University of Oulu

Ilkka T. Mehtonen, Aino K. Rantala, Timo T. Hugg, Maritta S. Jaakkola, Jouni J.K. Jaakkola, Dental caries is associated with lower respiratory tract infections: A population-based cohort study, Respiratory Medicine, Volume 158, 2019, Pages 1-5, ISSN 0954-6111,

Dental caries is associated with lower respiratory tract infections : a population-based cohort study

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Author: Mehtonen, Ilkka T.1,2; Rantala, Aino K.1,2; Hugg, Timo T.1,2;
Organizations: 1Center for Environmental and Respiratory Health Research, P.O.Box 5000, FI-90014, University of Oulu, Finland
2Medical Research Center Oulu, P.O.Box 5000, FI-90014, University of Oulu, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.4 MB)
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Language: English
Published: Elsevier, 2019
Publish Date: 2020-09-06


Introduction: Dental caries and respiratory tract infections are among the most common infectious diseases worldwide and they both are appearing in the respiratory system. However, their relations are still unclear. This study investigated the association of dental caries on the risk of lower respiratory tract infections (LRTI) in young adulthood.

Methods: The study population consisted of 1,592 Finnish young adults participating in the 20-year follow-up of The Espoo Cohort Study. The information on the occurrence of LRTIs (pneumonia or acute bronchitis) during the preceding 12 months was based on the follow-up questionnaire and the National Hospital Discharge Register. Lifelong caries on permanent teeth was defined as a self-reported number of filled teeth (FT). The risk ratios (RR) of LRTIs with 95% confidence intervals (CI) were estimated using Poisson regression models.

Results: High FT number was associated with an increased occurrence of LRTIs with an adjusted RR of 1.24 per interquartile range (IQR) of FT (95% CI 1.06–1.44). The risk of LRTIs increased according to the increasing number of FTs, being highest among those subjects with 10 or more filled teeth (adjusted RR 2.30; 1.27–4.17). Family’s socioeconomic status or smoking did not modify the effect.

Conclusions: Our results suggest that dental caries increases the risk of LRTIs. We did not find any significant effect modification by shared determinants of caries and LRTIs. However, it is possible, that common risk factors might explain at least partly the observed relation between FT and LRTIs or that the causality is bidirectional.

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Series: Respiratory medicine
ISSN: 0954-6111
ISSN-E: 1532-3064
ISSN-L: 0954-6111
Volume: 158
Pages: 1 - 5
DOI: 10.1016/j.rmed.2019.09.002
Type of Publication: A1 Journal article – refereed
Field of Science: 3142 Public health care science, environmental and occupational health
Funding: This study was funded by the Academy of Finland (grant number 129419 of Responding to Public Health Challenges Research Programme (SALVE) and grant numbers 138691 and 266314), Finnish Lung Health Association and The Research Foundation of the Pulmonary Diseases (HES) (I.T. Mehtonen's personal grant). The funding sources had no role in study design, data collection and analysis, or preparation of the manuscript.
Academy of Finland Grant Number: 129419
Detailed Information: 129419 (Academy of Finland Funding decision)
138691 (Academy of Finland Funding decision)
266314 (Academy of Finland Funding decision)
Copyright information: © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license