Education Technology in Orthodontics and Paediatric Dentistry during the COVID-19 Pandemic: A Systematic Review

Over the last decade, medical education changed from traditional teaching methods to telematic and networking scholar and e-learning approach. The objective of the present systematic review was to evaluate the effectiveness and teachers/student’s acceptability of e-learning applied to the field of orthodontics and paediatric dentistry. A database search of the literature was conducted on PubMed and Embase databases from January 2005 to May 2021. A total of 172 articles were identified by the electronic search, while a total of 32 papers were selected for qualitative analysis. Overall, 19 articles investigated the effectiveness of e-learning, and no difference of acceptability was reported between e-learning and traditional methods for a wide part of the articles selected. A total of 25 papers provided a satisfaction questionnaire for learners and all were positive in their attitude towards e-learning. The results showed that e-learning is an effective method of instruction, complementing the traditional teaching methods, and learners had a positive attitude and perception. The evidence of the present study reported a high level of acceptability and knowledge level of e-learning techniques, compared to frontal lecture methods, in the fields of orthodontics and paediatric dentistry.


Introduction
One of the most important developments in recent years is the evolution of technology, which has changed many aspects of our everyday life: our means of communication, information retrieval, even the way we spend our free time (e.g., computer games) [1,2] The importance of technology became even more evident during the COVID-19 pandemic that has had a massive impact on people's lives and habits. Restrictions limited people's mobility while remote working, e-learning, and online platforms started to grow, along with online leisure solutions, such as gaming and video streaming [3][4][5][6][7][8][9]. The COVID-19 Over the last decades, e-learning has rapidly expanded in medical education, health promotion, patients, and medical education that take advantage of a useful networking flow and flexibility of the communication system [33][34][35]. Moreover, healthcare education faces higher challenges determined by an increase in students' access to post-degree courses and specialisation that requires novel strategies to improve the quality of the scholarship and the didactic level [35][36][37]. E-learning allows students to learn anywhere and anytime outside the classroom, overcomes the shortages of teachers, and promotes learner's motivation, cognitive effectiveness, and flexibility, leading to a shift from passive, teacher-centred learning to active, student-centred learning. It is affordable, saves time, and reduces costs [27,38]. As stated by Zhang et al., the mass quarantine caused a feeling of fear [39], and Hasan et al. showed in their study that there can be a strong relationship between the e-learning-related breakdowns and the psychological status of the student [40]. In the past, education occurred by means of textbooks, handouts, and notes taken during courses. E-learning enables teachers to represent the information using media in the form of text, images, animation, video, and audio [41,42] (Figure 2). Over the last decades, e-learning has rapidly expanded in medical education, health promotion, patients, and medical education that take advantage of a useful networking flow and flexibility of the communication system [33][34][35]. Moreover, healthcare education faces higher challenges determined by an increase in students' access to post-degree courses and specialisation that requires novel strategies to improve the quality of the scholarship and the didactic level [35][36][37]. E-learning allows students to learn anywhere and anytime outside the classroom, overcomes the shortages of teachers, and promotes learner's motivation, cognitive effectiveness, and flexibility, leading to a shift from passive, teacher-centred learning to active, student-centred learning. It is affordable, saves time, and reduces costs [27,38]. As stated by Zhang et al., the mass quarantine caused a feeling of fear [39], and Hasan et al. showed in their study that there can be a strong relationship between the e-learning-related breakdowns and the psychological status of the student [40]. In the past, education occurred by means of textbooks, handouts, and notes taken during courses. E-learning enables teachers to represent the information using media in the form of text, images, animation, video, and audio [41,42] (Figure 2). There are several important factors that need to be considered for the success of elearning: human factors pertaining to the instructors, the instructors' and students' technical competency, the instructors' and students' attitudes, the level of collaboration, and the technical support [43]. E-learning is a generic term that refers to electronically supported learning and teaching. It includes a variety of modalities and terms such as webbased learning, online learning, computer-assisted instruction, internet-based learning, distance learning, and virtual learning [27,44,45]. E-learning can be synchronous or asynchronous. Synchronous e-learning requires participants to log on at the same time and allows students to interact with each other and their teachers during the lessons. Asynchronous e-learning refers to e-learning that is 'pre-recorded' or available to students at any time of the day, potentially from any place [46]. Numerous studies conducted on elearning in medical education showed that participants considered e-learning as an effective reinforcing method for medical training, without missing the traditional style of teaching [47][48][49][50]. A combination of traditional face-to-face learning and e-learning is called blended learning. The main advantage of blended learning is that it integrates the strengths of synchronous traditional face-to-face