Skip to content

The relationship between odontogenic infections and body mass index

By PJ van Wyk and M van der Walt

Introduction and literature review

Dental caries (tooth decay) is the most common childhood disease and the most frequent non-communicable disease worldwide1. In South Africa as in the rest of the world, most of the dental decay remains untreated with significant impact on general health, quality of life, development and educational performance of children2. Despite the pandemic character of dental decay, particularly in children, there are only a few studies that have examined the relationship between the severity of dental decay and the body mass index (BMI). Previous research concluded that children with early childhood caries (ECC) who needed tooth extraction had lower mean weights than those without treatment need3,4. In larger surveys among 1 to 6-year-olds, non-hospital visitors, the relationship between caries and underweight remained inconclusive5,6. A recent large population-based prospective cohort study in the United Kingdom among 5-year-olds, reported that children with tooth decay had slightly smaller increases in weight and height in the previous years than children without tooth decay7. In 2010 Monse et al developed the PUFA index to measure the clinical consequences of untreated dental caries. PUFA/pufa is an index used to assess the presence of oral conditions and infections resulting from untreated caries in the permanent (PUFA) and primary (pufa) dentition. The index is recorded separately from the decayed, missing and filled teeth (DMFTindex. The DMFT/dmft is one of the most common methods in oral epidemiology for assessing dental caries prevalence as well as dental treatment needs among populations and scores the presence of either a visible pulp (P/p), ulceration of the oral mucosa due to root fragments, (U/u), a fistula (F/f) or an abscess (A/a). The PUFA/pufa index per child is calculated in the same cumulative way as the DMFT/dmft index and represents the number of teeth meeting the PUFA/pufa diagnostic criteria8. The purpose of the study was to determine the association between untreated dental caries and BMI among 8 to 10-year-old children in the Ehlanzeni district of Mpumalanga.

Study methodology

The study sample comprised 250 children in the age group 8 to 10 years. Caries was scored according to WHO criteria (1997)9 and odontogenic infections using the PUFA index8. Anthropometric measures, height and weight, were used to compute the BMI10. BMI equals weight in kilograms divided by height in metres squared – weight (kg)/height (m2) for age. Low body mass was defined as a body mass below 1SD below the median of the WHO standards11. Economic determinants, such as employment status of the breadwinner, number of siblings in the family and the presence of a television set in the house were included as potential confounding factors. Logistic regression was performed with BMI as the dependent variable.

The protocol was approved by the Research Committee of the School of Dentistry and consent to conduct the survey was obtained from the children, the parents and the educational authorities.


A total of 250 (125 boys and 125 girls) 8 to 10-year-olds, with a mean age of 110.22 months or 8.7 years were included in the sample. The overall prevalence of caries (DMFT + dmft >0) was 79.2%. The overall prevalence of odontogenic infections due to caries (PUFA+pufa >0) was 26%. The mean dmft was 2.73 and the mean DMFT was 0.70. The BMI of 64% of the children was below normal and 24% were below 1SD of the median of the WHO standards.

The mean experience of dental caries and the mean experience of odontogenic infections due to caries in the 2 categories of BMI is shown in Figure 1.

The results of Figure 1 show that children with a low BMI have significantly higher levels of PUFA/pufa than children with a normal BMI (p<0.05) and children with a low BMI have less caries (total caries) than children with a normal BMI. This result was however not statistically significant (p>0.05).

The odds ratios (OR) (adjusted) obtained from logistic regression model with low BMI as the dependant variable are shown in Table 1.

Table 1: Odds ratios obtained from the logistic regression model

     Low BMI Odds Ratio P value [95% Conf. Interval]
(PUFA+pufa)>0 2.99 0.01 1.26 – 7.09
Large families versus small families 1.38 0.38 0.68 – 2.80
Employed versus unemployed 1.10 0.77 0.57 – 2.12
Boys versus girls 1.12 0.71 0.62 – 2.03
No TV at home versus TV at home 2.77 0.10 0.82 – 9.35
Total caries (DMFT+dmft) 0.92 0.16 0.82 – 1.03

The regression co-efficient between BMI and PUFA/pufa was significant, p = 0.01. Children with odontogenic infections (PUFA+pufa > 0) had a 2.99 times higher risk of below normal BMI as compared to those without odontogenic infections. Although boys in large families in which the breadwinner was employed with no TV at home also had a higher risk of a below normal BMI, the risk was not statistically significantly higher. Children with a high caries rate (total caries) had no increased risk of a below normal BMI.


The results of the current study show that children with odontogenic infections have an increased risk of below normal BMI as compared to those without odontogenic infections. According to Benzian et al there are three possible pathways for this association:

1) Pain and discomfort result in reduced food intake;

2) reduced quality of life affects children’s growth and development through restricted activity, reduced sleep, concentration deficits etc; and

3) odontogenic infections may result in cytokine release which might impact on growth.

