Malocclusion, Past Orthodontic Treatment, and Satisfaction with Dental Appearance among Canadian Adults

 

ABSTRACT

Objective: To examine whether malocclusion and past orthodontic treatment are associated with satisfaction with dental appearance among Canadian adults.

Methods: Using data from the 2007–09 Canadian Health Measures Survey, this cross-sectional study analyzed information from 2184 respondents (1005 men and 1179 women) aged 20–59 years. The outcome variable was satisfaction with dental appearance. Ordinal logistic regression was used to investigate the relation between satisfaction with dental appearance and 2 independent variables: malocclusion and past orthodontic treatment.

Results: Of the participants, 70% were “very satisfied” or “satisfied” with the appearance of their teeth. The prevalence of malocclusion and past orthodontic treatment was 25% and 20%, respectively. Controlling for the effect of covariates, malocclusion had a significant negative effect on satisfaction with dental appearance (p = 0.02), but past orthodontic treatment did not (p = 0.36). Satisfaction with dental appearance was greater among those in the higher-income group, never smokers, those with better self-rated health, those with no anterior decayed teeth, and those with no anterior filled teeth.

Conclusion: Past orthodontic treatment was not linked to satisfaction with dental appearance in this sample of Canadian adults. Public health programs and clinicians should focus on addressing esthetic problems by restoring inadequate anterior teeth fillings, restoring anterior tooth decay, and implementing smoking cessation programs before considering orthodontic treatment.

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Dental appearance is one of the most important components of facial appearance.¹ Satisfaction with dental appearance improves self-esteem² and quality of life,³ and dental professionals are often responsible for helping patients reach an acceptable level of such satisfaction. People who are dissatisfied with their dental appearance have a greater need for treatment.² Thus, satisfaction with dental appearance not only affects the individual but also influences overall use of oral health care services.

Malocclusion is an umbrella term that refers to a set of growth and developmental anomalies that affect jaws and teeth resulting in variations in their position. People with various traits of malocclusion, such as anterior irregularities, maxillary overjet and anterior spacing, report less satisfaction with dental appearance^4,5 as well as masticatory performance.⁶ However, these patients seek orthodontic treatment mainly because of dissatisfaction with the appearance of their teeth rather than problems with oral functioning.^7-9 Thus, the success of orthodontic treatment should be evaluated with regard to patients’ satisfaction with their dental appearance, and researchers and clinicians should consider patient-centred outcomes in addition to clinically determined criteria in evaluating the results of orthodontic treatment. This is particularly of note with respect to occlusion, as the professional perception of ideal occlusion could vary from that of patients.^10,11 As health services are adapted to meet patients’ needs, patients’ perceptions of orthodontic treatment cannot be underestimated, as it is the patient who receives treatment and must gain satisfaction from improved esthetics.

Dental professionals are becoming increasingly more aware of the importance of patients’ satisfaction with their dental appearance. In a study of orthodontics professionals in Finland, researchers suggested that priority should be given to patients’ opinions of dental appearance rather than professional views when assessing treatment outcome.¹² Despite this, a systematic review found that satisfaction with dental appearance following orthodontic treatment has rarely been investigated, particularly among adult populations.¹³

In this study, we use nationally representative data from the 2007–09 Canadian Health Measures Survey,¹⁴ to investigate whether malocclusion and past orthodontic treatment are associated with satisfaction with dental appearance among Canadian adults.

Materials and Methods

Dataset

Data for this study are from the 2007–09 Canadian Health Measures Survey (CHMS). This is the most recent national health survey of the Canadian population that collected data on oral health indicators. The CHMS is a probabilistic, multistage stratified survey of Canadian households. The sampling framework ensures representativeness of the Canadian population, by collecting data from various age–sex groups sampled from several sites across Canada and stratified by region. The CHMS aimed to provide national estimates by collecting data from a number of sites representative of 97% of the population of Canada.

Oral health data were collected using both household interviews and clinical examinations. Seven Canadian Forces dentists were trained, along with 2 back-up dentists/trainers. The instruction was led by a dentist trained to the World Health Organization (WHO) gold standard level and was intended to ensure both inter- and intra-examiner reliability among the survey dentists.¹⁵ Oral health examinations were conducted in accordance with WHO health survey methods. The methods and sampling framework of the CHMS are described by Statistics Canada.¹⁴

The CHMS collected data from 5604 Canadians aged 6–79 years. In this study, we aimed to study adults aged 20–59 years old (n = 2433). (Note: older adults aged 60–79 were not included because the CHMS had not collected data on the status of occlusion among this age group). From this subsample, we excluded edentulous participants (n = 51) and those currently receiving orthodontic treatment or had missing values (n = 198). Finally, we analyzed the data for 2184 adults aged 20–59 years (1005 men and 1179 women).