teaching and asynchronous/synchronous web-based learning activities [1,2]. Blended learning increases the learning flexibility in a demand-driven educational environment while maintaining the personal contact of the traditional face-to-face teaching, enhancing the classroom experience, and improving effectiveness and efficiencies by reducing lecture time [51,52]. It has been suggested that blended learning, i.e., e-learning and virtual learning environments mixed with a traditional lecture style, improve competencies and core knowledge of students [53]. During the last decade, the large use of smartphones and the internet has fostered widespread use of social media. Social networks such as Facebook, Twitter, YouTube, Google Drive allow people from different backgrounds to communicate and collaborate with other users across the world [53][54][55]. The growing interest in social media among students and the ubiquitous distribution of portable electronic devices has led instructors to improve their teaching and learning through combining social media applications, online platforms, and mobile technologies (Figure 3) [56][57][58][59]. There are several important factors that need to be considered for the success of e-learning: human factors pertaining to the instructors, the instructors' and students' technical competency, the instructors' and students' attitudes, the level of collaboration, and the technical support [43]. E-learning is a generic term that refers to electronically supported learning and teaching. It includes a variety of modalities and terms such as web-based learning, online learning, computer-assisted instruction, internet-based learning, distance learning, and virtual learning [27,44,45]. E-learning can be synchronous or asynchronous. Synchronous e-learning requires participants to log on at the same time and allows students to interact with each other and their teachers during the lessons. Asynchronous e-learning refers to e-learning that is 'pre-recorded' or available to students at any time of the day, potentially from any place [46]. Numerous studies conducted on e-learning in medical education showed that participants considered e-learning as an effective reinforcing method for medical training, without missing the traditional style of teaching [47][48][49][50]. A combination of traditional face-to-face learning and e-learning is called blended learning. The main advantage of blended learning is that it integrates the strengths of synchronous traditional face-to-face teaching and asynchronous/synchronous web-based learning activities [1,2]. Blended learning increases the learning flexibility in a demand-driven educational environment while maintaining the personal contact of the traditional face-to-face teaching, enhancing the classroom experience, and improving effectiveness and efficiencies by reducing lecture time [51,52]. It has been suggested that blended learning, i.e., e-learning and virtual learning environments mixed with a traditional lecture style, improve competencies and core knowledge of students [53]. During the last decade, the large use of smartphones and the internet has fostered widespread use of social media. Social networks such as Facebook, Twitter, YouTube, Google Drive allow people from different backgrounds to communicate and collaborate with other users across the world [53][54][55]. The growing interest in social media among students and the ubiquitous distribution of portable electronic devices has led instructors to improve their teaching and learning through combining social media applications, online platforms, and mobile technologies ( Figure 3) [56][57][58][59].  Mobile learning occurs when the student is not in a permanent and fixed location or if he is using mobile learning technologies. It is considered a part of e-learning [60]. Mobile devices such as smartphones, tablets, and laptop computers enable users to learn at any place and time, in different contexts and situations, and by interacting with others [30,[61][62][63][64][65][66][67]. Furthermore, the growing availability of smartphones and tablets allows the mobile use of augmented reality in medical education [68]. The development of technology has affected even the field of dentistry, and numerous studies have been conducted on digital development in dental education [69][70][71][72][73][74][75][76][77]. In recent years, the diffusion of social media activities and web-based technologies has potentiated the information flow shared in several medical contexts and also in dental field education [78]. This form of interaction is useful at many different levels, such as for the education of undergraduate students, to enhance the expertise of younger dentists, in addition to improving the learning processes of experienced clinicians ( Figure 4) [78][79][80][81][82][83][84][85][86]. Mobile learning occurs when the student is not in a permanent and fixed location or if he is using mobile learning technologies. It is considered a part of e-learning [60]. Mobile devices such as smartphones, tablets, and laptop computers enable users to learn at any place and time, in different contexts and situations, and by interacting with others [30,[61][62][63][64][65][66][67]. Furthermore, the growing availability of smartphones and tablets allows the mobile use of augmented reality in medical education [68]. The development of technology has affected even the field of dentistry, and numerous studies have been conducted on digital development in dental education [69][70][71][72][73][74][75][76][77]. In recent years, the diffusion of social media activities and web-based technologies has potentiated the information flow shared in several medical contexts and also in dental field education [78]. This form of interaction is useful at many different levels, such as for the education of undergraduate students, to enhance the expertise of younger dentists, in addition to improving the learning processes of experienced clinicians ( Figure 4) [78][79][80][81][82][83][84][85][86].

