Impact of exposure to positive images on dental anxiety among children: a controlled trial.
Abstract: AIM: To determine whether exposing children to images of positive dental care would have an effect on their degree of anxiety, assessing anxiety three separate times. study DESIGN: Controlled trial. METHODS: The 70 participants from 4-11 years of age were randomly assigned to one of two conditions. The intervention consisted of viewing positive images of dentistry and dental treatment (n=35). The control condition consisted of dentally neutral images (n=35). Outcome measures: Anxiety was assessed using the Venham Picture Test (VPT) prior to the intervention, immediately following the intervention and following the dental appointment. Statistics: Statistical analysis (chi-square and Mann-Whitney tests) was conducted blind to group allocation. RESULTS: No significant difference was detected between the scores of the VPT in the two groups at any evaluation time (p>0.05). Dental anxiety at the three evaluation times was not correlated to age. There was no difference in level of anxiety between male and female participants (p>0.05). CONCLUSIONS: Viewing positive images of dentistry and dentists did not have a greater effect on child anxiety in the dental setting than viewing neutral images, however, showed lower rates of anxiety for all children although this was not significant.

Key words: Dental anxiety, images, children.
Article Type: Report
Subject: Anxiety (Risk factors)
Anxiety (Diagnosis)
Anxiety (Research)
Children (Psychological aspects)
Dental care (Health aspects)
Dental hygiene (Health aspects)
Mouth (Care and treatment)
Mouth (Health aspects)
Authors: Ramos-Jorge, M.L.
Ramos-Jorge, J.
de Andrade, R.G. Vieira
Marques, L.S.
Pub Date: 08/01/2011
Publication: Name: European Archives of Paediatric Dentistry Publisher: European Academy of Paediatric Dentistry Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2011 European Academy of Paediatric Dentistry ISSN: 1818-6300
Issue: Date: August, 2011 Source Volume: 12 Source Issue: 4
Topic: Event Code: 310 Science & research
Product: Product Code: E121920 Children
Geographic: Geographic Scope: Brazil Geographic Code: 3BRAZ Brazil
Accession Number: 277106769
Full Text: Introduction

The anxiety that accompanies dental treatment is considered a universal problem and has piqued the interest of a large number of researchers [Aartman et al., 2000; Ramos-Jorge et al., 2006; Olumide et al., 2009; Wigen et al., 2009; Gustafsson et al., 2010; Nicolas et al., 2010; Sjogren et al., 2010]. One study found that, among a group of 118 children between 48 and 71 months of age with no prior dental experience, 75.6% exhibited some degree of anxiety prior to a clinical exam and dental prophylaxis [Ramos-Jorge et al., 2006].

There are a number of specific instruments widely cited in the literature for measuring child anxiety [Aartman et al., 1998; Ramos-Jorge et al., 2006; Howard and Freeman, 2007; Olumide et al., 2009; Nicolas et al., 2010; Sjogren et al., 2010]. In dentistry, the study of anxiety nearly always involves the use of projective techniques, questionnaires and the observation of physiological signs. Recent studies have determined the association between the anxiety of parents and children with regard to dental treatment and the risk of developing oral problems [Wigen et al., 2009; Themessl-Huber et al., 2010].

Paediatric dentists seek to prevent, eliminate or at least reduce the anxiety of young patients, as this feeling can compromise the quality of dental care as well as the well-being of the child in relation to his/her oral health [Colares and Richman, 2002]. Recent evidence has demonstrated that modelling has a positive effect on reducing anxiety among paediatric dental patients. The method involves a child watching another child receive dental treatment through direct observation, video or photographs [Adair, 2004; Wilson and Cody, 2005]. The study of Fox and Newton [2006] employed modelling using photographs and found the children exposed to positive dental care images in the waiting room while awaiting treatment exhibited less anxiety than those not exposed to positive images. This was the first study in which images were tested with regard to their efficacy in reducing child anxiety. However, the authors pointed out a number of methodological limitations: the considerable variation in the age of participants; small sample size; and the fact that the assessment of anxiety was only performed at one time (following exposure to the images).

Due to the important applicability of this method, the aim of the present study was to determine whether exposing children to images of positive dental care would have an effect on their degree of anxiety. For this, anxiety was assessed in three separate moments: prior to the intervention, immediately following the intervention and immediately following the dental appointment.

