L2 - Tour Continued Flashcards
vascular supply of periodontium in the maxilla
anterior and posterior superior alveolar arteries + the infraorbital artery and greater palatine artery
vascular supply of periodontium in the mandible
inferior alveolar artery and branches including the mental and sublingual branches
+ buccal
+facial arteries
remember the long buccal
gingival plexus importance?
the vessels supply major capillary plexuses that are located in the connective tissue adjacent to the otal epithelium and the junctional epithelium
- important that these receive the anesthetics that get put into the vascular system
so getting supply from the blood vessels within the alveolar process also contributing
anastamoses in the oral mucosa?
arteries that supply the oral mucosa with the branches of the superior and inferior dental artieries
gingiva dual blood supple?
YES
INTERNAL –> bone and PDL
EXTERNAL –> through periosteum
but ALSO within the alveolar process we have vessels contributing to regional blood supply
lymph drainage of gingival tissue mainly through?
submandibular lymph nodes
submental lymph drains?
mandibular anteriors
upper deep cervical lymph drains?
the third molars
deep cervical nodes drain?
palatal gingiva
what do the nerves of periodontium register?
pressure, touch, temperature, and pain
which branches provide sensory and propooceptive functions?
TRIGEMINAL
innervation of the max and mandibular GINGIVA
- maxillary –> anterior middle and posterior superior alveolar
- infraorbital
- greater palatine
- nasopalatine - mandibular –> long buccal, mental (vestibular) and lingual for lingual gingival tissue
what do autonomic nerves control within the periodontium?
smooth muscles associated with the periodontal vasculature – which originate from the superior cervical ganglion
three zones of the intraoral tissue and general description of each
- MASTICATORY MUCOSA – gingiva and the tissue covering the hard palate
- SPECIALIZED MUCOSA – the dorsum of the tongue
- ORAL MUCOUS MEMBRANE - lines the remainder of the oral cavity
4 main functions of the oral mucosa
- protection (primarily from keratinized)
- sensation (taste)
- secretion (minor salivary glands)
- thermal regulation
gingiva - general description and only one of periodontal tissues that is what?
only one that is VISIBLE IN HEALTH *
gingiva is part of the oral mucosa that covers the alveolar process of the jaws and the necks of the teeth
how is gingva attached to alveolus and tooth complex- general of each
TWO COMPONENTS
- fibrous connective tissue
- COLLAGEN FIBER BUNDLES that connect cementum and alveolar bone - epithelial attachment
- HEMIDESMOSOME -mediated attachments to an inner basement membrane lining the hard tissues surface of the tooth
clinical appearance of gingiva and its overall size
distinguished from the alveolar mucosa (more red) by its lighter more salmon color and is KERATINIZED surrounding the tooth anywhere from 1-9mm (depending on tooth and location in mouth)
- stippling
color of gingiva dependent on?
level of
- keratiization
- vascular supply
- thickness
- pigmentation
melanin pigment synthesized where and by?
MELANOCYTES IN BASAL LAYER OF EPITHELIUM
3 clinical boundaries of gingiva - general
- marginal
- attached
- interdental
is the gingival margin attached to tooth? location
NO - it is the most coronal boundary of the gingiva
marginal gingiva describe and what is the free gingival groove?
portion of gingiva near the gingival margin and is UNNATTACHED surrounding the tooth in a collar fashion
- usually about 1 mm wide and forms the soft tissue wall of the sulcus which we can probe
the free gingival groove is present in about 50% of people and demarcates the marginal gingiva from the attached gingiva
- DOES NOT signify health in presence or absence
mucogingival junction - location and what it separates
MOST APICAL part and separates the gingiva from the alveolar mucosa
describe palatal gingiva
THERE IS NO MUCO-GINGIVAL JUNCTION
- the gingiva blend in with the masticatory mucosa that protects the hard palate
“free” gingiva
the part of gingiva that surrounds the tooth and is not directly attached to the TOOTH SURFACE
- anatomically ‘incorrect’
“attached” gingiva
what is APICAL to the “free” gingiva
- firmly bound to underlying tooth and alveolar processes via collagenous inerstions into the periosteum
- firm
- dense
- excellent barrier to mechanical stress
shape of the interdental gingiva
PARABOLIC FORM with the interproximal tissue MORE CORONAL to the direct facial or lingual sufaces
“SCALLOPED” appearance
- can be pyramidal or have a “col” shape
interproximal papilla shape?