Satisfaction with Dental Appearance

The outcome of this study was satisfaction with dental appearance, which was determined through the question: “How satisfied are you with the appearance of your teeth and/or dentures?” Participants reported their satisfaction by selecting 1 of the following answers: very satisfied, satisfied, neither satisfied nor dissatisfied, somewhat dissatisfied, and very dissatisfied. For the purpose of data analysis, responses were collapsed into three categories: satisfied (very satisfied/satisfied), neither satisfied nor dissatisfied and dissatisfied (somewhat dissatisfied/very dissatisfied).

Independent Variable

The 2 main independent variables were malocclusion and past orthodontic treatment. Participants were clinically examined to identify malocclusion, which was defined as the presence of at least 1 of the following conditions: (a) anterior cross bite, (b) severe crowding, (c) severe spacing, (d) posterior cross bite, (e) anterior open bite (> 9 mm), (f) excessive overbite (100% or more), (g) excessive overjet (> 9 mm) and (h) midline shift (> 4 mm). With regard to past orthodontic treatment, participants were simply asked whether they had had orthodontic treatment in the past and the answers were recorded as yes or no. Data collection for the oral health components of the CHMS followed the CHMS Dentist’s Survey Manual and Coding Criteria, in which additional information is provided on the definition of these variables. (This document is available on request to the corresponding author.)

Control Variables

Five sets of control variables were included in the analyses: sociodemographic factors, health behaviours, dental service utilization, general health and clinical oral health. Sociodemographic factors were sex, age, income and marital status. Indicators of health behaviours were tooth-brushing frequency and smoking. Indicators of dental service utilization consisted of: visiting a dental professional in the past year and having dental insurance. General health was estimated using single-item, self-rated health. Indicators of clinical oral health were having anterior decayed teeth and having anterior filled teeth.

Data Analysis

We undertook a cross-sectional analysis of the CHMS survey data. We analyzed the data for the total adult population (20–59 years), young adults (20–39 years) and adults (40–59 years) separately. This classification for age groups was also adopted by the technical report on the oral health findings of the CHMS published by Health Canada.¹⁶  Bivariate and multivariate analyses were performed taking into account the sample weights, consistent with Statistics Canada’s recommendations to provide estimates representative of the Canadian population using STATA 11.1 software (StataCorp LP, College Station, Tex., USA). An ordinal logistic regression model was constructed. According to the approach recommended by Homer and Lemeshow,¹⁷ only variables with a statistical significance of p < 0.25 in the bivariate analyses were entered into the model. The significance level was set at p < 0.05. Interactions of sex with malocclusion and past orthodontic treatment were tested. Because none of these interactions was significant, a sex-stratified multivariate model was not constructed.

Results

Characteristics of the sample population are shown in Table 1: 70% of the participants were satisfied with the appearance of their teeth. On the other hand, 11% were dissatisfied and 19% were neither satisfied nor dissatisfied. The prevalences of malocclusion and past orthodontic treatment were 25% and 20%, respectively.

Satisfaction with dental appearance was examined for a number of variables in the entire population and both age groups (Table 2). Bivariate analyses for the entire population showed that satisfaction with dental appearance was significantly higher among those who had received orthodontic treatment in the past (p = 0.02) and those with normal occlusion (p = 0.01). Further, satisfaction with dental appearance was linked to higher income, brushing teeth twice a day or more, never smoking, visiting dental services in the past year, better self-rated general health, and having no anterior decayed teeth. Age-stratified analysis of the data suggested that some of the variables vary according to age group.

After accounting for other variables, past orthodontic treatment was no longer significantly related to satisfaction with dental appearance for the entire population (p = 0.36) (Table 3) or for either young adults (20–39 years; p = 0.39) or older adults (40–59 years; p = 0.94). However, malocclusion had a significant negative effect on satisfaction with dental appearance of the entire population (p = 0.02) and young adults (20–39 years; p = 0.004), but not older adults (40–59 years; p = 0.18). Having no anterior decayed teeth was the strongest determinant of satisfaction with dental appearance for total population, as highlighted by the highest odds ratio (OR = 3.1; 95% CI = 1.93–4.98)

Adjusting for all other variables in the model, for the entire population, satisfaction with dental appearance was greater among the higher income group, never smokers, those with better self-rated health, those with no anterior decayed teeth and those with no anterior filled teeth.