Materials and methods

The study was carried out at the Paediatric Clinic of the Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM, Brazil) and was approved by local ethics committee on research involving human subjects.

Participants The participants were a consecutive series of new and current patients treated at the paediatric clinic over a five-month period from July to November 2008.

Inclusion criteria

* Age between 4-11 years

Exclusion criteria

* Children with learning difficulties who were judged unable to understand the instructions

* Visual impairment

Sample size The calculation of the sample size was based on the mean and standard deviation (SD) of Venham Picture Test (VPT) scores obtained in a previous study [Fox and Newton, 2006]. Estimating that clinically significant difference between two groups would be 1SD and adopting an effect size of 1.1([micro]2-[micro]2/SD, i.e. mean of anxiety in children exposed to positive images =0.21--mean of anxiety in children exposed to positive images =3.31/0.42 [+ or -] 2.58). A sample size of 54 would therefore give 90% power to detect this a difference at a significance level of 0.01. However, 70 children were actually recruited in order to compensate for possible losses.

Null hypothesis In the population of children aged 4-11 years treated at the paediatric clinic of the UFVJM, there is no difference in mean dental anxiety scores (as measured by the VPT) between children exposed to positive images of dentistry and those exposed to neutral images prior to treatment.

Materials and methods

The participants were randomly allocated to either the intervention or control group. A computer was used to generate a random sequence of 70 numbers between 1 and 70, corresponding to the experimental (even numbers) and control conditions (odd numbers). Seventy identical envelopes were then prepared, each containing a single code from the random sequence (experimental or control). The envelopes were opened in sequence by a member of the research team who was not involved in assessing the children's anxiety (LSM).

Photographs of positive dental situations (Fig. 1) were shown to the children while awaiting treatment and their levels of anxiety and were compared with those of children in a control group who observed photographs of neutral images (Fig. 2). Anxiety was assessed using the modified VPT prior to the intervention, immediately following the intervention and following the dental appointment. The VPT uses a collection of figures from which the child choose the one with which he/she most identified. The children were shown 8 figures of pairs of children expressing a range of reactions and were asked to choose those that reflected their emotions.

The assessment of anxiety prior to and following the intervention was carried out in the waiting room, whereas the assessment following the dental appointment was carried out in the clinic. Each child responded to the VPT following instructions from the three researchers who were blind to the patient's group allocation and previously assessed anxiety level. During the explanation, neither the guardian nor the child were given examples of pictures that might represent positive images or neutral images so that it was unclear to them to which arm of the trial they pertained.

The parents were told that the aim of the study was to investigate whether viewing positive images of the dentist would reduce anxiety in children. The children were told that the study was to explore whether looking at the pictures would make children 'happier when visiting a dentist' [Fox and Newton, 2006].

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

One researcher (RGV) performed the initial assessment of anxiety. The participant was then allowed two minutes to look at the photographs (in any order and individually for any duration). The photographs were then retrieved and the dental nurse withdrew, keeping the envelope [Fox and Newton, 2006]. A second researcher (JR-J) then assessed each child's anxiety a second time and sent the child in for his/ her dental appointment. After the appointment, in which the examination of the oral cavity was performed (MR-J), each child's anxiety was collected a third time by a third researcher (MR-J). Both assessed patient's group code and anxiety scores were returned to the sealed envelope for analysis at the end of the study.

Data collection Data collection was carried out with the following procedures:

* Assessment of anxiety using VPT;

* Presentation of photographs to the children--positive dental images (intervention group) and neutral images (control group);

* Assessment of oral health status using the criteria of the World Health Organisation [WHO, 1999];

* Determination of demographic variables (child's gender and age and mother's schooling).

Positive images Four photographs (size A4) were chosen by a group of 10 children between 4-11 years of age who did not participate in the main study. These children were shown 20 images and asked to choose the four that most attracted them as positive and indicate the degree of positive attitude toward dentistry on a 10 cm visual analogue scale, for which higher scores indicated a greater degree of positive attitude. The average rating of the 10 children for all 2- images was 7.43 (SD [+ or -] 2.48).

