Virtual Reality Simulation for Cleft Education in a Low-resource Setting: Connecting Surgeons Worldwide

Abstract

Background:

Virtual reality (VR) has not been tested for cleft surgery training in low-resource settings where the surgical instructor provides the lesson from another continent.

Methods:

Fifty-one plastic and maxillofacial surgery trainees in India participated in a VR simulation of the Furlow palatoplasty given by a New York–based cleft surgeon. Participants completed pre- and postsurveys, which included a knowledge assessment regarding the Furlow technique, confidence in VR as an educational tool, and opinions on the use of VR in surgical education. Satisfaction and acceptance of the technology were assessed with learning measures postsimulation.

Results:

Knowledge scores significantly increased following the VR lecture (P < 0.001). Respondents’ confidence in using VR as an educational tool and their understanding of the Furlow repair significantly increased postsimulation (P < 0.001). The opinion that VR should be included in surgical education began high and remained high. Learners reported that the simulation was stimulating (4.63 ± 0.49), increased interest (4.51 ± 0.67), was clear (4.45 ± 0.67), and was effective for teaching (4.78 ± 0.47), and they would recommend the lecture to others (4.78 ± 0.46). VR simulation increased control and active learning (4.73 ± 0.49), facilitated comprehension (4.76 ± 0.51), allowed for reflective thinking (4.59 ± 0.57), had high fidelity (3.98 ± 0.93), was easy to use (4.29 ± 0.73), and was enjoyable (4.78 ± 0.42).

Conclusions:

VR cleft simulation can be effectively used in low- to emerging-resource settings. Surgical instructors can provide real-time, immersive surgical experiences to trainees across the world.

Takeaways

Question: Is a virtual reality (VR)-based simulation delivered by a remote cleft surgeon effective in teaching the Furlow palatoplasty for trainees located in a low-resource setting?

Findings: Pre- and postintervention surveys demonstrated that learners expressed satisfaction with and acceptance of the VR technology. Postintervention knowledge, assessed with a written test, and self-reported confidence with VR significantly increased.

Meaning: The incorporation of VR for cleft surgery teaching in low-resource settings is feasible and provides potential benefits for providing high-quality surgical training.

INTRODUCTION

Contemporary surgical training has faced increasing challenges globally, bringing the topic of surgical trainee education to center stage.^1,2 In low- to middle-income countries (LMICs), limited financial resources, nonformalized training curricula, and a lack of experienced surgical educators are barriers to operative education.^3–5 In high-income countries, strict trainee work-week hour restrictions and the increased complexities of surgical care result in less operating room time and reduced autonomy.^6,7 These limitations have precipitated a shift from the traditional Halstedian model of surgical training, which emphasizes caseload, to competency-based models.^8,9 Although surgical training models differ vastly between high- and low-resource settings, the need for sustainable and effective educational resources that supplement in-person training and promote trainee preparedness is universal.

Surgical simulation provides a risk-free environment where trainees can bridge knowledge gaps and build the necessary skills to perform safe patient care.^10,11 Commonly used simulation modalities such as synthetic, animal, or cadaver models hold disadvantages such as high costs, low accessibility, and ethical concerns.^12–14 Training via a workshop model often results in single use of simulator models and requires an experienced surgeon to be present in person for an optimal educational experience. The considerable financial and logistical resources expended to obtain simulator models limit access to this critical component of education in LMICs.^2,3,15

Virtual reality (VR) has emerged in response to these considerations, offering an entirely virtual 3-dimensional simulation space that allows for educators and learners from any location to interact in real time through a variety of surgical scenarios within an immersive digital environment.¹⁶ Previous studies have demonstrated that compared with traditional teaching methods, VR improves participant clinical decision-making, surgical planning, procedure completion time, and task accuracy.^17–19 However, most work assessing VR effectiveness has been conducted in high-resource settings,^20–22 limiting knowledge about the value of VR, specifically for surgical training, in LMICs.^17,23,24

Cleft lip and palate are common craniofacial anomalies.²⁵ Patients who do not receive timely cleft repair can experience medical complications, such as poor feeding,²⁶ speech difficulties,²⁷ and psychosocial challenges.²⁸ LMICs demonstrate lower rates of repair and a high incidence of delayed repair, given a shortage of experienced cleft surgeons.^1,3,15 Considering the advantages of VR over traditional simulation modalities, increased incorporation of VR in surgical training may work to address existing barriers to equitable cleft care education and expand patient access.

