The main objective of this study was to analyse whether QoL increases in children and adolescents with CL/P after their aesthetics and functionality have been treated with orthodontics and surgery. The results showed that patients perceive that their current QoL has increased after orthodontic and surgical treatment, in relation to all the evaluated domains (physical, psychological, and social health). The largest effect sizes were found in physical health, specifically in physical function and communication.
Although these results are generally consistent with those found in the literature, it is difficult to make specific comparisons by dimension, given the heterogeneity of measures used for the evaluation of QoL with regards to the instruments being not specific to children and adolescents with this condition.
Among the general QoL assessment instruments applied to CL/P, the Oral Health Impact Profile-14 (OHIP-14) should be highlighted owing to its high frequency of use. Thus, with this instrument, Beluci and Genaro [1] found QoL increases after treatment in the physical, psychological, and environmental domains (in line with our results), but reported no significant differences in social relationships before and after treatment. However, Antoun et al. [23], also using OHIP-14, reported a small change in OHRQoL pre-post treatment in a CL/P sample (in comparison with outcomes of surgical patients without a cleft). This small change is argued on the basis that cleft patients do not experience a drastic transformation of their appearance compared to other surgical patients. Broder et al. [2], using the Child Oral Health Impact Profile, found that surgical youth with a cleft experienced the greatest increase in OHRQoL in comparison with non-surgical youth with CL/P.
Other results using general QoL instruments (e.g. Michigan Oral Health-Related Quality of Life Scale) after treatment, in samples between 12 and 23 years of age, indicated adequate levels of QoL after treatment, particularly in the domain of oral functionality, consistent with our results [5].
As noted, other studies have used specific instruments to measure QoL in patients with CL/P. These include the questionnaire designed by Piombino et al. [24], whose adaptation we used in the present study. To our knowledge, this instrument is the only one that, administered only once, after the intervention, allows an assessment of the patient’s perception, before and after treatment, of different domains of QoL. The results, in an age sample of 16 to 23 year olds, showed improvements in the physical health domain and in psychological health (specifically the behaviour dimension), although they did not make a differential analysis of the effect sizes on the perception of improvement in the different domains [24].
The differential study of the self-perception of QoL improvement after treatment is a novel aspect of this research. Our results show that this self-perception of improvement (assessed at a single moment in time through both a current and a retrospective perception) coincides, as a whole, with the results of improved QoL observed in studies with ‘pre-post’ treatment designs [1].
In this context, effective treatment is important, particularly surgery, as its effect is a possible improvement on self-perception [19]. Few studies have placed value on the improvement in the psychological and social health areas in relation to the physical area after treatment in children and adolescents. Moreover, the few results in this regard are not conclusive. Albers et al. [19], in a population with CL/P (aged 12 to 63 years), observed a reduction in dissatisfaction with facial appearance after nose surgery, but found no significant change in self-concept in the short term. They concluded that, after years of psychological adaptation to the malformation, relatively small changes from functional and cosmetic surgery can result in a significant reduction in distress and increased psychological well-being. However, other studies have predicted improvements in self-concept after treatment [18, 26]. Self-concept has been conceptualized as a central element in most studies, looking at improving OHRQoL in children with CL/P after treatment [27].
Our results indicate significant ‘pre-post’ treatment improvements in all of the assessed QoL areas, from the young patients’ retrospective perception. Consistent with previous studies, the highest effect sizes were observed in physical health, particularly in physical function and communication, as they involve the direct results of the intervention itself. The psychological (self-concept and behaviour) and social health domains showed moderate effect sizes. In this context, and given the absence of studies carried out from this pre-post retrospective design in children and adolescents, future research should be directed at the mechanisms of improvement in the psychological and social areas after treatment.
Finally, another aspect of interest in this study, which has been absent in previous ones, is the possible interaction of gender and age in pre-post treatment improvements across the different domains of QoL. Regarding the interaction of gender in these domains, no direct effects on QoL were found after treatment improvement; however, a gender interaction was observed in the relation between the domains before and after treatment, particularly in behaviour and social function. Specifically, perception of post-treatment QoL was more influenced by perception of previous QoL in girls than in boys. This finding has important practical repercussions, as the effects of treatment on QoL will depend on perception of previous QoL to a greater extent in girls than in boys. Thus, differential and personalized preventative treatment actions must be applied in different domains. To our knowledge, no previous studies have specifically addressed this issue. However, although unrelated to treatment, different authors [2, 3, 10, 27] have reported greater perception of aesthetic and behavioural problems, dissatisfaction with their image, low self-concept, and emotional instability in women than in men with CL/P, and particularly, in the young and adolescent population. The differences with regards to social function are controversial, with studies indicating better [28] and worse scores [10] for women than for men in this domain.
Regarding age, no interaction effects were observed in the relation between QoL perceptions before and after treatment. We only found that social functioning after treatment improved with the age of the children and adolescents. However, while some studies have pointed to a better psychosocial adjustment in older adolescents [3], others have found worse psychosocial adjustment at a later age [23, 29]. These results could be explained by the disparity in the instruments and age ranges considered; in any case, none of the preceding studies have evaluated the influence of age on the relationship of QoL before and after treatment.
The present study has a number of limitations that need to be considered. The associations must be interpreted according to the observational nature of the study design, which does not allow inferences of causality. Although the advantage of the instrument used for the measurement of QoL, compared with the rest of the existing ones, lies in its assessment of variables before and after the treatment, it did so retrospectively, being administered at a single moment in time in our study. It is important to note that this assessment is not equivalent to the administration of the same instrument at two different times (before and after the intervention). In particular, the retrospective measure (especially the pre-treatment moment) could lead to an overestimation bias of the current QoL compared with the previous one.
Furthermore, the instrument does not allow to assess which treatment (surgical and/or orthodontic) produces the perception of improvement. The age range considered was wide, although relatively narrow compared with other studies [18, 19]. However, with regards to this limitation, our results indicated the absence of significant relations (except in the case of social function) between age and QoL. Finally, we should add the non-consideration of the type of cleft, and therefore the type of malocclusion, as an analysis variable (owing to the size of the sample), which made it impossible to evaluate the results according to the severity of the malformation. Nonetheless, the dimensions of QoL contemplated are common to all types of clefts. Thus, we encourage researchers to replicate these findings using different populations with CL/P and including other important variables such as clinical orthodontic outcomes.