Early dental caries is a relatively new form that describes rampant dental caries in infants and toddlers 1.
Dental caries is widely recognized as an infectious disease induced by diet. The main factors in the aetiology of the disease are (a) cariogenic bacteria, (b) fermentable carbohydrates, (c) a susceptible tooth and host and (d) time. However, in young children, bacterial flora and host defence systems are in the process of developing, tooth surfaces are newly erupted and may show hypoplastic defects, and their parents have to manage the dietary transition through breast/bottle feeding, first solids and childhood tastes 2. Recent Canadian reports suggest that the prevalence of early childhood caries may be ∼40–50%,but can be significantly higher in economically disadvantaged, first nations and emigrant populations 3. According to the WHO, iron deficiency is the most common and widespread form of nutritional deficiency worldwide 3. Iron-deficiency anaemia (IDA) is characterized by a defect in haemoglobin synthesis, resulting in red blood cells that are abnormally small (microcytic) and contain a decreased amount of haemoglobin (hypochromic). The capacity of the blood to deliver oxygen to body cells and tissues is thus reduced 4,5.
It was supposed that dental caries and its resulting discomfort and pain can interfere with proper nutrition, including iron intake, causing IDA 6; although major efforts have been initiated worldwide to reduce IDA and dental caries, both conditions continue to be common and are considered major health problems.
Aim of the work
The aim of this study was to examine the association between early dental caries and IDA in preschool children.
Patients and methods
This case–control study included 150 children. They were divided into two groups. The patient group included 100 children with early dental caries aged 2–6 years recruited from the outpatient dental clinic, Benha University hospitals. The control group included 50 caries-free healthy children. This study was carried out in the period from October 2012 to December 2013 after obtaining informed consents from their parents. Approval of the local ethical committee was obtained before initiating the study.
Apparently healthy 100 children aged 2–6 years with early dental caries.
- Acute or chronic illness.
- Known blood disease.
- Parasitic infestations by stool analysis.
- Children who had received iron multivitamin supplements in the last 3 months.
All groups were subjected to the following:
- Full assessment of history including personal history, history of age of first tooth eruption, family history of dental caries and IDA, nutritional habits, oral health, oral hygiene, dental habits including tooth brushing and socioeconomic status according to Fahmy and El-Sherbini 7.
- General examination including the following:
- Manifestation of iron deficiency; pallor, lack of concentration, pica and nail spooning 8.
- Manifestation of vitamin A deficiency: xeropthalmia, dry scaly skin, increased frequency of respiratory and diarrhoeal disease, growth retardation and defective enamel.
- Manifestation of vitamin B deficiency: irritability, angular stomatitis, glossitis, sleep disturbance, muscle cramps, red itchy eye and keratitis 9.
- Anthropometric measurements such as weight, height, BMI [BMI=weight (kg)/height (m)2], mid arm circumference and skin fold thickness using a skin fold VERNIER caliper.
- Local examinations of teeth were performed by a paediatric dentist to assess dental decay, number of teeth affected, pulpal affection and gum affection.
- Laboratory investigations including the following: complete blood count (CBC), haemoglobin, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and red cell distribution width (RDW).
- Measurement of serum iron, total iron-binding capacity and serum ferritin as they are key biochemical indicators of iron status.
- Measurement of serum albumin as an indicator of protein status.
- Stool analysis was carried out to exclude parasitic infestations.
Four millilitre samples were taken through venipuncture; 1 ml was preserved in a tube containing EDTA for CBC and analysed using Sysmex KX-21N (Japan) and 3 ml was preserved in a plain tube and left to coagulate. Then, serum was separated by centrifugation for 10 min and was stored at −20°C until the time of assay. Serum ferritin was measured using Abcam's ferritin (FTL) Human in-vitro enzyme-linked immunosorbent assay kit, das (Italy), plate reader A4 2006, and plate washer D1 979.
Normal laboratory reference values were adopted to determine whether each child had adequate or low concentrations of Hb, MCV, MCH, MCHC, serum iron, TIBC, serum ferritin and serum albumin. IDA was defined as Hb levels below 12 gm/dl, iron levels below 50 µg/dl and/or ferritin levels below 24 ng/ml. RDW more than 14.5% and MCV less than 80 fl 6. Participants were considered to be iron deficient if they had two out of three abnormal blood tests for Hb, ferritin and or MCV 10.
