Contact person:
Emma Göranson
  • Folktandvården Östergötland
  • Malmö Universitet
  • Folktandvården Stockholm
Responsible at MaU:
Mikael Sonesson
Project members at MaU:
External project members:
  • Lillemor Dimberg - Folktandvården Stockholm
Time frame:
01 September 2019 - 01 September 2027
Research subject:
  • Dentistry
  • Orthodontics
  • Oral Health Related Quality of Life
  • Equity of Dental Care

Project description

Approximately 70% of all children and adolescents have some form of malocclusion, and around 30% are in need of orthodontic treatment. A malocclusion is not a pathological condition or a disease, but many malocclusions, if left untreated, can lead to damage to teeth or other oral tissues, as well as reduced oral health-related quality of life (Thilander, 1973, Helm, 1968, Helm, 1975). In a systematic review from 2015, there was moderate to high-quality evidence that visible malocclusions have a negative impact on the oral health-related quality of life of children and adolescents (Dimberg, 2015). Regular updates of systematic reviews are recommended, which is even more crucial in the current field as several new studies have been published in recent years. Additionally, search methods, PECOS, RoB templates, and GRADE assessment need to be updated to current standards.

The most commonly used instrument for measuring oral health-related quality of life in children and adolescents is the Child Perceptions Questionnaire developed for 11-14-year-olds (CPQ11-14) (Jokovic, 2002). CPQ is a generic instrument aimed at children and adolescents in general. To more nuancedly measure the significance of malocclusions for oral health-related quality of life, it may be valuable to use a specific instrument containing more detailed questions about the appearance of teeth and psychosocial impact. One such instrument is the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) (Klages, 2006).

PIDAQ has been translated into several languages but has not been available in Swedish previously. Healthcare and dental care are required by Swedish law to be equitable. This issue became particularly relevant in 2021 when an investigation was published on how the dental care system can become more resource-efficient and achieve more equitable oral health (SOU 2021:8). Despite Swedish law, there are studies indicating inequalities in oral health and orthodontic care. The prevalence of caries and missed dental visits is higher in groups with lower socioeconomic status than in groups with better socioeconomic conditions (André Kramer, 2018).

Low caries risk and good oral hygiene are prerequisites for orthodontic treatment, which could result in socioeconomically disadvantaged groups receiving orthodontic care less frequently than socioeconomically advantaged groups. At the same time, demand for orthodontic treatment may differ between different groups. The relationship between socioeconomic status and orthodontic treatment can be complex. Another aspect of equitable care is gender equality. Of the patients starting orthodontic treatment in Östergötland in 2018, 60% were girls and 40% were boys, and similar figures are reported from other regions in Sweden. This is despite the fact that the overall prevalence of malocclusions is similar between genders (Thilander 1973, Helm 1968).

The reason for any dissimilarities between genders could be differences in demand for care. Girls have been reported to have a higher perceived need for orthodontic treatment and to be more dissatisfied with their teeth than boys (Lilja-Karlander 2003, Birkeland 2000). There is a lack of knowledge about how socioeconomic factors affect orthodontic care in Sweden. It is also unknown if there are significant differences between genders in receiving orthodontic treatment and demand for care. Therefore, the research project aims to map these equity aspects in Swedish orthodontic care.

Overall aim and specific objectives

The overall aim of the research project is to map equity aspects in orthodontic care and to investigate the impact of malocclusions on the quality of life of adolescents.

Study I

To update a previous systematic review (Dimberg, 2015) and add a meta-analysis to map the evidence on how malocclusions affect the oral health-related quality of life of children and adolescents.

Research question:

  1. Do malocclusions in children and adolescents aged 10-19 years affect their oral health-related quality of life?

Study II

To translate the PIDAQ questionnaire into Swedish and validate it for use on adolescents aged 12-19 years in a Swedish context.

Research question:

  1. Does the translated Swedish version of PIDAQ have good validity and reliability in a population of 12-19-year-olds? The translation of PIDAQ follows guidelines published in 'Guidelines for Establishing Cultural Equivalency of Instruments' (Ohrbach, 2013).

Study participants in the validation work are a consecutive sample of 12-19-year-old patients at the Center for Orthodontics/Pedodontics in Östergötland, and the responses from patients with malocclusions (before treatment) are compared with the responses from patients without malocclusions (after treatment).

Study III

To examine equity in orthodontic care by investigating whether the proportion of adolescents receiving orthodontic treatment differs between individuals from different socioeconomic groups and genders.

Research questions:

  1. Is orthodontic care equitable?
  2. Does the proportion of individuals receiving orthodontic treatment differ between individuals from different socioeconomic groups and genders (adjusted for the prevalence of caries)?

Study III is a register-based cohort study of approximately 20,000 adolescents from Östergötland. Data on performed orthodontic care within Public Dental Service Östergötland is linked with socioeconomic information from Statistics Sweden (SCB) and dental health data from the Swedish Quality Register for Caries and Periodontitis (SKaPa). Multiple logistic regression is used to calculate odds ratios adjusted for confounding factors.

Study IV

To use PIDAQ and CPQ11-14 short form to map the oral health-related quality of life in individuals with and without malocclusions.

Research questions:

  1. Is there a difference in oral health-related quality of life in individuals with and without malocclusions and with different types of malocclusions?
  2. Does oral health-related quality of life differ in relation to the degree and type of malocclusion among individuals of different gender and socioeconomic statuses?

Study IV is a clinical multicenter study; data is collected at Public Dental Service Östergötland, Public Dental Service Stockholm, and the MaU Faculty of Odontology. Adolescents to be recruited for the study are:

  • 500 individuals aged 12-19 with malocclusions (new patients at orthodontic specialist clinics)
  • 175 individuals aged 12-19 without malocclusions (recruited at general dentistry care clinics)

Study participants will be asked to complete questionnaires measuring oral health-related quality of life (CPQ 11-14 and PIDAQ), and clinical photos will document their bite. Socioeconomic data about the study participants will be collected retrospectively.