Neutral images Ten photographs (size A4) were selected by the research team from a collection of 20 postcards of the city of Diamantina, Brazil. These images were believed to be neutral in relation to dentistry. The pictures were validated as representing a neutral image by seven dentists working for the study who assessed the photographs by marking a score on a visual analogue scale from 0 to 10, for which scores closer to 0 denoted neutral images, whereas those closer to 10 denoted images depicting a positive attitude toward dentistry. The average rating of the seven dentists for all four images was 0.34 (SD [+ or -] 0.42).

Primary outcome measure Anxiety was assessed prior to the intervention, immediately following the intervention and following the dental appointment. The children were shown eight pairs of pictures and asked to indicate the pictures that most reflected their emotions. The researcher asked each child to respond to the following: "Imagine that you are one of these children. I want you to point to the child that is feeling the same thing you are feeling right now. Look at these children and tell me which one is going to the dentist." Each child pointed to the picture in each of the eight pairs of pictures that best reflected his/her emotions at that moment. The children were assigned scores from 0 to 8, for which a 0 denoted a lack of anxiety and 8 denoted a high degree of anxiety [Ramos-Jorge et al., 2006; Ramos-Jorge and Pordeus, 2004].

Masking The researchers (RGV, JR-J and MR-J) who collected the children's anxiety using VPT at three separate moments were masked to the children's allocation to either the intervention or control group. The children and their parents were not informed to which arm of the trial they pertained. Data analysis was conducted by an independent analyst masked to the coding used to indicate the experimental and control groups.

Statistical methods The data were entered and organised into a databank using the Statistical Package for Social Sciences (SPSS), version 14.0. Processing involved coding, entering and editing the data. The chi-square test was used to determine whether the two groups were similar with regard to gender, age, mother's schooling and oral health status. As the data were not distributed normally, the Mann-Whitney U-test was used to determine associations between each group and degree of anxiety before and after the intervention as well as after the dental appointment. The Wilcoxon Signed

Ranks Test was used to determine the distribution of anxiety scores measured by the VPT prior to the intervention, immediately following the intervention and immediately following the dental appointment. Spearman's correlation coefficients were calculated to determine correlations between these different anxiety scores and child's age, mother's schooling and number of carious teeth.

Results

Of the 70 participants, 36 (51.4%) were male. Mean age was 7.5 years (SD [+ or -] 2.5). There were no significant differences between groups with regard to gender, age, number of carious teeth, mother's schooling, toothache at the time of the appointment or in the previous three days or of children who were visiting a dentist for the first time (Table 1).

The mean VPT scores were similar in both groups, thereby confirming the null hypothesis (Table 2). Considering the overall sample, a reduction in anxiety was detected throughout the three evaluations. A statistically significant difference was detected between the anxiety scores before and after the intervention (p=0.009) as well as before the intervention and following a dental appointment (p= 0.014) (Table 3).

Data analyses were performed to investigate the impact of age, gender, number of carious teeth, mother's schooling, toothache at the time of the assessment or in the previous three days and first visit to the dentist on anxiety, by the Venham Picture Test. Toothache in the previous three days was the only variable to have a statistically significant association with anxiety prior to the intervention (p=0.002) and following the dental appointment (p=0.022).

Discussion

In the present study, the effect of positive dental images did not differ from that of neutral images in reducing anxiety, as measured by the VPT, which confirmed the null hypothesis. The potential biases pointed out in a previous study [Fox and Newton, 2006] were controlled. The intervention and control groups were paired with regard to gender, age, schooling, number of carious teeth, toothache experience and number of children on their first visit to the dentist. This pairing was important, as previous studies have demonstrated that these variables may be related to negative behaviour and high anxiety when facing dental treatment [Ramos-Jorge et al., 2006; Colares and Richman, 2002].

With the exception of the researcher who allocated the children to the different groups, all other members of the research team were masked to the allocation of the participants to the intervention and control groups. This factor is not reported clearly in the majority of studies. Moreover, special care was taken to ensure that the behaviour of the researcher who allocated the participants was similar when dealing with the children in both groups. Thus, this researcher was directly observed by another member of the team (MR-J) throughout the entire collection of the data. The observing researcher was unable to distinguish whether the researcher was with the intervention group or the control group.

In the previous study [Fox and Newton, 2006], the assessment of anxiety was performed only one time (after the intervention). Therefore, this previous study did not determine whether the difference found in the degree of anxiety was present prior to the intervention. To control this problem in the present study, anxiety was also assessed before the intervention.