knife edged when teeth in contact and should FILL ENTIRE GINGIVAL EMBRASURE COMPLETELY
col shaped or pyramidal shape of interdental gingiva?
pyramidal - more anterior teeth
col - more posterior shape and has a ‘valley’ like depression that connects the facial and lingual papilla which conforms to the shape of the interproximal contact - where it is more broad in the posterior
shape of ‘col’ depends on
gingiva in any interdental space is related to the CONTACT point b/w two interproximal surfaces
where is col most broad?
in a bucco-lingual direction in posterior teeth
is the col keratinized?
susceptible?
no not keratinized - so is more susceptible to noxious agents or trauma – so common site for initiation of periodontal pathologic breakdwon
what forms the col
fusion of interproximal junctional epithelia of two teeth
col if no contacts exists?
then the col does not exist and neither does the interdential papilla —> and the attached keritinized gingiva courses uninterrupted facio-lingually
describe alveolar mucosa
- moveable, delicate and poorly bound down to bone
- continous with vestibular mucosa and mucosa of floor of mouth and cheeks
- more reddish
If gingiva is lost beyonf the mucogingival junction?
goes right to alveolar mucosa which is a BAD REPLACEMENT for the gingiva
compare attached gingiva to alveolar mucosa 'keratinization? stippled? rete pegs? lamina propria? elastic fibers? submucosa? attachement?
THIS IS IMPORTANT
‘keratinization? ONLY attached
stippled? – only attached as alveolar is smooth unstippled
rete pegs? – wider/short/few in alveolar
lamina propria? – thick in attached
elastic fibers? - many in moveable vs few in attached
submucosa? - indistinct in attached and alveolar has distinct
attachement? non-moveable = attached vs moveable in alveolar
TWO cell layers in alveolar mucosa
- basal cell layer
2. stratum spinosum – ABOVE BASAL CELL layer
collagen in alveolar mucosa?
yes - but random arrangements
+ elastin and some muscle
cornoapical dimension of gingiva as ages?
tends to INCREASE with age
average thickness of attached gingiva?
relation to health?
1.41 mm (if went buccally into the tissue)
NO minimum thickness for health –> as long as oral hygiene habits are good
sulcus aka
DENTO-GINGIVAL SPACE
surfaces of sulcus and shape
tooth on one side anf the epithelial lining of the free gingival margin on the other
“V-shaped”
probing depth of clinically normal heathly sulcus?
crevice?
sulcus = 2-3 mm
(have seen 1.8mm to 6mm)
crevice = 0mm–> but only experiemntally
histological sulcus means
this is the term used for the gingival sulcus in the state of absolute clinical health
NEVER PROBE THE DEPTH OF THE HISTOLOGIC SULCUS
lateral boundary of the gingival sulcus
oral sulcular epithelium and enamel of tooth
coronal border of sulcular epithelium?
free gingival margin
apical /BASE aspect of sulcular epithelium?
coronal apect of the junctional epithelium
probe the histological sulcus?
NO - base is the coronal aspect of the JUNCTIONAL EPITHELIUM - and can be easily penetrated
- impossible to clinically identify the depth
histological sulcus vs. clinical sulcus
clinically - depth you prob from free gingival margin to the CEJ
histologically – depth to the coronal aspect of the junctional epithelium
clinical sulcus
potential space that spans from the free gingival margin down to the CEJ
- varies depending on probe, inflammation presnt, degree of force used with probe
three subdivisions of gingival epithelium
- oral epithelium
- sulcular
- junctional
oral epithelium extends from what to what?
