Smartphone Applications in Dentistry: A Scoping Review

This scoping review aims to investigate the latest literature concerning the use of smartphone applications (apps) in the prevention, management, and monitoring of oral diseases. Smartphone applications are software programs that are designed to run on smartphones. Nowadays, smartphones are regularly used by people of all ages, and mobile health apps (MHAs) represent an important means of spreading information related to oral health, which is the state of the mouth and teeth, including the gums and other tissues. Several apps have been designed to promote prevention, diagnosis, and therapeutic adherence monitoring. This scoping review considered randomized clinical trials, cross-sectional studies, before–after (pre–post) studies with no control group, and observational studies. Once the inclusion and exclusion criteria had been defined, a preliminary confined search was performed on PubMed and Scopus; key terms from the collected articles were selected to design a search strategy, and then a search of all the included articles’ reference lists was run for further research. Studies were excluded if they did not fulfill the inclusion criteria. The preferred reporting items for scoping reviews (PRISMA-ScR) consensus was followed. The risk of bias was evaluated by providing a qualitative analysis of the clinical studies via the National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment of Controlled Intervention Studies, Observational Cohort Studies, and Cross-Sectional Studies (NHLBI, NIH). A total of 21 studies were included in this review. As it is clear from the studies selected, the literature indicates that MHAs are effective in improving oral hygiene in adolescents and children and reducing the dental plaque index, including in patients undergoing orthodontic treatment. MHAs are also able to reduce the symptoms of patients affected by obstructive sleep apnea–hypopnea syndrome (OSAHS) and improve the swallowing-related quality of life of elderly patients. MHAs are furthermore recommended to decrease dental anxiety among patients, both during dental procedures and the post-operative period. MHAs are useful to spread knowledge about traumatic dental injuries among non-oral health professionals and to monitor dental erosion and awake bruxism. MHAs’ clinical outcomes might have been influenced by the demographic features of the subjects involved. Further studies considering a longer follow-up period and larger samples are needed. In conclusion, MHAs can be considered a useful tool to monitor oral disease and increase patients’ quality of life related to oral health.


Introduction
The concept of "mobile health" (mHealth) refers to the promotion of healthcare through mobile apps and wireless connections [1].
Nowadays, mobile phones are regularly used by people of all ages and may also be useful in medicine to promote prevention and healthy behaviors, allowing everyone to access reliable information anytime and anywhere [2].These tools aim to monitor significant factors related to diet, exercise, and therapeutic adherence, which play an important role in several diseases [3][4][5].The development of mobile apps was meant to promote prevention, diagnosis, disease management, and therapeutic adherence monitoring [6].
In recent years, dentistry has made steps forward as far as research and technological innovation are concerned, leading to significant progress in all the main dental fields [7].
The invention of 3D printing has revolutionized the production of drill guides and implants in oral surgery and of physical models in orthodontics and prosthodontics [8].
Intraoral scanners have become a fundamental part of the digital workflow; digital impressions allow a more precise bite registration, avoiding distortions related to analogue procedures [9].
Nowadays, it is possible to combine 3D printing and intraoral and extraoral scans to design and manufacture customized appliances for patients affected by craniofacial disorders [10].
Some authors have experimented with the ability of AI (artificial intelligence) to diagnose oral diseases, such as head and neck cancer lesions and periodontitis, but also to make therapeutic decisions, for example, to choose between an extractive and a nonextractive treatment for an orthodontic patient [11].
Research about the use of AI in dentistry is currently growing, involving mainly radiological diagnostic imaging [12].
AI can also play a significant role in orthodontics, helping clinicians to make diagnoses, manage orthodontic treatments, assess patients' compliance, and make patients feel more involved and cared for [13].
The introduction of teledentistry, a combination of telecommunications and dentistry, has represented an interesting innovation to improve oral healthcare [14].
MHAs represent one of the latest trends arousing interest in the literature [7].
MHAs also represent an important means of spreading oral health care information [15].In the last few years, an increasingly high number of available health-related apps has been evident, reaching 325,000 apps in 2017 [16], with 612 oral health-related apps that could be downloaded from the App Store in 2019 [17].MHAs provide meaningful information as far as different fields of dentistry are concerned.They motivate patients to maintain good oral hygiene using positive reinforcement to prevent dental caries [18].These tools could be particularly helpful for orthodontic patients to avoid plaque accumulation, gingival inflammation, and dental caries, which can lengthen treatment times and result in periodontal health worsening [19].
Studies have confirmed that facial scans obtained using mobile applications may be accurate enough for orthodontic assessments [20].
MHAs also help patients to manage and overcome dental anxiety, which is still very common despite technological advances in modern dentistry [21].Furthermore, some apps have been developed to increase parents' awareness about oral health in early childhood [22], for example, by teaching their children good eating habits and proper oral health practices [23].Other MHAs, on the contrary, are addressed to elderly people and provide specific oral exercises that could increase salivary flow rate, reduce xerostomia, and improve swallowing [24].Moreover, some MHAs have been created to monitor jaw-muscle behaviors, such as awake bruxism [25].
Other scoping reviews in the literature investigated the role of MHAs in dentistry.Vaid et al. analyzed the importance and clinical significance of MHAs in orthodontics [26].Ben-Omran et al. evaluated the use of MHAs to monitor older adults' oral health [27].
Considering the significant increase in MHAs related to oral healthcare in the last decade, the present scoping review aims to: -Analyze the latest literature regarding the prevention, management, and monitoring of oral diseases using MHAs; relevant articles were reviewed by analyzing their full texts, documenting the findings, and detecting any similar studies that followed the inclusion criteria adopted.The present protocol has been registered within the Open Science Framework platform (Registration DOI-10.17605/OSF.IO/A9CX2).
The elaborated strategies designed for each online database are exhibited in Table S2 (Supplementary Material).

