Anatomy of Periodontium Flashcards
What are the 4 components of the periodontium?
Gingiva
Cementum
PDL
Alveolar bone
_____ is the most common cause of adult tooth loss
Periodontitis
The oral masticatory mucosa that surrounds the cervical portion of teeth and covers the alveolar process of the maxilla and mandible comprised of:
Marginal gingiva (unattached or free gingiva)
Attached gingiva
Alveolar mucosa
Mucogingival junction (MCJ)
Gingiva
Free or unattached, cufflike tissue surrounding the teeth on facial, lingual, and interproximal surfaces
- MOst coronal portion of the gingiva
- Scalloped outline of teeth
Marginal gingiva
Space formed by tooth and sulcular epithelium and the coronal end of the JE
Sulcular measurements of 1-3mm considered WNL of gingival health
Gingival sulcus
Divides free gingiva from attached gingiva
- Shallow depression
- Only found in 50% of patients
Free Gingival Groove
- Occupies the interdental space (fills embrasure space apical to tooth contact)
- Attached to the tooth by the JE and connective tissue fibers
INterdental papilla
- Valley-like depression of the interproximal contact areas
- Connects lingual and buccal interdental papilla
- Absent when teeth are not in contact
- Nonkeratinized epithelium susceptible to inflammation and disease progression
The Gingival Col
- Nonkeratinized epithelium surrounding and attaching to the tooth on one side, and the gingival connective tissue on the other side
- Base of the sulcus/pocket
- more permeable to cells and fluid
- Serves as route of passage of fluid and cells from the connective tissue into the sulcus for bacteria/bacterial products from sulcus to connective tissue
- Easily penetrated by the periodontal probe, especially when gingiva is inflamed
- Length: 0.25-1.35mm (remember approx. 1mm)
Junctional epithelium
provides support for marginal gingiva, including the interdental papilla; keep tissue as close to the tooth as possible
GINIGVAL FIBERS
–encircle each tooth in a cuff-like fashion within the free gingiva
Circumferential or circular fibers
–embedded within the cementum; fan outward into the attached gingiva to the tooth
Dentogingival fibers
–embedded in the same portion of the cementum as the dentogingival fibers
Dentoperiosteal fibers
–inserted in the crest of the alveolar process and splay out through lamina propria into the free gingiva
Alveogingival fibers
–embedded in the cementum; run a horizontal path from adjacent teeth
Transseptal fibers
- Attached to the alveolar bone and cementum by connective tissue fibers and epithelial attachment
- Boundaries are apically demarcated by the mucogingival junction (MGJ); coronally demarcated by the base of the gingival sulcus
- Width varies from 1-9mm; widest in facial aspect of maxillary central incisors and narrowest in the mandibular premolar facial areas
- NOT to be measured on the palate
- Any changes in the width of attached gingiva results from changes at the coronal end (i.e., recession)
Attached gingiva
- Movable tissue, loosely attached to underlying alveolar bone
- Thin, nonkeratinized epithelium
- Separate from attached gingiva at the MGJ
- Darker shade of red than gingiva due to rich blood supply
ALVEOLAR MUCOSA
- Visible line where the pink keratinized gingiva meets the more vascular alveolar mucosa (see arrows)
- Found on the maxillary facial and the mandibular facial and lingual areas
Mucogingival junction
- Calcified connective tissue covering the roots of the teeth
- Least mineralized of the calcified tissues of the tooth
- function: to attach fibers of the PDL to the tooth (like cement)
- No blood, lymph vessels of innervation noted
- Continuously deposited in the apical area of the root throughout life
Cementum
What are the 4 functions of the PDL?
Supportive
Formative
Nutritive
Sensory
(functions of the PDL) anchors tooth to bone
Supportive:
(functions of the PDL) helps maintain biologic activity of bone and cementum
Formative:
(functions of the PDL) supplies nutrients and removes waste products via blood and lymph vessels
Nutritive:
(functions of the PDL) capable of transmitting tactile pressure and pain sensations
Sensory:
portion of PDL that insert into bone and cementum
•Sharpey’s fibers:
- Bone that forms and supports the alveoli (tooth sockets)
- Consists of alveolar bone proper and supporting bone
- Contour of the alveolar bone follows contour of the CEJ and arrangement of the dentition
- Shape of the alveolar crest is generally parallel to the CEJ of adjacent teeth; approximately 1.5-2mm apical to the CEJ
- Cortical plates are usually thicker in the mandible than in the maxilla
Alveolar bone
Does the max or mand arch have thicker cortical plates?
Mand
- Thin layer of bone that surrounds the root and gives attachment to the PDL
- Termed lamina dura in radiographic images
- Also termed cribiform plate
Alveolar Bone Proper
- Portion of alveolar process that surrounds the alveolar bone proper and gives support to the sockets
- Compact (cortical)
- Cancellous or trabecular (spongy) bone
Supportive Alveolar Bone
