Background
With the fast economic development, the internal migrant population in China who generally moved from the countryside to the city has grown rapidly. Guangdong Province has become the largest migrant population province, and has an extensive underage migrant population. Guangzhou is the capital of Guangdong Province, and represents one of the most developed cities in southern China. According to the 2010 data, the total of 2.738 million migrant children under 14 years old in Guangdong Province accounted for 12.0% of the national total, and approximately 20% of the school-age migrant children living in Guangzhou [
1]. The government has come to realize the large quantity of migrant children and has embarked on improving their physical and mental health. School-based health education has been implemented, focusing especially on oral health [
2].
Dental caries is one of the most common preventable childhood diseases and the most common chronic diseases worldwide, which greatly affects the children’s general health and quality of life [
3]. The caries status in China exhibits characteristics typically found in developing countries [
4,
5]. Specifically, carious teeth are left untreated among 97% of children aged 5 and 89% of children aged 12 [
6].This situation has barely improved, despite the economic development and oral health-care resource provision [
7]. In China, rural children always have a lower level of oral health than urban children [
8]. The oral health status among rural–urban migrant children may be even worse considering their relatively poor family economic status, less concern from parents, and limited basic health care. By 2011, the overall caries prevalence among rural–urban migrant children in South China was 85.5%, significantly higher than the averages statistics for both rural and urban areas [
9].
Adequate oral health knowledge and parental practices including caries attention and diet guidance are essential to equip children with appropriate oral health behaviors [
10‐
13]. A follow-up investigation is necessary and urgent to society’s increased attention to migrant children and the launch of related health planning policies in China [
14]. However, information about oral health knowledge, behaviors and parental practices among rural–urban migrant children are still scare. No longitudinal studies on the changes and influencing factors for changes in oral health knowledge and behaviors among migrant children have ever been conducted in China. Therefore, the objectives of the present study were: (1) to describe changes in terms of oral health knowledge, behaviors and parental practices over a period of one year; and (2) to investigate the possible factors influencing the changes of oral health knowledge as well as behaviors, including oral hygiene and dietary habits among migrant children.
Results
Demographic distribution of migrant children in five private primary schools
Table
1 shows the demographic information of the 1042 migrant children in the baseline survey. For migrant children, the average age was 9.56 ± 1.00and the gender ratio was 1.33:1 (boys: girls), respectively. The majority had one or more siblings (90.60%). More than half of the migrant children were born in Guangdong Province. Furthermore, 72.08% of the floating children had moved to Guangzhou before they went to the primary school (under six years old), and 65.36% of families were in median or poor economic status. With regard to gender differences, more boys came from other provinces, and girls were more likely to have good living conditions.
Table 1
Demographic distribution of migrant children in the baseline survey in 2011
Sample size | 1042 (100) | 594 (57.01) | 448 (42.99) | |
Age (year), mean ± sd | 9.56 ± 1.00 | 9.67 ± 1.02 | 9.41 ± 0.94 | <0.001 |
Grade | | | | 0.067 |
3 | 501 (48.08) | 271 (45.62) | 230 (51.34) | |
4 | 541 (51.92) | 323 (54.38) | 218 (48.66) | |
Siblings | | | | 0.398 |
0 | 98 (9.40) | 62 (10.44) | 36 (8.03) | |
1-2 | 590 (56.62) | 330 (55.55) | 260 (58.04) | |
3 or more | 354 (33.98) | 202 (34.01) | 152 (33.93) | |
Place of birth | | | | 0.037 |
Guangdong Province | 559 (53.65) | 302 (50.84) | 257 (57.37) | |
Other Province | 483 (46.35) | 292 (49.16) | 191 (42.63) | |
Age at moving to Guangzhou | | | | 0.055 |
0 ~ 3 | 413 (39.64) | 228 (38.38) | 185 (41.29) | |
3 ~ 6 | 338 (32.44) | 183 (30.81) | 155 (34.60) | |
6 and above | 291 (27.92) | 183 (30.81) | 108 (24.11) | |
Family economic status | | | | 0.007 |
Good | 361 (34.64) | 182 (30.64) | 179 (39.96) | |
Median | 555 (53.26) | 335 (56.40) | 220 (49.11) | |
Poor | 126 (12.10) | 77 (12.96) | 49 (10.93) | |
Accuracy of oral health knowledge of migrant children in 2011 and 2013
The mean accuracy of oral health knowledge in 2013 in migrant children was 59.42%, which was higher than that in the 2011 survey (53.17%;
p < 0.001). Table
2 shows a comparison of the accuracy of each item between two surveys, which ranged from 16.22 to 82.05% in 2011 and from 13.05 to 90.79% in 2013. Over a one-year period, the item, “Eating sweets in the bedtimes can lead to cavities,” received the most beneficial change.