Quality Assessment of Included Studies
In the present review, the risk of bias was evaluated by providing a qualitative analysis of the clinical studies via the National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment of Controlled Intervention Studies, Observational Cohort Studies, and Cross-Sectional Studies (NHLBI, NIH).

Results
Based on the MeSH terms, 158 articles were identified in the primary search.Subsequently, 126 articles were discarded (13 abstracts of articles published in languages different from English, 81 duplicates, 0 in vitro or animal clinical studies, 24 not pertinent, and 8 without Ethics Committee approval), and 32 articles were screened based on their titles and abstracts.The remaining 32 full-text articles were assessed for eligibility.Moreover, 11 full-text articles were further discarded as not relevant (4 articles were excluded because they were pilot studies that needed further insights, 6 articles were excluded since they evaluated mobile applications as a learning tool for dental students, and 1 article was excluded since it considered the role of smartphone applications as a means of communication with dental students).The remaining 21 articles were considered relevant and thus included in this review.Figure 1 below describes the flow chart of the review process.Table S3 (Supplementary Materials) shows the studies excluded from this review and the reasons for exclusion [30][31][32][33][34][35][36][37][38][39][40].

Risk of Bias
The Cochrane Collaboration tool was applied to assess the risk of bias in the articles included in this review (Table 1), using the judging criteria for risk of bias shown in Table S4 (Supplementary Materials).A moderate risk of bias was observed in this review.
Table 1.Risk of bias of the studies included in this review: the green symbol represents a low risk of bias, while the yellow symbol represents a high risk of bias.

Random Sequence Generation
[48]                    The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.

References
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.

References
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Ma- The key features of the patients included in the selected studies are set out in Table 2. Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Ma- The key features of the patients included in the selected studies are set out in Table 2. Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Ma-    The key features of the patients included in the selected studies are set out in Table 2. Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6   The key features of the patients included in the selected studies are set out in Table  The key features of the patients included in the selected studies are set out in Table     The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2.
Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (pre-post) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).The key features of the patients included in the selected studies are set out in Table 2. Table S5 (Supplementary Materials) explains the evidence of the studies included in this review (study design and aim, methods, results, and conclusions).
Table S6 (Supplementary Materials) illustrates the NHLBI Quality Assessment Tool for Controlled Intervention Studies.The NHLBI Quality Assessment Tool for Cross-Sectional Studies is shown in Table S7.The NHLBI Quality Assessment Tool for before-after (prepost) studies with no control group is represented in Table S8 (Supplementary Materials).The NHLBI Quality Assessment Tool for Observational Cohort Studies is provided in Table S9 (Supplementary Materials).

