“My Invisalign experience”: content, metrics and comment sentiment analysis of the most popular patient testimonials on YouTube

Personal stories of patients in the form of narratives, testimonials, or anecdotes are increasingly becoming available to the public as YouTube videos and discussion posts on social media and peer-support groups. Such anecdotal information is heavily weighed by health consumers when making treatment choices [1]. Health video blogs in video hosting services, also called vlogs, have the potential to impact patients’ psychological health, promote health education for youth and young adults, and improve health information literacy [2].

With over a billion users, YouTube is the fastest growing video sharing Web platform, ranked second in Internet traffic worldwide and in the United States (US) [3]. The educational value of YouTube in dentistry has been reported as underdeveloped and underestimated [4]. The quality and completeness of the dental information on YouTube have been disputed due to the minimal filtering of the uploaded material [5]. Numerous orthodontic videos are also available on YouTube, mostly originating from patients [4], and reflecting a general pro-orthodontics attitude. Referring orthodontic patients to YouTube for relevant audiovisual information resulted in a significant improvement in patient knowledge compared to verbal and written instructions [6].

Given YouTube is being largely used as a primary source of orthodontic information [4], it can be presumed that laypersons interested in contemporary systems like Invisalign are likely to access the video-sharing platform to answer their queries. Nowadays, 89% of US practices perform treatment with clear aligners, while the number of cases has almost doubled within a few years [7]. This upward trend did not slow down regardless of the limited evidence on the effectiveness of Invisalign compared to conventional orthodontics [8]. Interestingly, the manufacturer has recently announced to have reached 4.5 million Invisalign patients worldwide [9]. Without doubt, the growth rate of Invisalign suggests its continued popularity among clinicians and patients. It can be speculated that new communication technologies like YouTube and other social media might have contributed to the broad acceptance by patients, and especially at younger ages.

So far, the available Invisalign information on YouTube videos uploaded by patients-vloggers and the interaction between vloggers and viewers have not been investigated. Therefore, the aims of this study were (i) to determine the completeness of information of the most viewed YouTube patient testimonials regarding Invisalign treatment and the emotional content of viewers’ comments and (ii) to evaluate the association patterns between video metrics, information completeness, and sentiment of comments.

This study shows that YouTube users viewed massively videos related to Invisalign treatment and interacted with the creators and fellow viewers. Completeness of information, video duration, and lifespan did not significantly influence the numbers of views, subscriptions, likes, dislikes, and comments. On this basis, the viewing behavior of YouTube audience may be considered unpredictable, determined by random factors.

Almost half of the vloggers were treated by a dentist, a fact that reflects the reality in provision of orthodontic care in the US, where general dental offices have been carrying out up to 48.9% of orthodontic procedures [21]. Hypothetically, a similarly high prevalence of dentists may be expected in the 100,000 certified Invisalign providers around the world [9]. Comparison in the use of Invisalign showed that orthodontists treated generally more Invisalign cases, though dentists were building faster their caseload [22]. General dentists appeared also more willing to treat more complicated malocclusions with Invisalign [22, 23] adhere less to the digital treatment plan, and use fewer auxiliaries, perhaps demonstrating a difference in treatment goals [23].

Treatment procedures as well as complications were among the main themes identified in Internet discussion forums visited by orthognathic patients [24]. Problems experienced with braces were also primarily posted by orthodontic patients in Twitter communication [25]. IER or refinements were rarely described by the vloggers. Nonetheless, the Invisalign process is not relied on aligners alone. It requires the standard use of auxiliaries like attachments, interarch elastics, IER, and altered aligner geometries to improve the predictability of orthodontic movement [8]. Pain and oral symptoms were most frequently reported by vloggers, while they were also highly viewed as Invisalign’s disadvantage by the audience. Notwithstanding, Invisalign tends to cause less pain compared to fixed appliances during the initial stages of treatment, relatively high levels of pain may be anticipated in the first days after insertion [26] or after tray deformation [27]. Several vloggers complained about the need to brush teeth after snacking or tooth sensitivity that made them to adjust the frequency or type of meals (“Invisalign-diet”), which may question the advantage of Invisalign that allows aligner patients “to enjoy all foods” as Align Technology argues [28]. Speech impairment was frequently noted as side effect in the video testimonials. Patients with acrylic plates experienced significantly more pronounced speech difficulties than others with fixed appliances [29] and vacuum-formed retainers [30]. Plenty of viewers appeared to confuse Invisalign aligners with retainers, which might indicate a possible gap in providing sufficient information by specialists during consultation [24]. It is the anonymity of social media that allows patients to communicate topics that they felt uncomfortable to discuss in person or self-perceived inappropriate to ask directly to health care professionals [31].

Narratives are believed to provide essential emotional and social information not usually available through routine resources. Another’s experience helps others to understand their medical condition, cope, and adjust to treatment regimens [32]. Commenters were mainly former, active Invisalign patients or eager to start treatment and shared information about their treatment experience, occlusion, or even found similarities with the vlogger’s description. Like other patients participating in Internet forums [24], Invisalign patients sought online additional information, support, and reassurance from peers undergoing the same process.

A multifaceted audience was actively involved in watching Invisalign testimonials and sharing comments online. Besides channel subscribers or candidates for clear aligners, vloggers, professionals (orthodontists, dentists, practice staff, lab technician), the manufacturer, product promoters (i.e., vibration device claimed to facilitate tooth movement, aligner seating tool), and research recruiters intervened by posting comments. The interest of different viewers’ groups confirms the claimed potential of social media to monitor public response to health issues, identify misinformation, and identify targeted areas for intervention efforts [33].

As YouTube users commonly engage in active discussion by expressing either positive or negative emotions in their messages [34], this study further analyzed the emotional content of the comments about the vlogger’s experience with Invisalign. Overall, the positive loading of the comments was significantly more pronounced than the negative loading, though both positive and negative mean sentiment scores indicated mild emotions. Likewise, a recent Twitter analysis of the patient experience with braces vs Invisalign revealed more positive tweets about orthodontic treatment without significant differences in sentiment between braces and Invisalign tweets [13]. Viewer’s status, comment content, and sponsorship of videos were significantly associated with the sentiments lying behind the comments. Paid patient testimonials are nowadays commonplace across various specialties. Dental, ophthalmologic, and plastic surgery clinics are routinely recruiting patients to help advertise-witness their experience on video testimonials offering treatment discounts [35]. In the present study, the viewers questioned the consumer’s opinion in sponsored reviews and expressed negative comments about the reliability and the motives of the vlogger implying bias driven by financial interests.

Narrative communication through social media can improve users’ learning abilities by providing ideal health role models. On the contrary, sharing information within personal stories may also hide risks, especially when acting as a deterrent for patients from visiting health professionals or the public may not know how to correctly apply online information about their personal health situation. Since videos involving patient experiences are of lower educational value than expert led ones [36], professional associations and academic departments need to take the lead, to develop and disseminate online evidence-based educational videos. Several YouTube and Vimeo video links (i.e., patient testimonials, instructions about eating, brushing during orthodontic treatment, retention, etc.) are available on the Web site of the American Association of Orthodontists (AAO). Additionally, AAO has created its own YouTube channel, which currently hosts more than 50 videos that basically aim to promote the benefits of orthodontics to the larger society. By expanding topics to standard and innovative techniques and materials, users of video sharing platforms will get access to reliable and updated patient education materials. Clinicians should assist patients in navigating social media and embed on the web pages of their practices links to valid information sources [5].