Any deviation from the 'norm' will stigmatise a person and potentially make them less acceptable socially.1 Deviation can be as simple as dental anomaly or as complex as craniofacial deformity.2

Research to date confirms the concern expressed by patients in relation to their appearance, with any shortfall between the individual's ideal and perceived expectations resulting in discontentment and a possible desire for improvement.3 Unattractive people tend to be less liked, less preferred as friends and less desirable as 'dates' and marriage partners, less trustworthy, less intelligent, less successful, more aggressive, and anti-social.4,5,6,7,8,9 Conversely, subjects with a relatively normal dental appearance are judged as better looking, more desirable as friends, more intelligent, and less likely to behave aggressively,10 and teachers have higher expectations of them.11

There appears to be some evidence to suggest individuals who have unaesthetic occlusal traits can attract unfavourable social responses in becoming targets for nicknames, harassment and teasing from other school children.12 Nicknames referring to physical features were usually disliked and in a self-assessment of their own appearance, children mentioned teeth as a feature which they would like to change first.13 Individuals who are being teased and ridiculed tend to be unsure of themselves in social interaction and have low self-esteem.1,14 Thus, it is perhaps not surprising that appearance is usually the principle factor in the motivation for seeking orthodontic treatment amongst lay people.9,15 Both children and their parents alike believe that the cosmetic improvement as a result of orthodontic treatment will enhance the social acceptance and self-esteem of an individual.16

Traditionally, measures of orthodontic need and outcome have placed relatively little emphasis on the patient's perception of need and more importantly, the difference that orthodontic care makes to their daily lives.17 It is now increasingly accepted that measurement of the oral health-related quality of life has an important role to play in clinical practice and should form part of any preventative and/or therapeutic programme intended to improve oral health.18,19 Whilst the literature evaluates the importance of an increased overjet on psycho-social wellbeing,20,21 the impact of dental spacing on quality of life (QoL) has not been previously assessed. Furthermore, the impact of a child's malocclusion on family members has not been assessed using a validated measure of QoL. Thus, the aim of this study was to assess the impact of two different malocclusion traits on the QoL of children and their families.

Materials and methods

Study design

This study adopted a hospital based cross-sectional design. Ethical approval was obtained from North East London Health Authority. A minimum sample size of 30 subjects in each group was proposed to determine a difference of 35% in the impact of malocclusion on QoL between increased overjet, spaced dentition and control groups. This assumed that 15% of subjects in the control group would report impacts of occlusal status on their daily life, with 80% power at the 95% confidence level. Thus, 90 consecutive subjects and one of their parents were invited to participate in this study.


Subjects were recruited from orthodontic consultant clinics, joint orthodontic-restorative and paediatric dentistry consultant clinics at The Royal London Dental Hospital, between February 2002 and April 2003.

The inclusion criteria were patients aged between 13-15 years, who demonstrated the following occlusal traits:

  • Increased overjet (>6 mm and spacing of <1 mm between adjacent contacts)

  • Spaced dentition (open contact points >1.5 mm between adjacent teeth in the upper labial segment [from upper right to left permanent canines, inclusive, (3-/-3) and overjet <6 mm])

  • Control (no traits of malocclusion).

The control group included subjects with a class I incisor relationship (overjet = 2-4 mm) and well aligned upper labial segment accepting minor misalignment and/or spacing of less than 1 mm between adjacent contacts. Patients with a history of previous orthodontic treatment, learning difficulties and/or the presence of any restorations in the upper labial segment were excluded.

Study conduct

Each patient underwent an orthodontic assessment by a single investigator (M.C.). This was conducted in a dental chair, under optimal conditions, using a millimetre ruler to assess space distribution in the labial segment and to record the overjet. Applying the selection criteria outlined above, patients were consecutively recruited to the three groups. Once the sampling quota (n = 30) for any group was obtained, any new patients presenting with that particular occlusal trait were subsequently excluded from the study.

Both the patient and one of his/her parents underwent supervised completion of a questionnaire, independently and concurrently, at their initial consultation appointment, in a large and quiet room. The services of an interpreter were made available, if required. Socio-demographic variables and the parent component of the Child Oral Health Quality of Life (COHQOL) questionnaire were completed by the caregiver.22,23 The child themselves completed the COHQOL questionnaire, designed for children aged 11-14 years. These are valid and reliable measures, developed to assess the impact of oral and orofacial conditions on the QoL of children and their families.22,23 The questionnaire is divided into four sections: oral symptoms; functional limitations; emotional impacts; and social impacts, using five-point Likert scales, with high scores indicating more negative impact on QoL. Both the child and parental questionnaires were self-completed.

Data analysis

All subjects were allocated an identification number and data from the questionnaires were coded. The analysis of data was carried out using the Statistical Package for Social Sciences programme (SPSS Inc., 444 Michigan Avenue, Chicago, USA), version 12, for Windows. It included calculating the frequency distribution of the variables and the statistical significance of the differences on impact of QoL between groups. Non-parametric statistical tests were performed as the impact of QoL was measured using an ordinal scale and the data were not normally distributed. Chi-squared and Mann-Whitney U tests were used. Statistical significance was set at the 5% level.


Response rate

All patients and their accompanying parents recruited to this study agreed to participate, with no withdrawals. Thus, a response rate of 100% was achieved.

Socio-demographic characteristics

Table 1 demonstrates the socio-demographic characteristics of the 90 children in the study. Three ethnic groups were identified: Asian (33%), Caucasian (49%) and Black (18%), with the great majority belonging to the first two ethnic groups. Furthermore, approximately half of the sample was composed of males (54%).

