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Expert groups

Dental and oral diseases

Project goals

Oral health is an important part of general health. Dental caries and periodontal disease are a major health problem worldwide and are the most common oral diseases and the main cause of tooth loss throughout life. TMJ disorders are among the most common orofacial pain conditions.

The relationship between oral diseases and general health is complex and reciprocal. On the one hand, systemic diseases have an impact on oral health, either directly, e.g. through pathological pathways, or indirectly through disease- or therapy-related behavioural changes. On the other hand, changes in oral health also affect systemic health, such as cardiovascular disease, diabetes mellitus, respiratory infections and stroke.

The dental examination in the German National Cohort (NAKO) was designed to investigate possible causes and mechanisms for the occurrence and progression of population-relevant oral diseases, to identify risk factors, to derive measures for prevention and to investigate the effects of oral diseases.

Speakers

Prof. Dr. Stefan Rupf
PD Dr. Birte Holtfreter (Deputy)

Results

  • Pain in the temporomandibular joints or chewing muscles is common among the general population, especially among women and young adults. The symptoms are associated with biopsychosocial factors such as sleep problems, childhood trauma, anxiety and depression, while abnormalities in the teeth or jaw position appear to play a minor role.
  • Smoking: As shown in previous studies, smoking is a risk factor for periodontitis.
  • Dental health in the population: Based on the NAKO data, the researchers were able to show that a higher prevalence of periodontitis in certain groups of people with a migration background in Germany is associated with lower utilisation of healthcare services. The findings are to be used to improve healthcare services for these people.
  • Caries over the course of a lifetime: Overall caries experience increases significantly with age: the average total number of decayed, filled or extracted teeth increases from 0.2 teeth in 19-29-year-olds to 3.0 teeth in 60-75-year-olds. Fortunately, the number of decayed teeth remains low across all age groups (less than 0.9 teeth on average).
  • Regional differences: The prevalence of both tooth loss and periodontitis shows regional differences: it is highest in the Neubrandenburg study region and lowest in the Augsburg study region.
  • Dental and cardiovascular diseases in context: The PAROCARD study (Level 3 project) investigated associations between periodontitis, a chronic inflammation of the oral cavity, and atherosclerotic vascular changes. It was shown that intima-media thickness (IMT) was predominantly modelled by age (increased IMT) and gender (decreased IMT in females).

Publications

Herpel C, Becher H, Aarabi G, et al. Temporomandibular Disorders: Prevalence and Associated Biopsychosocial Factors. An Analysis of Data From the NAKO Health Study. Dtsch Arztebl Int. 2026(3) http://doi.org/10.3238/arztebl.m2025.0219

Samietz S, Borof K, Hertrampf K et al. Dental and oral health assessments in the German National Cohort (NAKO). BMC Oral Health 2025. https://pubmed.ncbi.nlm.nih.gov/39875848/

Holtfreter B, Samietz S, Hertrampf K, et al. Design und Qualitätskontrolle der zahnmedizinischen Untersuchung in der NAKO Gesundheitsstudie. Bundesgesundheitsbl. 2020;63(4):426-438. http://doi.org/10.1007/s00103-020-03107-w

Zimmermann H, Hagenfeld D, Diercke K, et al. Pocket depth and bleeding on probing and their associations with dental, lifestyle, socioeconomic and blood variables: a cross-sectional, multicenter feasibility study of the German National Cohort. BMC Oral Health. 2015;15(1):7. http://doi.org/10.1186/1472-6831-15-7

Hagenfeld D, Zimmermann H, Korb K, et al. Periodontal Health and Use of Oral Health Services: A Comparison of Germans and Two Migrant Groups. IJERPH. 2019;16(16):3000. http://doi.org/10.3390/ijerph16163000