Materials and Methods
This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement [87]. The article screening, selection for eligibility, and qualitative analysis of the study data were conducted by two independent paired reviewers (A.P., F.I.). If any disagreement occurred and unresolved issues were solved by consulting a third reviewer (F.L.). The screening phase was conducted on electronic databases which evaluated the manuscript title and abstract. The full text was collected for all identified articles in order to evaluate the qualitative analysis eligibility.

Eligibility Criteria
Articles in which the objective was to determine the effectiveness and acceptability of e-learning or to compare e-learning with conventional teaching methods were considered.

Materials and Methods
This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement [87]. The article screening, selection for eligibility, and qualitative analysis of the study data were conducted by two independent paired reviewers (A.P., F.I.). If any disagreement occurred and unresolved issues were solved by consulting a third reviewer (F.L.). The screening phase was conducted on electronic databases which evaluated the manuscript title and abstract. The full text was collected for all identified articles in order to evaluate the qualitative analysis eligibility.

Eligibility Criteria
Articles in which the objective was to determine the effectiveness and acceptability of e-learning or to compare e-learning with conventional teaching methods were considered.
The inclusion criteria were based on the PICOT question guidelines [88,89]: -Population: students from graduate and postgraduate courses in orthodontics or paediatric dentistry; university staff; dentists who used e-learning tools to update their knowledge and continuing formation; -Intervention: use of virtual environments for learning; -Comparison: traditional classroom learning; traditional methods of instruction through the lectures, the clinical or laboratory demonstration, tutorial, text-or notebased learning; -Outcome: effectiveness and acceptability of e-learning; -Types of study to be included: cohort, observational, retrospective, or prospective study with emerging effectiveness in the last 16 years. The inclusion criteria were based on the PICOT question guidelines [88,89]: -Population: students from graduate and postgraduate courses in orthodontics or paediatric dentistry; university staff; dentists who used e-learning tools to update their knowledge and continuing formation; -Intervention: use of virtual environments for learning; -Comparison: traditional classroom learning; traditional methods of instruction through the lectures, the clinical or laboratory demonstration, tutorial, text-or note-based learning; -Outcome: effectiveness and acceptability of e-learning; -Types of study to be included: cohort, observational, retrospective, or prospective study with emerging effectiveness in the last 16 years.
The inclusion filters were cohort, observational, retrospective, or prospective studies regarding the e-learning and virtual learning performance of dentistry specialisation of student scholars.

Exclusion Criteria
Reviews, letters, conference readings, editorial, personal opinion, and studies without abstracts were excluded. We limited the searches to articles that were published in the last 16 years.

Information Sources
A systematic electronic search on PubMed and EMBASE databases was performed limited to English language articles published between January 2005 and May 2021. A preliminary search was conducted by the Pubmed MeSH terms function of medical subject headings to identify the most appropriate descriptors and qualifiers of the present research topic to use for the Boolean search. The EMBASE Boolean search has been conducted by Emtree search algorithm. We used the following keywords: orthodontics, pedodontics, paediatric dentistry, e-learning, distance learning, web-based learning, and virtual learning.

