An investigation of the early effects of fixed orthodontic treatment on dietary intake and body weight in adolescent patients

Abstract

PhDAim: To investigate the effects of fixed orthodontic treatment on dietary intake and body weight. Methods: A hospital-based prospective cohort design undertaken in two distinctive parts: An initial qualitative study in which semi-structured one-to-one interviews using a topic guide, with 10 adolescent patients (4 male; 6 female) with a mean age of 13.21 (SD 0.71) years, were used to identify changes in dietary behaviour and intake in response to fixed appliance treatment. The topic guide was tested, in 4 pilot interviews (1 male; 3 female) with a mean age of 12.5 (SD 0.98), before using it in the final test sample. A framework analysis method was used for data analysis. A supplementary questionnaire was developed to assess dietary behaviour based on the main themes and subthemes identified. The second part was a quantitative study in which a total of 124 adolescent patients (41.9% male; 58.1% female) aged 11-14 (mean 13.1, SD 0.91) years were consecutively recruited and allocated to test and control groups. Both groups completed a socio-demographic questionnaire, food frequency questionnaire (FFQ) and child perception questionnaire (CPQ11-14) at baseline, 4-6 weeks and 3 month follow-up periods. On each occasion body mass index (BMI) and body fat percentage were measured. Patients completed a pain diary during the study period. In addition, the test group completed the supplementary questionnaire at both the 4-6 week and 3 month follow-up periods. Results: Qualitative study: All patients reported varying degrees of pain levels which declined within the first 2 weeks. All patients reported that their diet changed in response to pain, inability to bite and chew and in response to the dietary instructions given to them by their orthodontist. Patients felt that their eating habits had become healthier during treatment. Quantitative study: The response rate was 96.8% and the drop out was 12.1%. Both groups were comparable in relation to socio-demographic characteristics and baseline measurements. Patients adapted to pain by days 3 and 2 during the first and second follow-up periods, respectively (P<0.001), with pain intensity during the first period being the greatest. There was no significant difference between both 4 groups with respect to changes in energy, macro-nutrient intakes and BMI. Changes in fat percentage were significant between both groups (P<0.001). However, after adjusting for BMI status at baseline, changes in fat percentage between both groups were not significant. The impact on dietary behaviour was significantly higher at 4-6 weeks compared to 3 months (P<0.002). Only the oral symptoms domain of the CPQ11-14 worsened significantly during the first period of follow-up (P<0.001). BMI status at baseline appeared to be the only marginally significant moderator of change in fat percentage and impacts on dietary behaviour (P<0.05 and P<0.049, respectively) at follow-up. Conclusion: There were no significant statistical or clinical changes in dietary intake and behaviour, BMI and fat percentage during the first 3 months of fixed orthodontic treatment