Table 2
The accuracy of caries-related knowledge of rural–urban migrant children (n =1042)
Eating sweets in the bedtimes can lead to cavities | 69.67 | 89.73 | 20.06 | <0.001 |
Frequently eating vegetables can lead to cavities | 71.59 | 90.79 | 19.20 | <0.001 |
Failure to brush teeth in the morning and evening can cause tooth decay | 70.44 | 88.96 | 18.52 | <0.001 |
Irregular arrangement of teeth can cause tooth decay | 77.06 | 88.58 | 11.52 | <0.001 |
Hard toothbrush is harmful to teeth | 82.05 | 88.68 | 6.63 | <0.001 |
Cavities should be treated in time | 16.51 | 22.65 | 6.14 | <0.001 |
Drinking milk is good for tooth development | 16.22 | 21.31 | 5.09 | 0.002 |
Cavities will affect the general health | 75.82 | 80.52 | 4.70 | 0.009 |
Toothbrushes should be replaced at least every three months | 27.74 | 32.15 | 4.41 | 0.019 |
The most important time to brush teeth is during nighttime | 28.02 | 25.34 | −2.68 | 0.123 |
Fluoride toothpaste can prevent cavities | 78.98 | 71.50 | −7.48 | <0.001 |
Failure to drink milk can lead to cavities | 23.61 | 13.05 | −10.56 | <0.001 |
Only about one-fifth of the sample realized that milk is good for dental health (n = 222; 21.31%) and that cavities should be treated in time (n = 236; 22.65%); these data were different from the data in the 2011 survey (n = 169; 16.22% and n = 172; 16.51%, respectively). Approximately, 32% of respondents knew that toothbrushes should be replaced at least every three months, which was also different from the previous survey results (n = 289;27.74%). The accuracy of the items “Fluoride toothpaste can prevent cavities” and “Failure to drink milk can lead to cavities” decreased in the 2013 survey (p < 0.001). Additionally, no difference in the item “The most important time to brush teeth is during nighttime” was found. Regarding most of the knowledge items, the correct rates in 2013 were significantly higher than those in 2011.
Oral health behaviors of migrant children in 2011 and 2013
Responses to selected questions about oral health behaviors, including oral hygiene and dietary habits, are shown in Table
3. The percentage of migrant families who had their own toothbrush and cup increased from 56.14 to 67.37% in one year. In the baseline survey, 44.72% of migrant children were found to brush their teeth incorrectly, using methods such as horizontal brushing, vertical brushing, and casual brushing. However, one year later, the proportion dropped to 33.88%. Nearly half of the migrant children (
n = 513; 49.23%) brushed their teeth for less than two minutes per time in 2011; this number was higher than that in 2013 (
n = 455; 43.66%). The majority of respondents gargled after a meal (
n = 403; 41.27%), which was not significantly different from the results of the 2011 survey (
n = 455; 43.67%). Almost a fifth of the migrant children (
n = 212; 20.36%) brushed their teeth less than once per day, which differed from the results of the 2011 survey (
n = 157; 15.07%).