It is possible that anxiety scores immediately following a dental examination would be higher when a child is submitted to treatments other than a simple dental exam. This result is similar to that reported previously Olumide et al. [2009], who assessed the degree of anxiety among children between 8-12 years of age as two times: before and after obtaining prior information on what to expect from dental care. That study also found no significant differences in the degree of anxiety between the group that received prior information regarding dental care and the group that received information of another source. However, the general level of anxiety also diminished slightly following the reading of the pamphlets.

Limitations of our study should be considered, such as the adoption of a single outcome measure and the fact that the Venham Picture Test is a limited measure, as it is essentially not normally distributed. It may therefore be inferred that showing images on photographs, whether or not related to the dental setting, was an effective way of reducing anxiety in children. This finding is important, as a retrospective study carried out in 1999 involving 1,420 individuals found that, among the 16.4% of adult patients who were anxious with regard to dental care, 50.9% reported that this anxiety had begun in childhood [Locker et al., 1999].

In the present study, the age range was from 4-11 years. This was younger than that in another study [Fox and Newton, 2006], which was 5-17 years. We suggest that some positive dental pictures may be considered infantile for adolescent participants. This problem was avoided in the present study, as other children in the same age group chose the pictures they considered positive in relation to the dental setting.

The mean anxiety levels among the children in the present study were low. Although there have been a number of studies involving highly fearful children [ten Berge et al., 1999 and 2002], further studies with more anxious children should be carried out using the positive image method in order to determine the effect of the intervention on this specific group of children.

Conclusions

In the present study, the effect of positive dental images did not differ from that of neutral images in reducing anxiety, as measured by the VPT. However, it may be inferred that showing images on photographs, whether or not related to the dental setting, is an effective way of reducing anxiety in children.

Acknowledgement

The authors thank Rodrigo Cunha Fernandes, Natalia Ramos dos Santos and Juliana Valois Alves for their help during the data acquisition phase and Professor Saul Martins de Paiva for the final analysis of the manuscript.

References

Aartman IH, van Everdingen T, Hoogstraten J et al. Self-report measurements of dental anxiety and fear in children: a critical assessment. ASDC J Dent Child 1998;65:252-258.

Aartman IH, de Jongh A, Makkes PC et al. Dental anxiety reduction and dental attendance after treatment in a dental fear clinic: a follow-up study. Community Dent Oral Epidemiol 2000;28:435-442.

Adair SM. Behavior management conference panel I report: rationale for behaviour management techniques in pediatric dentistry. Pediatr Dent 2004;26:167-170.

Colares V, Richman L. Factors associated with uncooperative behavior by Brazilian preschool children in the dental office. ASDC J Dent Child 2002;69:87-91.

Fox C, Newton JT. A controlled trial of the impact of exposure to positive images of dentistry on anticipatory dental fear in children. Community Dent Oral Epidemiol 2006;34:455-459.

Gustafsson A, Broberg A, Bodin L et al. Dental behaviour management problems: the role of child personal characteristics. Int J Paediatr Dent 2010;20:242-253.

Howard KE, Freeman R. Reliability and validity of a faces version of the Modified Child Dental Anxiety Scale. Int J Paediatr Dent 2007;17:281-288.

Locker D, Liddell A, Dempster L et al. Age of onset of dental anxiety. J Dent Res 1999;78:790-796.

Nicolas E, Bessadet M, Collado V et al. Factors affecting dental fear in French children aged 5-12 years. Int J Paediatr Dent 2010;20:366-373.

Olumide F, Newton JT, Dunne S et al. Anticipatory anxiety in children visiting the dentist: lack of effect of preparatory information. Int J Paediatr Dent 2009;19:338-342.

Ramos-Jorge ML, Pordeus IA. Why and how to measure child's anxiety in the dental environment: the modified VPT. JBP Rev Ibero-am Odontopediatr Odontol Bebe 2004;7:282-290.

Ramos-Jorge ML, Marques LS, Paiva SM et al. Predictive factors for child behaviour in the dental environment. Eur Arch Paediatr Dent 2006;7:253-257.

