Oral Hygiene Behavior of Croatian Adolescents during Fixed Orthodontic Treatment: A Cross-sectional Study.

OBJECTIVE: To investigate the impact of fixed orthodontic treatment on adolescents' oral hygiene behavior and to examine their food consuption during fixed orthodontic treatment, as well as their motivation to maintain oral hygiene.
MATERIALS AND METHODS: This research was carried out in a form of a survey questionnaire consisting of 23 questions. The sample comprised 170 adolescent patients aged from 11 to 19 who underwent the fixed orthodontic treatment at the Orthodontic Clinic of the Zagreb University Hospital Centre.
RESULTS: The orthodontic appliance did not interfere with the patients' maintenance of oral hygiene, but it made the consumption of certain foods more difficult. Most adolescents brushed their teeth twice a day, using medium-soft brushes (35%). Regarding additional oral hygiene aids, 72.4% of the respondents used interdental brushes, more than 50% of the respondents used antiseptic mouthwashes for mouth rinsing, whereas only 31.2% of the tested population used dental floss (4.1% of which daily). The respondents were highly motivated to maintain oral hygiene by their orthodontists (96.5%), but only a small number of the respondents were informed about the importance of an adequate diet while undergoing a fixed orthodontic treatment.
CONCLUSION: Orthodontists should provide their patients with detailed instructions on hygiene maintenance and adequate diet during orthodontic treatment to minimize negative side effects of the fixed orthodontic treatment. Patients should be motivated upon each follow-up examination and encouraged to use as many oral hygiene aids in their daily routines as possible.

Introduction

The attitude towards oral health has been systematically neglected for years and has been based primarily on the removal of the adverse effects on teeth and gingiva that have already occurred. “Despite great efforts put into maintaining oral health, not only in the Republic of Croatia, but the whole world, oral diseases are on the rise” (). Dental caries is one of the most common diseases among children and adolescents (). The habit of maintaining oral hygiene is acquired in childhood, where parents play the greatest role by teaching, motivating and getting their children used to maintaining an adequate oral hygiene on daily basis from their earliest age. The transition from early childhood to puberty and adolescence brings along great and important challenges regarding oral health. Even though there is no unique definition of adolescence, it is usually considered to be the period in life which represents the transition from childhood to adulthood, the period between ages 11 and 20. Adolescence is a period of intense physical, psychological and emotional changes, which often results in risk behaviors (e.g. inadequate diet, consumption of alcohol and cigarettes), that might lead to inadequate oral health and hygiene (). Furthermore, adolescence is a period defined by three types of changes which reflect directly on oral health, i.e.: skeletal development: facial development and teeth positioning, hormonal changes, end of the transition from the primary to permanent dentition ().

For adolescent patients at the peak of their growth and development, orthodontic treatment is mostly indicated, and irregularities can be successfully corrected by fixed, removable or combined orthodontic appliances. A treatment involving fixed orthodontic appliances promotes the accumulation of food and plaque, and maintaining oral hygiene becomes difficult and demanding. An appliance itself creates plaque retentive sites for dental biofilm, which can lead to enamel demineralization and gingivitis ().

This research is conducted in order to examine the impact of orthodontic treatment on consumption of certain food and maintenance of oral hygiene. In addition, the aim of this research was to determine which supplemental oral hygiene tools are used among adolescents during orthodontic treatment in the Department of Orthodontics, School of Dental Medicine, University Hospital Centre, Zagreb, Croatia.

Material and methods

This study was carried out in a form of a survey questionnaire, comprising 23 questions in order to analyze the maintenance of oral hygiene in adolescents. The research questions were divided in several thematic units: Issues related to the impact of orthodontic treatment on food consumption and oral hygiene; Questions that collect information on the manner of implementation and use of supplementary oral hygiene tools; Questions that collect data on demographic and socio-economic characteristics of the respondents.

The G * Power program (6. 7) was used to determine the sample size. For this purpose, χ2 tests (Goodness-of-fit tests) were used, and for noticing an effect of 0.30 (medium effect), with a significance level of 0.05, strength of 0.8 and two degrees of freedom, the minimum required sample size was 108 subjects.