A critical advantage of VR, the ability to unite educators and learners regardless of location in a virtual operating room for real-time surgical training, has yet to be tested for cleft surgery teaching in a low-resource setting. This study assessed the feasibility of real-time, transcontinental VR surgical immersion to teach Furlow palatoplasty in which trainees are in a low-resource setting. Secondary outcome measures include learner acceptance and knowledge acquisition following the VR training.

METHODS

Simulation Development

The VR simulation was developed with the nonprofit organization Smile Train, Inc., and the biomedical software company BioDigital, Inc. (New York, NY). In August 2023, a multiuser-friendly cleft surgery VR platform that simulates a metaverse operating room was launched. Autodesk Maya (Autodesk, San Rafael, CA), a multiuser simulation system, was used for content creation. The surgical simulation experience includes an immersive virtual operating room in which an experienced surgeon provides step-by-step instruction and demonstration of a Furlow palatoplasty on a virtual patient (Fig. 1). All participants have an unobstructed “surgeon’s view” of the surgical field (Fig. 2) facilitated by the ability of the virtual avatars of each participant to be rendered transparently. Trainees can alter their view by physically moving their head or virtually moving their avatar with the headset controllers. The surgical trainer performs the entire Furlow palatoplasty as the trainees observe. Surgical anatomy, landmarks, flap design, and the steps of the surgical procedure are demonstrated during the procedure. The surgeon demonstrating the procedure used a Meta Quest 2 (Meta, Menlo Park, CA) headset; the participants used Meta Quest 3 headsets (Meta, Menlo Park, CA).

Fig. 1.

Virtual patient on the operating room table.

Fig. 2.

Unobstructed view of the virtual CP model.

Study Design

A total of 51 participants undergoing plastic or maxillofacial surgery training were recruited from 15 institutions in India by the senior author. This study was an educational quality improvement study, and institutional review board approval was exempt.

Each session consisted of 2–5 learners located in India along with a cleft surgeon educator in New York (Fig. 3). An experienced cleft surgeon (D.R.) in India offered participants general instructions on VR operability before the VR lecture. The surgeon based in New York (R.L.F.) directed participants to their proper positions in the virtual surgical field to obtain an unobstructed view of the palate. The surgeon began a step-by-step simulation of the Furlow technique on the digital palate, emphasizing the basic concepts of the repair. (See Video [online], which demonstrates a Furlow palatoplasty lecture given in a VR operating room.) Study teams communicated via a video conferencing platform throughout the sessions.

Fig. 3.

Virtual reality session. A, Cleft surgical instructor providing Furlow palatoplasty lecture in the metaverse operating room from New York to surgical trainees in India. B, Participants simultaneously engaging in the lecture in the metaverse operating room space from India.

Video 1. This video demonstrates a Furlow palatoplasty lecture given a virtual reality operating room.

Download video file ^{(59.6MB, mp4)}

Simulation Workshop Design

Before entering the metaverse operating room, participants completed a deidentified preintervention survey. (See survey, Supplemental Digital Content 1, which displays the pre-VR training survey, https://links.lww.com/PRSGO/E232.) The previously validated preintervention survey assessed confidence in VR as an educational tool, understanding of the Furlow cleft palate (CP) repair, and whether VR should be incorporated into surgical education.^29,30 Participants completed a knowledge-based survey of basic concepts of the Furlow unilateral CP repair. The knowledge component of the survey was written by the surgeon (R.L.F.) giving the course to ensure standardized lectures. Other elements in the preintervention survey included prior experience with VR, interest in VR as a surgical education tool, and formal training experience with cleft surgery (Supplemental Digital Content 1, https://links.lww.com/PRSGO/E232). Postsimulation surveys were administered, which included identical knowledge and confidence sections. (See survey, Supplemental Digital Content 2, which displays the post-VR training survey, https://links.lww.com/PRSGO/E233.) Additional elements included the modified version of the Student Evaluation of Educational Quality (SEEQ) survey and learning measures previously validated in VR educational contexts (Supplemental Digital Content 2, https://links.lww.com/PRSGO/E233).^31–33 Opinion-based questions were based on a 5-point Likert scale, with 1 indicating “strongly disagree” and 5 indicating “strongly agree.” Knowledge questions were assessed as the percentage of correct answers.

