The aim of this study was to investigate the level of satisfaction for orthodontic treatment among adult patients. In addition, the influencing host factors were monitored for their associations with satisfaction.
A questionnaire was designed to measure the level of satisfaction in 10 items; overall satisfaction, tooth alignment, facial appearance, eating and chewing, confident smile and self-image, retention state, treatment duration, treatment costs, intention to recommend, and relief of previous concerns, using a 5-point Likert scale. Total satisfaction was calculated by averaging the Likert scores from the 10 items. The survey was conducted, and the results from 298 adults were evaluated.
For the overall satisfaction item, 45.0% were very satisfied, and 39.9% were satisfied, resulting in a satisfaction ratio of 84.9%. Total satisfaction score was 3.9. The level of satisfaction for tooth alignment and confident smile and self-image were significantly higher than facial appearance and eating and chewing ( P <0.001). Patients aged 50 and above were more satisfied than the younger ones, and men were more satisfied than women ( P <0.05).
Overall, adult patients were highly satisfied with orthodontic treatment. Age, sex, motivation, expected concern, and discomfort influenced the level of satisfaction.
A questionnaire was developed to measure treatment satisfaction among adults.
In general, adult patients were highly satisfied with orthodontic treatment.
Adults age 50 and above were more satisfied than younger age groups.
Sex, motivation, concerns, and discomfort influenced the level of satisfaction.
As people continue to age, orthodontic treatment is becoming more commonly accepted by adults. In the United States, adult orthodontic patients increased from 15.4% to 23% between 1981 and 2013; accordingly, the proportion of orthodontists treating adults also increased from 51% to 98.6%. A survey of the members of the American Association of Orthodontists also reported that the proportion of adult orthodontic patients (ages 18-54) increased by 14% between 2010 and 2012. In Asian countries with aging populations, the ratio of middle-aged orthodontic patients (age 40 and above) also doubled between 2008 and 2012.
Adult patients often have complex treatment needs in addition to the predisposing malocclusion. Orthodontic treatment may be selected as part of interdisciplinary treatment for restoration or rehabilitation after tooth loss or periodontal breakdown, or to prevent further deterioration caused by oral diseases. Adults are more concerned about treatment and show active attitudes toward the progress and outcome of their treatment.
Motivation, expectation, and subjective level of satisfaction after orthodontic treatment in adult patients can be regarded as important parameters to measure the overall outcome and significance of orthodontic treatment. However, in current clinical settings, orthodontic outcome is mainly defined through objective morphologic features by orthodontic specialists, whereas evaluation of the subjective outcomes is still limited, especially in adults.
Patient satisfaction is generally defined as a perceived value judgment and sustained response to service-related stimuli before, during, and after use of the service. Patient satisfaction with orthodontic treatment has been previously reported at a broad range of 34% to 95%, but these figures mostly represent satisfaction for tooth alignment or simple satisfaction with treatment results in adolescent patients and their caregivers. Although reports on the level of satisfaction among adult orthodontic patients is limited, Riedmann et al reported that 78% of adult patients were completely satisfied with their treatment outcome. However, this is not enough to represent the satisfaction of adults with orthodontic treatment. Among the alternative options of satisfied or not satisfied with the treatment outcome, 97% answered satisfied but 22% of these respondents pointed out unsatisfactory matters, so 78% of them were classified as completely satisfied.
The aim of this study was first to develop a simple questionnaire that can be applied to evaluate the subjective level of satisfaction after orthodontic treatment. Second, we conducted a large-scale prospective survey to determine the level of treatment satisfaction among adult patients and evaluated how the host factors such as age, sex, treatment motivation, concerns, and discomfort can influence the level of satisfaction.
Material and methods
Before the development of the questionnaire, previous studies on satisfaction after orthodontic treatment were reviewed. These studies used different questionnaires, and there were no formal questionnaires. The overall guidelines for questionnaire development followed the guidelines of Williams.
First, a focus group was constructed to develop the questionnaire. The focus group consisted of the main researcher (R.L.), 2 experienced orthodontists, (C.J.C., S.H.) and 1 biostatistics professor (H.L.). The main researcher reviewed questionnaires in the previous studies that examined satisfaction after orthodontic treatment ( Supplementary Table I ). A draft questionnaire was developed to assess satisfaction, motivation, concerns, and discomfort of orthodontic treatment through focus group meetings.
Individual interviews of 5 orthodontists with various level of clinical experience and 10 patients using the draft questionnaire to accept a variety of opinions were performed by the main researcher. All 10 patients had undergone orthodontic treatment. Based on the results of the interviews, the questionnaire was reconstructed.
We conducted a pilot survey of 10 patients who had undergone orthodontic treatment. We asked for comments on various questions that were difficult to understand or unclear. The 10 respondents did not spend more than 10 minutes taking the survey.
The questionnaires consisted of questions to assess psychological status such as motivation for orthodontic treatment, expected concerns before treatment, discomfort during and after treatment, along with the level of satisfaction after orthodontic treatment ( Fig 1 ).
The motivation, concerns, and discomfort categories included multiple-choice questions. Taking into account that there can be multiple responses, patients were asked to rank their responses. The first response was used for statistical analysis. At the end of the closed-ended multichotomous questions, an other item was included to allow unexpected responses.
