Public perception of Invisalign^® clear aligner treatment: A cross-sectional survey-based study

INTRODUCTION

In recent years, developments in the field of orthodontics have led to a major increase in patients’ esthetic demands. Patients frequently express their desire to determine the aspects and objectives of treatments along with the orthodontist. This is largely driven by the influence that orthodontic appliances have on a person’s appearance. Traditional orthodontic treatments have been associated with a compromise in facial appearance, and this has raised concerns among patients seeking orthodontic treatment.^[1] Therefore, different esthetic materials and modalities have been developed to address these concerns and overcome existing limitations.^[2]

Clear aligner treatment has long been used in orthodontic practice.^[3] In fact, in 1946, Kesling introduced the concept of sequentially applying a series of thermoplastic tooth positioners to progressively reposition maligned teeth.^[4,5] Nonetheless, Align Technology Inc. (San Jose, CA, USA) was a pioneer in this field, introducing orthodontic treatments involving the sequential application of clear aligners made of thermoplastic material in the late 1990s.^[4-8] This system is known as Invisalign^®.

Due to recent advancements in applied biomechanics and the design and engineering of biomaterials, clear aligners have evolved drastically in recent years. Thus, they can now be applied for complete orthodontic therapy to treat various forms of malocclusions.^[9] However, even though these devices have benefits in terms of patient comfort and acceptability, oral hygiene maintenance, and esthetics, there is still significant debate regarding the efficiency of clear aligners, and a wide consensus on their clinical performance has not been reached in the literature.^[10-13]

As Invisalign is the leading and most popular brand of clear aligners, the present study investigates public knowledge regarding Invisalign clear aligner treatment and compares this treatment to traditional braces. Recently, there has been an increase in demand for clear aligner treatment driven by its increased marketing across various media platforms. The previous studies reported that approximately 33% of Invisalign tweets were categorized as adverts concerning the total proportion of Invisalign tweets and that 73% of patients had learned about clear aligners through external media advertisements.^[14,15] Although a few studies have already examined the clinical performance of clear aligners, public knowledge regarding clear aligner treatment is yet to be studied, as far as the author is aware.^[10-12]

MATERIAL AND METHODS

The Committee of Research Ethics at Qassim University approved this study (#ST/6039/2021). The key features of Invisalign treatment (in comparison to traditional braces) were gathered from literature and were classified into five general categories, namely:

1. Treatment efficiency

2. Appliance aesthetic attractiveness

3. Patient discomfort

4. Oral hygiene maintenance

5. Treatment esthetic results.

Based on the feature categorization, a web-based open survey in the Arabic language was built using the SurveyMonkey website (Momentive Inc., California, United States) following the Checklist for Reporting Results of Internet E-Surveys.^[16] Two experienced orthodontists tested the validity of the survey. Then, the survey was piloted with five patients visiting the orthodontic clinic to test the clarity of the survey questions for non-specialists.

The research purpose, survey-filling duration, data management, and the researcher’s contact details were outlined on the first page of the survey. Before progressing to the next section, respondents were required to agree to participate in the study. Furthermore, this section asked sociodemographic questions (nationality, age, gender, educational level, job title, and monthly income in Saudi Riyal). In addition, information regarding the respondents’ orthodontic treatment history was collected, and these details included the type of orthodontic appliance (traditional braces, self-ligating braces, lingual braces, removable functional appliances, or clear aligners) and treatment duration. The survey also collected information regarding the participants’ sources of orthodontic information (i.e., books and magazines, orthodontists, word-of-mouth, or social media platforms). Participants were also asked a yes/no question to determine whether or not they were familiar with Invisalign clear aligners. If the participant answers “no,” then no further questions will be asked. Instead, they will be asked to click the “submit” button to terminate the survey. However, if they respond “yes,” then the participant will be presented with further questions to gain insight into their understanding of Invisalign treatment and to determine whether participants believe that they are generally better to traditional braces (answered with “Yes,” “No,” or “Do not know”). After this, seven questions about the key features of Invisalign treatment were presented. The final question was designed to uncover participants’ opinions regarding the costs of Invisalign treatment. All items were measured using a 6-point Likert-type scale (0 – Don’t know, 1 – Strongly disagree, 2 – Disagree, 3 – Neutral, 4 – Agree, or 5 – Strongly agree).

Convenience sampling was employed to recruit adult participants through social media platforms, such as Facebook, Twitter, Telegram, Instagram, and WhatsApp. The survey link was available from January 3 to February 4, 2021, and was reposted at 1-week and 3-week intervals. An IP-blocking feature was enabled to ensure that each participant only completed the survey once.

