The effect of sleep hygiene and physiotherapy on bruxism, sleep, and oral habits in children with sleep bruxism during the COVID-19 pandemic

1.Introduction

The relationship between temporomandibular disorder (TMD) and sleep bruxism has long been a subject of interest but has not yet been fully clarified. There are many risk factors forming and triggering TMDs, and although these remain a matter of current debate, the most important risk factor has been reported to be bruxism [1, 2]. Bruxism is defined as repetitive jaw-muscle activity characterized by clenching or grinding of the teeth and/or bracing or thrusting of the mandible with circadian manifestations [1]. This behavior in individuals has been associated with TMD, fatigue, pain in the face, head, and neck, sleep apnea, and reduced sleep quality [3, 4, 5].

Although bruxism is known to increase with stress, the etiology has not yet been fully explained, and the formation and pathogenesis of bruxism are thought to be multifactorial. Researchers have determined that dental, systemic, genetic, and psychological factors play a role in bruxism, but which of these factors is predominant is still under debate [6, 7]. The prevalence of bruxism in children has been reported to be in a wide range between 6% and 58% depending on different evaluations, and it has been shown to decrease in adolescence with increasing age [8, 9, 10]. It has been emphasized that sleep bruxism (SB) can cause pathological dental erosion, pain, and loss of function in the temporomandibular joint (TMJ) and chewing muscles, limitations in mandibular movement, and headaches and neck problems. Morning pain in the jaw and surrounding muscles, headache, fatigue, difficulty in waking up, and mood changes have been reported to be signs of sleep bruxism [4, 5, 6].

The inability to sleep and poor sleep quality in children can cause daytime fatigue, lack of attention, and poor academic performance [11]. Sleep is of great importance in the development of children. In addition to sleep being an important factor in physical and emotional development and behavior, links have been found to cognitive functions, learning, and attention. It is thought that insufficient sleep in childhood and adolescence, when the brain is developing, has a negative effect on various brain functions and structures. Negative outcomes such as daytime sleepiness, aggressiveness, behavioral problems, learning difficulties, and poor academic performance can be prevented with early identification of sleep problems [11, 12].

Previous research has emphasized that sleep habits can affect sleep quality [4, 5], and SB can lead to sleep respiratory problems [13]. Manfredini et al. stated that bruxism should not be thought of as a disorder, but as a behavior with clinical outcomes [8]. Some studies have been conducted related to the opinion that there could be a relationship between this parafunctional behavior and other oral parafunctional habits [14, 15, 16], and these habits have been reported to be a risk factor for the development of bruxism. Examples of oral parafunctional activities include mouth breathing, chewing the lips and inside of the cheeks, nail biting, chewing pens, and tongue thrusting. These oral habits in children can lay the ground for bruxism. According to the results of a study by Serra Negra et al., in which the relationship between SB and other parafunctional habits were examined, there was determined to be a relationship between SB and daytime teeth clenching, nail biting, pen chewing, and breathing through the mouth [5].

In the treatment of bruxism, it is necessary to eliminate the factors causing the disease. However, as the etiology is multifactorial, a single treatment option may not be sufficient. Therefore, the factors causing the key points of the disease must be determined for an effective, high-quality treatment. Diagnosis in the early stage and taking preventative steps is important for children to be able to avoid TMDs that may develop at a later age. When bruxism continues, TMD symptoms increase, thereby creating higher costs and the need for time-consuming treatments. Several treatment modalities for the treatment of SB have been explained in the literature, including pharmacological, psychological, and dental approaches [17, 18, 19, 20, 21]. Educating children and parents about bruxism, sleep, and oral habits and increasing awareness are essential in early-stage preventative rehabilitation. However, treatment approaches in this regard are seen to be lacking in the literature. There are no studies in the literature that evaluated education on sleep hygiene and therapeutic exercises on SB in children. Educational practices are an essential part of preventative treatment. Providing information about primarly bruxism parafunctional oral and sleep habits is vital in creating awareness in children and parents. Our aims of this study were to determine the gender and age distribution of oral habits and sleep habits of children with SB and to examine the effect of an physiotherapy program on SB, oral, and sleep habits.

2.Materials and methods

2.1Subjects

In this cross-sectional study, initial screening was made of 217 children at Cukurova University Clinics of Pediatric Dentistry, Adana, Turkey. 82 children aged 6–13 years diagnosed with SB were evaluated. Among those, a convenience sample of 37 children who agreed to volunteer attended and completed an 8-week education and therapeutic exercise program (Fig. 1).

Figure 1.

Study flow chart.

