Risk factors of bruxism in children and adolescents: A case-control study

Abstract

Objectives

This study aimed to investigate the risk factors of bruxism in children and adolescents under 15 years old in Iran. 

Materials & Methods

This case-control study was conducted in day clinics of Shahid Beheshti Hospital in 2020. Fifty children with bruxism in the case group and 50 without in the control group were compared to five risk factors, including intestinal parasites, sucking the fingers, biting objects, a family history of bruxism, and secondhand smoking (SHS). The statistical tests of smoking, odds ratio, and logistic regression were used for data analysis.

Results

The mean age of the subjects was 10.6±3.2 and 10.8±2.9 years in the case and control groups, respectively. The bruxism showed significant relation with sucking the fingers, the family history of bruxism, and intestinal parasites. The SHS and biting objects showed no significant relation with bruxism. The logistic regression indicated that the study variables could explain the 22.6 to 30.1% of risk factors in bruxism.

Conclusion

Bruxism is a common disorder in children and adolescents. The intestinal parasites might be associated with bruxism. These infestations should be diagnosed and treated in children with bruxism.

Introduction

Bruxism is defined as a repetitive jaw-muscle activity characterized by clenching or grinding the teeth and/or bracing or thrusting the mandible. Bruxism can be seen in sleep bruxism and awake bruxism (1). The prevalence has been estimated at approximately 8–10% in the general adult population (2). The prevalence of bruxism has been highly variable in children. A review study reported a prevalence between 3.5 to 40.6% in children, with a commonly described decrease with age (3). Another systematic review estimated that the prevalence of sleep bruxism ranged from 5.9% to 49.6% in children and suggested that these variations might be associated with the diagnostic criteria (4). The etiology is multifactorial: mainly central (neuropathic disorder, anxiety) but also genetic and local (posture, mouth breathing) (5). Some suggest that bruxism neither a parasomnia nor a purely mechanical or psychological issue. Currently, it is considered primarily a sleep-related movement disorder with other multifactorial etiologies involving complex multisystem physiological processes (6).

Non-instrumental approaches (notably self-report) and instrumental approaches (notably electromyography) can be employed to assess bruxism (7). Bruxism can induce tooth-wearing, but it is still much more than that. It is currently linked to orofacial pain, headaches, sleep, and behavior disorders (8). Children and adolescents with bruxism usually need evaluation for other medical comorbidities such as sleep breathing problems, insomnia, attention deficit hyperactivity disorder, depression, moodiness, and gastroesophageal reflux disease (GERD) (9). Bruxism can have consequences in children and is related to the development of temporomandibular disorders (TMD) (10).

There are many treatments for bruxism and its associated headaches. Medications such as (hydroxyzine/trazodone/flurazepam), occlusal splints, orthodontic interventions, and psychological and physical therapy interventions have been used to treat bruxism. Alternative treatments, such as medicinal extracts of Melissa officinalis-L, also have been used for treatment (11). Hydroxyzine therapy showed the most vital efficacy on sleep bruxism, while Flurazepam and Melissa officinalis therapies presented lower effects on bruxism symptoms (12).

A systematic review and meta-analysis have reported many risk factors for bruxism in children, including gender (male), age, gene, anxiety, stress, secondhand smoke (SHS), high psychological reactions, moving a lot during sleep, sleeping with mouth open, snoring loudly, restless sleep, sleep hours, sleep with the light on, noise in the room, headache, biting, cheeks tonus, peer problems, emotional symptoms, birth weight, hyperactivity, and family income (13). Another systematic review found a relationship between sleep bruxism, SHS, and neuroticism in children (14). Stressed individuals showed a higher chance of presenting bruxism than healthy individuals (15).

There are a small number of studies with the primary objective of assessing bruxism in children, and there are still many questions about the exact prevalence, etiology, treatment, and risk factors of bruxism in children and adolescents. Using the case-control methodology, this study was designed to determine the risk factors of bruxism in children and adolescents under 15 years old.

Material & Methods

Study design and sampling

This case-control study was conducted in the day clinics of Shahid Beheshti Hospital in 2020. All the children and adolescents under 15 years old referring to the clinic with the diagnosis of bruxism were recruited to the study as the case group. Fifty subjects entered the case group. The 50 healthy children and adolescents without any signs or symptoms of bruxism referring to the clinics were selected conveniently as the control group. Five risk factors were studied in this research; the 50 subjects represent ten subjects for each risk factor, which seems adequate. The inclusion criteria were less than 15 years old, a definite diagnosis of bruxism in the case group, and the willingness of children and their guardians to participate in the study. Children with mental retardation or behavioral disorders such as autism were excluded from the study.

Data gathering: The subjects in both case and control groups were evaluated for intestinal parasites, sucking the fingers, biting objects, a family history of bruxism, and SHS. The stools of the subjects were studied for intestinal parasites in the hospital laboratory affiliated with Shahid Beheshti University of Medical Sciences. The sex and age of the children and adolescents also were recorded. A questionnaire containing the mentioned variables was developed to show acceptable internal consistency with 0.95 Cronbach's alpha.