Data Analysis

Data were analyzed using Statistical Package for the Social Sciences software (version 28.0, IBM Corp.). Wilcoxon signed-rank tests were used for pre- and postsimulation paired survey responses. Mann-Whitney U tests were used to investigate whether prior cleft surgery exposure impacted postsession survey response score. Data are reported as medians and interquartile ranges where appropriate. Results from the postsurvey SEEQ and VR-specific measures were analyzed using descriptive statistics, with results reported as means and SDs.

RESULTS

Prior Exposure to VR and CP Repair

A total of 51 surgical trainees participated in the VR Furlow palatoplasty simulation. A minority (21.6%) of participants reported prior exposure to VR technology. A minority (39.2%) of participants had prior resident training experience with CP repair with a mean of 11.85 ± 13.0 cases. A majority (86%) of participants were in their first 3 years of postgraduate training (Table 1).

Table 1.

Demographics of Participants

Level of Training	n (%)
PGY-1	12 (23.5)
PGY-2	11 (21.6)
PGY-3	21 (41.2)
PGY-4	2 (3.9)
PGY-5	1 (2.0)
PGY-6	1 (2.0)
Fellowship	3 (5.9)
Has participated in CP repair	20 (39.2)
Mean number of cases (SD)	11.85 (13.0)
Has used VR before	11 (21.6)

Pre- and Postintervention Confidence With VR Simulation

Before VR simulation, participants had a median confidence score of 4.00 (3.00–5.00). Immediately following the intervention, there was a statistically significant increase (P < 0.001) in the median confidence score to 5.00 (4.00–5.00). There was a statistically significant increase in understanding of the Furlow CP repair from a median of 3.00 (2.00–4.00) to 5.00 (4.00–5.00) following the lecture. Before the VR simulation, participants had a favorable attitude toward the incorporation of VR in residency training with a median response of 5.00 (4.00–5.00), which was maintained following the workshop (5.00 [5.00–5.00], P = 0.06, Table 2, Fig. 4). After the simulation, 96.1% of participants stated that their belief in incorporating VR into surgical training had increased.

Table 2.

Pre- and Postsurvey Confidence Scores

	Presurvey Median (IQR)	Postsurvey Median (IQR)	P
I am confident using VR as an education tool	4.00 (3.00–5.00)	5.00 (4.00–5.00)	<0.001*
I have a good understanding of techniques used for CP repair	3.00 (2.00–4.00)	5.00 (4.00–5.00)	<0.001*
I believe VR should be incorporated in medical and surgical education	5.00 (4.00–5.00)	5.00 (5.00–5.00)	0.060

*P < 0.05.

Fig. 4.

Pre- and post-VR confidence survey responses.

SEEQ Survey Results

Participants reported a high degree of satisfaction with VR as an educational tool for learning CP reconstruction. The majority were in strong agreement that the VR simulation was stimulating (4.63 ± 0.49), increased their interest in pediatric plastic surgery (4.51 ± 0.67), provided clear instructions (4.45 ± 0.67), and was effective for teaching CP reconstructive techniques (4.78 ± 0.47), and that they would recommend the VR lecture to others (4.78 ± 0.47) (Table 3, Fig. 5). The VR simulation obtained the highest rating as an educational resource (8.63 ± 1.11) compared with textbooks (7.55 ± 1.57), in-person lectures (7.57 ± 2.55), discussion-based seminars (7.75 ± 1.94), and internet searching (6.11 ± 2.30), when rated on a 10-point scale (Table 4). Postsimulation, most participants reported feeling somewhat (41.6%) or extremely comfortable (17.6%) performing the simulation alone (Table 3).

Table 3.

Postsurvey Satisfaction Scores and Learning Constructs

Dimension/Construct	Question	Mean	SD
Learning	The virtual learning model was stimulating	4.63	0.49
Learning	The virtual learning model increased my interest in pediatric cleft and craniofacial care	4.51	0.67
Organization	The virtual learning model was clear	4.45	0.67
Overall	Virtual learning models are an effective means of teaching CP repair skills	4.78	0.47
Representational fidelity	My experience in the virtual operation room seemed consistent with my experiences in the real world	3.98	0.93
Easy to use	Learning to operate this type of VR program is easy for me	4.29	0.73
Control and active learning	This type of VR learning program helps me to have a better overview of the content learned	4.73	0.49
Cognitive benefit	This type of VR learning program makes the comprehension easier	4.76	0.51
Reflective thinking	VR simulations enable me to reflect on how I learn	4.59	0.57
Enjoyment	I enjoyed the experience	4.78	0.42
Additional	I would recommend this virtual learning model to others interested in learning CP surgical repair	4.78	0.46
Additional	After the guided learning, I would feel comfortable doing the simulation alone	2.61	1.23
Simulator sickness	Did you feel any discomfort with the simulation	1.20	0.40

Fig. 5.