Approval for the study was granted by the Human Research Ethics Committee of Hasan Kalyoncu University, Turkey (protocol number: 2019/92). The study was registered on the WHO International Clinical Trials Registry Platform (NCT05323942). All procedures conform to the provisions of the Declaration of Helsinki. All children and their parents provided oral and written informed consent. The study was conducted between March 2020 and June 2021.

The study inclusion criteria were defined as age between 6 and 13 years, having a diagnosis of possible sleep bruxism (parental reported), and a signed parental informed consent form for participation in the study. Exclusion criteria were as follows: a history of TMJ surgery, ongoing maxillary orthopedic or orthodontic treatment, the presence of dentofacial anomalies, a medical history of neurological or psychiatric disease, received drugs and interventions and those who would receive them during the program, and inability to co-operate during the study.

2.2Methods

2.2.1Evaluation

Bruxism evaluation

Lobbezoo et al. proposed a system for grading bruxism assessments [1]. In our study, the international consensus on the assessment of bruxism was used in the evaluation of bruxism. The possible bruxism in the child was evaluated in detail through a face-to-face interview with the parents. The mothers of the children in the study were given information about the bruxism and were then asked, “During the past 3–6 months, have you noticed noises of your child clenching or grinding their teeth either when awake or at least 3–5 nights a week when sleeping?” The responses were recorded as parental-reported bruxism present or absent [1, 22].

In this cross-sectional study design, children with SB were recruited. To participate in this study, volunteers provided verbal consent to an oral examination, including dental impressions, and their guardians/parents provided oral and written consent. Of the 217 children, 135 were excluded from the study due to unsigned consent forms, or because they had ongoing maxillary orthopedic or orthodontic treatment or other exclusion criteria. Finally, the study group included 82 children with possible SB aged between 6 and 13 years. The evaluation was made by a pediatric dentist (I.Y). No dental treatment was offered or carried out as part of the invitation to participate.

Demographic information of the study participants was recorded. A TMJ examination was performed before and after the exercise program, and the children and parents were questioned about joint noises, crepitation, pain, and other symptoms. Information about the children was gathered through the application of the Oral Habits Questionnaire (OHQ) to the children, and the Children’s Sleep Habits Questionnaire (CSHQ) to the parents. The children received the education and home exercise program and were instructed to follow for 8 weeks by a physiotherapist (E.K). Throughout the 8-week program, a reminder message was sent once a week to the parents.

Pain evaluation

Pain severity was measured with a Visual Analog Scale (VAS) and the degree of pain was questioned in various circumstances. The children were instructed to mark the degree of pain felt on a scale marked from 0 = no pain to 10 = intolerable pain. These scores were supported by the Faces Pain Scale. The children were asked about headache on waking in the morning, jaw pain on waking, jaw pain when eating, jaw pain after eating, and jaw pain before going to bed at night. Each of these was measured with VAS [23].

Figure 2.

Sleep hygiene education [27, 28].

Figure 3.

5x5 therapeutic exercise program [29].

Evaluation of the Children’s Sleep Habits

The Children’s Sleep Habits Questionnaire (CSHQ) was used in this study. The original scale was developed by Owen et al. [24] to investigate the sleep habits of children and sleep-related problems. Validity and reliability studies of the Turkish version were conducted by Fiş et al. [25]. The CSHQ has satisfactory psychometric properties in children and has been used in previous investigations of sleep in children. The parents were given the necessary information about the questionnaire and were then instructed to complete it. The form has a total of 33 items in 8 subscales of resistance to bedtime, sleep latency, sleep duration, sleep anxiety, nocturnal waking, parasomnia, sleep respiratory disorder, and daytime sleepiness. A total of 41 points is accepted as the threshold and values above this are evaluated as “significant at a clinical level”, showing that the child experiences clinically significant sleep problems.

Evaluation of oral habits

The Oral Habits Questionnaire comprises 21 items with 5-point Likert-type responses of 4 = always, 3 = usually, 2 = sometimes, 1 = occasionally, and 0 = never. The total points can range between 0 and 84, with lower points indicating good oral habits and higher points indicating negative oral habits. The OHQ total score was used in the study analysis [26]. During completion of the form, first, it was ensured that the child correctly understood each question, then the responses were marked by the researcher.

2.2.2Education and physiotherapy

From the 82 children initially evaluated, 37 volunteer children received education about bruxism and parafunctional oral habits, sleep habits, sleep hygiene education [27, 28] (Fig. 2), and 5 x 5 therapeutic exercises [29] (Fig. 3). By explaining parafunctional oral habits individually, it was aimed to raise awareness in the children and their parents, and for the children to be conscious of these activities and not to perform them. In the OHQ, it was questioned whether or not they performed each of these oral parafunctional activities and how aware are of them they were. The parents were given education on the subject of sleep hygiene.