Table 3
Oral hygiene and dietary habits among migrant children in 2011 and 2013 (n =1042)
Oral hygiene |
Total score | 13.98 ± 2.25 | 14.30 ± 2.19 | 0.32 ± 2.72 | <0.001 |
Can each family member have their own toothbrush and cup? | 3.37 ± 0.87 | 3.58 ± 0.71 | 0.21 ± 1.02 | <0.001 |
Yes | 56.14% | 67.37% | | |
Sharing cup | 31.48% | 26.30% | | |
Sharing toothbrush | 5.66% | 3.07% | | |
Sharing toothbrush and cup | 6.72% | 3.26% | | |
Which manner are you using to brush your teeth every day? | 3.09 ± 1.13 | 3.29 ± 1.09 | 0.20 ± 1.42 | <0.001 |
Casual brushing | 13.82% | 11.90% | | |
Vertical brushing | 12.48% | 8.64% | | |
Horizontal brushing | 18.42% | 13.34% | | |
Vertical brushing with horizontal vibration | 55.28% | 66.12% | | |
How long each time do you brush your teeth? | 2.57 ± 0.97 | 2.68 ± 0.92 | 0.11 ± 1.21 | 0.004 |
Less than one minute | 14.59% | 9.88% | | |
1-2 minutes | 34.64% | 33.78% | | |
2-3 minutes | 30.23% | 35.12% | | |
More than three minutes | 20.54% | 21.22% | | |
Do you rinse your mouth after a meal? | 1.56 ± 0.50 | 1.59 ± 0.49 | 0.02 ± 0.62 | 0.213 |
Yes | 56.33% | 58.73% | | |
No | 43.67% | 41.27% | | |
How many times do you brush teeth each day? | 3.38 ± 0.78 | 3.17 ± 0.76 | −0.21 ± 1.01 | <0.001 |
None | 1.63% | 0.78% | | |
Once | 13.44% | 19.58% | | |
Twice | 29.94% | 41.94% | | |
Three times or more | 54.99% | 38.00% | | |
Dietary habits |
Total score | 10.33 ± 2.33 | 10.61 ± 2.15 | 0.28 ± 2.62 | 0.001 |
How often do you eat chocolate pie or cream cake? | 1.96 ± 0.74 | 2.08 ± 0.66 | 0.12 ± 0.91 | <0.001 |
Always eat | 29.27% | 18.33% | | |
Sometimes eat | 45.59% | 55.66% | | |
Rarely eat | 25.14% | 26.01% | | |
How often do you eat carbonated beverage? | 2.00 ± 0.73 | 2.10 ± 0.65 | 0.10 ± 0.84 | <0.001 |
Always eat | 26.58% | 16.31% | | |
Sometimes eat | 47.22% | 57.39% | | |
Rarely eat | 26.20% | 26.30% | | |
How often do you eat cheese? | 2.19 ± 0.73 | 2.25 ± 0.72 | 0.06 ± 0.92 | 0.026 |
Always eat | 19.19% | 16.22% | | |
Sometimes eat | 43.09% | 42.71% | | |
Rarely eat | 37.72% | 41.07% | | |
How often do you eat candy? | 2.16 ± 0.71 | 2.20 ± 0.63 | 0.04 ± 0.84 | 0.113 |
Always eat | 18.81% | 11.90% | | |
Sometimes eat | 46.55% | 56.24% | | |
Rarely eat | 34.64% | 31.86% | | |
How often do you eat ice cream or butter? | 2.03 ± 0.72 | 1.98 ± 0.68 | −0.05 ± 0.90 | 0.106 |
Always eat | 24.57% | 24.09% | | |
Sometimes eat | 48.18% | 53.65% | | |
Rarely eat | 27.25% | 22.26% | | |
With respect to dietary habits of migrant children, the numbers (percentages) of children who always consumed sweet foods in 2013 were as follows: 191 (18.33%) for chocolate pie or cream cake, 170 (16.31%) for carbonated beverage, 169 (16.22%) for cheese, 124 (11.90%) for candy, and 251 (24.09%) for ice cream or butter. The frequency of eating chocolate pie or cream cake, carbonated beverage and cheese significantly decreased since the 2011 survey (p <0.05).