SEEQ survey scores.

Table 4.

Responders Rated Comparison of Different Educational Tools

Tool	VR	Textbooks	In-person Lecture	Discussion-based Seminars	Internet Search
Mean (SD)	8.63	7.57	7.55	7.75	6.11
SD	1.11	1.57	2.55	1.94	2.30
Minimum	6.00	4.00	1.00	3.00	0.00
Maximum	10.0	10.0	10.0	10.0	10.0

VR-specific Survey Results

Most participants agreed that the VR simulation helped provide a better overview of the content (4.73 ± 0.49), facilitated comprehension (4.76 ± 0.51), was easy to use (4.29 ± 0.73), allowed for reflective thinking (4.59 ± 0.57), and felt consistent with real-world experiences (3.98 ± 0.93). Most participants strongly agreed that they enjoyed the simulation experience (78.4%) and did not feel discomfort during the simulation (80.4%) (Table 3, Fig. 6). Of participants who reported discomfort, “headache” was the most common experience (11.7%).

Fig. 6.

VR-specific learning measures.

Knowledge-based Test Results

The knowledge test was scored out of 8 points. Preintervention, participants had a mean score of 2.51 ± 1.41. There was a statistically significant increase in mean score to 4.76 ± 1.70 postsimulation (P < 0.001).

Cleft Exposure and Postsurvey Responses

There was no difference in postsurvey responses between groups with no previous exposure to cleft surgery and those with previous exposure (Table 5).

Table 5.

Postsurvey Responses by Cleft Exposure

Postsurvey Items	No Exposure, Median (IQR), N = 31	Exposure, Median (IQR), N = 20	P
I am confident using VR as an education tool	5.00 (4.00–5.00)	5.00 (4.25–5.00)	0.269
I have a good understanding of techniques used for CP repair	5.00 (4.00–5.00)	5.00 (4.00–5.00)	0.177
I believe VR should be incorporated in medical and surgical education	5.00 (4.00–5.00)	5.00 (5.00–5.00)	0.307
The virtual learning model was stimulating	5.00 (4.00–5.00)	5.00 (4.00–5.00)	0.791
The virtual learning model increased my interest in pediatric cleft and craniofacial care	5.00 (4.00–5.00)	5.00 (4.00–5.00)	0.929
The virtual learning model was clear	5.00 (4.00–5.00)	5.00 (4.00–5.00)	0.454
Virtual learning models are an effective means of teaching CP repair skills	5.00 (4.00–5.00)	5.00 (4.25–5.00)	0.435
I would recommend this virtual learning model to others interested in learning CP surgical repair	5.00 (5.00–5.00)	5.00 (5.00–5.00)	1.00
My experience in the virtual operation room seemed consistent with my experiences in the real world	4.00 (3.00–5.00)	4.00 (4.00–5.00)	0.180
Learning to operate this type of VR program is easy for me	4.00 (4.00–5.00)	5.00 (4.00–5.00)	0.222
This type of VR learning program helps me to have a better overview of the content learned	5.00 (4.00–5.00)	5.00 (5.00–5.00)	0.445
This type of VR learning program makes the comprehension easier	5.00 (4.00–5.00)	5.00 (5.00–5.00)	0.154
VR simulations enable me to reflect on how I learn	5.00 (4.00–5.00)	5.00 (4.00–5.00)	0.445
I enjoyed the experience	5.00 (4.00–5.00)	5.00 (5.00–5.00)	0.364
After the guided learning, I would feel comfortable doing the simulation alone	2.00 (2.00–4.00)	2.00 (2.00–3.75)	0.322
Postknowledge score	5.00 (3.00–5.00)	5.00 (4.00–7.00)	0.279

Simulation Feedback

Informal open-ended feedback regarding the VR technology was mostly positive. Respondents reported that simulation provided “better visualization of anatomic landmarks” than when assisting in the operating room. They felt that although much shorter than an operating room experience, the steps of simulation provided a concise way to aid in the conceptualization of the Furlow technique. Constructive feedback regarded the usability of the VR technology. Respondents reported that they had difficulties situating themselves in the correct position relative to the cleft model and may have benefited from more time spent orienting to the VR space. Participants reported that the simulation could be improved by incorporating neurovascular structures and annotations for important steps.

