Effectiveness of Visual Pedagogy-assisted Tooth-brushing Training Among Preschoolers With Special Needs for Oral Health Promotion
Phase: NA
Conditions: Intellectual Disability, Cerebral Palsy, Developmental Disorders, Developmental Delay, Autistic Spectrum Disorders, Down Syndrome, Epilepsy, Developmental Disability, Learning Disorders
Sponsor: The University of Hong Kong

Cover Page  
 
 
 
 
Official Title: 
 
Effectiveness of visual pedagogy-assisted tooth-brushing training among 
preschoolers with special needs for oral health promotion 
 
 
 
 
 
 
 
Date: 2015.11.22

Background 
Children with special needs are those who have physical, mental, sensory, behavioral, 
emotional, and chronic medical conditions that requires health care beyond that considered 
routine and which involves specialized knowledge, increased awareness, attention, and 
accommodation (Saravanakumar, et al.,2013). 
Previous studies showed that people with special needs, such as intellectual disability, had poor 
oral health (Yuki Oda, et al., 2015), exhibiting a higher risk of developing caries than normal 
individuals. Although sealant, fluoride, and oral hygiene maintenance are effective ways to 
prevent dental caries, 30% of mental impaired patients have never received dental treatment 
(Oliveira et al., 2013). Individuals with disability have a significantly reduced ability to 
understand new or complex information (Ayub M, et al., 2015), and it is hard for them to 
cooperate with dental treatment (Maeda S, et al., 2005). Blomqvist et al. also demonstrated that 
children with learning problems had significantly more dental behavior management problems 
compared with a control group (Blomqvist M., et al., 2004), which would make routine dental 
care less achievable, resulting in poor oral health and the progression of existing oral diseases 
(Chang et al., 2014). Most of the dental diseases are originated by plaque, and increasing 
numbers of studies about oral health promotions are focused on plaque control, such as 
utilization of antibacterial agents, and special cleaning devices. Among them, the mechanical 
means for plaque control are much safer and more practical (Garbin C., et al. 2009). In addition, 
Liu Z et al. showed that toothbrushing more than twice a day is one of the caries-protective 
factors experience in disabled children (Liu Z., et al. 2014). Toothbrush is a universally 
accepted method for oral hygiene promotion among children with special needs. However, 
majority of children show noncompliance toward brushing and they try to hide themselves 
from daily brushing task, because they considered it as tedious procedure and dislike the 
brushing (Ganesh M., 2012). As for children with special needs, the situation is much worse. 

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Researchers have used visual pedagogy to show a structured method and technique of tooth 
brushing by series of pictures. The pictures were placed in the bathroom or wherever tooth 
brushing was performed, and the visual pedagogy was proved to be a useful tool in helping 
children with special needs to improve their oral hygiene (Pilebro c., et al. 2005). Goyal S. et 
al. even showed that for mentally challenged individuals, manual toothbrushes reinforced with 
audio-visual instructions for brushing might be comparable to the use of powered toothbrushes 
(Goyal, S. et al. 2011). 
 
However, to date there has been limited researches focused on the effectiveness of tooth-
brushing assisted with visual pedagogy to promote oral health among special care communities. 
Community-based studies are necessary to provide reliable evidence to support or refute the 
interventions. In the proposed study, standard tooth-brushing training, along with a package of 
structured social stories illustrating the tooth-brushing procedure, healthy diets, and dental visit 
will be provided to preschool children with special needs. We hypothesized that oral-health 
related behaviours will be modified among children who receive visual-pedagogy (social story) 
-assisted tooth-brushing training, and thereby, their oral health status will be improved after 
intervention. 
 
Method 
Trial design 
This study will be designed as a block-randomised controlled parallel blind clinical trial. 
Duration of the study will be 24 months. 
Recruitment 