Parental practices among migrant children in 2011 and 2013
Table
4 reveals responses to questions on parental practices, including attention to children’s caries and diet guidance. Approximately 17.66% of migrant children indicated that their parents rarely paid attention to their teeth, which was different from the 2011 survey (
n = 271; 26.01%). Additionally, 34.84% of parents dealt with their children’s toothache and caries with a negative attitude. A year later, the proportion was still 30.71%. The mean score of parental attention was 4.67 ± 1.13 and 4.84 ± 1.05, with a significant difference observed between two years (
p < 0.05).
Table 4
Parental practices among migrant children in 2011 and 2013 (n =1042)
Parental attention to children’s caries |
Total score | 4.67 ± 1.13 | 4.84 ± 1.05 | 0.17 ± 1.31 | <0.001 |
Will your parents always pay attention to whether you have caries? | 2.14 ± 0.80 | 2.23 ± 0.73 | 0.09 ± 0.95 | 0.002 |
Always | 39.64% | 40.69% | | |
Sometimes | 34.35% | 41.65% | | |
Rarely | 26.01% | 17.66% | | |
If you have pain with your teeth or have caries, which of the following measures will your parents take? | 2.53 ± 0.70 | 2.61 ± 0.64 | 0.08 ± 0.86 | 0.003 |
Take you to the hospital and follow the doctor’s recommendations | 65.16% | 69.29% | | |
Left unchecked, or be ignored | 12.09% | 8.25% | | |
Depending on the state | 22.75% | 22.46% | | |
Parental diet guidance |
Total score | 12.02 ± 3.14 | 12.29 ± 3.43 | 0.27 ± 4.01 | 0.032 |
Do your parents often give you money for snacks? | 3.67 ± 1.10 | 3.80 ± 1.10 | 0.13 ± 1.34 | 0.002 |
Always | 3.74% | 4.80% | | |
Usually | 10.65% | 7.58% | | |
Often | 27.93% | 20.15% | | |
Sometimes | 29.94% | 37.43% | | |
Rarely | 27.74% | 30.04% | | |
When your parents give you money, do they tell you what to buy? | 2.54 ± 1.38 | 2.64 ± 1.52 | 0.10 ± 1.93 | 0.092 |
Always | 11.42% | 18.62% | | |
Usually | 14.78% | 13.05% | | |
Often | 23.61% | 16.79% | | |
Sometimes | 16.99% | 17.08% | | |
Rarely | 33.20% | 34.46% | | |
Do your parents often supervise what kind of snacks you buy? | 2.68 ± 1.43 | 2.71 ± 1.53 | 0.04 ± 1.91 | 0.538 |
Always | 15.36% | 20.35% | | |
Usually | 15.16% | 13.63% | | |
Often | 21.88% | 15.16% | | |
Sometimes | 16.99% | 18.71% | | |
Rarely | 30.61% | 32.15% | | |
Do you often discuss how to eat is a healthy diet at home with your parents? | 3.13 ± 1.36 | 3.13 ± 1.39 | 0.00 ± 1.77 | 0.986 |
Always | 21.02% | 22.46% | | |
Usually | 20.44% | 20.44% | | |
Often | 25.91% | 21.11% | | |
Sometimes | 16.12% | 19.87% | | |
Rarely | 16.51% | 16.12% | | |
No significant changes were observed in parental diet guidance, including informing and supervising what their children buy and eat. Nearly 67.47% of parents sometimes or rarely gave their children money for snacks; this number was higher than that in 2011 (n = 601; 57.68%). The mean score of migrant children’s parental diet guidance was 12.02 ± 3.14 and 12.29 ± 3.43, with a significant difference observed between the two years (p < 0.05).
Factors for changes of oral health knowledge, behaviors and dietary habits among migrant children
The results of ordinal logistic regression are presented in Table
5. All models presented a good fit (
p < 0.001): The parallel line test could not reject the null hypothesis (
p > 0.05) and the Pearson chi-square goodness-of-fit measure was always non-significant. These summary measures suggested satisfactory ordinal logistic regression models [
15].
