Background
The impact of orthodontic treatment on Oral Health-related Quality of Life (OHRQoL) in children has not yet been explored in longitudinal studies.
Methods
This prospective cohort study utilised the CPQ11-14 and previously validated malocclusion indices (IOTN, ICON, DAI, PAR) to investigate treatment-related changes in malocclusion and OHRQoL in a sample of patients drawn from a practice-based network of 19 specialist orthodontists in New Zealand. The participants underwent orthodontic treatment with a two- arch fixed appliance. They were followed during treatment (mean duration 26 months), and for an average of 21 months afterwards. Patient records were taken at 3 stages: prior to treatment beginning, at debond; and (within approximately 3 months of the 24-month anniversary of debond).
Results
At baseline, there were 174 patients (mean age 13.5; 64.4% female). The follow-up rate over treatment was 87.4%, but fell to 59.8% by the end of the study.
The CPQ11-14’s construct validity was confirmed. Baseline malocclusion indices were weakly correlated with CPQ11-14 and subscale scores, and varied considerably in their correlation with each other. The most consistent index was the DAI. The reduction in malocclusion was recorded with large effect sizes seen across all 4 malocclusion indices, this ranged from 88 to 99% depending on index. Little change in OHRQoL overall was detected during treatment, although differing impacts occurred with different subscales. The prevalence of impacts increased with treatment, the biggest increase being seen in the oral symptoms subscale.
In the period immediately after treatment, there was a large decrease in impact prevalence, predominantly seen in the emotional well-being and social well-being subscales. By the end of the study (21 months post-debond), the changes in CPQ11-14 scores were all substantial, and surpassed those found in comparable intervention studies. More than 97% of participants expressed satisfaction with their treatment. Males had greater reductions in malocclusion than females, but females had more positive OHRQoL changes.
Conclusions
Severe malocclusion has a significant negative impact on the OHRQoL of orthodontic patients prior to treatment. The finding of inconsistent gradients between the overall CPQ11-14, oral symptoms and functional limitations subscales with some of the malocclusion indices is concordant with the lack of physical impacts experienced with some malocclusions. Self-esteem does not change and females have less physical change, but they receive more psychological benefit than males from treatment.
There is a detectable association between malocclusion and OHRQoL prior to treatment and at some time after the completion of treatment. Orthodontic treatment itself is highly successful at reducing the severity of malocclusion. OHRQoL clearly improves following orthodontic treatment. However, a temporary increase in symptomatic impacts may occur during treatment. The reduction in impacts occurs later, after the braces have been removed, although some shorter-term improvement in emotional well-being may occur prior to this. The findings of this study may be unsurprising to orthodontists, but help to substantiate the validity of contemporary models of patient-based outcomes linking biological, social, and psychological factors. As far as orthodontic treatment is concerned, focus should be placed on its psychosocial benefits.
