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DENTIST 2025- 2026
- periodontium - functional system of TISSUES that surrounds teeth and attaches them to the jawbone
- "supporting tissues of teeth" or "attachment apparatus"
peri = around. odontos = tooth
- tissues of the peri- - gingiva odontium -^ cementum - periodontal ligament - alveolar bone
- gingiva the part of mucosa that surrounds CERVICAL portions of teeth and COVERS ALVEOLAR PROCESS:
- attached by specialized epithelial tissue (which makes up the junctional epithe- lium)
- composed of thin outer layer of epithelium and underlying layer of CT
- function of gingi- va
- gingival margin
- protects underlying tooth-supporting structures of periodontium from oral environment (thru defense mechanisms such as saliva and immune system)
DENTIST 2025- 2026
- upper edge (coronal)
- follows tooth contour creating a scalloped outline
- alveolar mucosa - lower edge (apical)
- free gingival groove
- mucogingival junction
- four anatomical areas of gingiva
a shallow linear depression separating FREE and ATTACHED GINGIVA (hard to see)
where the pink attached gingiva meets the red alveolar mucosa (clinically visible)
- free gingiva
- attached gingiva
- interdental gingiva
- gingival sulcus
- free gingiva - UNATTACHED, surrounds tooth in the region of CEJ
- "unattached gingiva" "marginal gingiva"
- turtleneck
- fits closely around the tooth but is not directly attached
- located ABOVE CEJ
DENTIST 2025- 2026
purpose of at- tached gingiva
- interdental gingi- va
- 2 interdental papillae
- withstand forces during chewing, speaking and brushing
- prevents free gingiva from being pulled apically from the tooth when tension is applied to alveolar mucosa
- fills the interdental space (embrasure) just below contact area
- prevents food between teeth
- gingival col
- FACIAL & LINGUAL
- lateral border and tip formed by free gingiva of adjacent teeth
- centre is formed by attached gingiva
- gingival col - valley-like depression apical to the contact area of 2 adjacent teeth that connects facial and lingual papillae
- col will NOT be present if there's a large space between 2 teeth/gingival recession
- gingival sulcus - v-shaped shallow space between free gingiva and tooth surface
- measured by probe (1-3mm)
- BASE OF SULCUS formed by JUNCTIONAL EPITHELIUM
DENTIST 2025- 2026
- gingival crevicular - seeps from underlying CT into the sulcular space fluid (GCF)
- periodontal liga- ment (PDL)
- 5 functions of periodontal liga- ment
- formative (func- tion of PDL)
- LITTLE TO NONE in a healthy sulcus
- increases with plaque, brushing and chewing, UNHEALTHY GINGIVA
- CT that covers the ROOT of the tooth and ATTACHES IT to the BONE of the tooth socket (cementum and alveolar bone)
- composed of DENSE FIBROUS TISSUE
- supportive
- sensory
- nutritive
- formative
- remodeling
providing cementoblasts and osteoblasts
DENTIST 2025- 2026
- hypercementosis excess deposit of cementum in apical third of root
- may obstruct apical foramen
- appears radiopaque on x-ray
- sharpey's fibres the terminal endings of periodontal ligaments attached to cementum
- EMBEDDED IN ALVEOLAR BONE PROPER
- alveolar bone mineralized CT that forms BONES OF UPPER AND LOWER JAW to support roots of teeth
- froms BONY SOCKETS
- existence is DEPENDENT OF PRESENCE OF TEETH (extracted= bone will resorb, no eruption= bone does not develop)
- alveolar bone 3 layers
comprised of 3 layers of HARD TISSUE covered by a layer of CONNECTIVE TISSUE
- alveolar bone proper
- cortical bone
- cancellous bone
DENTIST 2025- 2026
alveolar bone proper
aka cribiform plate is a thing layer lining the socket:
- alveolus, foramina, sharpeys fibres
- alveolus the BONY SOCKET that houses the tooth
- foramina holes that allow blood vessels to connect CANCELLOUS BONE to PERIODONTAL LIGAMENT (hence cribiform)
- cortical bone aka compact bone
- layer of COMPACT BONE that forms the outer wall on facial bone and lingual surfaces: alveolar crest
- alveolar crest "peak of the mountain"
- coronal-most portion of the alveolar process
- cancellous bone aka spongy/trabecular bone
- fills the interior portion of the alveolar process
- mostly in the interproximal areas
DENTIST 2025- 2026
- extracellular ma- trix in epithelial tissue
- connective tissue in epithelial tissue
- sparse
- thin mat called basal lamina underlies epithelium
- more plentiful (lots between cells)
- mucosa when epithelial tissue lines body cavities ex. oral mucosa
- epithelial tissue - body's skin "edidermis" and lines body cavities
- closely packed epithelial cells are bound into sheets or layers (strata) ex. stratified epithelium
- epithelial cells se- crete
- keratinized ep- ithelial cells
a thin mat of extracellular matrix called basal lamina
- process by which epithelial cells on a surface become stronger and waterproof