RESULTS

DISCUSSION

In recent years, the use of clear dental aligners has significantly grown in popularity, with more and more advertisements promoting it and garnering public exposure.^[14,15] This study examined the general public’s knowledge regarding Invisalign treatment and found that around one-fifth of the respondents were familiar with Invisalign aligners. This figure was lower than that was previously found in a report on direct-to-consumer aligners (45%).^[17]

Furthermore, previous studies have found that online information regarding clear aligners is generally inadequate.^[18-21] Given the growing patient interest in clear aligner treatment, health providers must strive to deliver credible and evidence-based information to patients. The present study found that participants had misconceptions about the Invisalign clear aligner treatment, with most respondents believing that such devices were generally better than traditional braces, particularly among individuals with average monthly income. Clear aligners are often promoted as an equally effective orthodontic treatment modality to traditional fixed appliances. Nonetheless, the current evidence-based research suggests that clear-aligner treatment is more suitable for mild-to-moderate malocclusions, whereas traditional braces remain the gold standard treatment choice in orthodontics.^[10-13]

In addition, most participants stated that Invisalign aligners are more aesthetically attractive than traditional braces, which is in line with the findings of other studies.^[1,22,23] Nonetheless, the increase in clear aligner attachments could compromise its esthetic attractiveness.^[22] Meanwhile, most participants stated that treatment using Invisalign aligners is easier to keep clean than traditional braces. One of the promoted advantages of clear aligners is easier oral hygiene maintenance because it is a removable appliance with fewer retentive parts than fixed appliances. Although the previous literature supports this claim, it is with low to very-low evidence certainty.^[12,24]

Moreover, this study revealed that almost one-third of participants believed Invisalign treatment to be faster and require fewer visits than traditional braces. However, prior meta-analyses have failed to identify significant differences in treatment duration between clear aligners and traditional braces.^[12,25,26] Nonetheless, a recent randomized clinical trial found that, when using Invisalign clear aligners to treat minor malocclusions, treatment duration was longer than traditional braces by 4.8 months.^[27]

Most respondents in the present study (especially males) believed that Invisalign treatment produces superior results to traditional braces. Very few studies have employed occlusal indices to measure the quality of treatment outcomes with clear aligners. Nonetheless, studies had shown that the treatment outcomes of clear aligners (rated using the American Board of Orthodontics Objective Grading System) were worse than traditional braces.^[12,26] However, no differences were found when the Peer Assessment Rating Index was employed.^[12] Most participants also stated that they believed Invisalign treatment causes less discomfort than traditional braces. This is in line with the findings of a previous work, which found that patient discomfort was reduced in the first few days of treatment, although the differences disappeared after that.^[28]

Invisalign treatment costs have been discussed in many YouTube testimonials and Twitter posts.^[21,29,30] However, most participants in this study did not know the cost of Invisalign treatment, except for those aged 55–64 years, who strongly believed it is less expensive. Over the past decade, more and more people have been using social media. It is also a vital source of information in many fields, including orthodontics.^[31] Previous studies showed that over 80% of orthodontic patients use social media, with the most popular platforms being Facebook and Instagram.^[32-35] In addition, Hanzell et al. found that only 6.7% of participants use social media to seek orthodontic information, whereas Siddiqui et al. found this figure to be 30%.^[33,35] The present study found that around half of the participants use social media to seek orthodontic information. The differences between these findings and those of the previous studies may be due to the research time frame, as well as participants’ ages and ethnicity. Moreover, research participants in this study were selected through social media sites, and thus their social media use may be over-represented.

It is not uncommon that public surveys are designed without patient input.^[33] The present study used a validated survey involving inputs from orthodontic patients. However, selection bias may be present in this work. Moreover, the survey link was shared through social media and thus not all Saudi citizens had an equal opportunity to be selected for participation. Furthermore, the findings cannot be generalized to any other countries except Saudi Arabia, as factors including ethnicity, educational level, population age and internet access may produce a different outcome. Thus, it cannot be assumed that the sample is fully representative of Saudi Arabia or any other country. In the future, researchers should examine public perceptions of Invisalign treatment in other countries.

CONCLUSION

In this study, only 19.6% of the 934 participants knew Invisalign, highlighting the lack of public knowledge regarding the treatment. Most participants perceived Invisalign treatment to be generally better, quicker and requires fewer visits, causes less discomfort, is easier to hygienically maintain, yields superior esthetics results, and is more aesthetically attractive than traditional braces. However, not many participants were aware of Invisalign treatment costs. Respondents aged 55–64 strongly agreed that Invisalign is cheaper than traditional braces. On the other hand, males and average-income participants were more likely to believe that Invisalign devices produce better results than traditional braces. The current results indicated the importance of ensuring public access to high-quality information.