04 - Clinical Indices and Epidemiology

epidemiology

study of distribution and dynamics of disease in human populations

• objectives:

  • identify risk factors or indicators

  • identify populations at high or low risk

  • identify trends in disease patterns

• populations are not homogenous

  • if clinically different groups are combined, meaningful differences disappear and conclusions become misleading

epidemiologic indices

indices convert clinical conditions into standardized numerical scores so populations can be compared

• quantify findings on graduated scale

• allow populations to be compared using same criteria and methods

• tend to underestimate true disease severity

  • studies often sample selected teeth and surfaces, simplifying clinical findings rather than performing complete examination

• indices should be easy to use, reproducible, amenable to statistical analysis, and define clinical condition objectively

• measure gingival inflammation, periodontal destruction, plaque accumulation, calculus accumulation

prevalence vs incidence

• prevalence → number of affected individuals in a population

  • who has it

• incidence → number of new cases during a specified time

  • who gets it

gingival index

assesses severity and location of gingivitis

• gingival units → distofacial papilla, facial margin, mesiofacial papilla, entire lingual surface

• periodontal probe used to assess bleeding potential of tissues

• scoring:

  • 0 — normal gingiva

  • 1 — mild inflammation → slight color change + slight edema

    • no bleeding on probing

  • 2 → moderate inflammation → redness + edema + glazing

    • bleeding on probing

  • 3 → severe inflammation → marked redness + edema + ulceration with spontaneous bleeding

• mean gingival index score per tooth = total gingival index scores / 4

• gingival index score per person = total mean gingival scores / # of teeth

plaque index

assesses severity and location of plaque accumulation

• gingival units → distofacial papilla, facial margin, mesiofacial papilla, entire lingual surface

• mouth mirror and explorer used to assess plaque accumulation

• scoring:

  • 0 → no plaque in gingival area

  • 1 → plaque not visible to unaided eye but detected on probe

  • 2 → thin to moderate thick plaque visible to naked eye

  • 3 → heavy soft-deposit accumulation; interdental space filled with debris

• mean plaque index score per tooth = total plaque index scores / 4

• plaque index score per person = total mean plaque index scores / # of teeth

Volpe-Manhold calculus index

assesses quantity of supragingival calculus accumulation

• periodontal probe used to measure deposits of calculus on lingual surfaces of six mandibular anterior teeth

  • major salivary gland ducts empty near mandibular anteriors, so they are common early/heavy calculus site

• utilized in longitudinal studies to assess treatment efficacy

periodontal index

assesses prevalence and severity of gingivitis and periodontitis

• combined index that records reversible changes and irreversible changes of periodontitis

• examines all teeth with mouth mirror and plain probe

  • all gingival tissue circumscribing a tooth is considered a scoring or gingival unit

  • score obtained by adding all individual scores and dividing by number of teeth present

• scoring:

  • 0 → normal gingiva with no inflammation or loss of function

  • 1 → mild gingivitis in part of free gingiva that does not completely circumscribe the tooth

  • 2 → gingivitis completely circumscribes the tooth but no apparent break in epithelial attachment

  • 6 → pocket formation due to broken epithelial attachment but function remains

  • 8 → advanced destruction with loss of masticatory function

• limitations:

  • does not distinguish between gingivitis and periodontitis

  • assessment of periodontal pockets visually without probing

  • underestimates true level of disease

periodontal disease index

improved periodontal epidemiology by measuring actual periodontal destruction and attachment loss by assessing gingival inflammation and attachment loss

• periodontal probe used to measure clinical attachment levels

• gingival units → teeth #3, 9, 12, 19, 25, 28 on all four gingival surfaces to determine gingivitis score

  • highest score is recorded for gingivitis

  • clinical attachment level measured at mid-facial and mesial surfaces

    • highest score is recorded; gingivitis score is discarded

• periodontal disease index score per person = total # of scores / # of teeth

Ramfjord teeth

#3, #9, #12, #19, #25, #28

risk assessment

• risk factor — environmental, behavioral, or biologic factor

  • has been comfirmed by temporal sequence

  • directly increases probability of disease when present

  • if absent or removed, reduces that probability

• risk indicator — probable/putative risk factor

  • often identified in cross-sectional studies

  • has not yet been confirmed longitudinally

  • association that has not been confirmed

epidemiology of periodontal disease

in the US, approximately 20 million individuals exhibit advanced periodontitis

• prevalence of early-onset periodontitis → 1% in industrialized population

• prevalence of moderate adult periodontitis → approximately 44%

  • 16-80% for ages 18-64 yeras old

• prevalence of advanced periodontitis → approximately 10-15%

peridontal risk factors

• established risk factors:

  • diabetes

  • smoking

  • certain bacteria → A. actinomycwetemcomitans, P. gingivalis, Bacteroides forsythus

• putative risk factors:

  • aging

  • gender

  • genetic predisposition

  • systemic diseases and conditions

  • nutrition

diabetes as periodontal risk factor

poorly controlled diabetes have greater susceptibility and inflammatory dysregulation, leading to increased periodontal destruction

• bidirectional relationship:

  • poor diabetes control → worsened periodontal condition

  • periodontal inflammation → worsens systemic glycemic control

smoking as periodontal risk factor

smoking causes vasoconstriction, which suppresses gingival redness and causes bleeding on probing

• smoking causes vasoconstriction, which decreases gingival blood flow and causes fewer inflammatory signs

• also impairs delivery of host-defense components, leading to weaker periodontal defense and greater periodontal destruction

• more smoking + longer duration → worse periodontal disease

multiple factors of periodontitis

microbial pathogens + susceptible host + risk factors = periodontitis

• different disease severity in every person

• non-modifiable components → genetic susceptibility, host predisposition

• modifiable components → smoking, diabetes control, oral hygiene, dental attendance, plaque/calculus control

clinical attachment level

gold-standard measurement of periodontal attachment loss, measured relative to the CEJ

• CAL = (gingival margin - bottom of periodontal probe) - (gingival margin - CEJ)

• healthy periodontium → bottom of gingival sulcus at CEJ