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Participants will be recruited from the Special Child Care Centers and Special Schools of The 
Spastics Association of Hong Kong (SAHK). Children aged from 2-6 years old with special 
care conditions such as Prader-Willi syndrome, intellectual disability (ID), autistic spectrum 
disorders (ASD), cerebral palsy (CP), Down’s syndrome (DS), attention deficit hyperactivity 
disorder (ADHD), delayed development, or learning disorders will be invited to participant in 
this study. Consent form and information sheet will be delivered to children meet the above 
requirement. Only children with informed consent signed by parents will be recruited.  
Exclusion criteria 
Children manifested with at least one of the following conditions will be excluded from this 
clinical trial:  
• Severe visually impaired  
• Severe hearing impaired  
• Severe physical disabled (cannot hold a toothbrush) 
• Requiring emergent dental treatment 
• Use of antibiotic within 3 months 
• Dental prophylaxes in the last 6 months 
Sample size calculation 
The primary outcome is the development of new dental caries in the children over the 24-month 
study period. Based on the previous oral health promotion conducted among healthy preschool 
children in Hong Kong (Jiang M., 2013), the mean dmfs in control group and intervention 
groups are 0.3 (SD = 1.3), 0.2 (SD = 0.7), 0.4 (SD = 1.2). We assumed that the mean dmfs in 
control group and test group are 0.7 (SD = 1.0) and 0.3 (SD = 0.5). The program G* power 
3.1.9.2 is used for sample size calculation: two-tail test, a =0.05, at a power of 95%. This give 

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a sample size target of 105 children per group. Considering 30% overestimation to allow for 
dropout in 2 years, totally 300 children will be invited, with 150 children per group. 
Baseline information  
Baseline information will consist of the following components: 
• Clinical oral examination  
• Tooth-brushing performance observation  
• Questionnaire-based survey  
Clinical oral examinations will be performed according to the following criteria: i) Caries 
status were assessed by the International Caries Detection and Assessment System(ICDAS); 
ii) Oral hygiene status by Simplified oral hygiene index of Greene and Vermilion (OHI-S); 
iii) gingival health status by Modified Gingival Index of Lobene (MGI). Dental examination 
will be performed at Special Child Care Centers by a pediatric dentist with a disposable 
mouth-mirror attached to an LED light.  Tell- Show-Do (TSD) technique will be used to 
improve children’s cooperation level. Tooth-brushing performance will be assessed by two 
observers. There will be 13 steps listed in the assessment form, steps which are performed by 
child or parent will be recorded respectively, as well as the total time for each tooth-brushing 
session. After dental examination and tooth-brushing assessment, a standard hands-on tooth-
brushing training will be provided immediately to each child and his/her parent. Oral health 
instruction will also be illustrated to the participants, reinforced by social stories or 
conventional leaflets. Questionnaires regarding children’s oral health related behaviours, 
family demographic information and parents’ oral health literacy assessment will be 
completed by parents, while questionnaires assessing children’s developmental profile will be 
filled by staff in Special Child Care Centers. 
Allocation 

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Concealed block randomization at school levels will be used to allocate subjects into 2 group. 
The randomised sequence will be generated by an investigator who do not participate in the 
outreach service. The allocation sequence will be sealed in an envelope, and opened at the 
Special Child Care Centres by an assistant, who will also be responsible for delivering the 
materials to children and their parents. Hence, children (participant) and investigators (outcome 
assessor) will not know the randomised sequence. After a standard tooth-brushing training and 
oral health instruction, Group 1 will be set up as a positive control, receiving standard oral-
health education leaflets issued by the local government, while Group 2 will act as test group, 
receiving social stories developed and validated by the investigators. 
Follow-up appointments 
Commercially available toothbrushes and fluoridated toothpaste will be delivered to each child 
and renewed at every three months. Meanwhile, the old toothbrush and remaining toothpaste 
will be returned, and toothpaste usage and toothbrush wear will be monitored. Follow-up 
assessments will be performed at 6-month, 12-month, 24-month. Education materials about 
“healthy diets” will be emphasized at 6-month follow-up, and dental-visit related education 
materials will be emphasized at 12-month follow-up. Tooth-brushing training was reinforced 
at each follow-up appointment. Education material about tooth brushing, healthy diets and 
dental visit will be illustrated to children and their parents, and parents will be encouraged to 
read those materials to their children in their daily lives. Oral examination and tooth-brushing 
assessment in follow-up appointment will be performed using the same methods and criteria 
as baseline; all parents or primary caregivers will complete a set of questionnaires on their 
attitudes towards the interventions and their children’s oral-health related behaviours.  
 
Significance 

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The present study will provide scientific evidence of effective oral health care for children 
with special needs. Meanwhile, the interventions adopted in the control group and test group 
have potential benefits to encourage the children with special needs to take care of 
themselves by learning tooth brushing independently at an early age status, supporting their 
relatively independent life in the future. 
 
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