiva/unattached gingiva
marginal gingiva/unattached gingiva epithelium type:
nonkeratinized epithelium [on the inner side]
most coronal portion of the gingiva.
scalloped outline of teeth.
about 1mm wide and forms the soft-tissue wall of the gingival sulcus
gingival margin
the shallow, natural space around a tooth bounded by the surface of the tooth on one side and epithelial lining the free margin on the gingiva on the other side
gingival sulcus
1-3mm for healthly
what time of epithelium is the sulcular epithelium
nonkeratinized
what are the boundaries of the gingival sulcus
sulcular epithelium and the tooth
occupies the gingival embrasure space between two adjacent teeth (inter-proximal space beneath area of tooth contact).
attached to the tooth by the JE and connective tissue fibers
interdental gingiva (papilla)
*part of free gingiva
valley-like depression of the interproximal contact areas.
connects lingual and buccal interdental papilla
the gingiva col
what is absent when teeth are not in contact
the col
what type of epithelium is the col which is susceptible to inflammation and disease progression
non-keratinized
divides free gingiva from attach gingiva.
shallow depression.
found only in 50% of patients.
free gingival groove
what type of epithelium is the gingival groove
keratinized
continuous with marginal gingiva; firm, resilient, tightly bound to underlying periosteum of alveolar bone
attached gingiva
what kind of epithelium is the attached gingiva
keratinized
what width varies with attached gingiva and where is the widest area located
and narrowest
1-9mm
widest area in facial aspect of max central incisors
narrowest in mand premolar facial areas
visible line where the pink keratinized gingiva meets the more vascular alveolar mucosa
mucogingival junction (MGJ)
movable tissue, loosely attached to underlying alveolar bone. thin, soft and darker shade of red than gingiva due to RICH blood supply (vascularization)
alveolar mucosa
what type of epithelium is alveolar mucosa
nonkeratinized
the gingiva is composed of _________epithelium and _____ tissue
stratified squamous epithelium and connective tissue
which is more cellular in nature and which is less cellular/mostly composed of collagen fibers and ground substances
[connective tissue vs epithelium]
epithelium is mostly cellular
connective tissue is less cellular
name 4 functions of the gingival epithelium
- physical barrier to infection
- helps respond to infection in signaling host response
- protection of deep structures
- allows selective interchange with oral environment
covers the crest and outer surface of marginal gingiva and the surface of attached gingiva
oral (outer) epithelium
how thick is the oral (outer) epithelium
0.2-0.3 mm
what type of epithelium is the oral (outer) epithelium
parakeratinized
then turns into keratinized
what 4 layers is the oral (outer) epithelium composed of
basal layer
prickle cell layer
granular layer
cornified layer
lines the gingival sulcus.
extends from the coronal limit of the junctional epithelium to the crest of the gingiva margin
sulcular epithelium
what type of epithelium is sulcular epithelium
nonkeratinized
thin
without rete pegs
this is extremely important in that it may act as a semipermeable membrane through which injurious bacterial products pass into the gingiva and seeps into the sulcus
sulcular epithelium
epithelium surrounding and attaching to the tooth on one side, and the gingival connective tissue on the other side.
base of the sulcus/pocket
junctional epithelium
what type of epithelium is the junctional epithelium
nonkeratinized
length of the junctional epithelium
0.25-1.35 mm
which is more permeable to cells and fluid
junctional epithelium or sulcular epithelium
junctional epithelium
serves as route of passage of fluids and cells from the connective tissue into the sulcus for bacteria/bacterial products from sulcus to connective tissue
junctional epithelium
connective tissue of the marginal gingiva is densely collagenous and contains a prominent system of collagen fiber bundles called:
gingival fibers
what type of collagen are the gingival fibers
type I collagen
what functions do the gingival fibers have
- brace marginal gingiva against tooth
- provide rigidity to withstand mastication
- unite free marginal gingiva with cementum of root and adjacent attached gingiva
5 gingival fiber groups
- dentogingival fibers
- alveolagingival fibers
- circumferential fibers
- dentoperiosteal fibers
- transseptal fibers
gingival fibers that are embedded in the cementum between the CEJ and crest of alveolar bone; fan outward into the attached and free gingiva; attach gingiva to the tooth apical to the epithelial attachment
dentogingival fibers
gingival fibers that are inserted in crest of alveolar process and splay out through lamina propria into the free gingiva
alveologingival fibers
encircle each tooth in a cufflike fashion within the free gingiva
circumferential fibers
embedded in the same portion of the cementum as the dentogingival fibers, but extend apically over the alveolar crest after passing through the lamina propria and the periosteum
dentoperiosteal fibers
embedded in the same portion of the cementum as the dentogingival and dentoperiosteal fibers; run a horizontal path from adjacent teeth
transseptal fibers
color of marginal and attached gingiva in health
coral pink
how does smoking affect the peridontium
-causes vasoconstriction affecting body’s natural defense system against infection
-leaves gingival tissue FIRM and FIBROTIC due to decreased blood flow and limits delivery of oxygen and nutrients to epithelium
composed of a complex vascular and highly cellular connective tissue that surrounds the tooth root and connects it to the inner wall of the alveolar bone.