from the mucogingival junction to the gingival margin – cotinuous with the LATERAL aspect of the sulcular epitelium
junctional epithelium extends from what to what
forms the dentoepithelial junction apical to the sulcus and is continous with the sulcular epithelium
so its coronal end = apical end of sulcus
oral epithelium compromised of?
free and attached gingiva that is keratinized stratified squamous with four classic strata
4 levels of the oral epithelium
stratum cornium (outermost)
stratum granulosum
stratum spinosum
stratum basale / basal cell layer
describe stratum basale
innermost layer
single layer of thick cuboidal cells attached to underlying connective tissue via the basement lamina
germinative element responsible for replacement
stratum spinosum
WIDEST with several layers and is known as the “prickle- layer”
dominant cytoplasmic processes
rich in tonofilaments
desmesomes evident
diminished cellular activity - compared to basale
stratum granulosum
above the spinosum –
several layers thich and has keratohyline – precursor to keratin
flattened appearance
diminished organelles and pykonotic nuclei
stratum cornium
outermost layer – may or may not have a nuclei in the cells here
- cells filled with keratin and are lost to oral cavity via desquamation
major role of oral epithelium - how it does this
protection and resistance to mechanical injury - especially through the INTERCELLULAR JUNCTIONS
- mostly desmosomes in the corniied layer - outermost
also relatively impermeable due to the narrow intercellular spaces so lack of diffusion and barrier to foregin particles
desmesomes vs hemidesmosomes
desmosomes = most common cell junction and consist of outer leaflet of cell membrane of two adjoining cells, - the thicker inner leaflets of the cell membrane and attachment plaques which are granular or fibrillar material in the cytosplams – more resistnat to inflammation
hemidesmosomes –> between the epithelial cells to basemement membranes AND TO TOOTH SURFACE (gingival epithelium to the tooth)
keratinocytes mostly found where?
basal cell layer – formation of keratin – then up to stratum granulosum where the granules are contained
epithelial cells in the basal cell layer
mostly keratinocytes (90%) then have inflammaotry cells, lymphocytes, melanocytes
cytoplasmic filaments of epithelial cells that are in basal cell layer
tonofilaments
describe melanocytes and function?
abundance?
location?
life cycle?
basal epithelial cells to melanocytes is 7:1
DO NOT MIGRATE UP but the basal epithelium cells will
PRODUCE MELANOSOME – which are packaged into keratinocytes as travel upwards
level of pigementation is dependent on?
ACTIVITY LEVEL of the melanocytes because EVERYONE HAS SAME NUMBER OF MELANOCYTES – so it is not a funciton of number but a function of their activity
merkel cells
where?
function?
in basal cell layer
function –> believed to act as touch-sensory cells and are NON-DENDRITIC which have sparse tonofilaments and associated more with nerve fibers
langerhans cells where? function? describe are they epithelial cells?
NOT EPITHELIAL CELLS
= derived from C.T and are suprabasalar and are DENDRITIC-SHAPED – so believed to be involved in uptake and processing of antigens
- immune surveillance system
- are processed by lymphocytes – so involved in cell-mediated immunity
- thought to be in first line of defense agaisnt surface penetration of host by antigens
epithelial - connective tissue interaction/ connection?
RETE pegs
through underlying connective tissues of lamina propria
rete pegs extend?
connective tissue – epithelium
papillary layer extending into depressions on the undersurface of the epithelium
lamina propria (baasement of epithelium)
two parts of the basement membrane
- lamina lucida – adjacent to the epithelial cells - clear zone on microscopy – have fibrils that are anchoring to lamina densa – TYPE VII
- lamina densa– lies adjacent to the connective tissue and is an electron dense zone – afibrillar TYPE IV collagen
- both are are derived from epithelium not connective tissue
- have glycoproteins and mucopolysaccharides
two purposes of the basement membrane
- protection from things coming up from underlying connective tissue
- attachment to the connective tissue via the
- hemidesmosomes
- connecting fibrils
- chemical attachements between anions and cations (cations in connective tissue)
where do you find type IV collagen
lamida densa in basement mebrane – which is afibrillar
where do you find type VII collagen
anchoring fibrills from the undersurface of lamina densa into the lamina propria
lamina lucida composed of?