Table 5
Ordinal logistic regression analysis for changes of oral health knowledge, oral hygiene and dietary habits
Intercept1 (Beneficial change) | 3.93 | 0.001 | . | 7.83 | <0.001 | . | 5.37 | <0.001 | . |
Intercept2 (No change) | 5.04 | <0.001 | . | 8.65 | <0.001 | . | 6.32 | <0.001 | . |
Age (year) | −0.06 | 0.475 | 0.94 (0.79,1.12) | −0.05 | 0.555 | 0.95 (0.81,1.12) | 0.03 | 0.758 | 1.03 (0.87,1.21) |
Gender |
Boy | 0.07 | 0.610 | 1.08 (0.81,1.42) | 0.09 | 0.502 | 1.10 (0.84,1.44) | 0.09 | 0.512 | 1.09 (0.84,1.42) |
Girl | Reference | . | . | Reference | . | . | Reference | . | . |
Grade |
3 | −0.11 | 0.518 | 0.89 (0.64,1.26) | −0.02 | 0.909 | 0.98 (0.70,1.36) | 0.16 | 0.341 | 1.17 (0.85,1.61) |
4 | Reference | . | . | Reference | . | . | Reference | . | . |
Age at moving to Guangzhou |
0 ~ 3 | 0.17 | 0.353 | 1.18 (0.83,1.67) | −0.10 | 0.546 | 0.90 (0.65,1.26) | −0.26 | 0.113 | 0.77 (0.55,1.06) |
3 ~ 6 | 0.10 | 0.570 | 1.11 (0.78,1.58) | −0.01 | 0.968 | 0.99 (0.70,1.40) | 0.04 | 0.815 | 1.04 (0.75,1.45) |
6 and above | Reference | . | . | Reference | . | . | Reference | . | . |
Siblings |
0 | −0.05 | 0.845 | 0.95 (0.58,1.56) | −0.30 | 0.235 | 0.74 (0.45,1.21) | −0.21 | 0.382 | 0.81 (0.50,1.30) |
1-2 | 0.10 | 0.526 | 1.10 (0.82,1.47) | −0.02 | 0.880 | 0.98 (0.73,1.30) | 0.01 | 0.926 | 1.01 (0.77,1.34) |
3or more | Reference | . | . | Reference | . | . | Reference | . | . |
Family economic status |
Good | −0.04 | 0.862 | 0.96 (0.60,1.54) | −0.21 | 0.381 | 0.81 (0.51,1.29) | 0.34 | 0.145 | 1.40 (0.89,2.21) |
Median | −0.19 | 0.421 | 0.83 (0.53,1.31) | 0.22 | 0.342 | 1.24 (0.80,1.93) | 0.12 | 0.590 | 1.13 (0.73,1.74) |
Poor | Reference | . | . | Reference | . | . | Reference | . | . |
Place of birth |
Other Province | 0.09 | 0.537 | 1.09 (0.83,1.44) | 0.15 | 0.285 | 1.16 (0.88,1.52) | 0.14 | 0.300 | 1.15 (0.88,1.49) |
Guangdong Province | Reference | . | . | Reference | . | . | Reference | . | . |
Oral health knowledge
|
Baseline score | 0.96 | <0.001 | 2.61 (2.33,2.93) | −0.01 | 0.888 | 0.99 (0.92,1.07) | −0.02 | 0.597 | 0.98 (0.91,1.05) |
Oral health behaviors
|
Baseline score of oral hygiene | −0.06 | 0.097 | 0.95 (0.88,1.01) | 0.68 | <0.001 | 1.96 (1.81,2.13) | 0.02 | 0.556 | 1.02 (0.96,1.08) |
Baseline score of dietary habits | −0.04 | 0.189 | 0.96 (0.91,1.02) | 0.05 | 0.103 | 1.05 (0.99,1.11) | 0.58 | <0.001 | 1.79 (1.66,1.92) |
Parental practices
|
Baseline score of attention to children’s caries | −0.09 | 0.181 | 0.92 (0.81,1.04) | −0.19 | 0.003 | 0.82 (0.73,0.93) | −0.07 | 0.264 | 0.93 (0.83,1.05) |
Baseline score of dietary guidance | −0.04 | 0.090 | 0.96 (0.92,1.01) | −0.06 | 0.012 | 0.95 (0.91,0.99) | −0.06 | 0.007 | 0.94 (0.90,0.98) |
The children with less oral health knowledge in the baseline were more likely to achieve significantly positive changes in their knowledge score (p<0.001) in the final survey. Migrant children who had worse performance on oral hygiene (beta estimate = 0.68, p < 0.001) and a higher frequency of consuming sugar-containing food (beta estimate = 0.58, p < 0.001) in the baseline survey were more likely to obtain beneficial changes. Regarding parental practices, children whose parents paid more attention to children’s caries (beta estimate = −0.19, p = 0.003) and gave children more reasonable dietary guidance (beta estimate = −0.06, p = 0.012) were more likely to receive beneficial changes in oral hygiene after one year. Meanwhile, children with parents who gave reasonable dietary guidance were less likely to frequently consume sugar-containing food (beta estimate = −0.06, p = 0.007) in 2013. No significant associations between demographic characteristics and changes in oral health knowledge and behaviors (p > 0.05) were observed.
