anatomy of the periodontium/ positioning/ gingival descriptors Flashcards
components of the perio
gingiva, cementum, alveolar bone, PDL
types of gingiva
Marginal gingiva (unattached or free gingiva)
Attached gingiva
Alveolar mucosa
gingiva derived from
ectoderm of pharyngeal arches
MARGINAL GINGIVA
→Free or unattached, cufflike tissue surrounding the teeth on facial, lingual, and
interproximal surfaces
Gingival Margin
most coronal portion of gingiva forming a scalloped outline of the tooth
gingival sulcus
normal measurement?
Free Gingival
Groove
Interdental gingiva (papilla)
part of free gingiva
• Occupies the interdental space (fills embrasure space apical to tooth contact)
• Attached to the tooth by the JE and connective tissue fibers
The Gingival Col
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
junctional epithelium
• 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
• JE 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)
GINIGVAL FIBERS provide support for?
provides support for marginal gingiva, including the
interdental papilla
types of gingival fibers
circumferential or circular fibers
Dentogingival fibers
Dentoperiosteal fibers
Alveogingival fibers
Transseptal fibers
circumferential or circular fibers
encircle each
tooth in a cufflike fashion within the free gingiva
Dentogingival fibers
embedded within the
cementum; fan outward into the attached
gingiva to the tooth
Dentoperiosteal fibers
embedded in the same portion of the cementum as the dentogingival fibers
Alveogingival fibers
inserted in the crest of the alveolar process and splay out through lamina propria into the free gingiva
Transseptal fibers
embedded in the cementum; run a horizontal path from adjacent teeth
Clinical Gingival Characteristics: Health VS. Disease
color, consistency, texture, contour, size
diseased
healthy with recession
healthy, amalgam tats and melanin
Attached Gingiva
attached to and how?
boundaries?
width? largest where, smallest where?
not measured where?
changes to width occur at which end?
• 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)
Measuring
Attached
Gingiva
ALVEOLAR MUCOSA
• 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
Mucogingival Junction (MGJ)
• Visible line where the pink keratinized gingiva meets the more vascular alveolar mucosa
• Found on the maxillary facial and the mandibular facial and lingual areas
Cementum
Calcified connective tissue covering the
roots of the teeth
cementum Calcification
Least mineralized of the calcified tissues
of the tooth
Cementum function
function: to attach fibers of the PDL to
the tooth (like cement)
Cementum blood, lymph, inn?
No blood, lymph vessels of innervation
noted
Cementum continuous depostion
Continuously deposited in the apical
area of the root throughout life
CEJ relationships
Cementum overlaps enamel (60-65%)
Cementum and enamel meet (30%)
Cementum and enamel do not meet (5-10%)
acellular cementum
first formed before tooth reaches occlusal plane
in the cervical third
mainly sharpeys fibers here
cellular cementum
secodary, formed after tooth reaches occlusal plane
irregular and less calcified
cementum absorption
trauma, orhto, cysts and tumors?
systemic factors?
subject to absorbtion due to trauma, ortho, cysts and tumors
systemically hypothyroidism, ca def and pagets dx
principal fibers of the PDL
largest PDL fiber
oblique
what PDL fiber are missing with hypoplastic roott
apical
what PDL fibers are only sound w multirooted teeth
interradicular
terminal portion of PDL fiber
shapreys fiber
What PDL fiber doesnt embed in bone
transeptal, runs from one tooth cementum over the alveolar crest to another tooth cementum
functions of PDL fibers
suppportive
formative
nutritive
sensoy
supportive function PDL
anchors tooth to bone
• Sharpey’s fibers: portion of PDL that insert into bone and cementum
PDL formative function
Formative: helps maintain biologic activity of bone and
cementum
PDL nutritive function
Nutritive: supplies nutrients and removes waste products
via blood and lymph vessels
PDL sensory function
Sensory: capable of transmitting tactile pressure and pain
sensations
physical functions of the PDL
Formative and Remodeling of the PDL
Cells of PDL participate in formation and resorption of cementum and bone during physiologic tooth movement
PDL constantly undergoes remodeling
Old cells and fibers are broken down and replaced by new ones
Nutritional and Sensory of the
PDL
• PDL supplies nutrients to and lymphatic drainage from cementum, bone, and gingiva through blood vessels
• PDL highly vascularized
• PDL has great supply of sensory nerve fibers capable of transmitting different sensations through the trigeminal pathways
Radiographic Imaging of PDL Space
PDL width (seen only in radiographs) depends on age, stage of eruption, function of tooth, and angle of film
Alveolar Bone
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 alveolar bone follows contour of the
CEJ and arrangement of the dentition
Shape of the alveolar crest is generally parallel to t
Shape of the alveolar crest is generally parallel to the CEJ of adjacent teeth; approximately 1.5-2mm apical to the CEJ
which arch has thicker cortical paltes
mandible
Alveolar Bone Proper
• Thin layer of bone that surrounds the root and gives attachment to the PDL
• Termed lamina dura in radiographic images
• Also termed cribiform plate
Supportive Alveolar Bone
• Portion of alveolar process that surrounds the alveolar bone proper and gives support to the sockets
• Compact (cortical)
• Cancellous or trabecular (spongy) bone
localized vs generalized
• Localized means <30% of teeth
• Generalized mean >30% of teeth
classes of inflam
Slight, moderate, and severe describe severity of inflammation
locations of gingival inflam
• Specify location (papilla, gingival margin,
etc.)
Patient Positioning
• Supine position is ideal (unless the patient cannot tolerate it)
• Knees, nose, toes in the same plane
right hand positioning direct and indirect vision
• Direct Vision: 9:00
–Lingual UL/LL
–Buccal UR/LR
• Indirect Vision: 11:00
–Lingual UR/LR
–Buccal UL/LL
Dental Assistant’s Chair
bv
