1. Introduction
Oral health is among the essential foundations of good health and is particularly important for adolescents. However, in this age group, oral diseases, including dental caries and periodontal infections, are prevalent [
1]. The prevalence of dental caries in the age group 12–19 years, based on National Health and Nutrition Examination Survey (NHANES) data, was 53.8% [
2]. Approximately 18.3% of this age group had untreated caries [
3]. Further, there has been no significant change in the dental caries rate among adolescents over the past decades [
1]. With the onset of puberty, the prevalence of gingivitis and periodontal diseases also increases [
4]. According to a previous study, halitosis or bad breath in adolescents was nearly 17.3% [
5]. A significant association between halitosis and a lack of daily flossing was also reported [
5]. Notably, poor oral health has been associated with poor growth, learning difficulties, behavioral problems [
2], and obesity [
6]. Therefore, it is imperative to improve the oral health of adolescents.
Adolescents belong to an important age group, as some preventive self-care behaviors (i.e., tooth brushing and flossing) are formed at this stage [
7]. One review study suggested that flossing and toothbrushing may help prevent halitosis, dental caries, and periodontal diseases [
5,
8]. Other studies found that flossing in this age group is associated with decreasing interproximal caries [
9] and proximal caries [
10]. However, daily flossing is often neglected by adolescents. A study among English adolescents found that flossing became less frequent with age, from 12 to 16 years, and only 6% of adolescents received advice regarding flossing at dental visits [
11]. Another study examined oral hygiene among Greek school students and reported that less than 37% of participants used floss [
12]. Basch and colleagues (2019) found that adolescents did not floss daily, especially in the evening. Further, the study found that boys associated flossing with health-related behaviors, while girls associated flossing with cleanliness [
13]. The NHANES data from 9056 US adults aged 30 years and above reported that approximately 30% floss daily [
14]. However, there are no national surveys available that provide an estimate as to what proportion of US adolescents indeed floss. The Behavioral Risk Factor Surveillance system (BRFSS) has no questions regarding flossing behavior, and they do not even appear in state-specific oral health questions. However, data from other countries show flossing to be generally low among adolescents (e.g., England 8%, Canada 22%, and Norway 27%) [
11].
Adolescents from minority groups are particularly susceptible to poor oral hygiene behaviors, including lack of daily flossing. A study with Mexican adolescents from rural and urban areas found that rural adolescents were more susceptible to poor oral hygiene behaviors and dental caries [
15]. A study with Mexican American teens found that the primary barriers to flossing include the lack of understanding of the proper flossing technique and the messages encouraging flossing [
16]. A study found that Brazilian adolescents’ primary barriers to flossing were laziness, lack of motivation, and problems related to manual dexterity [
17]. Another qualitative research study performed among rural and low-income minority adolescents in the US reported a lower level of the perceived threat from dental diseases among this group [
18]. In addition, this group needed more information and implementation targeting preventive oral health behaviors [
18,
19]. Studying and promoting oral health among African American/Black and Latinx/Hispanic adolescents is an area of research to reduce health disparity.
Few behavioral and educational interventions have been implemented to promote flossing among adolescents. A low-fear educational intervention based on locus of control theory found no change in flossing compliance among adolescents compared to a control group [
20]. Using a cluster randomized controlled trial, a social cognitive theory-based brief intervention with adolescent girls improved flossing behavior with self-efficacy, planning, and intention as the key constructs [
21]. However, the intervention was limited to only one gender and had a relatively short follow-up. There is a need for more interventions to promote flossing behavior among adolescents, particularly from minority groups. Conducting theory-based research to identify evidence-based approaches to promote flossing among African American/Black and Latinx/Hispanic adolescents will help reduce oral health disparities affecting these subgroups.
The multi-theory model (MTM) of health behavior change uses salient constructs from several behavioral and social science theories that have proven their usability in explaining several health behaviors among different target groups [
22,
23]. The MTM can deliver precise and brief interventions for facilitating behavior changes tested in experimental designs. It showed significant and substantial predictability in explaining other behaviors, for instance, promoting physical activity behavior [
24,
25,
26], fruit and vegetables consumption behavior [
27], portion size behavior [
28], replacing sugar-sweetened beverages with water [
29], replacing binge drinking with responsible drinking [
30], increasing mammography [
31], promoting HPV vaccination [
32], reducing water-pipe smoking [
33,
34], promoting low salt intake among hypertensives [
35], promoting good sleep behavior [
36], promoting stress management behaviors [
37], and promoting nature contact behavior [
38].