Discussion
Limited data are available to analyze and supervise oral health knowledge, behaviors and parental practices among rural–urban migrant children in China. In general, the situation of oral health knowledge, behaviors and parental practices among migrant children significantly improved during the study, but the overall level was still poor at the follow-up evaluation. Our results showed that oral health knowledge, behaviors and parental practices in the baseline survey were associated with changes of oral health knowledge and behaviors (including oral hygiene and dietary habits) one year later. Migrant children with less oral health knowledge and worse performance on oral behaviors in the baseline were more likely to achieve significantly positive changes. Our findings also confirmed that parental attention to caries and reasonable dietary guidance were related to beneficial changes in the final survey.
The average awareness rate of oral health knowledge was 53.17% among migrant children in the 2011 survey. However, limited studies regarding the level of oral health knowledge of migrant children in China are available. Most previous studies explored the difference between children in urban and rural areas [
8,
14]. Compared with previous studies, the level of oral health knowledge among migrant children in Guangzhou is not optimistic. For example, 70.44% children knew that brushing teeth can protect from dental decay while the corresponding percentage in Ethiopia was 85% [
16]. Only 27.74% had accurate knowledge on the importance of replacing the toothbrush at least every three months, which was lower than the rate in Nepal [
17]. A total of 75.82% of the respondents were aware that dental caries can affect general health, whereas only 16.51% understood that cavities should be treated in time. The level of oral health knowledge increased significantly since the survey in 2011. The reason for the improvement may be related to the existing school-based oral health education programs conducted by the government in Guangzhou, such as teacher training, oral health lectures and knowledge competitions. However, the correct rate of the following two questions, “Fluoride toothpaste can prevent cavities,” and “Failure to drink milk can lead to cavities,” decreased significantly. This finding suggests that certain sorts of knowledge (e.g. the above two) may be less emphasized or even ignored in the current health education programs. A more comprehensive design for health education programs from the government and school is needed to promote the oral health knowledge of migrant children.
Given the lack of oral health knowledge, the majority of migrant children in our study had unhealthy oral behaviors. Approximately 15.07% of migrant children in the baseline survey reported that they brushed their teeth once a day or had never cleaned their teeth over the last month. Nearly half of the respondents brushed their teeth in an incorrect manner and for less than two minutes only. About 43.86% of children shared brushing tools with their family members. These proportions of unhealthy oral behaviors were higher than those found in central and northern China [
13,
18] and several other developing countries [
17,
19,
20]. The findings may result from poor oral health knowledge among migrant children and insufficient concern from their parents. Over a period of one year, albeit not always statistically significantly, most of oral hygiene behaviors achieved beneficial changes. Migrant children tended to improve the most in their performance on sharing brushing tools with family members, but the least in frequent brushing. Regular and frequent brushing shall be promoted, considering that brushing is the most common and effective method to mechanically remove plaque and white scale [
21], and that brushing teeth at least twice a day can more effectively remove plaque and maintain oral hygiene [
22]. Overall, oral health education programs should focus on teaching migrant children to brush regularly and correctly and not to share brushing tools with others. Regarding the dietary habits of migrant children, the frequency of consuming sweet-containing food was lower than that of urban children in China [
13] and several other developed countries [
23]. Moreover, the frequency of consuming chocolate pie or cream cake, carbonated beverage and cheese tended to decrease significantly in the 2013 survey. These findings might be partly explained by the low income among migrant families, who were limited in their financial capabilities to purchase sugar and snacks. To some extent, these situations can help maintain and promote oral health in migrant children.