Discussion
In the last few years, mHealth has improved to become a useful tool in modern dentistry.It allows practitioners to collect data about oral healthcare and to constantly monitor and motivate patients.Many MHAs have been developed to spread oral health information among people of all ages.MHAs are meant to educate patients about the importance of proper oral hygiene, which is essential for good oral health [61].Apps for smartphones and tablets provide patients with reliable information and alert them through push notifications to raise awareness about proper dental behaviors [62].MHAs could therefore be used to prevent, manage, and monitor oral disease, promoting a more active and appealing involvement of patients in their oral healthcare.As described in the recent literature, several authors tested many MHAs on patients of different ages to assess their effectiveness in preventing oral diseases, spreading positive behaviors, and promoting good oral hygiene.
The studies included in this review showed that MHAs are effective tools to improve the prevention, management, and monitoring of oral disease.Nevertheless, MHAs' outcomes might differ according to the demographical features of the subjects to whom they are addressed, affecting their effectiveness in some contexts.Furthermore, MHAs' outcomes should be evaluated over a longer follow-up period and on larger samples.
The present scoping review aims to evaluate the clinical outcomes of MHAs in different branches of dentistry and on patients of different ages, as opposed to other studies published in the literature focusing on single fields and patients of a particular age.
This scoping review aims to detect the clinical outcomes of MHAs related to oral healthcare in the general population.

Oral Hygiene
The role of microbial plaque in the etiology of dental caries and periodontal disease is well-known and documented [63].
Although most of the population performs daily oral hygiene, several studies have reported that most individuals fail to reduce their mouth plaque scores [64].
According to Toniazzo et al., MHAs can represent an effective tool to improve patients' oral hygiene [65].
Some studies showed that MHAs providing patients with brushing instructions resulted in raising awareness of the importance of proper brushing and improving patients' brushing techniques [42,44].
MHAs have proved to be effective in reducing mouth plaque scores and, consequently, periodontal inflammation and gingival bleeding [42, 44,47].Alkadhi et al. observed that MHAs providing oral hygiene instructions can the decrease dental plaque index compared to verbal oral hygiene instructions, although further studies with longer follow-up periods are recommended.A short-term follow-up is mentioned as the limitation of the study.[41] Similarly, Alkilzy et al. found out that MHAs are useful to reduce plaque accumulation; the results might have been influenced by Hawthorne effects, according to whom subjects involved in a study may tend to modify their behaviors.Furthermore, a longer follow-up period should be considered [42].Kay et al. showed that MHAs are successful in improving brushing outcomes, at least in the short term [44].
It has been observed that adolescents prefer receiving oral health information through smartphone applications and social media [66].In fact, Marchetti et al. showed that the use of a mobile oral health app leads to an improvement in adolescents' periodontal health over a long period of time.The study was conducted in a single school, and this could be a limitation, even if subjects were selected to be representative of the study population.Another limitation is the absence of validation of the questionnaire used [47].

Children's Oral Health
Early childhood caries (ECC) is known to be the most common chronic disease in early childhood [67].Young children are not typically able to perform proper brushing autonomously, so the supervision of parents plays a fundamental role in their oral hygiene [68].Parents must teach little children health skills and good eating habits [23].Morais et al. described MHAs in their integrative review as effective tools for children, combining educational and interactive approaches [69].
It has been shown that the use of MHAs improves mothers' knowledge and practice about children's oral health.In particular, MHAs were successful in improving children's gingival status over a long period of time.The study faced some limitations: some smartphones blocked notifications because of security systems, and subjects without smartphones and preschoolers could not take part in it [50].Moreover, MHAs represent a modern and particularly successful tool to teach children the correct brushing technique, as reported by the work of Desai et al., in which a significant positive impact on children's brushing skills was noticed compared to traditional oral hygiene instructions.The limitations of the study are that the sample may not be representative of the study population, a longer follow-up should be taken into consideration, subjects not using a smartphone cannot be involved in the study, and tongue cleaning was not contemplated.Furthermore, the study promoted the modified bass technique, which is difficult to learn for children [43].A reduced dental plaque index and better hygienic control were observed in children whose mothers used oral health mobile applications.Nevertheless, it would be necessary to analyze MHAs' outcomes on dental caries over time and to investigate mothers' oral hygiene to seek a correlation between mothers' and children's oral healthcare [51].Oral health practitioners have shown to be favorable to advising MHAs to little children's parents.Further studies are recommended, extending the research to all the existing app stores and adopting different scales to evaluate clinical outcomes in children's oral hygiene [52].