Table 1 Frequency distribution of socio-demographic characteristics in groups (n = 90)

The first stage of data analysis was to test for the presence of any confounding factors. The results (Table 1) demonstrated that groups were similar in relation to age, gender and ethnicity. Differences in the distribution of socio-demographic characteristics between the groups were not statistically significant (Table 1; p > 0.05).

Impact of malocclusion trait on QoL of children

Table 2 reports the impact on the QoL of children in each group and compares the groups. Highly statistically significant differences were observed between children in the control group and their counterparts in the increased overjet (p = 0.002) and spaced dentition (p < 0.001) groups. However, there were no such differences detected between children in the increased overjet and spaced dentition groups (p = 0.5). This suggested that both malocclusion traits have similarly highly significant impacts on QoL.

Table 2 Impact of malocclusion traits on quality of life of children in control, increased overjet and spaced dentition groups

Impact of malocclusion trait on QoL of parents of children

Table 3 shows the impact on the QoL of the parents of children in each group and compares the groups. Parents of children in the increased overjet (p = 0.007) and spaced dentition (p = 0.003) groups reported statistically significant greater impacts on QoL than parents of children in the control group. Similarly to their children, there were no such differences detected between parents of children in the increased overjet and spaced dentition groups (p = 0.9). Again this suggested that both malocclusion traits have a similarly highly significant impact on QoL.

Table 3 Impact of malocclusion traits on quality of life of parents of children in control, increased overjet and spaced dentition groups


This study demonstrated that having an increased overjet or spaced dentition has a statistically significant impact on the QoL of children and their parents. The findings of the present study confirm previous findings in relation to increased overjet: that patients dissatisfied with their malocclusion might have their self-concept impaired and psychological functioning reduced.21,24,25 In addition, and perhaps more importantly, they also offer strong evidence in support of the negative impact on QoL of differing occlusal traits (dental spacing) on both the child and their parents, thus adding to the field of knowledge, as such factors have not been previously evaluated. These findings are supported by a more recent study, which demonstrated that adolescents who never had orthodontic treatment but were found to have high need, were 1.43 times more likely to report having experienced one or more dental impacts on their daily lives, compared with those who have completed such treatment.19 It should however be noted, that a limitation of this latter study was that it did not assess which occlusal traits specifically contributed to the impacts on daily lives for either the children or their parents.19 Subjects with a facial disfigurement frequently complained of rejection and negative behaviour from others in society.26,27 These reported findings along with those of the current investigation serve to highlight the very negative impact that facial and dental aesthetics can have on a child's QoL.

The presence of a malocclusion, in the form of an increased overjet or dental spacing, also affected the life of the parent/family member. This finding, in conjunction with the sound methodology applied, adds to the strength of this research. Whilst it has been generally accepted that parents play a very significant role in a child's motivation for orthodontic treatment, previous studies have not assessed the impact of malocclusion on family members. The finding of agreement between the child and their parent, in relation to the impact of malocclusion, is significant. This highlights the fact that the malocclusion not only has a direct impact on the child themselves but also has an effect on parents and other family members. For example, from the parent questionnaire it was reported they felt uncomfortable in public places with their child. This was felt to be relevant and the findings highlight the potential role of the parent in influencing the child's uptake of orthodontic treatment. Such evaluations may in turn offer the clinician a measure of treatment support and compliance. Both of these can prove to be very important in achieving a successful outcome, as a lack of cooperation from patients has been reported to be the most common cause of orthodontic treatment failure.28

The impact of malocclusion on a subject's QoL is currently lacking in the dental literature, as traditional measures of orthodontic need adopt indices which focus more specifically on the occlusal traits present.28,29 Furthermore, there is no currently available QoL instrument which can specifically be applied to malocclusion alone. Attempts have been made to introduce such measures,17,30 however their validity remains to be tested. The current study utilised the Child and Parental-Caregiver Perceptions questionnaires, which are components of the COHQOL.22,23 The principle limitation of this questionnaire is that it does not elicit the specific cause(s) of the impacts recorded, which can be related to a variety of oral health conditions and not necessarily the subject's malocclusion. However given that the patient demographics were similar between groups, the highly statistically significant differences observed between children with 'normal' occlusion and their counterparts in the increased overjet and spaced dentition groups suggested the results are not due to confounding factors. Thus, if orthodontic treatment is undertaken to improve dental aesthetics and self-esteem,12,31 then the inclusion of a QoL measure may prove to be a valuable adjunct to the more traditional indices applied in the assessment of orthodontic treatment need and their perceived benefits.

The inclusion of patients presenting at the dental hospital in the current study could have introduced an element of bias. It may be that these patients report greater oral health impact in the hope of receiving orthodontic treatment or that those seeking treatment report a greater impact than those not seeking treatment. Furthermore, there is potential bias due to the fact that the study did not fully control for oral health status. This is likely to have reflected on the assessment of impact arising from the two occlusal traits tested. Whilst the test groups (spaced and increased overjet) were free of untreated caries and other oral diseases, the control group had, by definition, some level of disease. Thus, it is likely that the impact of these two occlusal traits would have been higher than that identified in this study had the control subjects been healthy individuals, devoid of any dental disease.

Having established from the current research the impact of these two occlusal traits, further research is needed to test the impact of additional malocclusions, which may similarly impact negatively on both the child and their family, and evaluate orthodontic treatment of these conditions on QoL of children and their parents.


The presence of occlusal traits, such as an increased overjet and spaced dentition, have a significant negative impact on both children's and their families' quality of life.