Related Experiment Video
Updated: Aug 13, 2026
08:12
Micro-dissection of Enamel Organ from Mandibular Incisor of Rats Exposed to Environmental Toxicants
Published on: March 29, 2018
Applying modern survival analysis methods to longitudinal dental caries studies
T Härkäne1, M A Larmas, J I Virtanen
1Rolf Nevanlinna Institute, University of Helsinki, Finland. Tommi.Harkanen@RNI.helsinki.fi
Journal of Dental Research
|February 6, 2002
Summary
Dental caries risk has significantly decreased over recent decades. Contemporary tooth-specific caries risk is low, with no clear age-dependent pattern observed in younger individuals.
Area of Science:
- Dentistry
- Epidemiology
- Public Health
Background:
- Historically, tooth-specific caries risk peaked 2-4 years post-eruption.
- Contemporary caries trends and risk patterns require updated investigation.
Purpose of the Study:
- To investigate secular changes in tooth-specific caries risk.
- To analyze caries risk based on individual tooth age in contemporary Finnish cohorts.
Main Methods:
- Longitudinal study of 4072 individuals across three birth cohorts (1960s, 1970s, 1980s).
- Annual follow-up from age 6 to 18+ years.
- Survival modeling and Bayesian inference applied to tooth-specific caries risk data.
Main Results:
- A substantial overall decrease in dental caries prevalence was observed.
- In earlier cohorts, molar caries risk was highest shortly after eruption.
- In the most recent cohort, tooth-specific caries risk was uniformly low, obscuring age-dependent patterns.
Conclusions:
- Significant decline in dental caries observed across birth cohorts.
- Caries risk patterns have shifted, with reduced age-dependency in recent years.
- Public health interventions have likely contributed to lower caries incidence and altered risk profiles.
Related Concept Videos
02:20Longitudinal Research
Sometimes we want to see how people change over time, as in studies of human development and lifespan. When we test the same group of individuals repeatedly over an extended period of time, we are conducting longitudinal research. Longitudinal research is a research design in which data-gathering is administered repeatedly over an extended period of time. For example, we may survey a group of individuals about their dietary habits at age 20, retest them a decade later at age 30, and then again...
01:15Teeth
The formation of teeth, also known as odontogenesis, is a complex process that begins in utero, around the sixth week of embryonic development. There are three stages to this process: the bud stage, the cap stage, and the bell stage.
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
01:26Longitudinal Studies
Longitudinal studies are also widely used in other medical and social science fields. For instance, in cardiovascular research, they can monitor patients' health over decades to identify risk factors for heart disease, such as high cholesterol or smoking, and evaluate the long-term effectiveness of preventive measures. Similarly, in mental health studies, researchers might follow individuals from adolescence into adulthood to understand the development and progression of conditions like...
01:18Introduction To Survival Analysis
Survival analysis is a statistical method used to study time-to-event data, where the "event" might represent outcomes like death, disease relapse, system failure, or recovery. A unique feature of survival data is censoring, which occurs when the event of interest has not been observed for some individuals during the study period. This requires specialized techniques to handle incomplete data effectively.
The primary goal of survival analysis is to estimate survival time—the time until a...
The primary goal of survival analysis is to estimate survival time—the time until a...
01:20Actuarial Approach
The actuarial approach, a statistical method originally developed for life insurance risk assessment, is widely used to calculate survival rates in clinical and population studies. This method accounts for participants lost to follow-up or those who die from causes unrelated to the study, ensuring a more accurate representation of survival probabilities.
Consider the example of a high-risk surgical procedure with significant early-stage mortality. A two-year clinical study is conducted,...
Consider the example of a high-risk surgical procedure with significant early-stage mortality. A two-year clinical study is conducted,...
01:21Cancer Survival Analysis
Cancer survival analysis focuses on quantifying and interpreting the time from a key starting point, such as diagnosis or the initiation of treatment, to a specific endpoint, such as remission or death. This analysis provides critical insights into treatment effectiveness and factors that influence patient outcomes, helping to shape clinical decisions and guide prognostic evaluations. A cornerstone of oncology research, survival analysis tackles the challenges of skewed, non-normally...