According to the authors the latter is however highly speculative12.

However, it is also possible that under-nutrition which will impact negatively on the BMI could result in increased susceptibility to dental caries. Under-nutrition refers to the insufficient intake of energy and nutrients that support growth and development as well as the maintenance of health13. Under-nutrition may also affect the development and integrity of the oral cavity as well as the progression of oral diseases14. There are four possible mechanisms to explain the relationship between under-nutrition and more specifically protein-energy malnutrition (PEM) and dental caries. Psoter et al 200515 indicated that one of the local effects of under-nutrition was enamel hypoplasia, which, in turn, has been associated with caries development. Another local change associated with under-nutrition is salivary gland hypofunction which may increase caries risk via decreased salivary flow rate, decreased buffering capacity, and decreased salivary constituents, particularly proteins15. The same authors also argued that under-nutrition may cause altered eruption timing of the teeth and that an advanced or delayed eruption would increase or decrease, respectively, the age-specific exposure time to cariogenic conditions, so age-specific caries rates may be confounded by altered eruption15. A forth possible mechanism was provided by Cunningham-Rundles et al (2005), under-nutrition results in immunological deficiencies which play an essential role in the aetiology of chronic multifactorial infectious diseases, including dental caries16.


The results of this study show that children with odontogenic infections (PUFA+pufa >0) had an increased risk of below normal BMI, but that there was no relationship between high total caries levels and a below normal BMI. The current study design is a cross-sectional study, which limits the ability to identify causative factors. A longitudinal design would be more adequate to reveal cause and effect relationships.


  1. Edelstein BL. The dental caries pandemic and disparities problem. BMC Oral Health. 2006;6 (Suppl 1):S2. doi: 10.1186/1472-6831-6-S1-S2. [PMC free article] [PubMed] [Cross Ref]
  2. Van Wyk PJ, Van Wyk C. Oral health in South Africa. International Dental Journal (2004) Vol. 54/No.6 (Supplement) 373–377
  3. Acs G, Lodolini G, Kaminsky S, Cisneros GJ. Effect of nursing caries on body weight in a pediatric population. Pediatr Dent. 1992;14:302–305.
  4. Ayham H, Suskan E, Yildirim S. The effect of nursing caries or rampant caries on height, body weight and head circumference. J Clin Pediatr Dent. 1996;20:209–212.
  5. Cleaton-Jones P, Sinwell R, Mogotsi M, Richardon BD, Granath L, Fatti LP, Walker AR. Nutritional status and dental caries in a large sample of 4-and 5-year-old South African children. SA J Clin Nutr. 2000;90:631–635.
  6. Oliviera LB, Sheiham A, Bönecker M. Exploring the association of dental caries with social factors and nutritional status in Brazilian preschool children. Eur J Oral Sci. 2008;116:37–43.
  7. Kay EJ, Northstone K, Ness A, Duncan K, Crean SJ. Is there a relationship between birthweight and subsequent growth on the development of dental caries at 5 years of age. A cohort study. Community Dent Oral Epidemiol. 2010;38:408–414
  8. Monse B, Heinrich-Weltzien R, Benzian H, Holmgren C, van Palenstein Helderman W. PUFA – An index of clinical consequences of untreated dental caries. Community Dent Oral Epidemiol. 2010;38:77–82
  9. World Health Organisation. Oral Health Surveys, Basic Methods. 4th ed. Geneva: World Health Organisation; 1997. p.39.
  10. Lohmann TG, Roche AF, Martorelli R. Anthropometric standardization reference manual. Chamaign, IL: Human Kinetics; 1988.
  11. World Health Organisation [Internet BMI-for-age. Cited 2013 May 24; Available from: html
  12. Benzian H, Monse B, Heinrich-Weltzien R, Hobdell M, MulderJ and Van Palenstein Helderman W. Untreated severe dental decay: a neglected determinant of low Body Mass Index in 12-year-old Filipino children. BMC Public Health. 2011; 11: 558
  13. Hark L, Morrison G (eds). Medical Nutrition and Disease: A Case-Based Approach, 4th ed. Oxford: Jon Wiley & Sons, 2009.
  14. Naidoo S, Myburgh N. Nutrition, oral health and the young child. Matern Child Nutr 2007; 3: 312–321.
  15. Psoter WJ, Reid BC and Katz RV. Malnutrition and Dental Caries: A Review of the Literature. Caries Res. 2005; 39(6): 441–447
  16. Cunningham-Rundles S, McNeeley DF, Moon A. Mechanisms of nutrient modulation of the immune response. J Allergy Clin Immunol 2005; 115: 1119–1128.





















Last Updated on 7 October 2015 by HPCSA Corporate Affairs