01 - Normal Periodontium

normal periodontium

group of tissues that surround, support, and attach the tooth to the jaws

• consists of gingiva, periodontal ligament, cementum, alveolar bone

gingiva

portion of oral mucosa that covers the alveolar processes of the jaws and surrounds the necks of the teeth

• usually pinker, more keratinized, and firmer

• gingival anatomy (coronal to apical) —

  • free/marginal gingiva → unattached gingiva surrounding tooth

    • approximately 1mm wide

    • free gingival groove separates it from attached gingiva

  • attached gingiva → continuous with marginal gingiva

    • firm, resilient, tightly bound to underlying periosteum / alveolar bone

    • apical border is mucogingival junction

  • mucogingival junction → separates attached gingiva from alveolar mucosa

  • alveolar mucosa → redder, less keratinized, more movable

gingival sulcus

small space between tooth and free gingiva, reaching to junctional epithelium

• healthy sulcus = 1-3mm; mean of 1.8mm

  • facial = 2mm, lingual = 2mm, interproximal = 3mm

  • interproximal probing is deeper because gingival architecture between teeth rises coronally and includes the COL area

• probing affected by many factors → inflammation, morphology, angulation, interproximal anatomy, tissue resistance

attached gingiva width

amount of attached gingiva varies depending on location and between individuals

• least attached gingiva occurs around first premolars

  • maxillary anterior → 3.5-4.5 mm

  • mandibular anterior → 3.3-3.9 mm

  • maxillary first premolar → 1.9 mm

  • mandibular first premolar → 1.8 mm

keratinized gingiva

keratinized gingiva = free gingiva + attached gingiva

• hard palate consists of firmly attached keratinized tissue

interdental gingiva

pyramidal or col-shaped gingiva that occupies space between adjacent teeth

• col conforms to shape of interproximal contact

  • col → depression or valley between facial and lingual portions of interdental papilla

• shape of interdental gingiva is a function of the contact point

embrasures

space created around contact area between adjacent teeth

• buccal, lingual, incisal, gingival

• in healthy gingiva → gingival embrasure normally filled by soft tissue

• important in restorative and prosthetic treatment

  • if contact-to-bone distance is ≤ 5mm, the papilla is more likely to fill the embrasure

  • as distance becomes > 5mm, probability of papilla to fill embrasure decreases and leads to an open gingival embrasure or “black triangle”

diastema

space between adjacent teeth

• no normal interdental papilla within open contact area

• gingiva becomes firmly bound over underlying interdental bone

clinical features of healthy gingiva

• color → coral pink

  • depends on blood supply, thickness of tissue, degree of keratinization, pigmented cells

  • alveolar mucosa = red, smooth shiny

  • attached gingiva = pink, stippled

  • color alone does not diagnose periodontal disease, but is useful for monitoring gingivitis and response to therapy

• pigmentation → melanin is a non-hemoglobin-derived brown pigment responsible for pigmentation of skin, gingiva, oral mucosa

• size → depends on cellular components, intercellular components, blood supply, genetic tissue thickness

  • enlargement due to inflammation and edema or fibrosis

  • gingival overgrowth produced by some medications

  • can be indication of health or disease following therapy

• contour → depends on shape of teeth, alignment, contact, embrasures

  • healthy gingiva described as scalloped with knife-edge margin

  • parabolic when interproximal more coronal than direct facial or lingual

• shape → shape of interdental gingiva depends on proximal tooth contour, embrasures, contact relationship

  • broad vs narrow papilla

  • bone loss or disease if teeth are in contact but papilla is blunted or craters

• consistency → firm, resilient in health

  • gingival fibers contribute to firmness; diseased if spongy

  • free gingiva not bound to underlying bone

• texture → related to keratinization that protects against friction, microbial invasion, desiccation

  • stippling is small dimpled surface texture on attached gingiva, produced by protuberances and depressions in gingiva

  • in health, free gingiva is smooth or stippled

  • edema caused by inflammation forms a glossy surface and loss of stippling

• position → relationship between gingival margin, sulcus, junctional epithelium, tooth changes as teeth erupt

  • margin normally at CEJ, but moves coronal to form pseudopocket in hyperplasia or edema

  • position of mucogingival junction influences amount of attached/keratinized gingiva

continuous tooth eruption

when teeth reaches their functional antagonists, gingival sulcus and gingival epithelium are still positioned on enamel and clinical crown is about 2/3 of anatomic crown

• active eruption → tooth moves towards the occlusal plane

  • compensates for attrition to preserve vertical dimension of occlusion

  • cementum deposited around root apices and furcation areas, with bone forming at crest

    • as crown structure wears down, eruption/tooth-related changes maintain tooth’s functional relationship

• passive eruption → gingiva moves apically, exposing more tooth structure

  • normal apical migration doesn’t occur appropriately, resulting in gingival attachment on enamel and clinical crown appearing shorter

• anatomic crown is covered by enamel; clinical crown is clinically exposed or visible

• anatomic root is covered by cementum; clinical root is covered by PDL

bleeding on probing

healthy sulcus will not bleed upon probing

• with inflammation:

  • sulcar epithelium becomes ulcerated

  • underlying connective tissue undergoes vasodilation

• bleeding is an indicator of gingival inflammation

purulent exudate

no purulent exudate in health

• purulent → containing or accompanied by pus

• exudate → material that escapes blood vessels, usually as part of inflammation