Implication of thyroid function in periodontitis: a nationwide population-based study

Bidirectional Association between Periodontitis and Thyroid Disease: A Scoping Review

Periodontitis is a chronic inflammatory disease of the tissues surrounding and supporting the teeth. Due to the development of chronic inflammation, periodontitis can contribute to the development of several systemic diseases, including thyroid disease. Thyroid pathology includes benign, malignant, and autoimmune conditions leading to hypothyroidism, hyperthyroidism, or euthyroidism. Alterations in thyroid hormones, especially hypothyroidism, can reveal significant oral manifestations, including periodontitis. This scoping review aims to explore the probable causal relationship between periodontitis and thyroid disease, in terms of epidemiology, pathogenesis, and treatment. The search strategy follows the PRISMA-ScR guidelines. PubMed, Scopus, Web of Science, and Cochrane were searched from January 2014 to January 2024, entering the MESH terms "periodontitis" and "thyroid". Of 153 initial records, 20 articles were selected and discussed. There is a high prevalence of periodontitis among patients with thyroid disease, including thyroid cancer. The causes at the basis of this association are genetic factors, the oral microbiome, and proinflammatory cytokines. Periodontal treatment, specifically scaling and root planning, can ameliorate thyroid parameters. Although there are a few randomized controlled studies in the literature, this review lays the foundation for a bidirectional relationship between periodontitis and thyroid disease, the link to which is, once again, systemic inflammation.

Periodontal disease in patients with thyroid diseases: A systematic review with meta-analysis

PURPOSE

The imbalance of thyroid hormones affects the metabolic activity of various tissues, including periodontium. Also, autoimmune diseases present an increased tendency to suffer from periodontal disease. Therefore, our systematic review was designed to answer the question "Is there a relationship between thyroid diseases and periodontal disease?".

MATERIALS AND METHODS

Following the inclusion and exclusion criteria, 10 studies were included in this systematic review using the databases PubMed, Scopus and Web of Science (according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines).

RESULTS

Based on the meta-analysis, patients with thyroid diseases (especially with hypothyroidism) demonstrated significantly worse periodontal status than systemically healthy controls. Moreover, according to the cross-sectional studies, 5.74 ​% of periodontitis patients reported the concomitance of thyroid diseases.

CONCLUSIONS

In summary, the included studies suggest a potential relationship between thyroid diseases and periodontal disease. However, further research is necessary to reliably assess the oral health in patients with hypothyroidism and hyperthyroidism.

Periodontitis and thyroid function: A bidirectional Mendelian randomization study

BACKGROUND AND OBJECTIVE

Previous studies suggest interaction between periodontitis and thyroid function, while the causality has not yet been established. We applied the Mendelian randomization (MR) method to assess bidirectional causal association between periodontitis and thyroid-related traits, including free thyroxine (FT4), thyroid stimulating hormone (TSH), hypothyroidism, hyperthyroidism and autoimmune thyroid disease (AITD).

METHODS

Genetic instruments were extracted from large-scale genome-wide association studies on normal-range FT4 (N = 49 269) and TSH (N = 54 288) levels, TSH in full range (N = 119 715); hypothyroidism (discovery/replication cohorts: N = 53 423/334 316), hyperthyroidism (discovery/replication cohorts: N = 51 823/257 552), AITD (N = 755 406) and periodontitis (N = 45 563). Here, the inverse variance weighted (IVW) method was applied as the primary analysis, and robustness of results were assessed by several pleiotropic-robust methods. Results were adjusted for Bonferroni correction thresholds with significant p < .004 (0.05/13) and suggestive p between .004 and .05.

RESULTS

The IVW analysis revealed a suggestively causal linkage between genetic predisposition to periodontitis and the increased risk of hypothyroidism (discovery cohort: odds ratio [OR] = 1.24, 95% confidence interval [CI] = 1.05-1.46, p = .012; replication cohort: OR = 1.06, 95% CI = 1.01-1.11, p = .011). No evidence was found for supporting the impact of periodontitis on hyperthyroidism and AITD risks (associated p ≥ .209), as well as thyroid-related traits on periodontitis risk (associated p ≥ .105). These findings were robust and consistent through sensitivity analysis with other MR models.

CONCLUSION

This bidirectional MR reveals periodontitis should not be attributed to variations in thyroid function but it has potential causal effect on hypothyroidism risk, which provides a better understanding of the relationship between periodontitis and thyroid function, and potential evidence for the clinical intervention of hypothyroidism. Further investigations are warranted to elucidate the nature and underlying mechanisms of this finding.

Reduction in Gingival Bleeding after Atelocollagen Injection in Patients with Hashimoto's Disease-A Pilot Study

Periodontal diseases are one of the main causes of tooth loss and the second most common oral disease after carries. Patients with autoimmune diseases, such as Hashimoto's disease, are more often vulnerable to infection. In the study group of patients, despite the lack of other signs of gingivitis, bleeding occurred after tooth brushing or minor trauma. Bleeding on probing is the first objective sign of ongoing inflammation. The study was conducted on a group of 17 patients diagnosed with Hashimoto's disease. The atelocollagen Linerase (100 mg) thinned with 5 mL 0.9% NaCl was used. A total of 0.05 mL of solution was injected into keratinized gingiva, two millimeters above the gingival papillae basement, four times in two-week intervals. The greatest decrease in the number of bleeding points was observed after the first and second injections of atelocollagen. After the third and fourth injections, the average BOP continued to decrease, but the decline was very slow. The use of atelocollagen made it possible to eliminate bleeding symptoms in the study group.

Prevalence of periodontitis in dentate people between 2011 and 2020: A systematic review and meta-analysis of epidemiological studies

AIM

The aim of the study was to evaluate the prevalence of periodontitis in dentate people between 2011 and 2020.

MATERIALS AND METHODS

PUBMED, Web of Science, and LILACS were searched up to and including December 2021. Epidemiological studies reporting the prevalence of periodontitis conducted between 2011 and 2020 were eligible for inclusion in this review. Studies were grouped according to the case definition of confidence as confident (Centers for Disease Control [CDC] AAP 2012; CDC/AAP 2007; and Armitage 1999) and non-confident (community periodontal index of 3 or 4, periodontal pocket depth >4 mm, and clinical attachment level ≥1 mm). Random effects meta-analyses with double arcsine transformation were conducted. Sensitivity subgroup and meta-regression analyses explored the effect of confounding variables on the overall estimates.

RESULTS

A total 55 studies were included. The results showed a significant difference, with confident case definitions (61.6%) reporting nearly twice the prevalence as non-confident classifications (38.5%). Estimates using confident periodontal case definitions showed a pooled prevalence of periodontitis of 61.6%, comprising 17 different countries. Estimates reporting using the CDC/AAP 2012 case definition presented the highest estimate (68.1%) and the CDC/AAP 2007 presented the lowest (48.8%). Age was a relevant confounding variable, as older participants (≥65 years) had the highest pooled estimate (79.3%).

CONCLUSION

Between 2011 and 2020, periodontitis in dentate adults was estimated to be around 62% and severe periodontitis 23.6%. These results show an unusually high prevalence of periodontitis compared to the previous estimates from 1990 to 2010.