The therapeutic exercises given included diaphragmatic breathing training, relaxation, and head-neck stretching and strengthening exercises. The effects of the education were examined after the 8-week program. After ensuring that the children had learned the exercises correctly, an exercise brochure was given and the children were instructed to perform 5 repetitions of each exercise 5 times a day for 8 weeks. The parents were instructed to monitor the home program and a reminder message was sent once a week. Evaluations and measurements were made before and after the 8-week program.

3.Results

From the initial screening of 217 children aged 6–13 years, 82 with SB were identified (37.8% SB). The demographic variables of the 82 children with SB first evaluated (44 males, 38 females). Among those, 37 children (19 males, 18 females) who received the education program are shown in Table 1. Mouth breathing was determined in 3 children, the presence of an allergy in 15 children, and the presence of primary dentition in 71 children. Among children having SB reported by the parents, ringing in the ears in 6.1%, earache in 3.7%, dizziness in 1.2%, headache in 9.8%, facial pain in 2.4%, difficulty swallowing in 3.7%, and neck pain in 1.2% were determined. According to the parental reports following the education and exercise program, SB was not seen in 7 children but continued in 30 children. A reduction of approximately 20% in SB was obtained following the 8-week education and exercise program.

The comparisons of the oral and sleep habits of the 82 children according to the age groups of 6–9 years and 10–13 years are shown in Table 2. A statistically significant difference was determined between the 6–9 years and 10–13 years age groups in respect of the CSHQ subcategories of resistance to bedtime 95% CI: mean (min-max) 9.70 (6.00–17.00) to 7.59 (6.00–12.00), p= 0.001; sleep anxiety 95% CI: mean (min-max) 6.62 (4.00–12.00) to 5.69 (4.00–10.00), p= 0.04; parasomnia 95% CI: mean (min-max) 9.92 (7.00–15.00) to 10.86 (7.00–19.00), p= 0.040; and sleep respiratory disorder 95% CI: mean (min-max) 3.68 (3.00–9.00) to 3.83 (3.00–5.00), p= 0.041.

No statistically significant difference was determined between the children according to gender in respect of the OHQ, CSHQ, and subscale mean points (p> 0.05) (Table 3). The VAS values of the children before and after the 8-week program are shown in Table 4. With the exception of jaw pain after eating (p= 0.180), a statistically significant difference was determined after the 8-week program in the VAS values of headache on waking in the morning decreased significantly 95% CI: mean (min-max) 0.36 (0.00–4.00) to 0.19 (0.00–3.00), p= 0.027; jaw pain on waking in the morning decreased significantly 95% CI: mean (min-max) 0.85 (0.00–8.00), to 0.50 (0.00–5.00), p= 0.027; jaw pain when eating decreased significantly 95% CI: mean (min-max) 0.70 (0.00–5.00), to 0.39 (0.00–3.00), p= 0.026; and jaw pain before going to bed decreased significantly 95% CI: mean (min-max) 0.61 (0.00–5.00), to 0.28 (0.00–2.50), p= 0.007.

The comparisons of the OHQ and CSHQ values of the children before and after the 8-week program are shown in Table 5. A statistically significant decrease was determined in OHQ, 95% CI: mean (min-max) 22.14 (12.00–40.00), to 19.76 (11.00–36.00), p= 0.000. Statistically significant changes were obtained in the CSHQ subcategories of resistance to bedtime 95% CI: mean (min-max) 9.22 (6.00–17.00), to 8.73 (6.00–16.00), p= 0.001; sleep duration 95% CI: mean (min-max) 3.78 (3.00–8.00), to 3.59 (3.00–8.00), p= 0.008; and parasomnia 95% CI: mean (min-max) 10.43 (7.00–19.00), to 11.49 (m7.00–18.00), p= 0.000 after the 8-week education and exercise program.

4.Discussion

There are few studies in the literature that have shown a relationship between therapeutic exercises and bruxism [35, 36]. However, there are still no guidelines for the treatment of bruxism in children and adolescents, and the need for multidisciplinary approaches has been emphasized [6, 10, 31]. In this study, the effects of children’s sleep and oral habits on sleep bruxism as well as an 8-week education and exercise program were evaluated to establish subsequent protective and preventative approaches. Of 82 children initially evaluated, 37 children and their parents volunteered to receive education about bruxism, parafunctional oral and sleep habits, and sleep hygiene and then received an exercise program. The children were shown how to perform the therapeutic exercises. Parafunctional oral habits were explained separately to create awareness in the children and parents, and the children were instructed to be conscious of these activities and not to engage in these habits. At the end of the 8-week program, a close relationship between oral and sleep habits and sleep bruxism was determined.

