What do systematic reviews say?

Periodontitis vs Individuals without periodontal disease (by LOA)

Periodontitis is associated with roughly a threefold higher odds of oral cancer (pooled OR 2.94, 95% CI 2.13-4.07; low certainty of evidence), though heterogeneity is moderate (I2=52.4%).

• Periodontitis and the risk of oral cancer: a meta-analysis of case-control studies. 2024 All outcomes

  Not specified · Case-control studies conducted in Asia (n=6), Europe (n=5), USA (n=2) and other countries (n=3) · Overall (random-effects pooled estimate)
  OR 2.94 [2.13, 4.07]
  8 studies · 6927 participants
  Low

Higher number of lost teeth (per one additional lost tooth) vs One fewer missing tooth

The number of missing teeth (per tooth) was not significantly associated with oral cancer (OR 0.96, 95% CI 0.92-1.01); ungraded.

• Periodontitis and the risk of oral cancer: a meta-analysis of case-control studies. 2024 All outcomes

  Not specified · Case-control studies conducted in Asia (n=6), Europe (n=5), USA (n=2) and other countries (n=3) · Missing teeth (per tooth)
  OR 0.96 [0.92, 1.01]
  2 studies
  GRADE not reported

Missing teeth / tooth loss vs Fewer or no missing teeth

Pooling across all missing-teeth measures, the overall association with oral cancer was not statistically significant (OR 1.20, 95% CI 0.97-1.48; high heterogeneity, I2=82.8%); ungraded.

• Periodontitis and the risk of oral cancer: a meta-analysis of case-control studies. 2024 All outcomes

  Not specified · Case-control studies conducted in Asia (n=6), Europe (n=5), USA (n=2) and other countries (n=3) · Overall (all missing-teeth measures pooled)
  OR 1.20 [0.97, 1.48]
  6 studies
  GRADE not reported

Non-syndromic cleft lip and palate (CLP) status and its oral microbiota (exposure/grouping) vs Children and adolescents aged 0-18 years without CLP (controls)

Pooling 3 studies, children/adolescents with CLP were about 2.03 times more likely to have dental caries than non-CLP controls (p<0.005; low heterogeneity), though most included studies were at high risk of bias; the evidence is ungraded.

• Characterization of the oral microbiota and the relationship of the oral microbiota with the dental and periodontal… 2024 All outcomes

  Multiple countries; pediatric cleft/craniofacial care; saliva, dental plaque, subgingival plaque and nasal/oropharyngeal samples
  OR 2.03 [1.46, 2.84]
  3 studies · 688 participants
  GRADE not reported

Non-syndromic cleft lip and palate (CLP) status and its oral microbiota (exposure/grouping) vs Children and adolescents aged 0-18 years without CLP (controls)

A meta-analysis found no significant difference in mean Lactobacillus spp. levels between children with and without CLP, with high heterogeneity; the evidence is ungraded.

• Characterization of the oral microbiota and the relationship of the oral microbiota with the dental and periodontal… 2024 All outcomes

  Multiple countries; pediatric cleft/craniofacial care; saliva, dental plaque, subgingival plaque and nasal/oropharyngeal samples
  For the outcome of the presence of Lactobacillus spp., there were no significant differences between patients with CLP and healthy patients, and the diversity of the studies led to high heterogeneity; however, the p…
  Studies not reported
  GRADE not reported

Non-syndromic cleft lip and palate (CLP) status and its oral microbiota (exposure/grouping) vs Children and adolescents aged 0-18 years without CLP (controls)

A meta-analysis of 2 studies found no difference in mean Streptococcus mutans levels between children with and without CLP, with very high heterogeneity; the evidence is ungraded.