The MTM, unlike previous theories of behavior acquisition, is about behavior change. It conceptualizes the behavior change into two components: (a) initiation and (b) sustenance or maintenance. There are distinct and parsimonious constructs for each component. For initiation, three constructs help with behavior change. The first one is participatory dialogue in which the advantages of the behavior change must be emphasized over the disadvantages. This has been derived from value expectancy theories. The second construct is behavioral confidence, derived from Bandura’s social cognitive theory [
39,
40], and the construct of perceived behavioral control is from the theory of planned behavior [
41]. However, behavioral confidence is a little different than the concept of self-efficacy (behavior-specific confidence emanating from self) and perceived behavioral control (how much a person feels they are in command of enacting a behavior) in several ways: First, behavioral confidence is not just restricted to the self but can come from outside influences too, such as belief in a higher power, confidence in a deity, and confidence in a powerful other. Second, behavioral confidence is not “here and now”, like self-efficacy, but can be futuristic, and one may have the belief to acquire it over time. The third construct for the initiation model is the changes in the physical environment, which refers to the tangible resources necessary for starting the behavioral change. In our study, both the actual availability of floss (used as a covariate) and the construct of “changes in the physical environment”, operationalized as the perceived situational availability or the degree of surety that participants could floss while traveling and that floss had a place in the house and was easily accessible, were used.
Figure 1 depicts the MTM-based initiation of flossing in African American/Black and Latinx/Hispanic adolescents.
Likewise, for sustenance or maintenance of behavior changes in the MTM, there are three constructs. The first one is emotional transformation derived from emotional intelligence theory, which requires transforming one’s emotions into goals for making the behavior change. The second construct is practice for change, derived from Freirean praxis [
42]. It entails constant thinking about the behavior change or active reflection and reflective action for incorporating it into one’s life. The final construct for the sustenance model is changes in the social environment, which requires social support from family, friends, professionals, and others to continue with the behavior change. These are shown in
Figure 2, as regard the flossing behavior of African American/Black and Latinx/Hispanic adolescents. Given the lack of a robust theoretical model to measure flossing behavior, this study served two objectives: first, to develop/validate a survey tool based on the fourth-generation MTM framework and, second, to test the applicability of the MTM in explaining flossing behavior among African American adolescents and Hispanic/Latinx adolescents.
4. Discussion
Our study aimed to explain flossing behaviors utilizing the MTM among adolescents from the minority African American and Hispanic/Latinx communities. The study found that 50.4% of the adolescents were not flossing their teeth at least once daily and 21.7% did not have access to floss. As expected, it was also confirmed that the availability of floss made a significantly higher proportion (87%) of minority adolescents floss. As pointed out earlier, there are no national surveys that report flossing rates among adolescents; however, NHANES data among adults demonstrate that 30% of adults do not floss [
14]. Our study’s finding of higher rates among minority adolescents points to the need for greater programmatic efforts toward the promotion of flossing in this target group, including making floss available to this group. It is also worth noting that a large majority of the adolescents (71%) received no instruction in school regarding flossing, which again points to the need for greater educational efforts through schools in promoting flossing behavior among minority adolescents. Further, approximately 25% of minority adolescents who did not floss had not visited the dentist over the past year, as opposed to 15% who were flossing. This finding points to the need to make dental care more accessible and affordable to the minority subgroup.
Regarding the MTM constructs, as expected, the mean scores on all constructs were statistically significantly higher for those who were already flossing compared to those who were not. For the minority adolescents who were not flossing, the MTM construct of behavioral confidence along with instruction of flossing in school played an important predictive role, accounting for 37.8% of the variance, which is in the higher range for behavioral studies [
22,
23]. Behavioral confidence is the ability of the adolescent to have the surety to perform the flossing. Such confidence is futuristic and can arise from self or powerful others, or belief in a higher power or any other such influence. This can be built by exploring and building on sources of confidence for the adolescent, helping them gain mastery over the skill of flossing, teaching flossing techniques in small steps, helping them overcome anxiety or other barriers related to changing the habit of flossing, and other such measures. This finding regarding the role of behavioral confidence is supported by several studies utilizing the MTM with different behaviors [
50,
51,
52]. Further, the inferential finding substantiated the descriptive findings regarding the role that instruction in school settings can play for minority adolescents in changing their flossing behavior. Teachers, school nurses, guest speakers, school health educators, and others in the schools can help minority adolescents develop flossing behavior through concerted messaging.