Severe Apnea-Hypopnea Sleep Obstructive Syndrome
Obstructive sleep apnea-hypopnea syndrome (OSAHS) causes impaired sensorimotor deficits in the upper airway muscles [70].Myofunctional therapy with daily exercises is one of the most novel treatments designed to reinforce the oropharyngeal muscles to avoid the collapse of the upper airways [71].According to the recent literature, MHAs provide healthy sleep habits and raise enthusiasm among patients with OSAHS, although further studies are needed to achieve major accuracy and reliability in these apps [72].
Patients can learn oropharyngeal exercises using MHAs.It has been shown that oropharyngeal exercises performed with the support of mobile applications reduce OS-AHS gravity and symptoms.Future studies involving a large number of participants are encouraged to support this evidence.[48].

Compliance and Duration of Treatment of Orthodontic Patients
In recent years, research has led to significant advances in fixed orthodontics, improving bonding techniques with high-performance and innovative materials [73].It is well documented that fixed orthodontic appliances make it more difficult to maintain good oral hygiene [74].As a result, patients with fixed orthodontic appliances might undergo plaque accumulation, which can lead to the development of white spot lesions or even dental caries [75].The duration of orthodontic treatment might be influenced by behavioral factors such as missed appointments, an unplanned debonding of brackets, and bad oral hygiene, which are signs of poor patient compliance [76].
According to a systematic review, professionals should recommend MHAs since they can be effective in reducing the duration of orthodontic treatment and the intensity of self-reported pain among orthodontic patients [77].Furthermore, MHAs can also remind patients about elastic and mobile device wear, promote better oral hygiene, and result in earlier treatment outcomes [78].
However, it has been observed that a very low to moderate level of evidence supports the effects of MHAs in improving orthodontic patients' behaviors [79].
It has been shown that MHAs providing oral hygiene instructions and timely reminders through push notifications improve the oral hygiene of patients with fixed orthodontic appliances, leading to reduced plaque indices and gingival inflammation levels [41,49].
According to Li et al., MHAs are effective in reducing orthodontic treatment duration by improving patients' compliance and decreasing bracket bond failure.It would be necessary to perform the study on larger samples, involving complex orthodontic cases and adopting a longer follow-up period [46].

Oral Care and Swallowing-Related Quality of Living in Elderly Age
Many elderly people experience xerostomia, swallowing alteration, reduced tongue pressure, and functional impairment of the tongue, mouth, and lips [80], which can interfere with proper food intake and digestion and, consequently, a good quality of life [81].Recently, several MHAs addressed to elderly people have been devised to improve their health and related quality of life [82].In particular, some MHAs have been designed to teach elderly people to perform oral exercises and intraoral and extraoral massages to improve their oral health.As a result, Ki et al. described positive effects on elderly people's oral care: tongue pressure increase, oral dryness reduction, basal salivary flow rate increase, and swallowing-related quality of living improvement.Further studies adopting a longer follow-up period and a larger number of participants are required [45].

Dental Anxiety
Despite the impressive technological innovation of modern dentistry in recent years, many people still suffer from dental anxiety [21].Due to this condition, anxious patients tend to postpone or even avoid dental treatments, with consequent negative outcomes for their oral health and related quality of life [83].It has been proven that mHealth may be useful to overcome this issue; mobile applications can produce large effects in reducing dental anxiety compared to other non-pharmacological methods [84].
Huang et al. reported that MHAs allow dentists to perform a teleconsultancy assessing both the physical and psychological patient status.Using this effective tool, the oral health practitioner can follow the patient before the dental procedures, helping to manage dental anxiety up to the post-operative period and addressing possible complications.It should be considered that MHAs' impact on dental anxiety might be influenced by some aspects, such as sex, age, and possible anxiety disorders, which were not homogeneously represented in the study population [53].