Sjogren A, Arnrup K, Jensen C et al. Pain and fear in connection to orthodontic extractions of deciduous canines. Int J Paediatr Dent 2010;20:193-200.

ten Berge M, Veerkamp JS, Hoogstraten J et al. Behavioural and emotional problems in children referred to a centre for special dental care. Community Dent Oral Epidemiol 1999;27:181-186.

ten Berge M, Veerkamp JS, Hoogstraten J et al. Childhood dental fear in the Netherlands: prevalence and normative data. Community Dent Oral Epidemiol 2002;30:101-107.

Themessl-Huber M, Freeman R, Humphris G et al. Empirical evidence of the relationship between parental and child dental fear: a structured review and meta-analysis. Int J Paediatr Dent 2010;20:83-101.

Wigen TI, Skaret E, Wang NJ. Dental avoidance behaviour in parent and child as risk indicators for caries in 5-year-old children. Int J Paediatr Dent 2009;19:431-437.

Wilson S, Cody WE. An analysis of behaviour management papers published in the pediatric dental literature. Pediatr Dent 2005;27:331-338.

World Health Organisation (WHO). Oral health surveys. Basic methods. Geneva: WHO; 1999.

M.L. Ramos-Jorge *, J. Ramos-Jorge **, R.G. Vieira de Andrade ***, L. S. Marques ***.

* Department of Paediatric Dentistry, School of Dentistry, Federal University of Vales do Jequitinhonha e Mucuri, Diamantina, MG, Brazil.**Department of Paediatric Dentistry, School of Dentistry, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil. ***Department of Orthodontics, University of Vale do Rio Verde (UNINCOR), Tres Coragdes, Brazil.

Postal address: M.L. Ramos-Jorge , R. Arraial dos Forros, 215, Centro, Diamantina, MG, Cep: 39100-000, Brazil.

Email: mlramosjorge@gmail.com
Table 1. Distribution of children regarding gender, age, mother's
schooling, number of carious teeth, dental appointment and
toothache in intervention (n=35) and control (n=35) groups.

                Intervention    Control      Total      p-value
                  Positive      Neutral
                   images       images

Gender

Female               16           18          34       0.632 (c)
Male                 19           17          36

Age (years)

Mean (SD)        7.2 (2.8)     7.4 (2.2)   7.5 (2.5)   0.826 (u)

Mother's
schooling *

Mean (SD)        7.2 (3.1)     6.9 (3.1)   7.3 (3.1)   0.865 (u)

Number of
carious teeth

Mean (SD)        5.1 (5.6)     4.0 (3.0)   4.3 (4.3)   0.581 (u)

First dental
appointment

No                   25           24          49       0.794 (c)
Yes                  10           11          21

Toothache (1)

No                   29           25          54       0.255 (c)
Yes                  6            10          16

Toothache (2)

No                   27           21          48       0.122 (c)
Yes                  8            14          22

(c) Chi square test; (u) Mann-Whitney test;
* years completed; (1) at assesement;
(2) previous (3) days

Table 2. Distribution of anxiety scores using VPT
before intervention, after intervention and after
dental exam in intervention (n=33) and control
(n=33) groups.

VPT             Intervention      Control      p-value
                 Exposed to       Exposed
               positive images   to neutral
                                   images
Before
intervention
Mean (SD)         3.2 (2.8)      2.7 (2.4)    0.692 (u)
Median               2.0            2.0
After
intervention
Mean (SD)         2.9 (2.6)      2.6 (2.4)    0.871 (u)
Median               2.0            2.0
After exam
Mean (SD)         2.4 (2.7)      2.3 (2.4)    0.660 (u)
Median               1.0            2.0

(u) Mann-Whitney test

Table 3. Distribution of anxiety scores using VPT before
intervention, after intervention and after dental exam.

                       Mean (SD)          Median

VPT before       3.1 (2.7) x 2.5 (2.6)   3.0 x 2.0   0.009 (w)
intervention
x VPT after
intervention

VPT before       3.1 (2.7) x 2.3 (2.7)   3.0 x 1.0   0.014 (w)
intervention x
VPT after exam

VPT after        3.1 (2.7) x 2.3 (2.7)   2.0 x 1.0   0.521 (w)
intervention x
VPT after exam

(w) Wilcoxon Signed Ranks Test
Gale Copyright: Copyright 2011 Gale, Cengage Learning. All rights reserved.