Evaluation by app in smartphones of awake  bruxism at the return of presential classes in two university centers

Introduction

The multifaceted clinical relationships raised by the debate on bruxism in dentistry and other professions is diverse, also controversial, arousing interest in periodic research¹ on its effects and consequences. Definitions on the different types of bruxism have been agreed by expert panels (dentists, psychologists, orofacial pain experts) focusing on assessment strategies,² the evaluation of bruxism (SB) by polysomnography (PSG), electromyography (EMG) is considerably high in research, but daytime bruxism (AB) is limited instead. “Muscle activity during wakefulness that is characterized by repetitive or sustained dental contact, accompanied by pushes or mandibular reinforcements (movements) is the current concept of awake bruxism, clarifying the concept is not necessarily pathological, however the evidence indicates clinical consequences appear.^3,4

The frequency of AB in healthy individuals when comparing other populations with possible risk factors for additive bruxism (psychological factors, depression, suicide delusions, etc.), evaluating consequent clinical signs (fatigue, muscle pain, attritions and dental openings) is the evidence found, it is also recommended to evaluate intercultural comparisons that identify the influence of different social environments and habits in the lifestyle of the population that may have a diagnosis of bruxism.^5,6

EMA assessment allows us to see the limitations of traditional methods, such as retrospective reports questionnaires,^6,7 allowing and collecting data in real time over a certain period of time by recording multiple recording points coinciding with real experiences in their environment,^8–10 of great utility in diagnosis of oral activity, however the data obtained in EMA on AB are fragmented, limited to investigations that address only selected behaviors.^11–13 To control this limitation, the use of smart phones to implement EMA is introduced and adapted to collect data on the signs determined in AB such as dental contact, jaw clenching, tooth compression and teeth grinding.^9,14 The initial report provided by this application provides data on the frequency of GA behavior for the period of one week, for example the findings indicated 28.3%, low coefficient of variation of muscle contraction of the relaxed jaw.¹⁵

The study is proposed to demonstrate the influence of returning to presential classes affects students, through the application visualize which of the 5 signs raised is the most representative. The objective was to evaluate the frequency of AB behaviors through the use of this app on smartphones in dental students returning to presential classes.

Methods

Ethical approval was granted from the Bioethics Committee of the University of the Americas (CEBE-2022-0601). Three hundred (n = 300) young adults legally enrolled in two different Ecuadorian universities (*UDLA/UESG) in Quito and Guayaquil respectively, after signing the informed consent and agreeing to be part of the study, were randomly selected after providing written informed consent and agreeing to be part of the study. They underwent a one-week registration period with a smartphone app (BruxApp, BruxApp Research^®, Pontedera, Italy)¹⁶ developed by Dr Alessandro Bracci et al with the aim of reporting and monitoring the frequency of AB behaviours in an individual’s natural environment.

The sample was selected among fifth, sixth, seventh, eighth and ninth semester students (age 18-28 years old) legally enrolled and who are attending face-to-face Faculty of Dentistry classes in two different Ecuadorian universities (Quito and Guayaquil). Inclusion factors: owning smartphones in recent generations, good general health (without systemic diseases) and absence of temporomandibular joint disorder (TMD)/orofacial pain and/or any documented degenerative, neurological or systemic disease (e.g. rheumatological, hormonal). An informative meeting was held where the students maintained contact with the principal investigators (BV, VM, PP. MRT, EAL, LCH, AO).

During that session, the objective of the study was explained, and training was provided on how to use the app (Figure 1).

Figure 1. Flow diagram research.

The Bruxism app collects the experience of the person in a self-informed way in their daily life with an EMA approach (ecological approach), sending random messages during the day that alert the person of the conditions of their oral cavity in teeth and jaw muscles, responding within 5 minutes by touching the cone of the screen of their cell phone, Marking the current condition of the jaw muscles: relaxed jaw muscles, contact with teeth, jaw clenching, teeth clenching and teeth grinding (Figure 1).

