This study used clinician exams to assess the DAI [10] to simulate the dental analysis. This index attributes a mathematical score that reflects the severity of malocclusion and uses a cut-off point to determine the need for orthodontic treatment focusing on the aesthetic aspects of occlusion [14]. There are possible limitations with the use of the DAI as well as the other orthodontic treatment need indices; however, these indices can be used in epidemiological research and in treatment planning [15].
The perception of orthodontic treatment need was not associated with gender, in contrast to the treatment need according to DAI, which provides information depending on the variable (OR = 2.44, 95 % CI = 1.33–4.45, p = 0.03). Furthermore, gender can be associated with dental appearance according to the mothers and children’s perception, so it was noted that mothers of girls tended to be dissatisfied with the dental appearance of their daughters, which could be observed with regard to the child’s self-perception. This issue is controversial in the literature, and there are studies that either prove this association [16, 17] or not [18, 19]. However, the variability in the methodological approach of these studies is well known, with different designs, samples, and indicators.
The types of malocclusion were associated with certain components of the DAI in both groups of individuals. Dental crowding, maxillary overjet, and maxillary and mandibular misalignment were directly associated with the need perceived in 12-year-old children and their mothers (Table 1). Dias and Gleiser [16] observed this fact in a similar sample, but with a different data collection methodology. There is an agreement between the perception of orthodontic treatment need and some types of malocclusion, with propensity for the most prevalent anterior disorders. Moreover, changes in occlusion might cause dissatisfaction with appearance and influence psychological health in terms of self-concept, quality of life, and treatment decision [4, 20, 21]. When the types of malocclusion were analyzed by a logistic regression, the maxillary overjet, spacing, and crowding were predictable variables for orthodontic treatment need in children, with chances of 1.86, 1.93, and 3.46, respectively. On the other hand, the maxillary overjet and anterior open bite increased at three and six times the chance to the negative perception of mothers regarding the child’s necessity of treatment. The adjustment of multivariate logistic regression minimized the number of covariables performing a plausible and clinically generalized model, without confounding factors (overall statistics p < 0.00).
Satisfaction with the appearance of teeth and the perception of orthodontic treatment need showed the same trend in both groups studied, with significant association. This study found that children and their mothers more frequently realize the need for orthodontic treatment, which might be associated with satisfaction with the appearance of teeth and suggested a possible impact of these children’s oral conditions on their mothers’ lives. Badran et al. [2] found the association between self-perception of dental aesthetics and the perception of mothers about their children’s dental appearance and orthodontic treatment need.
The literature is contradictory with regard to parental knowledge about their children, especially on issues related to activities outside the home and deepest feelings [4]. Jokovic et al. [22] observed that many parents reported not knowing about issues related to their children’s welfare. However, orthodontic treatment need might be directly connected to aesthetics, determined by cultural and social issues, suggesting that there should be consensus between parents’ and children’s perception of what is considered satisfactory.
The ideal orthodontic treatment might be overestimated by clinicians when compared to patients’ smile perception [23]. There is an association between what it is evaluated clinically and what it is bothering the child, but these aspects must be evaluated with caution. There is a low correlation between what it is determined by the dentist (DAI) and the treatment need perceived by children and mothers. Comparably, Spalj et al. [24] showed a positive significant association between objective (DAI) and subjective assessment of orthodontic treatment need in children, in addition to showing that the aesthetic evaluation of parents had low predictive value.
The high prevalence of dissatisfaction with appearance and the subjective need for orthodontic treatment was relevant in this study. This fact might be attributed to body changes, increasing interest in dating and relationships, which makes body and physical attributes especially important at this stage of development [4, 7]. Shalish et al. [25] reported that self-satisfaction with dental appearance had a greater effect on the self-perception of orthodontic treatment need in pediatric patients.
Additionally, it is important to emphasize that socioeconomic issues might also influence individuals’ perceptions. This study comprised a population with low socioeconomic level and high need for orthodontic intervention (76.3 %) in 12-year-old children. Piovesan et al. [26] showed that parents with low incomes were more likely to categorize the oral health of their children as “poor,” but they did not explain the relationship of this dissatisfaction with malocclusion. This is important to emphasize that social disparities might be associated with this perception. Such inequalities could affect the well-being of families and children, resulting in a negative impact due to psychosocial and environmental influences and even to material deprivation [27].
The association between the need for orthodontic treatment (DAI) and the child’s satisfaction with chewing was not significant, suggesting that malocclusion has no direct impact on the perception of masticatory function, as was as also observed by Tessarollo et al. [20]. Therefore, the limitation of the method should be emphasized, because it failed to assess changes that caused greater masticatory discomfort such as overbite, posterior tooth loss, open bite, and posterior cross bite [5].
This study did not evaluate the social impact of malocclusion and all the variables that influence the need for orthodontic treatment in children; in this case, it focused only on factual and not causal relations. More importantly, the present findings, based on a representative sample, can be used to formulate hypotheses for populations with similar demographic and cultural characteristics, low socioeconomic status, and living in an underdeveloped country.
It is important to recognize the limitations of the present study. First, the inherent limitations of cross-sectional studies in which exposure and outcome are determined simultaneously, and the time sequence is often impossible to define. Secondly, the risk of bias from the answers on the questionnaires is also important to consider. Therefore, to minimize this latter limitation, a pilot study was performed.
Clinically, it is important to emphasize that the subjective nature of DAI, which depends on the cultural aspects of the country, was limited for assessing the psychosocial aspects of oral health and the quality of life of the individuals [28]. Thus, the use of a personal questionnaire that includes the perception of children and parents regarding the orthodontic treatment need is necessary before formulating a treatment plan, for a more contextualized and effective approach.