The impact of orthodontic treatment on eating related quality of life on different cultures and different age groups (United Kingdom and Kurdistan populations)

Abstract

Orthodontic treatment is a lengthy procedure that is likely to introduce changes to the patient’s Oral Health Related Quality of Life (OHRQoL) and affect some daily activities. Eating is one such activity, however our knowledge of these impacts is limited. In addition there are no existing patient reported outcome measures to assess the effect of orthodontic treatment on eating related quality of life (ERQoL). The aim of this study was to explore ERQoL of orthodontic patients by conducting a qualitative study and developing and validating an ERQoL specific measure. This will expand our existing knowledge of ERQoL and form the foundation of dietary instructions provided before and during orthodontic treatment. Items for the ERQoL measure were generated from a previous UK based qualitative study conducted at Newcastle University with child orthodontic patients aged 11-14 years old. The data was re-analysed for the current study and the analytical framework (index) used as the information source for question generation. Initially 45 questions were generated and the research team undertook question reduction and categorised the questions into themed domains. In the UK, 12 orthodontists assisted with content analysis to determine the relevance and clarity of the questions according to their own clinical experience and 15 orthodontic patients aged 11-16 years evaluated the measure in the face validity stage. The questionnaire was modified following each of these stages. Finally, 30 British child orthodontic patients answered the questionnaire twice, two weeks apart to determine reliability of the questionnaire. Internal consistency was examined using alpha correlation giving a range of 0.5- 0.84 at a domain level. Test re-test reliability (using intra class correlation coefficient, paired t-test and Wilcoxon rank test) was used to determine the stability and reproducibility of the questionnaire. According to these tests most of the participants gave consistent answers 2 weeks apart. Two questions (adaptation to the orthodontic treatment and swallowing difficulty) did demonstrate statistically significant differences at the two time intervals but were retained due to their perceived importance and relevance to orthodontic treatment. This relevance was confirmed by findings from the UK and Kurdistan qualitative studies. The final questionnaire was composed of 28 questions within 6 domains. 26 questions were quantitative, using a Visual Analog scale (VAS) as a rating scale and 2 questions were qualitative with a free text area for writing the answers. The ERQoL questionnaire was found to be an acceptable and reliable measure to determine ERQoL during orthodontic III treatment in a larger sample in the UK. To expand our existing knowledge about ERQoL of orthodontic patients during the time of the treatment 30 semi-structured interviews and 4 focus groups were conducted with Kurdish children (11-16 years old) and adults (17-25 years old) in Kurdistan of Iraq. The qualitative data was analysed using a framework analysis and different themes and subthemes were identified in relation to the functional, social, emotional and psychological experiences of the patients during their orthodontic treatment. Participants confirmed that ERQoL in orthodontic patients is affected by orthodontic treatment, particularly at the start of the treatment. The most common features described were pain and the physical obstacle of the appliances which leads to functional and social limitations. This treatment also introduced some eating habit changes as a reaction to the difficulties and affected the enjoyment of eating. Chopping some foods into smaller pieces, reducing eating speed, using smaller mouthfuls and retaining the food for a longer time in the mouth were the most common eating habit changes. Moreover most of the participants had a softer diet and avoided hard and chewy food particularly at the start of the treatment. Most of these difficulties were found in both adult and child age groups. Additionally most of the difficulties especially the functional problems were found to be similar between both British and Kurdish cultures. The quantitative and qualitative findings of this research suggests consistency in eating related difficulties during orthodontic treatment across different ages and cultures. The ERQoL questionnaire may therefore be suitable for use in a wide range of contexts.