Traumatic Dental Injuries
Dental trauma often occurs in children and adolescents; a proper diagnosis and timely treatment are necessary to allow a favorable long-term prognosis [85].In their review, van Mechelen et al. included 18 MHAs, among which only 1 app recommended the use of mouth guards to prevent dental injuries, while none of them suggested how to manage them [86].Parents have to be able to properly manage dental trauma.Iskander et al. compared the effectiveness of MHAs and posters to deliver dental trauma information to parents and showed that both these tools were effective [87].It is also extremely important to spread knowledge about the management of traumatic dental injuries among non-oral health professionals such as teachers, gym instructors, etc., for whom MHAs have been designed.Zaror et al. validated an MHA regarding dental injury identification and related epidemiologic information collection.The next step is to test this MHA in real cases of trauma in different settings (e.g., schools and gyms) to evaluate its usability in stressful conditions [61].

Dental Erosion
The prevalence of dental erosion is increasing, mainly among young people [88].This process has a multifactorial etiology and, if not correctly diagnosed and treated, can lead to esthetic and functional problems [89].MHAs have been designed to improve the management of dental erosions.These tools are addressed both to oral practitioners and patients, promoting a stronger relationship between professionals and patients.Butera et al. demonstrated that oral practitioners can use this type of app to monitor the status of patients' dental erosion over time, detecting possible progressions in the erosive process, while patients can receive personalized oral hygiene instructions from oral practitioners to avoid further deterioration.Preliminary clinical results have been encouraging, and important enhancements to these apps are expected in the future [54,90].

Awake Bruxism
Bruxism has been described as a jaw-muscle behavior in otherwise healthy individuals [91].Several studies recommended the use of ecological momentary assessment (EMA) principles to study awake bruxism [25].A smartphone application has been developed for the EMA of awake bruxism.By sending push notifications, it alerts patients and collects data about their jaw-muscle condition in real time.A good compliance rate has been detected, encouraging further adoption of this tool both for clinical management and research [56].Câmara-Souza et al. managed to evaluate awake bruxism frequency in college preparatory students in correlation to psychological factors thanks to MHAs.The authors did not find any difference as far as compliance is concerned between workdays and weekends but noticed that some subjects showed a lack of compliance, probably due to the impossibility of using their smartphones during the day and, consequently, of reacting to the alerts.Therefore, it would be necessary to rely on other technological devices, such as smartwatches [55].
According to the studies included, MHAs are an effective tool to gather data about awake bruxism that can be used both for clinical activity and research.In fact, these data enable patients to become aware of their habits and monitor their changes over time, promoting a deeper knowledge of this condition [39,58].
It is desirable to carry out further studies involving MHAs to detect the frequency of AB in healthy subjects and in subjects with conditions such as orofacial pain, sleep disorders, and psychosocial impairment to better analyze the correlation with this phenomenon [57,59].

Limitations and Future Perspectives
This scoping review has some limitations: The results might have been influenced by demographical factors, such as age and geographic localization.Eight studies were excluded because of the absence of Ethics Committee approval.MHA development involves high costs both for professionals and patients; therefore, it might be difficult and expensive to develop and maintain high-quality applications.A further challenge is undoubtedly meeting the requirements of different populations with different levels of oral knowledge and healthcare.The approach should be adapted to the population groups; for example, MHAs for children should be provided with gamification to promote their use.
Furthermore, some MHAs need to be improved as far as accuracy and reliability are concerned to be effective.
It is desirable that future studies evaluate long-term results to confirm MHAs' effectiveness and use them as part of daily clinical activities.Furthermore, studies involving larger samples are needed.MHAs' success in different populations and settings and for longer periods should be investigated.It would be necessary to design more user-friendly and engaging MHAs to entice consumers to use them.MHAs should be advertised by dental practitioners to make patients aware of their existence and benefits.The ethical and legal implications of the use of MHAs should be carefully considered.It would also be interesting to combine MHAs with AI, which is an arousing and current research topic.

Conclusions
Several MHAs have been recently designed to promote the prevention, diagnosis, and therapeutic adherence monitoring of oral disease.MHAs seem to be effective in improving adolescents' and children's oral hygiene, including patients undergoing orthodontic treatment; promoting proper oral behaviors; raising awareness about dental injuries; reducing dental anxiety; monitoring oral disease and parafunctions; and increasing patients' oral health-related quality of life.These outcomes should encourage researchers to enhance existing MHAs and design new ones, improving some features, such as user-friendliness and appeal.Patients should be informed about the positive clinical results of MHAs to encourage them to trust these innovative tools.Further studies are required to evaluate the results in the long term and to assess their possible use as part of daily clinical activities.Most studies included in this review provided a short follow-up period; it would be

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