Students are instructed to download the BruxApp app, recommending that the first data collection session commences the next morning, it is set for 20 alerts per day at random intervals, it is indicated that they must comply with at least 60% per day of replies (answered within the first 5 minutes, otherwise the screen sends an error message), Discarding from the study automatically by the app students who did not reach <60%, the data were recorded during a period of 7 days calibrating the record from 8.00 to 12.30 and from 14.30 to 22.00, subjects were instructed to ignore alerts during meals and particular activities (smoking, singing), the application records the record all day. After monitoring the seven valid days of recordings, the software generated an anonymous.csv file, which the students send to the researchers by a pre-arranged email. Data were collected by the lead author BV in collaboration with two resident dentists of the Specialty of Oral Rehabilitation VM, PP, MRT, EAL of dentistry and two professors LCH and AO of the Faculty of Dentistry of the University of Guayaquil).

To maximize the recording window, lunchtime was excluded, with the app instructing subjects to ignore alerts during meals and particular activities (smoking, singing). If the minimum number of valid responses per day was not obtained, the software automatically generated another recording day to ensure completion of the 7-day protocol.

Results

The study obtained 95% reliability and 5% error in research, sample size of n=300 young adults from the two universities involved in the study. Table 1 shows the characterization of participants by gender.

The proportion of females among the selected sample was 84.33%, compared with 15.67% of males. Thus, the proportion of females was significantly greater than that of males in this study. It was found that 79% of the participants were aged 21 to 22 years, which was expected since this sample set consisted of young adults studying at a university (Table 2).

The relaxation condition (muscles, teeth and psychological aspects in neuromuscular stability) was evident in all users, but 40% of the alerts were associated with jaw and tooth discomfort, 39% corresponded to the discomfort of mandibular clenching, and 24% corresponded to tooth contact (Table 3).

Thus, among the aforementioned symptoms, 63% of the alerts by the BruxApp were concentrated. The study was conducted in one week, in which it was observed that on the first day, 33% of the participants reported discomfort; on the second day, 61% reported maxillary discomfort; on the third day, 64% reported decreased discomfort; on the fourth day, 21% reported a decrease in discomfort; on the fifth day, the discomfort percentage was maintained; on the sixth day, 41% of the participants reported being relaxed; and on the seventh day, the percentage of participants who reported being relaxed increased by 51%, according to the alerts reported by the BruxApp (Table 4).

For this study on daytime bruxism, the chi-square statistical test (Table 5) is considered to determine the degree of association between the condition of relaxation and nonrelaxation in the alerts collected from the app. The relaxation condition refers to the state of perceived relaxation of the jaw muscles without tooth contact. Relaxation is considered the state of relaxation perceived by the jaw muscles without occlusal contact between the teeth.

The condition of nonrelaxation refers to the states of tooth contact, clenching of the jaw, clenching of teeth, and grinding of teeth. There is a significant direct association between the state of relaxation and nonrelaxation; when reporting a state of mandibular relaxation, there is a high probability that a condition of nonrelaxation would be reported (p≤0.05).

Discussion

The behavior of the AB was demonstrated in this study, the approach with EMA provided information on the frequency of the symptoms raised in the app, finding a higher percentage in women 84%, population considered young (21/22 years) 79%. The population acceptance with the use of the app on their phones, is forming part of everyday life¹⁷ adequately accepting the ecological assessment, with an average alert rate higher than 70%.

Given the different frequencies and percentages of BruxApp alerts, depending on gender, age and age groups.¹⁸ Of the sample of 300 young adults from two universities aged between 18 and 25 years, it was found that 32.13% and 5.91% of females and males, respectively, had maxillary discomfort. The alerts through the BruxApp application were useful for the study of the behavior of maxillary discomfort. Of all the alert responses, 60% were reports of a relaxed state (i.e., without maxillary discomfort). By excluding the state of relaxation from the alerts, mandibular tightening corresponded to 39% of the alerts received by BruxApp. The frequency of five specific conditions (i.e., relaxed jaw muscles, tooth contact, jaw bracing, teeth clenching, and teeth grinding) was reported over a 7-day observation period. Such an approach allowed us to collect data from the > 6000 alerts (up to 20 alerts × 300 participants × 7 days). During the observation period for 7 days, 42000 data were collected (20 alerts × 300 participants × 7 days). Alerts, varied in the 5 specific conditions incorporated in the app: relaxed jaw muscles, dental contact, jaw reinforcement, teeth clenching and teeth grinding.