The collected data were analysed using the SPSS version 16 software (IBM, Chicago, Illinois, USA). Categorical data were presented as number and percentages whereas quantitative data were expressed as mean and SD. The χ2-test and the student (t) test were used as tests of significance. The level of significance in this work was set at 0.05 (P<0.05 was considered significant). Values of anthropometric measurements were converted into standardized values (Z scores) to determine the difference between the groups using the Mann–Whitney U-test for comparisons between them; P less than 0.05 was considered significant.
A total of 150 children were enrolled: 100 with early childhood caries (the patients group) and 50 caries-free children (the control group).
There were no significant differences between the patients and the controls in age (P=0.145), sex (P=0.142), age of first tooth eruption (P=0.942), residence, urban (P=0.158) and rural (0.158), and socioeconomic status (Table 1). Among the patient group, there was a significant increase in dental caries among children from urban areas than those from rural areas (P=0.047), and children from middle class families than those from low and high social class families (P=0.019) (Table 2).
In terms of the dietetic history, there was a significant decrease in dental caries considering the history of milk formula intake (P=0.001) and plant supplementation of iron (P=0.049), but no significant differences between the studied groups for history of breast milk feeding (P=0.708), intake of animal milk (P=0.438) and animal sources as a supplement of iron (P=0.466).
For some risk factors, there was no significant difference in excess sweet intake (P=0.639) whereas there was a significant increase in the number of siblings affected (P=0.014) and a significant decrease with the use of toothpaste (P=0.015) and plaque control (P=0.001) in patients than among the controls.
There was no significant difference between patients and controls in weight, height, mid arm circumference and skin fold thickness, but a significant decrease in BMI in the patients than the controls (P=0.002) (Table 3). In terms of manifestations of iron and other vitamins deficiencies, there was a significant increase in pallor (P=0.001), lack of concentration (P=0.001) and manifestation of vitamin A (P=0.001) and vitamin B (P=0.009) deficiency among patients than the controls, but no significant differences in nail spooning and pica.
Local examination of teeth of the studied children showed that there was a significant increase in gum affection (P=0.001) among the patients than the controls (Table 4).
For CBC, there was a significant decrease in Hb (P=0.024), red blood corpuscles (P=0.050), haematocrit (P=0.042), MCV (P=0.032), MCH (P=0.049) and MCHC (P=0.049), and a significant increase in RDW (P=0.050) among the patients than the controls, whereas no significant difference in the other CBC parameters (Table 5).
There was no significant difference between the patients and the controls in serum albumin (P=0.636) whereas there was a significant decrease in serum iron (P=0.014) and serum ferritin (P=0.001), with a significant increase in TIBC (P=0.006), in the patients than the controls (Table 5).
There were significant negative correlations between Hb (P=0.008), serum iron (P=0.006) and serum ferritin (P=0.009) with the number of teeth affected whereas there were no significant correlations between age (P=0,745), socioeconomic class (P=0.096), weight (P=0.526), BMI (P=0.635), skin fold thickness (P=0.699), serum albumin (P=0.285) and number of teeth affected (Figs 1–3).
This study was carried out to explore the relation between early dental caries and nutritional status including IDA in children.
In this study, in terms of demographic data such as age and sex, there were no significant differences between the two groups (patients and controls), which is in agreement with the results reported by Shaoul et al.6 and Schroth et al.11.
In this study, there was no significant increase in dental caries with age, in contrast to the result obtained by Schroth and Cheba 3, who reported that the prevalence of early childhood caries increases with age; this may be attributed to the fact that children who visit the dentist at later ages have more teeth for longer lengths of time, increasing their odds of developing decay.
In the patient group, there was a significant increase in dental caries in children from urban areas than those from rural areas (P=0.047); this may be attributed to excess intake of sweets and fast food in urban areas than rural areas, which is not in agreement with the results of Schroth and Cheba 3 and Mattila et al.12. They found increased incidence of early childhood caries in children from rural areas. This may be attributed to shared patterns of poor health in these communities including chronic health conditions, infant and maternal health problems, presence of communicable diseases and injury.
In terms of socioeconomic status in the patient group, there was a significant increase in the incidence of dental caries in children from middle class families than those from low and high social class families; this may be attributed to poor eating habits of intake of fast food and excess sweets. This was not in agreement with the results of Schroth and Cheba 3, Hooley et al.13, Gerdin et al.14, Hongl et al.15 and Marshall 16, who showed that lower socioeconomic status was associated with a risk of higher caries, which might be attributable to the low parental education level and limited access to services and support, associated with low socioeconomic status 3.
In this study, there was no significant difference between the two groups in weight and height and this is in agreement with Shaoul et al.6, but Acs et al.17, reported that children with early dental caries had lower mean weights than caries-free children, suggesting that children with early dental caries had inadequate caloric consumption.