- must have NO NUCLEI
DENTIST 2025- 2026
- most heavily kera- - palm of hands and feet tinized body parts
- nonkeratinized epithelial cells
- blood supply ep- ithelial cells
- HAVE NUCLEI
- SOFTER, more FLEXIBLE
- found in mucosa: LINING OF CHEEKS allows flexibility to speak and chew
- epithelial cells are AVASCULAR (NO blood vessels
- receive o2 and nourishment from vessels in underlying CT by DIFFUSION
- connective tissue - fills space between tissues and organs in the body and supports or binds other tissue
- CT cells are sparsely distributed (more apart then in epithelial tissue) in extracellular matrix
- EXTRACELLULAR MATRIX is the major component of CT
- connective tissue is composed of
- fibroblasts
- macrophages
- neutrophiles
- lymphocytes
- fibrobalsts form extracellular matrix
- macrophages destroy invading MOs
- neutrophils destroy invading MOs
DENTIST 2025- 2026
- binding is needed to form a structurally strong unit
- the more the mechanical stresses, the more the abundant cell junctions
- types of epithelial cell junctions
- desosome connects two neighbouring epithelial cells together:
- CELL-TO-CELL connection
- found in gingivannectionl epithelium
- hemidesmosome connects epithelial cells to the basal lamina
- CELL-TO-BASAL LAMINA connection
- also found in gingival epithelium
- epithelial vs con- nective tissue
DENTIST 2025- 2026
- microscopic anatomy of gingival epithelium
- 3 anatomical ar-
STRATIFIED SQUAMOUS EPITHELIUM in oral vanity functions well in a wet envi- ronment
- oral epithelium (OE) eas of gingival ep- 2. sulcular epithelium (SE) ithelium
- cell layers of gin- gival epithelium
- junctional epithelium (JE)
- oral epithelium - covers OUTER SURFACE of FREE GINGIVA and ATTACHED GINGIVA from the crest of the gingival margin to the mucogingival junction
- keratinized or parakinized (partially keratinized)
- joins CT wavy interface with epithelial ridges
- 4 layers of strat- ified squamous epithelium
- CUBE shape cells in the BASAL cell layer
- SPINE like cells in the PRICKLE cell layer
- FLATTENED cells in the GRANULAR cell layer
Cianna TCDHA PERIO MIDTERM EXAMS FOR DENTIST 2025- 2026 sulcular epitheli- um
- 3 cellular layers
- the epithelial lining of the gingival sulcus is THIN and NONKERATINIZED
- continuous with oral epithlium extending from crest of gingival margin to coronal edge of junctional epithelium
- PERMEABLE, allowing fluid to flow from gingival CT into sulcus (gingival crevic- ular fluid)
- joins CT with a SMOOTH interface and no epithelial ridges
- basal cell layer of sulcular epithe- - prickle cell layer lium - superficial cell layer
- junctional epithe- lium
- forms the BASE OF THE SULCUS and joins gingiva to the tooth
- THIN and NONKERATINIZED, easily penetrable by bacteria, etc.
- easiest entry point for bacteria to invade into CT
- SMOOTH tissue interface with CT
- attaches to the tooth slightly CORONAL (above) the CEJ
cianna TCDHA PERIO MIDTERM
- junctional epithe- closely packed epithelial cells lium comprised of - has a sparse extracellular matrix with a thin basal lamina between JE and the tooth surface and JE and gingival connective tissue
- 2 layers of junc- tional epithelium
- cells next to the tooth form
- basal cell layer
- prickle cell layer
15-30 cells thick at CORONAL zone (the highest attachment one) and tapers to 4-5 cells thick at the APICAL zone
hemidesmosomes that attach the INTERNAL basal lamina with the tooth surface
cianna TCDHA PERIO MIDTERM
- fibroblasts
- mast cells
- immune cells (macrophages, neutrophils, lymphocytes)
- fibrooblasts produce extracellular matrix
- transportation of water, nutrients, o2 and metabolites to the gingiva occurs within this matrix
- % of protein fibers including collagen fibers in gingival tissue - 55-65%
gel like material 30-35%
- collagen forms the rigid "cutt" around the tooth
- supragingival fiber bundles
- dentogingival unit
- network of rope-like COLLAGEN fibre bundles located coronal to the crest of alveolar bone
- strengthen attachment of JE to tooth by bracing the gingival margin against the tooth
junctional epithelium + gingival fibres
- provides structural support tho the gingival tissue
cianna TCDHA PERIO MIDTERM
- supragingival fiber bundles function
- 9 supragingival fiber bundles
- reinforce attachment of JE to tooth
- provide rigidity to free gingiva so it can withstand chewing forces
- connect free gingiva with root cementum and alveolar bone
- connect adjacent teeth to one another
- alveologingival
- circular
- dentogingival
- periosteogingival
- intergingival
- intercircular
- interpapillary
- transgingival
- transseptal
- alveologingival attach gingiva to the bone
- circular encircle the tooth in a ringlike manner
- dentogingival attach gingiva to the teeth
