Lecture 1 Flashcards
periodontology
the study of the supporting structures of the teeth referred to as the periodontium
the periodontium exists in 3 different states
health
gingivitis
periodontitis
tissues of the periodontium
gingiva
cementum
periodontal ligament
alveolar bone
macroanatomy
clinical and radiographic features
microanatomy
histologic features (microscopic structures)
gingiva
part of the oral mucosa that surrounds the cervical portions of the teeth and the alveolar process of the jaw
anatomical areas of the gingiva
free gingiva
gingival sulcus
interdental papilla
attached gingiva
function of gingiva
protects underlying periodontium
boundaries of gingiva
gingival margin to the alveolar mucosa indicated by the mucogingival junction MGJ
gingival width
the area measured from the gingival margin to the MGJ
free gingiva
the unattached portion of the gingiva
surrounds the tooth like a turtleneck
space between the free gingiva and the tooth surface is the gingival sulcus
gingival sulcus
space between the free gingiva and the tooth surface
normal depth is 1-3mm
coronal boundary is the gingival margin
base is formed by the junctional epithelium
contains gingival crevicular fluid (GCF)
when does gingival crevicular fluid increase
in the presence of plaque biofilm resulting in gingival inflammation
interdental papilla IP
fills the interdental embrasure between two adjacent teeth apical to the contact area
consists of a facial and lingual papilla connected by the gingival col apical to the contact area
lateral borders formed by the free gingiva
prevents food impaction
shape depends on width of tooth contacts (no contact-blunted, narrow contact-pyramid)
attached gingiva AG
lies between the free gingival groove and the alveolar mucosa clinically indicated by the mucogingival junction
keratinized: protective, fibrous structural protein protecting epithelial cells during mastication
firmly connected to the cementum and the periostem of the alveolar bone
attached gingiva on facial and on lingual
facial
widest on incisors and molars
narrowest on canine and bicuspids
lingual
widest on molars
narrowest on incisors
alveolar mucosa
apical to the MGJ
epithelium is thinner and nonkeratinized
loosely connected to underlying tissues
cementum
hard, mineralized connective tissue covering the root surface
overlies dentin
light yellow
softer than dentin and enamel
more resistant to resorption than bone
typically not visible on radiographs
functions of cementum
provides attachment for the collagen fibers of the periodontal ligament
protects dentin and seals open dentinal tubules
compensates for tooth wear due to attrition by forming at the apical area of the root
periodontal ligament
a layer of soft connective tissue covering the root surface of the tooth
connects root to the tooth via cementum to the alveolar bone of the tooth socket
functions of periodontal ligament
support of the tooth in socket
sensory feeling to the tooth
nutrients to cementum and bone
formative- builds and maintains cementum and bone
resorptive- can remodel alveolar bone
PDL space radiographically
radiolucent
0.1-0.25 mm wide
narrowest near middle of root
increased width with increased function
alveolar bone
portion of the maxilla and mandible that forms and supports the tooth sockets
provides anchorage for roots
existence depends on presence of teeth
alveolar bone should be how many mm from CEJ in health
1-2
components of the alveolar process
alveolar bone proper
cortical bone
cancellous bone
interdental septum
alveolar bone proper
thin, compact, dense bone lining the alveolus or tooth socket
provides attachment for PDL
perforated by many neurovascular canals
radiographically known as the lamina dura
cortical bone
compact, dense bone
forms facial and lingual cortical plates
gives support to the socket
not seen radiographically
thickness and morphology of cortical bone depending on tooth position
thinner from incisors to biscuspids
thicker in molar regions
the cortical bone is covered by the
periosteum (a thin layer of vascularized/sensory connective tissue)
cancellous bone
spongy bone, lacelike
fills interior portion of the alveolar process between the alveolar bone proper and the cortical bone
visible radiographically
interdental septum
portion of the alveolar process between the roots of adjacent teeth
interdental bony crest (IBC) is the coronal portion of the interdental septum
interdental bony crest (IBC)
coronal portion of the interdental septum
important in perio
shape is dependent on the relative alignment of the CEJs of adjacent teeth and the morphology of the IP contacts
IBC is narrower in ant
IBD is broader in post
healthy interdental bony crest
1-2mm apical to CEJ
parallel to adjacent CEJ
sharp, pointed corners
crest is corticated (outlined in dense bone)