DISCUSSION

This study assessed the feasibility and effectiveness of VR simulation to teach palatoplasty across continents and within lower resource regions. Confidence in the VR platform as an educational tool, understanding of the Furlow techniques, and knowledge of the principles of the Furlow unilateral CP repair significantly increased following the simulation. Participants reported that the VR simulation model was stimulating, facilitated learning, was clear, and was effective for learning, and that they would recommend the model to others. Additionally, participants felt that the VR program had high representational fidelity, was easy to use, increased control and active learning, allowed for reflective thinking, and was an enjoyable experience. These findings are consistent with previous studies assessing this VR platform as a supplemental educational tool for cleft training.^30,34,35

In the face of an evolving surgical training paradigm, mindfulness for surgical trainee preparedness at the time of graduation spans both high- and low-resource training programs.^6,7,36 For high-income countries such as the United States, strict resident work-week hour restrictions imposed by national regulating bodies (ie, The Accreditation Council for Graduate Medical Education) have influenced the growing role of supplementary educational tools, including simulation, to reduce the implications of less time spent in the operating room throughout training.^36–43 In LMICs, insufficient resources and lack of trained specialists are barriers to cleft operative education, ultimately perpetuating surgical backlog and hindering patient safety.^3–5 Therefore, supplementary educational tools, including simulation, should target surgical trainees via a cost-effective and practical means of knowledge dissemination. Disadvantages of traditional simulator models such as high cost, low accessibility, and 1-time use have allowed for the emergence of metaverse-based tools such as VR,^12–14 which serve as both simulation modalities and educational tools.^16–18 The nature of these virtual platforms is attractive for low-resource settings, as experts can teach and interact with trainees from any location. The effectiveness of VR to supplement in-person learning is evaluated via the methodology of this study.

Our findings suggest that VR simulation delivers educational material in a manner that supports procedural understanding and confidence with the platform as an educational tool. Studies have determined that VR significantly improves self-rated procedural confidence in trainees in neurosurgery,⁴⁴ plastic surgery,^30,34 and gynecologic surgery,⁴⁵ among other specialties. Although certain studies suggest that novice surgeons demonstrate the greatest benefits in performance confidence following the VR simulation experience,^23,34 other work suggests that benefits in objective performance exist across various training levels.^46–51 In a study assessing motivational states and VR performance, low self-efficacy and poor stress-coping strategies in the untrained group were associated with lower VR performance, suggesting benefits for structured VR training.⁵² Early incorporation of VR may positively impact trainee motivational states and affect surgical performance at an earlier stage.

VR simulation provides realistic, immediately accessible, and reusable 3-dimensional representations of surgical pathology and procedures within an immersive setting. This technology allows for residents to conduct risk-free and deliberate repetitions of a surgical procedure before entering an operating room, improving trainee knowledge and preparedness. This specific VR platform was developed between a software company and an experienced surgeon over the course of 5 years with considerable resources. It is originally based on a Smile Train–distributed CD resource created in 2002, which was later repurposed into an internet and phone-based simulator to teach Furlow palatoplasty.^53,54 The medical director of this platform has more than 15 years of experience creating digital models, simulations, and surgical training resources that optimize workflow, cost control, and educational value. Surgeon-educators interested in developing similar modules are recommended to gain knowledge of the relevant workflow processes of digital content creation, particularly the complexities involved in making modifications during certain phases of development.