Our reserch comprised 170 adolescent patients aged between 11 and 19 (73 males and 97 females), who underwent a treatment with fixed orthodontic appliance at the Department of Orthodontics, School of Dental Medicine, University Hospital Centre, Zagreb, Croatia. Patients data were collected by the investigators M.C.Š. i Ž.M. in the period from December 2020 until March 2021. The sample comprised 77 respondents aged between 11 and 13 (45.3%), 51 respondents aged between 14 and 16 (30.0%) and 42 respondents aged between 17 and 19 (24.7%). Such representation and distribution of the sample were dictated solely by the current need for dental examinations, i.e. therapies. The treatment (straight-wire technique) consisted of 18-slot metal brackets in the Roth prescription, with 0.010-inch steel ligatures (Forestadent, Pforzheim, Germany). Since the respondents were mainly minors, informed consents were signed by their parents or guardians who also had an insight into the questionnaire for the entire period until its completion.

Statistical analysis

The results of the research were processed and analyzed using statistical methods with the software package IBM SPSS, STATISTICS version 23.0 (Osijek, Croatia). To offer the most complete answers to the set hypotheses, the processing of the data collected during research was performed in two stages of statistical procedures. The first stage produced a tabular representation of frequency distribution, whereas the second stage consisted of comparison and determination of statistical significance of differences between categorical variables. Differences in categorical variables were tested by the χ2-test. The level of statistical significance was set at P < 0.05.

The research procedures were carried out following the Decision of the Ethics Committee of the School of Dental Medicine of the University of Zagreb. Research participation was voluntary, whereas the participants were guaranteed anonymity and confidentiality.

Results

Even though the fixed orthodontic treatment typically requires more effort, attention and additional dental aid during oral hygiene maintenance, the largest number of respondents, i.e. 63.5%, responded that orthodontic appliances did not interfere with their maintenance of oral hygiene, however, 62.4% of the respondents stated they had issues with the consumption of certain foods (Table 1).

Table 1

Effect on fixed orthodontic treatment on oral hygiene maintenance and foods consumption

		FREQUENCY	PERCENT
Was it difficult for you to maintain oral hygiene while in orthodontic treatment?	YES	62	36.5%
	NO	108	63.5%
	TOTAL	170	100.0%
Was it difficult for you to consume certain foods while in orthodontic treatment?	YES	106	62.4%
	NO	64	37.6%
	TOTAL	170	100.0%

A majority of the respondents, i.e. 55.9%, maintain their oral hygiene twice a day using medium-soft brushes (35%), (Figure 1).

Figure 1

Frequency of brushing in relation to age

If the duration of brushing (Figure 2) is taken into consideration, the largest number in all age groups (over 80% of each group) brush their teeth for over a minute, but there is a significant difference between groups among those who brush their teeth for over a minute (150 respondents), because over 45% of them represent the youngest population. Regarding additional dental aids for oral hygiene maintenance, adolescents mostly use interdental brushes (see Table 2), which are used daily, or sometimes, they are used by 72.4% of adolescent respondents in treatments with fixed orthodontic appliances. The relationship with chosen orthodontist, where trust and effective communication may lead to the prevention of oral diseases and enhancement of oral health, plays an important role in development of hygiene habits and oral health maintenance while in treatment with fixed appliances.

Figure 2

Duration of brushing

Table 2

Use of additional dental devices in oral hygiene maintenance

INTERDENTAL TOOTHBRUSH	FREQUENCY	PERCENT
YES, DAILY	53	31.2%
YES, SOMETIMES	70	41.2%
NO	47	27.6%
TOTAL	170	100.0%
DENTAL FLOSS	FREQUENCY	PERCENT
YES, DAILY	7	4.1%
YES, SOMETIMES	46	27.1%
NO	117	68.8%
TOTAL	170	100.0%
MOUTHWASH	FREQUENCY	PERCENT
YES, DAILY	23	13.5%
YES, SOMETIMES	66	38.8%
NO	81	47.6%
TOTAL	170	100.0%

When asked: “Have you received instructions regarding hygiene maintenance during orthodontic treatment from your orthodontist?” the respondents could choose among multiple answers, the total number of which is given in Table 3. In the research, 41.8% of the respondents stated that they had been warned about unsatisfactory oral hygiene, which suggests that a large number of adolescents do not maintain adequate oral hygiene, even though 91.2% of them stated they brushed their teeth two or more times a day (-).