it diminishes around teeth that are not in function/ unerupted teeth, but increases in teeth that are hyperfunction
PDL
most important elements of the PDL and arranged in bundles of 6 groups.
located in peridontal space between cementum and bone.
composed of connective tissue cells and intracellular substance
periodontal/principle fibers
the periodontal/principle fibers are inserted in the cementum on one side and bone on the other which are called
sharpey’s fibers
physical functions of PDL
- casing that protects vessels and nerves
- transmission of occlusal forces to bone
- attachment
- resistance to impact of occlusal forces (like shock absorption)
this supplies nutrients to cementum, bone, and gingiva by way of blood vessels; also provides lymphatic drainage
PDL
PDL is abudantly supplied with sensory nerve fibers that are capable of transmitting tactile, pressure, and pain sensations via the what pathways
trigeminal pathways
principle fiber group from the root apex to adjacent surrounding bone to resist vertical forces
apical fibers
principle fiber group from the root above the apical fibers obliquely toward the occlusal to resist vertical and unexpected strong forces
oblique fibers
principle fiber group that extends interproximally over the alveolar bone crest and are embedded in the cementum of adjacent teeth
transseptal fibers
principal fiber group from the cementum in the middle of each root to adjacent alveolar bone to resist tipping of the tooth
horizontal fibers
principle fiber group from the alveolar crest to the cementum just below the CEJ to resist intrusive forces
alveolar crest fibers
principle fiber group from the cementum between the roots of multirooted teeth to the adjacent bone to resist vertical and lateral forces
interradicular fibers
calcified, avascular mesenchymal tissue covering the roots of the teeth
cementum
least mineralized of the calcified tissues of the tooth
cementum
what are the 2 types of cementum
acellular(primary) and cellular(secondary)
consisting of a calcified interfibrillar matrix and collagen fibrils
what is the function of the cementum
to attach fibers of the pdl to the tooth (like cement) to seal the tubules of the root dentin
what is the first cementum formed
acellular cementum
which cementum contains cells and which does not?
name of cells?
cellular contains cells called CEMENTOCYTES in individual lacunas which communicate via canaliculi
acellular cementum does not contain cells
when are acellular and cellular cementum formed
acellular formed before tooth reaches occlusal plane
cellular forms after tooth reaches occlusal plane [deposited throughout life of tooth]
local abnormal thickening of parts of the cementum
hypercementosis
where is hypercementosis usually found?
what is it seen as a result of?
found apically
result of chronic inflammation of tooth, no opposing tooth, additional eruption, tooth becoming fused to surrounding alveolar bone
most common CEJ cases
[rank them]
60% of cases are cementum overlapping enamel
then end to end 30%
10% space exposing dentin
bone that forms and supports the alveoli (tooth sockets); tooth dependent-structures
alveolar process
when does the alveolar process form?
describe its progression
when the tooth erupts to provide osseous attachment to forming PDL; disappears gradually after tooth is lost
the alveolar process consists of an external plate of cortical bone formed by
haversian bone and compacted bone lamellae
the inner socket wall of thin compact bone of the alveolar process is called the:
contains holes for neurovascular bundles to link PDL with cancellous bone
alveolar bone proper
alveolar bone consists of _____ inorganic matter and ____ organic matrix
2/3 inorganic
1/3 organic
this is responsible for normal pigmentation of the skin, gingiva, and remainder of the oral mucous membrane
melanin
melanin is presented in all people but can be absent/severely diminished in:
and prominent in:
absent: albinos
prominent: dark skin tones
how does melanin pigmentation variation from normal (WNL)
diffuse, deep-purplish discoloration or as irregularly shaped brown and light-brown patches
