Effects of Parental Migration and the Caregiver’s Response to Health Advice on Oral Health of 6-to-8 Years Old Rural Children: A Cross-Sectional with Short Follow-up Study

Abstract

Background International and internal parental migration have been steadily increased with urbanization and globalization. Children with parental migration are called "left-behind children (LBC)". Parental migration has been shown to have a negative effect on the children's health and oral health. No studies have explored the complex association between parental migration and dental caries in children and examined the responses to professional advice on oral health care between caregivers of left-behind children (LBC) and non-left-behind children (NLBC). Understanding those will help policymakers develop a specific and effective policy and improve the healthcare services for left-behind children. Objectives The objectives of this study were 1) to compare the oral health behaviours between the 6-8-year-old children with different parental migration duration; 2) to investigate whether parental migration is associated with dental caries among 6-8-year-old children, and 3) to compare the responses to the dental professional advice of the caregivers of LBC and NLBC. Methods There were 2 parts to the study. Part I aims to answer objectives 1 and 2 and was the cross-sectional study. Moreover, Part II was a prospective cohort study for objective 3. This study population was children aged 6-8 years old. The sample size was calculated with a 5% replacement for the non-response total getting at least 466 children. It was conducted in 7 primary schools in three rural counties in Yunnan, China. The multi-level stratified cluster sampling was used to select the samples. The questionnaires were modified from the 4th National Oral Epidemiological Survey in China. Part I, the caregivers of all children were interviewed using structural questionnaire on demo-socioeconomic characteristics, children's oral health behaviours, and oral health care utilization. An oral health examination based on the criteria of the WHO oral health survey was conducted on children. The advice was given to caregivers after an oral health examination. After 2-3 months, the questionnaire regarding response to advice for self-care and professional care and the reasons were collected from the caregivers. The weighted descriptive statistics were used to estimate a representative oral health situation among the targeted population accounting for the cluster of the studied samples. A Chi-square test for survey data was used to compare the difference in outcome variables among parental migration durations. A Chi-squared test for trend in proportions for weighted proportions was performed to test a linear trend between dental caries and parental migration durations. The effect of parental migration on dental caries in children was analyzed by Structural Equation Modelling (SEM) to investigate the complex relationships between the exposures and outcomes as well as their mediators and confounders. Results Data were collected from 500 Chinese children aged 6-8-year-old with their caregivers. There were 191 children without parental migration (38.2%), 50 children with parental migration of less than 6 months (10%), 87 children with parental migration of 6 to 12 months (17.4%), and 172 children with parental migration of more than 12 months (34.4%). Primary caregivers of children with parental migration were more likely to be mothers or non-parents, had older ages, had lower than elementary school, and had no jobs. This study found a high prevalence and number of total caries (91.6% and 7.53 ± 4.27, respectively). The univariable analysis showed no significant differences in frequency of toothbrushing, fluoride toothpaste, dental attendance, and the number of dental caries (p > 0.05) but significant difference in the frequency of snacking consumption between different parental migration durations (p < 0.02). In addition, there was a statistically significant linear increase in caries prevalence in the primary teeth (dft) and total caries (DMFT + dft) with increased parental migration durations (p < 0.05). The SEM showed that after controlling for the socioeconomic status of the caregiver, there was an association between parental migration and dental caries in number of permanent teeth in the children through snack consumption. Longer parental migration duration and non-parental or single parent caregivers increased the snack frequency of the children, and consequently increased the risk of dental caries in number of permanent teeth. In part II, 389 children with their caregivers participated. It consisted of 183 NLBC (47%) with No or < 6 months of parental migration and 206 LBC (53.0%) with ≥ 6 months of parental migration. Significantly, more NLBC's than LBC's caregivers supervised their children for daily oral health behaviours or self-care (p < 0.04). About one-third of the caregivers took their children to visit the dentist after getting professional advice. There was no significant difference in response to the advice for professional care between LBC and NLBC's caregivers. The main reason for not bringing children to visit dentists was that caregivers thought that dental disease was not severe and the child had no pain. These reflected no concern about their children's oral health among most caregivers. Conclusions This study demonstrated that after controlling for SES, parental migration increases dental caries in number of permanent teeth in children through snacking frequency. Caregivers had good compliance with self-care or supervising children's daily oral health behaviours, but not professional care or bringing children to the dental clinic. There is a need to develop the policy and oral health promotion programs specific to the children and caregivers in parental migration families. More oral health education should provide to all caregivers in the rural families to raise oral health knowledge and awareness. Interdisciplinary cooperation research should conduct in this group to understand the impact of parental migration on children's health, oral health, and well-being.