We compare the findings found in studies by Zani et al. (2021) collected self-reported data at unique time points.^19,20 Observational studies have as a characteristic massive collection of EMA data with referential values of frequency of the behavior of AB²¹ complementing with stressors associated with the return to face-to-face classes in universities. Tightening the jaw (15.28%) has the highest value in monitoring during the 7 days, the least frequent tooth pain (0.17%). The relaxed maxillary muscles 68.9%, indicates that the combined frequency of the various behaviors related to AB was 23.6%. The absence of reference values for the EMA-based frequency of AB behaviors in the literature could be considered as a reference point for future research on the epidemiological characteristics of AB in healthy young adults.^22,23

The potential importance of psychological factors as etiological factors of AB, in addition to the relationship that the female gender is more prone to stress than the male gender that controls their emotions more,²⁴ these results are related to the Bracci et al. (2018) studies and Dias et al. (2021), found a slight gender difference in the frequency of AB, with EMA evaluations not being determinant.^13,24,25 The methodology used explains gender-related differences.²⁶

No significant differences were found between the population that participated in the research (UDLA; USG), finding that is considered important in self-reported strategies for AB, which may give a high bias in the data.²⁷ The heterogeneity of the information was limited to the minimum by the ease in the calibration of the individual and group self-report, the training given to the two populations of the study, indicate the download of the same BruxApp version, even independent of the model of smart phones.²⁸ Being dental students the population may have positively influenced the results, having knowledge of what determines the app limited the bias in the study, we would recommend developing the same study in the general population with limited knowledge of what is being investigated.²⁹

On the first day of alerts, 33% of the participants reported discomfort; on the second day, 61% reported maxillary discomfort; on the third day, 64% reported decreased discomfort; on the fourth day, 21% reported a decrease in discomfort; on the fifth day, the discomfort percentage was maintained; on the sixth day, 41% of the participants reported being relaxed; and on the seventh day, the percentage of participants who reported being relaxed increased by 51%, according to the alerts reported by the BruxApp. The natural fluctuation, the difficulties in the consistent recognition of the symptomatology reported the specific behaviors of the BA demonstrated a lot of variability,³⁰ these findings indicate that the relaxed muscles are recognized in a high percentage of the population investigated, taking as a starting point of baseline results when evaluating combined frequencies in all the symptomatology of the BA indicated in the app.^31,32

The EMA strategy indicated the mean frequency value estimating reliability in AB, this reduces the influence of natural fluctuation directly related to the specific symptomatology of AB.^33,34 It is indicated that registration by email limits daytime contact in patients with TMD.^35,36 It would be recommended that future research evaluate the increase or decrease in the frequency of BA symptoms, relating them to eating habits, smoking, medication use and psychological problems.^37,38 The data can contribute to updating the definition of bruxism (2018), refinement of evaluation strategies.^39,40 Population comparisons are made more accessible by the possibility of translation of the application indicating the step-by-step procedure led by mother tongue experts in the field,^41,42 ongoing multicenter project on the epidemiology of bruxism.

Conclusion

Bruxism awake with the app was evaluated, identifying 5 behaviors such as: relaxed mandibular muscles, dental contact, mandibular effort, clenching and grinding teeth, frequent conditions in the population; reporting a state of mandibular relaxation, there is a high probability that a condition of nonrelaxation would be reported (p≤0.05).

The study was developed properly, the information obtained allowed to raise real data that indicate the relationship of stress with parafunctions (AB), the drawback we found was that some participants being a self-assessment forgot to register some alerts considering a weakness of the app. We would recommend future research with the participation of teachers.