Risk of Bias Assessment
The assessment of the risk of bias of the included studies was independent and in duplicate in accordance with the EPOC guidelines [90]. A contribution was considered at high risk of bias in case of high/unclear risk of the 'random sequence generation' criterion. The risk of bias assessment was performed by a special data form by the software package Review Manager RevMan V 5.1 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Danmark).

Study Selection
Study selection was accomplished through three different levels as follows: (1) Screening: all articles retrieved from these initial search criteria were subjected to a screening process by reading titles and abstracts; (2) Eligibility: in a second phase, the eligibility criteria were applied to the full-text version of the selected articles; (3) Inclusion: the remaining articles were included in the qualitative synthesis.
The following data were extracted from each study: year of publication, country and setting of the study, aims of the research, number of participants, e-learning teaching method, comparison with traditional teaching methods, effectiveness and acceptability to students, teachers, or private practitioners of e-learning.

Results
The article search identified 172 studies consisting of 83 papers from electronic database search and 89 contributions detected manually. After the initial screening identification process, a total of 54 articles met the inclusion criteria applied to the title and abstract assessment. The full texts were evaluated for the eligibility criteria, and a total of 32 papers were deemed suitable for inclusion in this review. The study selection process is illustrated in Figure 5. The included studies are summarised in Table 1.   Records identified through manual searching (n = 89) Figure 5. Selection of studies for the systematic review.

Characteristics of the Studies Included
The studies were conducted in the United States (10), United Kingdom (8), Brazil (5), Germany (3), Australia (3), Greece (1), Iran (1), and Saudi Arabia (1). Among the selected studies, 20 analysed the use of the e-learning teaching method in orthodontic education, while 11 studies evaluated the efficacy of e-learning in paediatric dentistry. One study evaluated the effectiveness of web-based self-instruction in both orthodontics and paediatric dentistry. The sample size for the included studies ranged from 9 to 430 participants. Participants were mostly undergraduate and postgraduate students or faculty members. Three studies involved dentists working in PHC, and one study involved private orthodontists. Studies evaluated many different educational interventions of varying duration, frequency, and format. The delivery modes used to deliver the educational materials included CD-ROM, learning management systems (e.g., WebCT, Moodle, and Blackboard), DVD, web browsers, and virtual learning environments. The methods used for interaction between trainers were videoconference, telephone, internet chat, or e-mail. Additionally, 16 articles included a comparison between e-learning or blended learning and traditional teaching methods.

Risk of Bias Assessment
The outcome of the risk of bias assessment of the included articles was reported in Figures 6 and 7. The 48.38% of articled reported a low bias of randomisation protocols, while the similarity of outcome measurements and selective reporting of outcomes presented a low risk of bias. The blinding approaches presented an unclear risk of bias of the studies selected. In most of the articles, the contamination bias was low.

Risk of Bias Assessment
The outcome of the risk of bias assessment of the included articles was reported in Figures 6 and 7. The 48.38% of articled reported a low bias of randomisation protocols, while the similarity of outcome measurements and selective reporting of outcomes presented a low risk of bias. The blinding approaches presented an unclear risk of bias of the studies selected. In most of the articles, the contamination bias was low.

