Development of the Malocclusion Impact Questionnaire (MIQ) to measure the oral health-related quality of life of young people with malocclusion: part 2 – cross-sectional validation

Abstract

Objective: To test the items, identified through qualitative inquiry that might form the basis of a new Malocclusion Impact Questionnaire (MIQ) to measure the oral health-related quality of life (OHQoL) of young people with malocclusion. Methods: Piloting with 13 young people reduced the number of items from 37 to 28. Cross-sectional testing involved a convenience sample aged 10-16 years, attending the Orthodontic Department of the Charles Clifford Dental Hospital, Sheffield. The fit and function of the initial MIQ questions were examined using item response theory. Results: 184 participants (113 females; 71 males) completed a questionnaire (response 85%), seven participants were excluded due to missing responses. The mean age of participants was 12·9 years (SD 1·4) and they had a wide range of malocclusions. The majority were White British (67·4%). Data from 47 participants were used to analyse test-retest reliability. Rasch analysis was undertaken, which further reduced the number of items in the questionnaire from 28 to 17. Unidimensionality of the scale was confirmed. The analysis also identified that the original 5-point response scale could be reduced to three points. The new measure demonstrated good criterion validity (r = 0·751; P < 0·001) and construct validity with the two global questions ('Overall bother' ρ = 0·733 and 'Life overall' ρ = 0·701). Internal consistency (Cronbach's alpha = 0·906) and test-retest reliability Intraclass correlation coefficient (ICC = 0·78; 95% CI 0·61-0·88) were also good. Conclusion: Cross-sectional testing has shown the new MIQ to be both valid and reliable. Further evaluation is required to confirm the generalisability as well as the ability of the new measure to detect change over time (responsiveness).

Does orthodontic treatment before the age of 18 years improve oral health-related quality of life? A systematic review and meta-analysis

“…One such instrument has been devised and the details of this malocclusion-specific instrument have recently been published. 36,37 Clearly, the impact of orthodontic care on OHRQoL following completion of treatment needs to be explored further using high quality research methodology. Such studies need to be prospective in nature, with appropriately selected and sized study and control groups, using a malocclusionspecific and a generic OHRQoL outcome measure.…”

Malocclusion-Related Quality of Life Questionnaire (MRQoLQ): Development and validation of a new psychometric tool for older adolescents with malocclusion

“…All the available condition-specific tools to assess malocclusion-related quality of life has been created for English-speaking developed countries. [7][8][9][10] Translation and cross-cultural adaptation is done prior to its application in countries of different language and culture. No condition-specific malocclusion scale has currently incorporated socioeconomic status of the subjects, even though it has influence in malocclusion-related quality of life among adolescents.…”

“…2,3 There has been a paradigm shift in this concept with the introduction of psychometric scales to measure this intangible dimension of health. [4][5][6][7][8][9][10] Children with malocclusions are often subjected to bullying in schools. 11 They, even at the age of 8 or 9 are conscious about their appearance.…”

“…4,5,[7][8][9][10]12 Marshman and Robinson 13 have expressed the inappropriateness of using generic questionnaires for subjects with malocclusion. Among the available condition-specific tools, [7][8][9][10] Orthognathic Quality of Life Questionnaire (OQLQ) is exclusively for orthognathic patients 7,8 and Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) is primarily for adults. 9 The recently published Malocclusion Impact Questionnaire (MIQ) developed in UK can be used for young adolescents between 10 to 16 years.…”

“…9 The recently published Malocclusion Impact Questionnaire (MIQ) developed in UK can be used for young adolescents between 10 to 16 years. 10 However, two problems noted among the existing condition-specific questionnaires were: lack of a conceptual model explaining the theory behind the scale, and none of them contained items related to socioeconomic status of individuals seeking orthodontic treatment. Orthodontic treatment is subsidized only in certain countries and the uptake is based on the normative criteria.…”