Specific levels of satisfaction were further divided into 10 items in the questionnaire. Along with overall satisfaction, we asked about satisfaction for tooth alignment, facial appearance, eating and chewing, and confident smile and self-image to monitor the satisfaction levels of the treatment outcome. The level of satisfaction of the retention state, treatment duration, costs, intention to recommend orthodontic treatment to others, and relief of previous concerns related to orthodontic treatment were also included, since these items reportedly influence, or are influenced by, the level of satisfaction.
The Likert scale was used for each satisfaction item from very dissatisfied (1 point) to very satisfied (5 points). The last item, relief of previous concerns, was scored inversely ( Supplementary Table II ). Satisfaction ratio was defined as the summated ratio of very satisfied and satisfied. An average of the 10 scores was calculated and defined as total satisfaction. The Cronbach alpha was calculated to measure the internal consistency of the 10 satisfaction items.
Methods for evaluating validity, reliability, and acceptability of newly developed questionnaires are listed in Table I .
|Psychometric property||Tested||Methods used in this study|
|Content validity||Yes||The experts reviewed whether the items in the questionnaire represent items to be measured.|
|Face validity||Yes||This was assessed by the orthodontist and patients who completed the orthodontic treatment.|
|Criterion validity||No||There are several measurement tools, but no standardized tool is considered a gold standard.|
|Reliability||Yes||The Cronbach alpha was used to measure internal consistency of the items. Kappa values and intraclass correlation coefficients were calculated for intrarater reliability.|
|Acceptability||Yes||We checked the time it took to complete the questionnaire in the pilot study and confirmed that there were unclear questions.|
The survey was approved by the institutional review board of Gangnam Severance Hospital, Yonsei University, in Seoul, Korea.
In the study of Riedmann et al, the satisfaction rate of orthodontic treatment in adult patients was 78%, and the sample size was obtained using this. One sample proportion test was used with 95% confidence intervals and margin error of 5%. The estimated sample size was 264 subjects. The proportion of patients aged 19 years or older in 2012 was 54.6%, as a result of checking the age distribution of patients at Yonsei University Dental Hospital. For a sample size of 264 adults, an estimated total of 484 subjects was required.
The questionnaire was given to all patients who visited the Department of Orthodontics at Gangnam Severance Hospital for regular checkups after active orthodontic treatment between July 25, 2015, and December 30, 2015 (total of 493).
Two assistants unrelated to the orthodontic treatment distributed and retrieved the questionnaires. They emphasized that the questionnaire was approved by the institutional ethics committee, the responses would be used for research purposes only, and the respondents and nonrespondents were not disadvantaged by their participation or responses.
Among the 493 subjects, 3 refused the questionnaire. A total of 490 questionnaires were collected. Among the participants, 9 subjects had 2 visits during the questionnaire period and participated twice. These data were used to calculate intrarater reliability, but the results from the first survey were only included for the final calculation.
After the survey period, 1 examiner (R.L.) retrospectively investigated the age when orthodontic treatment began and the total treatment duration for each subject. Subjects who started orthodontic treatment before the age of 18 years (n = 183) were excluded. The questionnaires of subjects who initiated orthodontic treatment at age 19 years or older was used for the analysis of adult patients ( Fig 2 ).
Frequency analysis was performed for sociodemographic parameters and 10 satisfaction items. The differences in the levels of satisfaction were analyzed using descriptive statistics and repeated-measures analysis of variance with the Bonferroni correction. Total satisfaction score was used as a dependent variable to analyze the relationships with sex, age, and psychological status. The t test and 1-way analysis of variance were used to analyze the relationships between sex, age, and psychological state of treatment on satisfaction with the Bonferroni correction and the Dunnett test. Multiple regression analysis was used to control the effect of disturbance variables and to determine the effect of individual independent variables. Software (version 9.2; SAS Institute, Cary, NC) was used for these statistics.
The Cronbach alpha was 0.83 for the 10 questions of satisfaction. As a result of analyzing the internal consistency of the multiple respondents during the survey period, the intraclass correlation coefficient was 0.852 for the satisfaction items. The motive, concern, and discomfort factors showed a kappa coefficient of 0.693.
Among the 298 respondents, the numbers of men and women were 91 (30.5%) and 207 (69.5%). Ages ranged from 21 to 67 years. The age distributions in their 20s, 30s, 40s, and above 50 were 124 (41.6%), 95 (31.9%), 52 (17.4%), and 27 (9.1%), respectively ( Table II ).
|Frequency (n)||Percent (%)|
|50 and above||27||9.1|
We measured pretreatment psychological status, motivation, and concerns, and discomfort during or after treatment.
The most common motive for orthodontic treatment was to improve tooth alignment (30.5%), followed by to continue interdisciplinary treatment related to surgery, prosthetics, and so on (24.8%), to improve eating and chewing (17.1%), and to improve facial appearance (16.8%) ( Table III ).
|What was your main purpose/motive for considering orthodontic treatment?||Frequency (%)|
|1. To align teeth||91 (30.5)|
|2. To improve facial appearance||50 (16.8)|
|3. To improve eating and chewing food||51 (17.1)|
|4. To smile with confidence and make good impression on others||15 (5.0)|
|5. To prevent future oral cavity or gum disease||6 (2.0)|
|6. Recommendations from friends, family members, or others||8 (2.7)|
|7. To continue interdisciplinary treatment related to surgery, prosthetics, etc.||74 (24.8)|
|8. Other||2 (0.7)|