Effectiveness and Acceptability of the E-Learning Methods
Two outcome measurements were considered in this review: effectiveness and acceptability. The effectiveness of e-learning was investigated in 19 studies evaluating the quantity of knowledge gain using multiple-choice questionnaires, open-ended questions, or practical exams. A significant improvement in participants' knowledge after web-based courses was reported in eight studies. Mulgrew et al. concluded that travel commitments for trainees have reduced as a result of introducing the web-based resource but not as expected [97]. Camargo et al. found that graduate students finished the course with better performance than undergraduate students [107]. Of the 32 studies, 16 compared e-learning with traditional learning. In the majority of the studies, no difference was observed in knowledge gained between the two methods, whereas two studies concluded that e-learning was more effective than traditional methods. Papadopoulos et al. found a statistically significant difference between the group that used a virtual patient and the control group showing a gain in knowledge in the simulation group [106]. Luz et al. assessed that the ICDAS e-learning programme was more effective than traditional learning in improving dental students' ability to use ICDAS [108]. Bains et al. compared e-learning with blended learning and face-to-face learning and he found that e-learning was less effective, while blended learning was the most preferred [99]. The changes in performance following learning were evaluated in five studies. Schorn-Borgmann et al. evaluated the performance of students in the construction of orthodontic appliances, and no significant improvement in the practical result was identified [110]. Ludwig at. al also failed to identify significant differences between face-to-face learning and the use of cephalometric imaging software [111], while Al-Riyami et al. found no difference in student performance in diagnosing TMD after VLE learning or face-to-face learning [98]. Luz et al. evaluated students' performance in detecting dental caries [108]. Students' acceptability was considered as an outcome in 25 studies. Seven of these studies mentioned that student satisfaction was evaluated with a Likert-scale questionnaire. The other studies used different types of questionnaires or surveys without mentioning the use of the Likert scale. All these studies reported a positive response from students when using online learning. In six studies, the students viewed online learning helpful as a supplement to their learning rather than a replacement for traditional teaching methods. Linjawi et al. stated that students responded 'very positive' to 'positive' for orthodontic e-course design, course delivery, and course outcome, but the orthodontic e-course was considered by most students as an adjunct and not a replacement of the traditional teaching methods [96]. Asiry found that few students preferred the online teaching method, and fewer students agreed to replace traditional lectures and live demonstrations with online tutorials, while most students preferred a combination of these teaching methods [113]. Mulgrew et al. concluded that despite the popularity of web-based learning resources, trainees continue to value the opportunity to interact face-to-face with their teachers [97]. Zafar et al. found in their study that 80% of the participants disagreed that virtual reality should replace conventional simulation [119]. In another article, Zafar et al. assessed that the use of VR simulation can be an additional tool that enhances students learning experience, without replacing traditional training methods [122]. According to the majority of studies, online courses were easy to access, well constructed, and understandable. However, Klein et al. found that the logistics of scheduling distant seminars, and uneven quality of the audio and video recordings were the major concerns of participants. They also assessed that students' perceptions of the quality of the learning material were influenced by the depth of their preparation [103]. In the article of Peterson et al., students preferred the online textbook to traditional textbooks, but they had technical problems associated with online use of computers running obsolete (internet) browser software [93]. Bednar et al. stated that acceptability of the distance seminars appeared to be influenced by the instructor's personality and teaching style, the seminar subject, and the residents' technological level [92]. Only two studies evaluated the opinions of faculty members that showed a positive attitude towards e-learning. Klein et al. concluded that faculty members were somewhat more enthusiastic about the experience than were residents, and they would like to use this approach to distance learning again [104]. Mulgrew et al. found that the trainers felt that teaching has been more interactive and enjoyable since the introduction of the web-based learning resource even if they stated that it has changed but not reduced teaching commitments [97].