Table 3

Receiving instructions on oral hygiene maintenance from the orthodontist

INSTRUCTIONS ON ORAL HYGIENE MAINTENANCE FROM THE ORTHODONTIST	FREQUENCY	PERCENT	PERCENT OF CASES
Yes, instructions on how to brush your teeth properly	136	48.7%	80.0%
Yes, instructions on using an interdental brush, dental floss or mouthwash	72	25.8%	42.4%
Yes, instructions on proper nutrition	63	22.6%	37.0%
No	8	2.9%	4.7%
Total	279	100.0%	164.1%

Discussion

Orthodontic elements such as brackets, bands and wires make daily hygiene more difficult because they create plaque retentive areas which are hard to clean with regular brushes () and it is mandatory for the patient to establish a satisfactory oral hygiene before any orthodontic treatment (). The study subjects stated that the appliance itself did not interfere with their oral hygiene maintenance which they carried out two times a day. A study carried out at the Faculty of Dental Medicine in Thailand, in which subjects were aged between 13 and 41 (mean age: 20 years) shows slightly more optimistic results because over 50% of the respondents brush their teeth after each meal (). Unfortunately, the researchers did not make a distinction within the group, which could answer the question of whether the awareness of oral hygiene was growing with years during the orthodontic treatment. The authors of a study carried out in Lithuania on a sample of patients similar to ours showed that older adolescents (aged 16 to 18) paid more attention to oral hygiene maintenance than the younger ones (aged 12 to 15) (). The results of their study are supported by this research as well since only two respondents in the oldest group (4.8%) stated that they brushed their teeth only once a day.

Even though some studies suggest that there is a difference in the frequency of brushing between the genders to the advantage of the females (), a statistically significant difference between the genders was not found in this study.

The patients included in this study stated that an orthodontic appliance did not interfere with their maintenance of oral hygiene, however over 60% of the respondents pointed out that this treatment made the consumption of certain foods more difficult. Some studies suggest that before orthodontic treatment, patients are not worried about diet limitations, but rather focus on the esthetics and treatment outcomes instead. However, while in the treatment, the main complaints are directed to the difficulties of the solid foods intake, as well as the pain in the first stages of the leveling phase as well as periods following orthodontic follow-up examinations (). The reasons for the food intake difficulties are surely caused by the pain in the first days after the appliance was bonded as well because chewing food is painful and many patients avoid solid foods. Moreover, doctors provide instructions for patients regarding proper diet during the bonding of an orthodontic appliance to prevent any damages to the appliance itself. It has been recorded that patients mostly avoid consuming apples, carrots, chips, nuts, chewing gums, crackers and popcorn and that they believe they have improved their dietary habits during the orthodontic treatment, either by changing meal preparation methods, reducing the intake of “unhealthy food”, or reducing the number of snacks between the meals (). A study that analyzed the patients' diet three days before and three days after starting orthodontic treatment or after follow-up examinations, showed that due to the painful sensations, the patients consumed softer foods. Consequently, this led to decreased levels of copper, magnesium and fiber in their diets and increased the intake of fat. The authors, therefore, recommend nutritional counselling for all the patients who consume soft, liquid foods (). The studies that have compared diets of adolescents in the orthodontic treatment with fixed orthodontic appliances and control groups of adolescents (without orthodontic appliances) have shown that the former group consumed more total fats, saturated fats, monounsaturated fats, polyunsaturated fats, linolenic fat, linoleic fat and cholesterol, but showed significantly lower intakes of fiber, chromium and beta-carotene, even though the total caloric intake was about the same in both groups ().

The oral hygiene maintenance tools market offers a wide range of options available for buyers to choose from. As this study has shown, most respondents use regular (manual) brushes for oral hygiene maintenance which they usually change every two to three months. The largest numbers of respondents, (72.4%), have stated that, besides regular or electric brushes, they used interdental brushes, whereas 68.8% of the surveyed population did not use dental floss. “The choice of an interdental oral hygiene maintenance device should primarily be defined by the size and shape of the interdental space, teeth position and location as well as the patient’s capabilities and motivation. Interdental spaces are the starting point for the development of periodontal diseases, including dental caries, which increases the importance of everyday use of interdental devices for oral hygiene maintenance” (). Mouthwashes were, according to the data of this study, used by over 50% of the surveyed population.

