|Year : 2008 | Volume
| Issue : 7 | Page : 91-97
Study of the relationship of psychosocial disorders to bruxism in adolescents
E Katayoun1, F Sima2, V Naser3, D Anahita4
1 Department of Pediatric, Dental School, Islamic Azad University, Tehran, Iran
2 Department of Educational Science and Psychology, Shahid Beheshti Medical University, Tehran, Iran
3 Ms in Statistical Science, Shahid Beheshi Medical University, Tehran, Iran
4 Dentist, Tehran, Iran
Department of Pediatric, Islamic Azad Dental School, No 4, 10 Neyestan Street, Pasdaran Ave, Tehran
| Abstract|| |
Background and Aim: Bruxism has been defined as a diurnal or nocturnal parafunctional habit. Etiology of bruxism has remained controversial and some investigators believe that psychological factors may play a major role in promoting and perpetuating this habit. The aim of this case-control study was to assess the existence of an association between bruxism and psychosocial disorders in adolescents., Participants were chosen among 114, 12-14 year old students (girls). They were divided into two groups, bruxers and nonbruxers, on the basis of both validated clinical criteria and interview with each patient. A few participants were excluded on the basis of presence of systemic disorders, TMJ disorders, other oral habits, primary teeth, defective restorations and premature contacts. Following matching of two groups in regard to parent's age and education, mother's marital status, child support status, mother's employment status, and socio-economical status, 25 cases and 25 controls were enlisted. A self report validated questionnaire (YSR, 11-18 yr) was then filled out by both groups for the evaluation of 12 psychosocial symptoms.
Results: Remarkable differences in certain psychosocial aspects were found between the two groups. Prevalence of psychosocial disorders including Thought Disorders (P < 0.005), Conduct Disorders (P < 0.05), Antisocial Disorders (P < 0.06) as identified by YSR was significantly higher in bruxers. Significant differences between the two groups also emerged in total YSR scores
(P < 0.005). The results of Odds Ratio revealed that a bruxer adolescent has 16 times greater probability for psychosocial disorders than a non-bruxer one. Fischer exact test and T-test were used and Odds Ratio and Confidence Interval was estimated.
Conclusion: Support to the existence of an association between bruxism and psychosocial disorders has been provided.
Keywords: Adolescents, antisocial behavior, bruxism, conduct disorders, psychosocial disorders, thought disorders
|How to cite this article:|
Katayoun E, Sima F, Naser V, Anahita D. Study of the relationship of psychosocial disorders to bruxism in adolescents. J Indian Soc Pedod Prev Dent 2008;26:91-7
|How to cite this URL:|
Katayoun E, Sima F, Naser V, Anahita D. Study of the relationship of psychosocial disorders to bruxism in adolescents. J Indian Soc Pedod Prev Dent [serial online] 2008 [cited 2013 May 19];26:91-7. Available from: http://www.jisppd.com/text.asp?2008/26/7/91/44834
| Introduction|| |
Bruxism has been defined as a diurnal or nocturnal parafunctional habit, including clenching, grinding and bracing of the teeth that can happen consciously or unconsciously and is considered one of the most destructive habits., Estimates of the incidence of bruxism range from 38% in patients below 17 years old to 74% of 15-18 years and 77% in 7-14 year olds.
,,,, Etiology of bruxism has remained controversial. Psychological problems, stress, depression, hostility, and anxiety were claimed to be related to bruxism.,,,, Malnutrition, calcium, magnesium and vitamin deficiencies, chronic and parasitic colon diseases, consistent and recurrent dysfunction of urinary system, otic disorders, allergic edema of ostash tube, mouth breathing, asthma, pubertal hormonal changes and hypothyroidism are among other related factors.,,,, Defective restorations at nonworking side, and increased distance between centric occlusion and centric relation were claimed to be the most important occlusal factors related to bruxism.,, However some studies didn't find any correlations between bruxism and occlusal factors. Bruxism can result in tooth wear, tooth fracture and tooth mobility, pain and tenderness of facial muscles, TMJ disorders, trauma to soft tissue, and headache.,,,,,
Due to the lack of agreement on the etiology of bruxism and since some patients continue to brux even after local and systemic factors have been dealt with, and high prevalence of bruxism and its consequences, the aim of this study was to determine the correlation between psychosocial disorders and bruxism in 12 to 14 year old student girls in summer campuses of Tehran junior high schools in 1385 .
If such correlation exists between bruxism and psychosocial disorders, the findings can be used for further studies and preventive attempts to reduce the incidence of bruxism and its known consequences.
| Materials and Methods|| |
Subjects were selected among 114, 12 to 14 year old student girls attending summer campuses of Tehran junior high schools in 2006. Inclusion criteria were as follows:
- Report of morning fatigue or pain in facial muscles.
- Report of grinding behavior.
- Report of grinding bruxism sounds during sleep by subject's room partner or family members.
- Report of bruxing behavior in thoughtful and/or stressful situations.