Previous studies illustrated that the practices of caregivers could influence the health behaviors of their cared [
13,
24]. This study showed that the parental practices towards their migrant children, including attention to their children’s caries and dietary guidance, were relatively negative. Only 39.64% of parents were always concerned with the oral health of their children. Nearly a third of parents preferred to ignore children’s toothache and caries development. The dental caries of migrant children did not receive prompt treatment, similar to the situation in most developing countries [
17,
25,
26]. This situation had improved in 2013 but was still unsatisfied. These results could be partly explained by the poor economic condition, the lack of medical resources, and the social and cultural isolation of migrant children’s parents. Given the intense life and work pressures, communication between parents and their migrant children is less effective than that of local residents, which reduces the influence of parents on children’s health behaviors [
27]. With regard to diet, low income allows only 3.74% of migrant parents to always give their children money for snacks, which to some extent prevents the incidence of unhealthy dietary habits. However, only 11.42% and 15.36% of the parents always supervised the purchase choices of their children. These findings indicated that fewer migrant parents could provide their children with reasonable diet guidance, and such situation did not significantly improve in the finial survey. It is thus recommended that the future health education programs should cover relevant workshops or lectures to improve the migrant parental practices regarding dental health.
Oral health knowledge and behaviors are influenced by many factors. This study shows that the level of oral health knowledge, behaviors and parental practices at the baseline significantly affected the changes of the oral health knowledge, oral hygiene and dietary habits of migrant children in the final survey. The association between oral health knowledge and oral behaviors has also been confirmed in many other studies [
28‐
30]. In the present study, our findings suggest that children with less oral health knowledge were more likely to achieve significantly positive changes one year later. Thus, health education programs should target the different between migrant children with various levels of oral health knowledge, and the dental health curriculum content should be designed depending on the children’s current oral health knowledge. Additionally, we found that migrant children who had a relatively worse performance on oral health behaviors and dietary habits tended to increase their oral hygiene behaviors and to consume sugary food rarely. These findings suggest that school-based dental health programs should pay particular attention to the children with worse oral hygiene and dietary habits, because they are more likely to achieve beneficial changes. Significant associations between the changes of oral behaviors and parental practices were observed; this finding correlates with other studies reporting that parental oral behaviors and attitudes are related with the oral health of children [
26,
31,
32]. Migrant children with less parental attention and unreasonable dietary guidance were less likely to achieve beneficial changes in the final survey, indicating that increasing parental practices could positively influence the oral behaviors and dietary habits of migrant children. However, the status quo is that migrant children always experience ineffective communication with parents who are often busy working and confronted with poor living conditions. Migrant children and their parents should both take part in health education programs by strengthening the communication in family members to raise oral health knowledge and promote healthy oral behaviors.
Limitations of this study should be noted. First, five migrant children’s schools were selected by purposive sampling owing to the instability and overcrowding of migrant children. Despite the limitation of sampling, our communication with the local administration and education organizations suggest that the five schools are typical migrant schools in terms of tuition fee, geographic location, and students’ demographic and socioeconomic profiles. Second, the oral health-related behaviors were self-reported, which might be subject to recall bias. Third, a high follow-up loss, which was mostly attributed to the high mobility and instability of the migrant population, was observed. However, no significant differences were found in characteristics (age, sex, family economic status, the baseline scores of oral health knowledge, etc.) between the children who were followed up throughout the study and those who dropped out during the follow-up.
Acknowledgements
The study was supported by the Guangzhou Women's Federation. The authors appreciate the support of the participating school and the assistance of the school teachers and the staff members.