• Characterization of the oral microbiota and the relationship of the oral microbiota with the dental and periodontal… 2024 All outcomes

  Multiple countries; pediatric cleft/craniofacial care; saliva, dental plaque, subgingival plaque and nasal/oropharyngeal samples
  Two studies were analyzed that reported the outcome in means of the presence of Streptococcus mutans, and that there was no difference between the means for healthy patients and those with CLP. The results of these…
  2 studies
  GRADE not reported

Non-syndromic cleft lip and palate (CLP) status and its oral microbiota (exposure/grouping) vs Children and adolescents aged 0-18 years without CLP (controls)

Narrative synthesis of 6 studies suggests children/adolescents with CLP have poorer periodontal status (higher gingival and plaque indices, deeper probing, more bleeding and attachment loss) and harbor periodontopathogens; no pooled estimate and the evidence is ungraded.

• Characterization of the oral microbiota and the relationship of the oral microbiota with the dental and periodontal… 2024 All outcomes

  Multiple countries; pediatric cleft/craniofacial care; saliva, dental plaque, subgingival plaque and nasal/oropharyngeal samples
  Six studies (Ahluwalia, Rawashdeh, Funahashi, Perdikogianni, Quirynen, Costa) reported that patients with CLP had higher gingival index and biofilm/plaque index, deeper probing depth, more bleeding on probing and…
  6 studies
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes

  4 months
  Little 1997 observed and rated participants on flossing skill; Analysis of Covariance found a significant difference favouring the intervention group.
  1 study · 107 participants
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes
  The impact of psychological interventions on clinical markers was assessed in three studies (Little 1997; Stewart 1991; Weinstein 1996). All three found that psychological interventions resulted in improved plaque…
  3 studies
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes
  Stewart 1996: the psychological intervention group demonstrated significantly higher change in self efficacy scores for flossing at post-intervention compared to the other two groups (control and educational). Flossing…
  1 study · 117 participants
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs attention control

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes
  Weinstein 1996 reported that the psychological intervention led to improvements in plaque score greater than that noted in the attention control group; however the sample size in each arm was very small (n=5) and the…
  2 studies
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes

  4 months
  Little 1997: no change in pocket depth; there were no differences between the intervention and control groups in overall change in pocket depth. (Some analyses suggested greater change in the intervention group when…
  1 study · 107 participants
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes

  4 months
  Little 1997 reported decreased gingival bleeding in the active intervention group: gingival bleeding present in 9% of the intervention group at baseline and 4% at 4-month follow up, versus 10% of the control group on…
  1 study · 107 participants
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes

  4 months
  Little 1997: no change in attachment loss; no differences between the intervention and control groups in overall change in attachment (loss of attachment) markers.
  1 study · 107 participants
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs attention control

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes

  5 weeks (2 weeks post-intervention)
  Stewart 1991: there were no differences between the attention control group and the cognitive behavioural (psychological) intervention group for self reported flossing; it cannot be concluded that the cognitive…
  1 study · 50 participants
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes

  4 months
  Little 1997 observed and rated participants on brushing skill; Analysis of Covariance found a significant difference favouring the intervention group (one of four measures on which significant differences were found…
  1 study · 107 participants
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes
  Stewart 1996: for dental knowledge the control group showed no change pre- and post-intervention, whereas the psychological intervention group improved dental knowledge significantly (both intervention groups improved…
  1 study · 117 participants
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes
  Stewart 1996: the psychological intervention had no discernible effect on self efficacy beliefs concerning tooth brushing; the data on perceived self efficacy for tooth brushing were not analysed due to ceiling effects…
  1 study · 117 participants
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs usual care or no treatment

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes
  Self assessed flossing was assessed in two studies (Little 1997; Stewart 1991); both reported improvements for the intervention groups. Little 1997: Analysis of Covariance found significant differences favouring the…
  2 studies
  GRADE not reported

Psychological intervention based on a specified psychological model/theory (to increase adherence to oral hygiene instructions) vs attention control

• Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases 2007 · Cochrane All outcomes

  5 weeks (2 weeks post-intervention)
  Stewart 1991: for self reported brushing only the comparison of the control group with the cognitive behavioural intervention was significant; the cognitive behavioural (psychological) intervention conveyed no…
  1 study · 50 participants
  GRADE not reported