chapter 1: periodontium- the tooth-supporting structures

periodontium

the set of tissues surrounding the teeth and anchor them to the jaw bone

tissues of the periodontium

gingiva

PDL

cementum

alveolar bone

gingiva function

provide tissue seal around cervical portion

covers alveolar processes and holds tissues against the tooth during mastication

PDL function

suspends and maintains the tooth in its socket

alveolar bone function

supports the roots of the teeth

nerve supply of the periodontium

trigeminal- pain, touch, pressure, movement, tooth position

blood supply of periodontium

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lymphatics of the periodontium

drainage:

submandibular nodes- most

deep cervical- palatal gingiva of mx

submental nodes- md incisor gingiva

jugulodigastric- gingiva of 3rd molar region

parts of the gingiva

free gingiva

gingival sulcus

interdental gingiva

attached gingiva

free gingiva

boundaries: coronal boundary and free gingival groove

unattached portion of the gingiva that surrounds the tooth in CEJ region (attaches by junctional epithelium)

gingival sulcus

boundaries- free gingiva and tooth surface

v-shaped shallow crevice around tooth- depth shows periodontal health

interdental gingiva

boundaries- free gingiva of adjacent teeth

fills interdental embrasures, prevents food from being trapped during mastication

attached gingiva

boundaries- free gingival and alveolar mucosa

texture- dimpled/stippled (varies- indicative of healthy gums)

withstand mechanical forces (brushing, chewing, speaking)

prevents free gingival groove from being pulled apically with tension

PDL

soft connective tissue network- attaches root to bony walls of tooth socket

PDL functions

support- suspend and maintains tooth in socket

sensory- specialized nerve endings for pain and pressure

nutritive- blood vessels provide oxygen and nutrients to PD tissues

formative- build and maintain attachment apparatus (+ HERS remnants)

remodeling- remodel alveolar bone in response to pressure

cementum characteristics

light yellow, softer, resistant to resorption (allows pressure), decreases in thickness with age

cementum function

give attachment to the collagen fibers of PDL (via Sharpey’s fibers), protects underlying dentin

formation compensates for toothwear by attrition

alveolar bone

surrounds roots of teeth

forms bony sockets for tooth support

alveolar bone layers

alveolar bone proper- holes for blood vessels to connect to vessels of PDL space

cortical- hard, compact bone, supports the socket (facial and lingual sides)

cancellous- spongy, mostly interproximal (more in mx)

periosteum- connective soft tissue covering the outer surface of bone (outer collagenous tissue + inner elastic fibers)