Professor Philip Benson BOSF Grant 2005

Does undergoing orthodontic treatment affect the quality of life of adolescents? - A longitudinal study.

BOSF Grant

Primary investigator

Dr Philip Benson (Sheffield)

Secondary investigators

Dr Ama Johal (Senior Lecturer/Hon Consultant Orthodontist, Institute of Dentistry, Barts and the London School of Medicine and Dentistry) assisting students with the questionnaire.

Dr Alison Williams (previously Consultant Orthodontist, Institute of Dentistry, Barts and the London School of Medicine and Dentistry) undertakes the orthodontic examination of a participant.

Project summary

Practitioners of healthcare specialties must present evidence of efficacy and effectiveness to justify the use of and, in publicly financed systems the funding for their specific intervention. Orthodontics is no exception.


Only weak associations have been found between orthodontic treatment and improvements in the dental health of individuals; therefore the benefits would appear to be largely related to life quality. A recent longitudinal study (Kenealy et al., 2007, Shaw et al., 2007) found that orthodontic treatment in childhood had little impact on psychological health in adulthood; however quality of life and, in particular oral health related quality of life are relatively new concepts and were not part of the original investigation. In addition the study did not address the issue of whether psychological factors were influenced by or simply influencing the outcome of treatment. For example, Shaw and colleagues found that those who had had orthodontic treatment in childhood were those with higher self-esteem. This might suggest that the direction of the relationship is not that treatment of malocclusion increases a person's self-esteem; rather that self-esteem influences who seeks and receives treatment.


The aim of our BOSF funded study was to examine the relationships between clinical and non-clinical factors, such as oral health-related quality of life (OHRQoL), which might explain the effect of a malocclusion on an adolescent’s life quality. We have followed a group of schoolchildren longitudinally over 3 years. To determine the complex inter-relationships between these factors we have used a simplified theoretical model of health (Wilson and Cleary, 1995) that has not been applied to malocclusion before.


The analysis of the data from our cohort of 374 schoolchildren suggests that the impact of malocclusion, in terms of OHRQoL, is inconsistently related to clinical factors, such as the IOTN index, but is more influenced by other factors, such as self-esteem and socio-economic status (Benson et al., 2015). This confirms the findings from other studies that self-esteem is a mediator in the relationship between OHRQoL and the clinical status of schoolchildren, rather than being influenced by it, i.e. those with higher self-esteem have less frequent impacts on their life quality from their malocclusion. This might explain the findings of Shaw and colleagues that, after 20 years, those who had received orthodontic treatment did not have significantly higher self-esteem than those who had not received orthodontic treatment. Other work would indicate that although subject to short term variation, self-esteem shows similar stability to other personality traits within individuals over time (Trzesniewski et al., 2003). In addition, people respond and adapt to new situations (such as straightened teeth) and therefore any positive effect will diminish with time (Diener et al., 2006).

Benefit to orthodontics

Since undertaking the BOSF funded study above we have development and validated a condition-specific patient reported outcome measure that aims to quantify the impact of malocclusion on the life of young people (Benson et al., 2016, Patel et al., 2016). We hope that this measure will be used to help answer the important question of whether orthodontic treatment has any benefit, in terms of OHRQoL. Further longitudinal studies are required, using these measures, and taking into account the other individual and environmental factors involved.

What has receiving BOSF funding meant for you in terms of being able to carry out and complete your project?

Without this grant we would not have been able to undertake the lengthy task of visiting schools and recruiting participants, then revisiting them again after 3 years.


Benson PE, Da'as T, Johal A, Mandall NA, Williams AC, Baker SR, et al. Relationships between dental appearance, self-esteem, socio-economic status, and oral health-related quality of life in UK schoolchildren: A 3-year cohort study. Eur J Orthod 2015; 37: 481-490.

Benson PE, Cunningham SJ, Shah N, Gilchrist F, Baker SR, Hodges SJ, et al. 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. J Orthod 2016; 43: 14-23.

Diener E, Lucas RE, Scollon CN. Beyond the hedonic treadmill: revising the adaptation theory of well-being. Am Psychol 2006; 61: 305-314.

Kenealy PM, Kingdon A, Richmond S, Shaw WC. The Cardiff dental study: a 20-year critical evaluation of the psychological health gain from orthodontic treatment. Br J Health Psychol 2007; 12: 17-49.

Patel N, Hodges SJ, Hall M, Benson PE, Marshman Z, Cunningham SJ. Development of the Malocclusion Impact Questionnaire (MIQ) to measure the oral health-related quality of life of young people with malocclusion: part 1 - qualitative inquiry. J Orthod 2016; 43: 7-13.

Shaw WC, Richmond S, Kenealy PM, Kingdon A, Worthington H. A 20-year cohort study of health gain from orthodontic treatment: psychological outcome. Am J Orthod Dentofacial Orthop 2007; 132: 146-157.

Trzesniewski KH, Donnellan MB, Robins RW. Stability of self-esteem across the life span. J Pers Soc Psychol 2003; 84: 205-220.

Wilson IB, Cleary PD. Linking clinical variables with health-related quality of life. A conceptual model of patient outcomes. The Journal of the American Medical Association 1995; 273: 59-65.

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