In terms of BMI, in this study, there was a significant decrease in the patients than in the controls, in agreement with Shaoul et al.6, who found significantly lower BMI values in the study group. Hooley et al.13 showed three main patterns of relationships between dental caries and BMI; in 23 of their 48 studies, they found no association between BMI and dental caries, in another 17 studies, they found a positive relationship between them and in the last eight studies, they found an inverse relationship. They suggested that methodological factors including sample demographics, the sensitivity of the dental examination and the nature of the data analyses carried out influence whether or not an association is detected.
In this study, in terms of dietetic history, there was a significant decrease in dental caries in children with a history of milk formula intake and plant supplementation of iron, but no significant differences between the groups studied in history of breast milk feeding, intake of animal milk and animal source as a supplement of iron. The difference between the plant and the animal source of iron may be attributed to easy mastication of the plant source compared with difficult mastication of red meat because of pain, which affects efficiency of mastication.
In this study, in terms of some risk factors of dental caries, there was a significant increase in siblings affection and a significant decrease with the use of toothpaste and plaque control among the patients than the controls; this is in agreement with Schroth and Cheba 3, who showed that early childhood caries is prominent in children with limited access to care.
This might be attributable to the following:
- Siblings share the same quality of life; also, dental caries is an infectious disease.
- Frequent tooth brushing decreases fermentable carbohydrates, which is a good medium for dental caries.
- Dental care by frequent visits to dental clinics enables early treatment of minor dental problems.
In this study, in terms of manifestations of iron and deficiency of other vitamins, there was a significant increase in pallor, lack of concentration and manifestations of vitamin A and vitamin B deficiency, and a non significant difference in nail spooning and pica between both groups, which is in agreement with Oliveria et al.18, who reported that children with severe early childhood caries (S-ECC) also have deficiency in important vitamins and nutrients.
In this study, there was a significant increase in gum affection in the patients than in the controls on local examination of teeth.
In the present study, for CBC, there was a significant decrease in Hb and MCV, and a significant increase in RDW in the patients than in the controls, but no significant difference between them in platelets and WBC; this is in agreement with Shaoul et al.6. Also, Schroth et al.11 reported that children with S-ECC had significantly lower mean Hb levels than controls.
In this study, there was a significant decrease in serum iron and serum ferritin in patients than controls, and this is in agreement with Shaoul et al.6, who reported a significant relationship between rampant caries during childhood and low ferritin level; this may be attributed to either pain during mastication and therefore decreased consumption of iron-enriched food or secondary to the inflammatory process of caries. Also, Clarke et al.10 found that the majority of S-ECC had evidence of inadequate iron and low serum ferritin, but Ramos-Gomez et al. 19 showed that there was no relation between early childhood caries and iron deficiency. This could be attributable to differences in the severity of caries.
In this study, for serum albumin, there was no significant difference between both groups; this might be attributed to the fact that malnutrition was not severe enough to affect the level of serum albumin, and this is in agreement with Shaoul et al.6, but not in agreement with Schroth et al.11.
Finally, there were significant negative correlations between Hb, serum iron and serum ferritin with the number of affected teeth, and non significant correlations between age, socioeconomic status, weight, BMI, skin fold thickness, serum albumin and number of affected teeth.
This indicates the relation between early childhood caries and iron deficiency, and may be explained as follows:
One hypothesis is that the low haemoglobin levels often observed in S-ECC children may be attributed to the body’s inflammatory response, which may accompany rampant forms of dental caries (especially those involving pulpitis or abscesses) as this inflammation may trigger a series of events that ultimately lead to the production of cytokines, which may, in turn, inhibit erythropoiesis and thus reduce the level of haemoglobin in the blood 20. It is also recognized that the pain experienced by children with S-ECC may lead to altered eating habits 21 and to nutritional deficiencies such as low iron levels. In addition,differences in nutritional status between caries-free children and those with S-ECC may also be governed by household economics. Limited funds may restrict a family’s ability to purchase nutritious foods. Low socioeconomic status is known to be associated with an increased risk for anaemia 21.
Early dental caries had an impact on iron status in preschool children, resulting in significantly greater odds of developing IDA.
Thus, the iron profile of children with early dental caries should be evaluated , and they should receive iron supplementations and a diet rich in animal and plant sources of iron.
Also, parents should be advised to take their children to dental clinics and encouraged to adopt hygienic measures among family members as dental caries is an infectious disease.
Finally, primary care providers and dentists should be aware of this oral–systemic relationship.
Conflicts of interest
There are no conflicts of interest.
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