laminin + other glycoproteins
what layer does the sulcular epithelium lack?
stratum corneum
general description of sulcular epithelium
STRATIFIED SQUAMOUS
NON -KERATINIZED or PARA
coronally –> border is the free gingival margin
apically –> base is the coronal portion of the junctional epithelium
compare sulcular epithelium to oral and juncitonal
shares more with oral – good resistance to stresses and impermeable but fewer rete egs than oral and less/ no keratinization
compared to junctional – few transmigrating inflammatory cells in the sulcular
3 facts of keritinization of the sulcular epithelium
- remove it away and it will keratinize – so if exposed to oral cavity it will keratinize (if you physiclaly remove it away)
- if you put the keratinized sulcular epithelium back – it will lose its keritinzation
- so it CAN BUT DOES NOT KERATINIZE because of inflammation caused by normal, everl present microorganisms in the flora
so remove the inflammation – will keratinize – but since impossible to remove all there is a constant turn over rate of sulcular epithelium - less time to differentiate or keratinize before they are lost
histological inflammation refers to
- subclinical inflammation the lack of keratinization of the sulcular epithelium
- completely normal - but presence is because sulcular epithelium does not keratinize
junctional epithelium - describe
STRATIFIED NON-KERATINIZED
- surrounds the tooth like a collar
- provides attachemtn mechanism of the epithelium to the surface of the tooth
- limited protection for the PDL
tooth – junctional epithelium — gingival connective tissue
intercellualr spaces in the junctional epithelium?
yes – spaces are wider than those in the oral epithelium
- so LOWER DENSITY OF INTRACELLULAR JUNCTIONS / desmosomes present
- approx. 1/3 junctions as seen in oral and sulcular epithelium
permeability of junctional?
more permeable than the oral and sulcular so preferential route for the passge of bacterial products from sulcus into the C.T
layers in junctional?
HAS BASALE
no stratum spinosum, granulosum, or corneum
- all cells NOT IN BASALE – FOUND IN THE “SUPRABASAL CELL LAYER”
2 basal laminas in the junctional epithelium
internal –> faces the tooth
external –> faces connective tissue
does desquamination occur in junctional epithelium?
YES- occurs at its coronal end (bottom of the sulcular epithelium)
proliferative cell layer in junctional epithelium?
in conteact with connective tissue so more associated with the external basal lamina
T/F it is not uncommon to see marked distension of the intercellular spaces by PMN’s in junctional epithelium
TRUE
- also fluide exudate - gingival crevicular fluid from C.T also flows into sulcus through enlarged intercellular spaces present
does C.T adjacent to junctional epithelium become infiltrated with chronic inflammatory cells?
YES - mostly lymphocytes and plasma cells becayse permeablity in junctional epithelium
attachment apparatus
internal basal lamina and hemidesmosomes that connects junctional epithelium to the tooth surface
Is attachment appratus synonymous with junctional epithelium
NO – JUNCTIONAL IS ENTIRE EPITHELIUM
attachemnt is just internal lamina to the tooth surface
most coronal part of junctional epithelium
becomes connected as the ‘col’ near the interdental gingival margin
sulcular fluid orginiates where?
in the gingival connective tissues – specifically from the blood vessels of the C.T
can fluids seep out oral aspects of gingiva?
NO – because of the keritnization
flow of sulcular fluid
gingival connective tissue –> through epithelium –> and out through the sulcus
primary protein in sulcular fluid?
primary composition in normal conditions?
albumin = primary protein
but mostly amino acids, peptides, suagars, epithelial cells, and some inflamamtory cells (primary one is neutrophil)
amounts of sulcular fluid and its implications?
normal human – smal amounts
absolute state of clinical health – no flow of fluid
so result of a subclinical or histological inflammation
turnover in keratinized vs non-keratinized epithelium
keratinized = longer
rate of turnover in oral epithelium?
normal/ health = 21 days
rate of turnover in sulcular epithelium?