Discussion
To the best of our knowledge, this is the first systematic review examining the use of e-learning in paediatric dentistry, while several reviews have been published in orthodontics [123]. This review showed that the use of e-learning has a positive impact on healthcare education. The rationale of the present investigation considered only the bodies of evidence on e-learning methods in the last 16 years in accordance with the first worldwide expansion of scholarship using social media platforms, while Facebook reported, on 1 October 2005, a total of 21 universities in the UK and others around the world use the platform. This evidence is commonly considered the beginning of the social media application in a scholarly environment.
The limits of the present investigation regarded the several differences of learning methodologies, the wide heterogeneity of the study population (undergraduate students/ specialisation-related courses/teachers), and the feedback measurements modalities of the acceptability and effectiveness level. According to these bias factors, a statistical consideration/meta-analysis approach was not applicable for the present investigation.
On the contrary, the rationale of the present study design offered the widest possible level of scholars, from novice/undergraduate students to those with advanced levels of expertise, not dispersing the sensitivity of the study.
Most studies reported a significant gain in knowledge after e-learning, which confirms that e-learning is effective in increasing knowledge after training in both orthodontics and paediatric dentistry. Studies that compared e-learning to traditional methods concluded that e-learning was at least as effective as traditional learning.
These results agreed with those of Lima et al. [124]. In a review, they evaluated the impact of tele-education in the field of orthodontics and concluded that orthodontic distance learning is an effective but complementary element, with no significant differences from the traditional methods of learning [124]. Kumar found that e-learning classes are at least as good as and/or better than face-to-face classroom learning and the blended approach which combines both traditional face-to-face learning and e-learning is the best method of teaching and learning [125]. Our secondary aim was to assess the acceptability of e-learning from students and teachers. This topic was explored in the interviews and questionnaires. The majority of participants considered e-learning to be effective and easy to use. According to Bednar et al., there are two benefits from using distance learning. It can enhance the experience of residents by exposing them to a variety of different thoughts, ideas, and other residents and instructors, and it can alleviate problems associated with decreasing numbers of experienced full-time faculty [92]. Many studies underlined the importance of interaction with faculty members. According to Camargo et al., interaction with tutors should provide motivation, guidance, and support to students. Klein et al. found that 92% of the participating residents thought the post-seminar discussion was an important part of the learning experience [103]. Furthermore, Miller et al. stated that participants preferred post-seminar videoconference in comparison with audio-only or chatroom interaction [101]. The studies we reviewed suggest that students prefer that online modules are used as a support to learning, and they dislike the replacement of traditional lectures with online instruction. In fact, a blended approach, mixing person-toperson contact with e-learning methods, seems the most preferred. Possible explanations could be as follows: (1) compared with traditional learning, blended learning allows students to review electronic materials as often as necessary; (2) compared with e-learning, blended learning learners are less likely to experience feelings of isolation or reduced interest in the subject matter [126].
A particular type of e-learning is virtual learning. Only four articles included in this review examined the use of virtual reality. Kleinert et al. described the use of an interactive, multimedia virtual patient module developed on compact disc (CD-ROM) to increase students' competence in caring for children with developmental disabilities [95]. Papadopoulos et al. demonstrated that a paediatric dentistry virtual patient built in a virtual world offers significant learning potential when used as a supplement to the traditional teaching techniques [106]. This result agreed with Zafar et al. who assessed that the Simodont simulated learning environment could be used as an adjunct in training dental students for preclinical paediatric dentistry restorative exercises [119]. Finally, Zafar et al. [122] presented the use of a VR simulator tool for local anaesthesia teaching in paediatric dentistry.
Our study has several limitations. There are many confounding factors in learning that were not controlled for in the studies, such as the level of motivation of the studies, previous knowledge, and teaching style of the educators. The protocol of the present review excluded studies with no abstract. Interventions, topics, durations, and settings were different for every study. Traditional evaluation methods such as written texts, questionnaires were used for evaluation knowledge gain. It is unclear to what extent these methods can measure the effectiveness of e-learning, and how they may have influenced the outcome.
The number of studies published on the use of e-learning, in comparison with traditional learning methods, was relatively limited. Other limitations were found in the selected studies, especially due to the failure to define the content quality and type of specific e-learning intervention being analysed.
Moreover, studies did not report motivations that led to choosing a specific teaching method. Furthermore, we observed that the impression of the educator was evaluated in few studies.

Conclusions
The Sars-CoV-2 pandemic worldwide emergency produced deep modifications of the institutional educational system with increased use of the smart-working approach, e-learning platforms, and limited use of traditional methods of academic learning. Within the limits of the study, the effectiveness of the present investigation demonstrated that e-learning is effective as traditional classroom methods, and the learners in these studies reported positive attitudes about e-learning with a high level of efficacy and acceptability by the operators and students. More detailed studies are necessary to understand the integration of e-learning into the learning methods in academic institutions and the implementation of interactivity in learning environments of dental students with special attention to the practicing clinical decision-making skills and operative procedures.

Data Availability Statement:
All experimental data to support the findings of this study are available contacting the corresponding author upon request. The authors have annotated the entire data building process and empirical techniques presented in the paper. The data underlying this article are not freely available by agreement with our partners to protect their confidentiality.

Conflicts of Interest:
The authors declare no conflict of interest.