Data analysis: The frequencies of the risk factors and variables were reported. The chi-square, odds ratio, and logistic regression statistical tests were used for data analysis. All the analysis was done with SPSS software version 16.

Ethical considerations: The research was approved by the Ethics Committee of Kashan University of Medical Sciences. The study's objective was explained to the children and their guardians, and the guardians completed written informed consent. The participants were assured that participating in the study would not influence their treatments. The ethical codes suggested in the Helsinki Declaration have been respected in this study.

Results

The mean age of the subjects was 10.6±3.2 and 10.8±2.9 in the case and control groups, respectively. In the case group, there were 20 girls and 30 boys. The control group contained 22 girls and 28 boys (p≥0.05). The bruxism showed significant relation with sucking the fingers, the family history of bruxism, and intestinal parasites. The SHS and biting objects did not show a significant relation with bruxism. (Table 1). The logistic regression showed that the study variables could explain the 22.6 to 30.1% of risk factors in bruxism (Table 2).

Table 1.

The frequencies and odds ratio of risk factors in the children and adolescents with bruxism in case group and control group

Odds ratio	Control group	Case group	Risk Factors
1.52*	21 (42%)	32 (64%)	Sucking the fingers
1.36	22 (44%)	30 (60%)	Chewing materials
2.187*	16 (32%)	35 (70%)	Family history
1.47*	21 (42%)	31 (62%)	Intestinal parasites
1.04	25 (50%)	26 (52%)	Second hand smocking

Significant relation*

Table 2.

The logistic regression of risk factors in case and control groups

Odds Ratio	P value	Wald statistic	Standard Error	B	Risk factors
3.273	0.016	5.782	0.493	1.181	Sucking the fingers
2.114	0.153	2.045	0.523	0.749	Chewing materials
5.307	0.000	12.375	0.474	1.669	Family history
1.716	0.258	1.281	0.477	0.540	Intestinal parasites
1.286	0.612	0.257	0.496	0.251	Second hand smocking

Discussion

In the current study, a significant relation was found between sucking fingers, family history of bruxism, intestinal parasites, and bruxism, while this study found no significant relation between bruxism and biting objects and SHS. A study showed a relationship between biting objects, especially pens and pencils, and sleep and awake bruxism in children (16). Another study also showed a relationship between bruxism, parafunctional habits (nail/pen/pencil/lip/cheek biting, resting one's head on one's hand, and gum chewing), and painful temporomandibular disorders in adolescents (17). In a study, the prevalence of sleep bruxism was 27.8% among the examined children. Only oral breathing was statistically associated with sleep bruxism with an odds ratio of 2.71 (18). Another study indicated that sleep bruxism was significantly more prevalent in children with a history of nail-biting and biting objects and less prevalent among girls (19). In the present study, the subjects in the control group were selected with the same age and gender as the case group. Thus, this research could not analyze the relation of these variables with bruxism. As mentioned earlier, the studies show that parafunctional habits such as biting objects and sucking fingers have significant relation with bruxism. This study found this relationship only in sucking fingers, not biting objects.

A study showed that a history of bruxism in parents was significantly related to bruxism in children and suggested that bruxism tends to be hereditary (20). A study found certain genes that were related to the occurrence of bruxism in children (21). A review of the literature except one study showed that bruxism seems to be genetically determined. Parents should be informed that teeth-grinding is more common in families with a positive history of bruxism (22).

The current study found a significant relationship between intestinal parasites and bruxism in children. There are few studies about infestations and bruxism. There is uncertainty about the relationship between intestinal parasites and bruxism. A study found no relationship between bruxism and intestinal parasites in 4964 children aged three to six (23). Another study also did not support an association between intestinal parasitic infestation and bruxism among the evaluated pediatric population (24). However, Tehrani et al., like the current study, found a statistically significant relationship between infection with pathogenic parasites and bruxism in Iran (25). It seems this subject needs further investigation.

Some studies have reported a significant relationship between SHS and bruxism in children (14, 26), although this study did not find such a relationship. The diagnosis of bruxism in children is mainly based on parents’ reported signs and symptoms. A study showed that proxy-reported sleep bruxism differed for each socioeconomic layer (27). Another study also indicated no association between parental reports and objective assessment of rhythmic masticatory muscle activity in children with bruxism, suggesting the need to improve parental knowledge of children's bruxism (28). The parents might underreport the symptoms, or be more aware of some problems. This is an essential limitation in studies of bruxism in children.

Author’s contribution

Dr. Ahmad Talebian: Development of original idea, study concept, and design; Dr. Mohamad Reza Sharif: Study concept and design, writing, and revision of the manuscript; Dr. Hamid Reza Gilasi: Statistical analysis; Dr Morteza Ghafeli Bidgoli: Collecting data; Dr. Negin Masoudi Alavi: Data analysis, and preparing the manuscript.

Conflict of interest

None