- Observation of tooth wear or facets on occlusal tables, cusps, and incisal edges in clinical examinations.
Subjects had to report at least one of the 4 above mentioned symptoms of bruxism and/or exhibit wear facets in clinical examinations.
Criteria for exclusion from the study were: presence of systemic disorders, TMJ disorders, oral habits, primary teeth, defective restorations, and premature contacts.
| Procedure|| |
After obtaining permissions from the ministry of education headquarters and its offices of the city districts, students' parents were informed of the study purpose and signed a consent form at the initial visit. In order to diagnose bruxism, a form including student's name and age, school name and type and district, along with four questions on bruxism symptoms was completed by each student. Clinical examinations were then performed according to a second form, using a pair of disposable gloves, dental mirror and explorer in natural daylight. Occlusion was determined according to Angle classification of molar relationships to classes I, II and III, TMJ disorders were examined through palpation of condylar heads and movements in closed mouth while subjects were pressing their teeth and in rest position, and while the subject was opening her mouth and then looking for crepitus or any other abnormal sounds. Premature contacts were evaluated using Hanel articulation paper of 8µ thickness, defective restorations were evaluated by presence of wear or shiny spots on restorations. Deciduous teeth were observed clinically. To determine oral habits, students were asked to answer if they were used to lip or nail biting, mouth breathing, tongue thrusting or thumb sucking. To determine systemic backgrounds, students and their parents were asked questions on the symptoms of diseases including a history of difficulty in breathing, severe coughing, and chest wheezing for asthma, consistent pain or feeling of fluid in ear for otic disorders, obesity, facial edema and cold feelings on skin for hypothyroidism, excessive weight loss, and pain around navel for chronic and parasitical colon diseases, inconvenient and frequent urinating, pain under the stomach and sides for consistent or recurrent urinary system dysfunction, feeling of fullness in ear for allergic edema of ostash tube. Students with TMJ disorders, premature contacts, defective restorations, deciduous teeth, oral habits or history of systemic diseases were excluded from the study. Those who answered positively to at least one question regarding bruxism symptoms or facets were observed in their clinical examinations, were defined as bruxers and those with none of the symptoms were defined as non-bruxers. 84 subjects satisfied inclusion/exclusion criteria. A third form was then filled out by the two groups, including questions on parents' age and education and employment status, mother's marital status, child support status and birth order, accommodation ownership and size, family size and school type. A score was given to each socioeconomic factor including father's employment status, accommodation ownership and size, family size and school type and finally subjects were put in one of the socioeconomic groups of good, medium or weak. The two groups were then matched accordingly.
The Youth Self Report Questionnaire for 11 to 18 year olds was then answered by the two groups. The reason that a self report questionnaire was used was essentially practical, since it requires only about 20 minutes to be completed and it is more easily accepted by non-psychiatric patients than an extended psychiatric interview. YSR questionnaire is composed of 112 questions in the form of very true with the score of 2, often or occasionally true with the score of 1, and false with the score of 0 providing ratings for psychosocial disorders of clinical (above-threshold), sub clinical (borderline), and normal domains in experience based scales including: anxiety/depression, seclusion/depression, social problems, thought disorders, attention disorders, antisocial behavior, aggressive behavior, and DSM scales including: emotional disorders, anxiety disorders, attention deficit-hyperactive disorders, antisocial disorders, and conduct disorders. Definition of each disorder according to YSR questions is provided in Appendix 2. Three scores were then developed for each scale, raw values, percentages, and T scores. Raw values were made by adding the 0s, 1s and 2s of all questions in every scale. Percentages showed the distributing percentages that were equal to or below a specific numerical value, and T scores were the most obvious indicator of subject's function in YSR scales, they were the transformed form of raw values that made an average and standard deviation for all scales. Psychological problems were scored as follows: For the seven disorders of experience based scale and the five disorders of DSM scale, in clinical domain a score of 2, in borderline domain a score of 1, and in normal domain a score of 0 was specified. Subjects could get a maximum score of 24 and a minimum of 0, while 0 scores were defined as "no psychosocial disorder", between 0 and 12 as "minor psychosocial disorder", and above 12 as "major psychosocial disorder". We also determined that each subject of both case and control groups was exposed to which one of the twelve psychosocial disorders.
This was a double blind study in that the three forms were encoded by the professor, and the coded YSR forms were then sent to the psychologist for evaluation of subjects' psychosocial disorders. Neither the professor, nor the psychologist was aware of the presence or absence of bruxism in the subjects.