The prevalence of bruxism seen in children has a very wide range in literature because of the differences in evaluation methods [7, 8, 9, 19]. SB in children was determined at the rate of 38% in this study and 32% in a previous prevalence study in Turkey [32]. It was thought that the higher rate in the current study could have been due to the effect of conducting the study during the COVID-19 pandemic.

Although previous studies in the literature have shown bruxism at equal rates in both genders [8, 13], it has also been stated that girls aged 3–7 years are more predisposed to bruxism than boys [14]. Results in the literature on this subject differ greatly. In the current study, bruxism was observed more in boys (54%) than girls (46%), but no difference was determined between the genders in respect of oral habits and sleep habits.

It has been reported that SB is seen at higher rates in childhood and the prevalence decreases together with age in adolescence [8, 22, 33]. The high prevalence of bruxism in childhood has been suggested to be due to tighter control of younger children by parents and therefore, the prevalence is affected by the parents noticing SB [22]. Most studies have recorded the presence of bruxism according to reports taken from parents and this has been defined as possible SB [22, 32]. In parallel with findings in the literature, the possible SB rate in the current study was seen to decrease together with aging. Of the 82 children with SB, 53 (65%) were in the 6–9 years age group and 29 (35%) in the 10–13 years age group. Although the reliability of parental reports is discussed in the literature, parents are an important source for the collection of findings in children. It is also thought that as the parents notice the regularity of sleep and sleep problems and bruxism, there is increased awareness of SB and its effects.

The etiology of SB is multifactorial, and several treatment modalities have been described, including pharmacological, psychological, and dental approaches [20, 31, 32, 33, 34]. For the treatment of bruxism in adults, stretching exercises, electrotherapy, massage, muscle relaxation, and manual therapies have been used as physiotherapeutic approaches [21, 30, 35, 37]. Several non-invasive methods are applied for the treatment of bruxism in children, including oral appliances, biofeedback, cognitive-behavioral approaches, and pharmacological approaches [17, 18, 19, 20, 33]. Although discussions and different approaches are ongoing in the treatment of SB in children, the approach that has come to prominence is that it must be considered that the maxillary structures are at the growth and development stage in every intervention applied [19]. It has also been reported that physiological wear in the teeth is required for the development of the jaw structure in children aged 3–5 years [38]. The approach taken to other treatments considers the fact that the rate of bruxism decreases with increasing age, and adults do not perform these activities [8, 22, 38]. It has been recommended that researchers follow up on the signs and symptoms of bruxism, such as tooth wear, craniofacial pain, headache, and TMD or restricted mouth opening [6, 20]. The collaboration of the child, parents, and clinician has been emphasized as important in the treatment of bruxism in children and adolescents. Therefore, increasing children’s and parents’ awareness is a critical approach to establishing collaboration. Learning about parafunctional oral habits, being aware of these, and awareness of and avoiding incorrect postural behavior in daily activities and when lying in bed is an important stage. Behavioral strategies include biofeedback, relaxation, and sleep hygiene [27, 28, 29]. Sleep hygiene precautions include ensuring that the bedroom is quiet and well-ventilated, that the child is relaxed before going to bed, and that fluid intake is avoided before bedtime [27, 28]. These precautions aim to reduce the effect of mental stress on SB.

In a previous study of 54 university students, the 5 x 5 therapeutic exercises used in the current study were effective on the head and neck posture, increased sleep quality, and reduced neck disability and fatigue [29]. Educational practices are an important part of preventative treatment. In the current study, the 37 children with SB who volunteered to participate in the education and 5 x 5 therapeutic exercises were taught how to apply these exercises and received sleep hygiene education. According to the parental report, after the 8-week program, 7 children no longer had SB, and SB persisted in 30 children. This showed a decrease of approximately 20% in a period of 2 months.

5.Conclusion

The results of the study demonstrated that there was no relationship between SB and gender, but a relationship was found with age. The rate of bruxism was seen to decrease with an increase in age. The resistance to bedtime, sleep anxiety and sleep respiratory disorder values were found to be higher in the 6–9 years age group, and parasomnia values were higher in the 10–13 years age group. It was determined that oral and sleep habits and bruxism are closely related, and the rates at which bruxism is seen are affected by oral habits. 8-week education and physiotherapy program increased the parents’ and children’s awareness of SB, oral, and sleep habits.

In the future, we recommend a randomized controlled trial for longer-term and more comprehensive programs with a control group to prove the efficacy of education and exercises in children with bruxism.

Funding

The authors did not receive any financial support for this study.

Author contributions

All listed authors made valuable contributions to the development of this manuscript. Conception and design: AT; Collection and assembly of data: EK; Analysis and interpretation of the data: AT; Drafting of the article: AT, IY; Critical revision of the article for important intellectual content: AHT; Final edition of the manuscript: AT, İY.