Of lack sizes, sample approaches, randomisation

The gap

Evidence profile

Stated in the limitations and inline gaps and cells future research sections of the source papers, classified as general, spanning 4 journals.

Supporting evidence — 4 representative gaps

• A Systematic review and Meta-analysis of studies assessing correlation between Gingival biotype and Schneiderian membrane thickness (2026) · International Journal of Drug Delivery Technology · doi

  of lack sizes, sample approaches, randomisation, inconsistent reporting of confounders, and heterogeneity in periodontal status. The cross- studies prevents sectional nature of establishing causation and indicates the need for longitudinal research. Publication bias assessment, although statistically fully exclude suppressed negative findings.

  generalstated in limitationsevidence 5/5
  Keywords: lack sizes sample approaches randomisation inconsistent reporting confounders heterogeneity periodontal status cross prevents sectional nature
• Physical activity and periodontitis among US adults (2026) · Journal of Public Health · doi

  This study benefits from a large, diverse, nationally representative sample and standardized periodontal assessments using established surveillance case definitions, which improves comparability with national estimates. Nonetheless, several limitations should be emphasized. First, NHANES is cross-sectional, so temporality cannot be established; periodontitis-related pain, tooth mobility, or comorbidity burden could reduce PA engagement. Second, PA was self-reported, introducing recall and social desirability bias. Third, although we adjusted for multiple confounders, residual confounding is possible, particularly from oral hygiene behaviors, dental care utilization, diet quality, psychosocial stress, and inflammatory biomarkers not included in the final model. Finally, our exclusions (pregnancy and diabetes history) improve internal validity for isolating associations, but may limit generalizability to populations at highest periodontal risk. Still, intervention evidence in people with type 2 diabetes mellitus suggests that increasing PA can improve periodontal indices, supporting the plausibility of a beneficial pathway even in higher-risk groups (Wernicke et al. 2021). Public health implications and future directions Given the substantial burden of periodontitis and its links to inflammatory comorbidities, identifying modifiable behaviors associated with periodontal health is important (Tonetti et al. 2017). Importantly, only 26.4% of US adults met national PA guidelines in 2024 (ODPHP 2024), which include recommendations to engage in 150–300  min of moderate-intensity or 75–150 min of vigorous-intensity aerobic exercise, or a combination of those, along with muscle-strengthening activities at least 2 days per week (HHS 2018; Bull et al. 2020). Moreover, recent global surveillance estimated that more than one third of US adults were insufficiently active in 2022 (Strain et al. 2024), underlining a unique opportunity to promote PA among the US population as a strategy to improve inflammation-related health outcomes, such as periodontitis. Longitudinal cohort studies and pragmatic interventions using objective activity measures (i.e., accelerometry), domain-specific activity characterization, and richer oral health behavior data are needed to clarify causality and mechanisms.

  generalstated in limitationsevidence 5/5
  Keywords: health periodontal periodontitis improve using established surveillance national related burden engage third oral behaviors inflammatory
• Beyond the Red Complex: De Novo Marker Discovery Uncovers Novel Periodontitis-Associated Taxa and Enables Non-Invasive Machine Learning Diagnosis (2026) · medRxiv · doi

  A limitation of this study is its cross-sectional, case–control design, so markers—however robust—reflect association with periodontitis status at sampling, not causation or temporal sequence in disease progression; longitudinal cohorts would be needed to determine whether marker abundance changes precede, accompany, or follow clinical attachment loss.

  generalstated in inline gapsevidence 5/5
  Keywords: limitation cross sectional case control design markers robust reflect association periodontitis status sampling causation temporal
• Cost-Effectiveness of Periodontal Intervention Combined with Diabetes Management in China: A Markov Analysis (2026) · International Dental Journal · doi

  Future studies should evaluate the cost-effectiveness of integrating periodontal intervention with diabetes management in other populations, such as those with type 1 diabetes or other forms of periodontitis. - Future studies should also evaluate the clinical effectiveness of different periodontal treatments, such as scaling and root planing versus laser therapy. - Future studies should develop more sophisticated models to simulate outcomes for patients with comorbid T2DM and periodontitis, accounting for the bidirectional relationship between the two conditions.

  generalstated in cells future researchevidence 5/5
  Keywords: future studies evaluate cost-effectiveness integrating periodontal intervention diabetes

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