This study demonstrated that knowledge of the Furlow repair significantly increased after simulation training. Several randomized controlled trials have demonstrated that when compared with traditional teaching methods, VR resulted in significantly improved procedure time, time to task completion, and accuracy of task performance across training levels.^17,46–51 Furthermore, VR was found to be superior to video in skill transfer effectiveness, with 60 minutes of the VR experience equivalent to 47.4 minutes of operating room time.⁵⁵ Although VR cannot serve as a replacement for operating room time, supplementation of VR for surgical training has been shown to increase trainees’ technical skills, which promotes patient safety. Moreover, VR simulations can be programmed to provide endless iterations of different clinical scenarios and can be used to periodically assess proper skill acquisition and retention, even after the novice learner becomes experienced.⁵⁶

Although simulation has been determined to be an important part of surgical education, studies assessing the acceptance of VR in surgical education in LMICs are scarce.^24,57 A bibliometric study determined that the largest producers of metaverse-related research were the United States, China, and Germany, with little research originating from LMICs.²⁴ Our study findings add to the limited data assessing the acceptance of VR for education in these settings.⁴⁵ Postintervention SEEQ and VR learning construct results were favorable. Furthermore, learners ranked VR higher than traditional methods of learning, consistent with our previous work assessing the Furlow VR module.⁵⁸ Participants reported that visualization of the surgical procedure and relevant anatomy was clearer than the view obtained during live surgery, and that the conciseness of the simulated procedure aided in procedure conceptualization. Overall, VR was broadly accepted in this setting. Widespread adoption of VR technology could alleviate certain challenges to medical education in LMICs, translating into higher quality education and promoting comprehensive cleft care.⁵⁹

Concerns for VR accessibility such as internet connectivity and financial costs of individual headsets remain. However, previous studies have completed entire simulations using a phone personal hotspot with no interruptions in usage, suggesting that high-speed internet connectivity may not be needed.³⁰ Furthermore, a recent United Nations report demonstrates steadily increasing rates of internet connectivity worldwide and proposes solutions for expanding internet access to the least developed areas.⁶⁰ Of note, the average price of a VR headset is $430 in the United States, which is more affordable than many smartphones.⁶¹ Other learning modalities such as textbooks can be cost-prohibitive and unavailable in many regions.⁶¹ The creation and maintenance of the simulation used in this study have been completely supported by philanthropic funding (Smile Train) and are freely available at certain locations with the goal of expanding usage. VR simulation was determined to be 34 times more cost-effective for learning compared with technical video instruction, given the high estimated costs of training and the opportunity cost of lost operating room time.⁵⁵ Additionally, as VR is used for a variety of applications outside of simulation, the global VR market is projected to increase, which will improve accessibility as the technology becomes ubiquitous.^62,63 Although participants noted the absence of haptic feedback as a disadvantage of VR in comparison to other simulators, haptics-enhanced VR has been described and will likely become further widespread as the technology advances.⁶⁴

This study is not without limitations. The study population is self-selected and nonrandomized, where residents are trained in a similar fashion. This may limit the generalizability of the results as well as potentially inflate the preintervention opinion of VR use for an educational purpose. However, participants were from multiple institutions, and this simulation has been previously tested at a high-resource institution in the United States, suggesting acceptance of VR in education across different socioeconomic settings.⁵⁸ Furthermore, although India has some high-resource healthcare institutions, more than 80% of the population has limited access to healthcare infrastructure.⁶⁵ As India broadly experiences high internet connectivity, VR tool performance may not translate to other LMICs that may have lower levels of internet access. Although participant knowledge of the basics of the Furlow technique was objectively measured through the completion of a postintervention written test, the study is limited by the absence of a control group using a traditional educational tool for comparison. Future studies will seek to conduct a randomized control trial comparing the VR simulation to a traditional educational tool to assess the effectiveness of VR for learning cleft care techniques.

CONCLUSIONS

VR-based simulation lectures can significantly increase a learner’s confidence in VR and knowledge of the Furlow palatoplasty. Learners in low-resource settings find VR simulations to be an effective simulation modality with high representational fidelity and positive effects on various learning dimensions and recommend its incorporation into surgical training. The adoption of VR in low-resource settings may circumvent existing barriers to comprehensive cleft care education by allowing for remote education and offering a cost-effective and safe way for simulating complex procedures, thereby promoting high-quality surgical training across various resource settings.

DISCLOSURE

Dr. Flores is a member of the SmileTrain Medical Advisory Board. This is an uncompensated volunteer position. Aaron Oliker was the cofounder and Chief Innovation Officer at BioDigital, Inc, at the time of manuscript preparation. No financial support was received from BioDigital, Inc, or Smile Train for the preparation of this manuscript. The other authors have no financial interest to declare in relation to the content of this article.