Among those minority adolescents who were flossing as expected, the intention to sustain flossing was significantly predicted by the three constructs of the MTM, namely, emotional transformation, practice for change, and changes in the social environment along with the grade level and instruction in school and accounted for almost 31% of the variance, which is a higher range for behavioral studies [
22,
23]. Among those who were not flossing, also, all three constructs of the MTM, namely, emotional transformation, practice for change, and changes in the social environment, were statistically significant predictors along with instruction regarding flossing in school and being African American and accounted for a substantial proportion of variance (42%), which is high for behavioral studies [
22,
23]. Emotional transformation is about changing the feelings toward the goal of daily flossing and is crucial for maintaining behavior, which was supported by this study and found to be a significant construct in many other studies [
26,
34,
35,
37,
38]. Adolescents can be taught to recognize their feelings and direct them toward the concrete goals of flossing. Such an approach will strengthen the maintenance of the flossing habit, which has a high relapse rate. Practice for change was found to be significant in this study and has also been an important construct in many other studies with the MTM [
26,
34,
35,
37,
38]. Thinking about flossing by adolescents and thinking of ways to overcome barriers in the process are a part of the practice of change and are essential for the habit formation of flossing. Educational programs must build on this aspect. Finally, the construct of changes in the social environment was found to be significant in this study and has also been an important construct in many other studies with the MTM [
26,
34,
35,
37,
38]. It is important for family, peers, and other professionals, including teachers, dental hygienists, dentists, and primary care providers, to underscore the importance of flossing among minority adolescents.
4.1. Implications for Practice
The study underscored the need for education in schools regarding flossing for minority adolescents. This task can be built into the curriculum and imparted by the teachers or separately by the school nurses. Additionally, guest lectures by dental hygienists to schools can be arranged. As pointed out earlier, Aguirre-Zero et al. (2016) found that not knowing the proper technique for flossing and a lack of messages regarding flossing were barriers among Mexican children, and a study by Mattos-Silveira et al. (2017) pointed to a lack of motivation and lack of skills [
16,
17]. Our findings also supported this gap and underscored the importance of behavioral confidence in starting to floss. Further, our study pointed out the need for the availability and accessibility of floss among minority subpopulations. Here, the corporate sector and governmental subsidies can potentially play a role in making floss available to all, irrespective of their being able to afford it. The three constructs of the MTM, namely, emotional transformation, practice for change, and changes in the social environment, will go a long way in building the habit of flossing and must be the cornerstone of all educational interventions. Finally, our study found that visits to dentists also play a potentially important role in facilitating flossing behavior, as shown by a higher proportion of the adolescents flossing in this subgroup. Once again, dentists can provide free visits for those who cannot afford to pay, insurance companies can extend dental visits at low premiums, governmental subsidies can be instituted, etc., to promote access to dental care.
4.2. Strengths and Limitations
Our study was the first study to utilize a fourth-generation behavioral model to explain the correlates of flossing among minority adolescents. This study will pave the way for designing robust educational interventions for the promotion of flossing in schools and other settings. However, there were some limitations to our study. The data were collected by self-reports, which have the potential for several biases, such as dishonesty, exaggeration, under-reporting, acquiescence bias, recall bias, and social desirability bias. However, for gauging attitudes, this is the only way to collect data. In this study, intention for flossing was used as a proxy measure of actual flossing. Future studies can utilize experimental designs with interventions to gauge actual behavior change. Further, we did not test for stability reliability in our study. Future studies can conduct the test–retest reliability of the instrument, especially before conducting interventional studies. Finally, the cross-sectional study design did not allow for establishing causality, as both the independent and dependent variables were measured at the same point in time. Future work with interventional experimental studies can overcome this limitation.