14 days
rate of turnover in junctional epithelium? and describe movement
7 days
cells shed from here travel to the histologival sulcus and combine with cells desquamated there – then into orla cavity
time it takes for chemical attachment to be restored b/w enamel and junctional epithelium should it be broken by like probing
5-20 days to reattach
gingival TISSUE migration rate
6-8 weeks / .5-1mm a day
- if surgically excise gingiva - you will reformation of sulcus and juncitonal epithelium in 6-8 weeks
timeline of restoration after gingival surgery?
6-8 weeks so we can safely pinpoint where gingiva will end up
which width is altered when we have gingival attachment loss? must be maintained for proper gingival attachment?
distance between CEJ and bone whcih is approximately 1 mm
YES
3 compositions of biological width
- non-attached sulcular space / gingival crevice
- epithelial attachment - 1mm dimension w/ the junctional epithelium
- connective tissue attachment
1-2 mm with supra-crestal collagen fiber bundles
describe gingival connective tissue
gingival fibers, ground substance, cells, including neural and vascular elements
- PRINCIPLE FIBERS – dense collagenous matrix running in recognized fiber groups
- LAMINA PROPRIA
- GINGIVAL CORIUM
Where do all the gingival fibers that attach into cementum attach?
in the 1mm of free cementum that exists between the CEJ and osseous crest of bone
dentogingival fibers
location
function
location
attach to cementum then travel HORIZONTALLY AND CORONALLY and terminate in the free gingival margin area
function - provide gingival support
dentoperiosteal fibers
location
function
location
attach to cementum and run HORIZONTALLY THEN APICALLY and merge with the periosteum that covers the bone
function - anchor tooth to bone and protect PDL
alveologingival fibers
location
function
location
“fan” out CORNOALLY into the lamina propria from the periosteum at the alveolar crest
function attach gingiva to bone
transseptal fibers
location
function
location
INTERDENTAL fibers that go from MESIAL aspect of one tooth to the DISTAL aspect of the adjacent tooth and inserts into the CEMENTUM OF BOTH TEETH
function maintain relationship between adjacent teeth and protect interproximal bone
circumferential fibers
location
function
location
DO NOT ATTACH TO CEMENTUM AT ALL - they are present in the free gingival margin area and WRAP AROUND TOOTH circumferentially
function maintain contour and position of the free gingival margin
five primary gingival fibers
- dentogingival
- dentoperiosteal
- alveologingival
- transspetal
- circumferential
secondary gingival fiber groups
- periostogingival
- interpapillary
- transgingival
- intercircular
- intergingival
- semicicular
most fibers in gingival C.T.
typep I collagen
ground substance of C.T?
occupies space between cells, fibers, and neurovascular elements – major components are water glycoproteins and proteoglycans
- PERMITS DIFFUSION of biological substances between various structural elements
principle cell type in gingival C.T? what else?
fibroblast - 65%
- responsible for production of ground substance and fibers - type 1 collagen is majority of fibers
2-10% are inflammatory cells - lymphocytes
what do fibroblasts produce?
structural components of the C.T. like collagen, elastin, oxytalin plus GAGS
secrete MMPs (matrix-metalloproteinases) and the inhibitors (TIMPs) - homeostasis maintainance
Gelatinase
MMP number
substrate
MMP-2, -9
denatures collagens
Collagenases
MMP number
substrate
MMP-1, -8
collagen I,II,III,VII,VIII and X
Stromelysins
MMP number
substrate
MMP number
-3, -10, 11
substrate
fibronectin, laminin, collagen IV, V, Ix, X, elastin
Matrilysin
MMP number
substrate
MMP-7
fibronectin, laminin, and collagen IV
theory of fibroblasts in gingival in bacteria present?
phenottypically distinct and functionally different subpopulatiouns of fibroblasts exist in periodontium - even if similar on LM or EM
- different subsets have different roles in CT
cells in this theory ARE NOT DYSFUNCTIONAL DUE TO INJURY – but cells present in pathologically altered tissues are functioning as prescribed by genetic predispositions