In the final part of the questionnaire, the respondents were asked whether they had received instructions from their orthodontists on proper brushing, use of additional dental aids for oral hygiene and proper diet. They could circle multiple answers. Most respondents, (80%), stated that they had been given instructions on proper brushing, 43.5% of them answered that they had been given instructions on the use of the interdental brush, dental floss or mouthwash, whereas 36.5% of the respondents received instructions on proper diet. Slightly less than 5% of the respondents stated they had not received any instructions from their orthodontists (Table 3). The results regarding instructions on oral hygiene are in accordance with the results of other studies, which suggests that patients received instructions in 82.9% of cases. Instructions on adequate diet were given to 43.8% of patients, and it is apparent that patients are less informed in this study on the importance of an adequate diet (). A study carried out in Great Britain on a large number of orthodontists showed that all orthodontists provide information to their patients on proper brushing, whereas 84% of them provide information on proper diet during the orthodontic treatment (). They stated that they have started using mobile applications only recently to improve patients' motivation for brushing (). These data differ significantly from the data in our study, thus suggesting that Croatian orthodontists should become more involved. Considering adolescence as a very sensitive period, in which diet plays an important role and is required for proper growth and development of young persons, the results of this study have shown that more time needs to be dedicated to the education of patients on proper diet during the orthodontic treatment. Azaripour et al. suggest that during each follow-up examination patients need to be warned of regular and adequate oral hygiene maintenance because, even though they receive instructions at the beginning of the treatment, they do not implement them in their daily routines. Unlike the control group, the respondents who had undergone the fixed orthodontic appliances treatment suffered from gingivitis caused by plaque accumulation on teeth (). Besides instructions, orthodontists should provide specific warnings to their patients as well. In our research, 71 respondents (41.8%) stated that they had been warned about unsatisfactory oral hygiene, which suggests that a large number of adolescents do not maintain adequate oral hygiene, even though a majority of them have been given instructions. By crossing brushing frequency variables with the variable of warning of the inadequacy of their oral hygiene, a statistically significant difference between the present variables has been noticed ((DF=2, P= < 0. 05). We may, therefore, conclude that the warning about inadequate oral hygiene was given mostly to those who brushed their teeth once a day (73.7%), (Table 4).

Table 4

Orthodontists’ warnings of oral hygiene and brushing frequency

HOW MANY TIMES A DAY DO YOU BRUSH YOUR TEETH?	DURING YOUR APPOINTMENT WITH THE ORTHODONTIST, ARE YOU WARNED THAT YOUR ORAL HYGIENE IS NOT SATISFACTORY?
	YES	NO	TOTAL
Once a day	73.3%	26.7%	100.0%
Twice a day	41.9%	58.1%	100.0%
Three or more times a day	35.0%	65.0%	100.0%

Furthermore, this study pointed to the significant role of the orthodontist and his/her active involvement in the education, control and adoption of oral hygiene habits. It provides to adolescents great, if not the biggest, motivation for adequate oral hygiene maintenance since 96.5% of respondents reported that their orthodontist motivated them sufficiently regarding proper hygiene maintenance, whereas only 3.5% of them stated otherwise, i.e. that they had not been sufficiently motivated by their orthodontists.

Due to sample-related limitations (the majority of parents had the same level of education), it was not possible to examine the impact of parents' level of education on maintaining children’s oral hygiene. Additional research is needed to examine the factors that influence the selection of supplementary oral hygiene tools, such as the parents' level of education, the financial situation, the number of household members etc.

Conclusions

The results of this study showed that during the treatment with fixed orthodontic appliances, patients need to change their dietary habits since the appliance interferes with consumption of certain foods. More than half of the respondents stated that the orthodontic appliance did not interfere with their oral hygiene maintenance. This study showed that the majority of the respondents (72.4%) used interdental brushes, more than 50% of the respondents used antiseptic mouthwashes for mouth rinsing, whereas only 31.2% of the tested population used dental floss (4.1% of which daily). Orthodontists provide their patients with detailed information on oral hygiene maintenance, but they do not provide sufficient information on adequate diet during the fixed orthodontic treatment.