ANATOMY AND PHYSIOLOGY OF THE PERIODONTIUM Flashcards
ANATOMY AND PHYSIOLOGY OF THE PERIODONTIUM
periodontal disease
General term used to describe a chronic infectious inflammatory process that affects the supporting structures of the dentition.
It is the most common chronic infection in humankind
gingivitis
inflammation involving only the gingival (gum) tissues 90% of population
Chronic Periodontitis:
Chronic Periodontitis: Progress of inflammation resulting in loss of collagen attachment to the root surface, apical migration of the pocket epithelium, formation of deepened periodontal pockets and resorption of alveolar bone.
PERIODONTUM=
Periodontal Attachment Apparatus + Gingiva
Periodontal Attachment Apparatus
Alveolar Bone
Periodontal Ligament
Cementum
Periodontium: Histologically includes:
Periodontium: Histologically includes: Attached gingiva, oral epithelium, sulcular epithelium, Junctional epithelium, periodontal ligament, cementum, and alveolar bone
masticatory mucosa
25% of total mucosa
free attached and interdental gingiva
keratinized
lining mucosa
veral(underside of tongue , alveolar mucosa, cheeks, lips,and soft palate
NON KERATINIZED
Types of gingiva
Marginal
- Attached
Interdental
free/marginal
Coral pink/physiologic pigmentation in health
Surrounds teeth in a collar like manner
Forms soft wall of the gingival sulcus
gingival groove
depression on the facial surface of the gingiva
Separates the unattached gingiva (free gingiva) from the attached gingiva
when can the gingival be seen
in 50% of patients
not seen during inflammation
gingival sulcus
Shallow, “v” shaped crevice/space that surrounds the tooth Its measurement (in health 0-3 mm) is a diagnostic clinical parameter
gingival sulcus boundries
Laterally: the tooth and free gingiva
Coronally: the margin of the free gingiva
Apically: junctional attachment epithelium
attached gingiva extends ..
Extends apically from the free gingival groove to the mucogingival junction
attached gingiva
facial / lingual :widest and narrowest regions
Facial widest: Maxillary incisor region
Facial narrowest: Mandibular PM region
Lingual widest: Mandibular molar region
Lingual narrowest: Mandibular incisor region
attached gingiva
Firmly bound down to the underlying periosteum of the alveolar bone
col ?
valley like depression that connects facial and linguial papilla
MUCOGINGIVAL JUNCTION locations ?
Maxillary buccal, Mandibular buccal and lingual.
where can’t MUCOGINGIVAL JUNCTION be found
There is NO MGJ on palate because palatal tissue is
all bound down to periosteum of the hard palate, there is NO alveolar mucosal tissue on the palate.
alveola mucosa
Non-keratinized
Movable
Loosely connected to the underlying tissues
Smooth surface
Darker color than gingiva due to proximity to underlying blood vessels and lack of keratinization
composition of gingiva
Collagen fibers and ground substancfe
overlying stratified squamous epithelial surface
3 distinct areas of gingival epithelium
outer, sulcular and junctional
outer gingival epithelium
4 stratum layers(all except lucidum)
sulcar epithelium
Lines the sulcus
Acts as a semi-permeable membrane through which bacterial byproducts pass from the gingiva (via the sulcus) into the gingival tissue fluids
SULCULAR EPITHELIUM contain what kind of cell
langerhan
what type of epithelium is found in junctional epi
Band of stratified squamous non-keratinized epithelium
junctional epithelium
Part of the attachment between tooth and gingiva. Firmly attached to the tooth surface forming an epithelial barrier against bacterial plaque invasion
Permable to passage of gingival fluid, host defense inflammatory cells to the gingival margin
AVASCULAR
layers of the junctional epithelium
2 layers thick: basal layer and prickle layer
GINGIVAL CONNECTIVE TISSUE COMPOSITION?
Composed of fibers, fiberblasts, blood vessels, nerves and ground substance
Fibers of GINGIVAL CONNECTIVE TISSUE?
Type I collagen: predominant fiber type-add stability
Other fiber types: Reticular, Elastic, Oxytalan
ground substance of GINGIVAL CONNECTIVE TISSUE?
Ground substance: water, sugars, proteins
PDL
Vascular and cellular connective tissue that goes around the root and connects the tooth to the bone
.25mm
Sharpey’s fibers
Calcified insertions of bundles of PDL fibers into cementum and bone
GINGIVAL FIBER GROUPS?
Dentogingival, dentoperiosteal, circular, circumfrential, intercircular, intergingival
fibers of gingiva:
Dentogingival vs dentoperiosteal
Dentogingival
On the facial, lingual and interproximal surfaces
Extend from the cementum to the gingiva
Provide gingival support
and
Dentoperiosteal
Extend from the cementum to the periosteum
fibers of gingiva:
circular
intercircular
intergingival
Circular/Circumferential
Encircle the tooth in a ringlike manner
Maintain the contour & position of the free marginal gingivaInterpapillary
Provides support for the interdental gingiva
Intercircular
Stabilizes the tooth within the arch
Intergingival
Provides support and contour of the attached gingiva
Principle Fibers of the PDL
Type I collagen (80%), Type III collagen (20%)
Oxytalan fibers: function in supportive, developmental and/or sensory role associated with blood vessels and nerves, not attached to bone and cementum
Six PDL fiber groups (Dentoalveolar)
transeptal, alveloar crest and horizontal
PDL fiber groups (Dentoalveolar)
transeptal, alveloar crest and horizontal ,oblique, apical and interradicular
PDL fiber groups (Dentoalveolar)
transeptal, alveloar crest and horizontal
Transseptal – prevent teeth from losing contact
Alveolar Crest-help prevent extrusion (keeps tooth in alveolus), resist lateral tooth movement and protect deeper PDL structures
Horizontal- opposes lateral forces
PDL fibers : oblique, apical and interradicular
Oblique - largest fiber group, bears the brunt of vertical chewing forces
Apical – prevents tooth from tipping and extruding, protects blood vessels and nerve supply to the tooth
Interradicular - prevents tooth from tipping and extruding
Epithelial Rests of Malassez
Epithelial Rests of Malassez are remnants of Hertwig’s Epithelial Root Sheath that occur as nests of cells within the periodontal ligament. These cells may proliferate and form a cyst
PDL FUNCTIONS
Supportive, Transmission of occlusal (biting) forces to the bone, Attachment of the teeth to the bone, Shock absorber
Formation and resorption
Nutritional and Sensory
CEMENTUM
Calcified, avascular, mesenchymal tissue that covers the anatomic root
