Putting Health into the Mouth

Oral health is an important indicator of systemic health and quality of life. However, little is known about the causal relationships. In order to close this knowledge gap, the project "Oral Health in Switzerland" [OHiS] proposes an innovative research strategy based on the principles of open research data and linking the Swiss dental university centers in Zurich, Basel, and Bern.

The aim is to develop a research platform with a web-based network solution to compile epidemiological population statistics on oral health in Switzerland, to identify dental risk factors, to determine the correlation between oral and systemic health, and thus, ultimately to enable personalized health prognoses.

OHiS is an epidemiological investigation, planned as a population-based longitudinal cohort study. It would be the first open research study to create an interdisciplinary network for electronic health data of the German-speaking dental university centers in Zurich, Basel, and Bern.

The overall aim is to build and establish a new research platform using a web-based network solution for collecting, storing, and sharing structured health data as a prerequisite for systematic analyses and predictive modeling using Artificial Intelligence (AI) and Machine Learning (ML); secondly, to intensify the link between oral and systemic health, and to identify new medical risk factors.

Swiss residents will be randomly selected based on defined age groups between 21 and 80 years, equally distributed for gender, with recruitment in 3 superordinated regions: 1. Canton Zurich (ZH); 2. Cantons of Basel-Stadt (BS), Basel-Land (BL), Solothurn (SO); and 3. Canton Bern (BE). The defined regions are located within a reasonable radius of the 3 university dental centers in urban and rural areas representing the most populous regions of Switzerland.

The primary outcome is to analyze the correlation of oral health (i.e. number of teeth, caries activity, periodontal condition, level of prosthetic restorations) with systemic health in terms of inflammatory, cardiovascular, and metabolic diseases, COPD, mental stability, cognitive abilities, and frailty of the elderly. The secondary outcomes are to develop an AI-enriched predictive model for prevention of future tooth loss and to enable personalized dental therapy according to patient-specific risk profiles.

Variables will be derived from clinical examinations and medical imaging:

• MEDICAL: systemic health, medication, socio-economics, mental health, nicotine and alcohol consumption, nutrition, frailty; and
• DENTAL: oral health, dental status, intraoral scanning, oral hygiene, saliva samples, temporo-mandibular joint [TMJ], oral health impact profile [OHIP].

In contrast to selective data collection in a classic epidemiological study, the focus of the OHiS project is on continuous data generation for a fixed cohort of participants (9 years).

This is a major challenge for implementation:
(1) provision/financing of specialist staff for the studies;
(2) motivation/incentives for the study population; and associated with this
(3) localization of the studies/clinical examinations.

The team sees particular challenges in the duration of the study and the scale: according to statistical calculations, a cohort of 6’000 study participants would be the minimum number of participants. A dental examination (clinical/digital impressions/questionnaires) would take 30 minutes per participant. Calculating repeated examinations every 3 years with drop-out rates of 20%/30%/40% after 3/6/9 years results in a total of 9’300 working hours (4.5 years of 100% employment).

Track-A "Explore-Projects" was the basis for the team to plan the management of digital health data in dental research.

In a joint exchange between the centers in Zurich (Leading House), Basel, and Bern, Work Package 1 (WP-1) defined the standards for the collection of digital health data, used statistical assumptions and calculations to determine the necessary study population and calculated the associated financing costs for a possible implementation (Milesstone-1).

Work-Package-2 (WP-2) focused on the technical aspects of how an IT platform could look in concrete terms and how calibration between the centers could be implemented (Milesstone-2). The REDCap software already established in Zurich-Basel-Bern appears to be the best possible platform for this. This is a licensed web-based solution for electronic case report forms in clinical research. Access from the individual centers, the question of data security and the storage capacity are secured by the software itself.

Milesstones-1 and -2 were achieved as part of the concept phase Track-A "Explore-Projects" (the project objective was to analyze the feasibility). As planned, the project duration was limited to the calendar year 2023. Following this concept phase, the implementation of the project, including third-party funding, is now planned.

OHiS is an early-phase exploration of a potential open research data practice to build communities. Oral healthcare in Switzerland is relatively unique, as patients usually pay for their therapy themselves and insurance companies cannot exert any (in)direct influence on treatment. Cross-sectional studies on oral health in Switzerland are scarce and based on specific point-in-time analyses, data collection mostly by questionnaires and surveys, rather than large-scale longitudinal cohort studies with clinical examinations.OHiS has raised awareness for the implementation of an open research data network between dental university centers in Zurich, Basel, and Bern. At the same time, it was the starting signal for a first step into the longitudinal collection of dental health data.

However, it also revealed the difficulties and necessity of the enormous resources that such a project requires. Based on the existing possibilities at the 3 dental centers, such a project can never be carried out. In this context, OHiS must be combined synergistically with other epidemiological studies in Switzerland. This is the only way to ensure continuity and secure resources over several years.