Subjects were divided into two groups (bruxers and non-bruxers) with a case-control study design. Fischer exact test was used for the variables, T-test for age difference, and Fischer exact test for other indicators. In case the correlation between the two groups in being exposed to psychosocial disorders was proved by the statistical analysis, Odds Ratio and Confidence Interval with confidence of 95 percent was estimated in the normal population.
| Results|| |
A total of 114, 12 to 14 year-old student girls attending summer campuses of Tehran junior high schools in 1385 were evaluated, among which bruxism was diagnosed in 42 students (37 percent) while the remaining 72 students (63 percent) did not meet the criteria for bruxism. 14 students among the bruxers and 16 among the nonbruxers were excluded due to oral habits, presence of deciduous teeth, defective restorations, premature contacts and history of systemic diseases. Ultimately 50 subjects including 25 students with bruxism and 25 students without bruxism were chosen from 28 students (33%) with bruxism and 56 students (67%) without bruxism. None of the subjects had deciduous teeth, oral habits, history of orthodontic treatments, systemic diseases, defective restorations and premature contacts, and none of them had class III occlusion, less than high school diploma for father, divorced or widowed status for mother, and good socioeconomic status. Both groups answered the YSR psychosocial questionnaire. Distribution of the two groups according to matching criteria showed that in addition to similar inclusion and exclusion criteria, subjects were also similar in regards to age, occlusion type, parents' age and education, birth order, and socioeconomic status, and the minor difference between them was statistically insignificant (P < 0/9).
Prevalence of psychosocial disorders in bruxers and non-bruxers in [Table 1] shows that 21 subjects (84%) in the case group were at least exposed to one psychosocial disorder, while 6 subjects (24%) in the control group were found to be exposed to the least psychosocial disorders. This difference was statistically significant (P < 0.0001) and subjects with bruxism were found to be 16 times more probable for psychosocial disorders (O.R = 16.6), and adolescents with bruxism were estimated to be 4 to 68 times more probable for psychosocial disorders in the normal population (C.I O.R = (4 to 68)).
Prevalence of minor and major psychosocial disorders in bruxers and non-bruxers is shown in chart A. While 76% of non-bruxers were not exposed to any psychosocial disorders, only 16% of bruxers were not exposed to these disorders. Twenty-four percent of non-bruxers were exposed to minor psychosocial disorders, while this was 84% in bruxers and finally none of the nonbruxers were exposed to major psychosocial disorders while 4% of bruxers had major psychosocial disorders. This difference was statistically significant (P < 0.0005).
Prevalence of 12 psychosocial disorders in bruxers and non-bruxers is shown in [Table 2]. Findings are as follows:
Thought disorders: 28% of bruxers were exposed to thought disorders, and this disorder was not present in their controls. This difference was statistically significant (P < 0.005) and bruxers were many more times likely to be exposed to thought disorders than their controls.
Conduct disorders: 24% bruxers and 4% of nonbruxers were exposed to conduct disorders and this was also statistically significant (P < 0.05). Bruxers were 7.5 times more likely to be exposed to conduct disorders than non-bruxers. (O.R. = 7.5). The actual probability for this disorder was estimated to be 2.4 to 22 in the normal population.
Antisocial behavior: 16% of bruxers were exposed to antisocial behavior, and none of the control group showed such problems. This difference was statistically significant and bruxers were many times more probable for antisocial disorders than nonbruxers, which could also be generalized to the normal population.
Other disorders: Despite the prevalence of other disorders including anxiety/depression, seclusion/depression, social problems, attention disorders, aggressive behavior, emotional disorders, anxiety disorders, and attention deficit-hyperactive disorders being higher in bruxers than non-bruxers, this was not statistically significant (P < 0.2).
To diagnose bruxism in this study, both clinical criteria and interview on bruxism symptoms were used. Seven out of 25 (28%) of bruxers had wear facets, while facets were not found in the remaining 18 subjects (72%).
Prevalence of four indicators of bruxism in interviews with bruxers is shown in chart B. The most common symptom as reported by subjects was pressing teeth during daytime or in thoughtful/stressful situations (60%) and the least common of all was report of grinding sounds during sleep by room partner or family members (8%).
| Discussion and Conclusions|| |
Etiology of bruxism is to a great extent unknown and controversial, and many theories have been developed. The etiological significance of occlusal factors is debatable and most investigators today believe that psychological factors play a major role in promoting and perpetuating the parafunctional habit. Bruxism has been defined as "an anxiety response to environmental stress" and emotional factors such as anxiety, fear, frustration and emotional stress have been recorded in a clear relationship with muscular hyperactivity, and nocturnal bruxism has been reported to be a sleep disorder related to emotional conditions. Some research has provided evidence that psychological variables such as anxiety, hostility, and intropunitive reactions to frustrating situations are significantly correlated with bruxing behavior.,,,,, Emotional stress is one common factor that has often been linked to increased bruxing behavior. Conversely, other research suggests that bruxers are normal individuals without higher levels of these disorders.,
In addition to personality characteristics, other researchers have explored the effect of life events on bruxing and found that bruxism correlated with both experienced and anticipated life stress, and suggested that life stress plays an important role in the frequency, duration, and severity of bruxism.
There is diverse evidence that suggests that bruxing behavior during sleep is a centrally mediated problem. Many studies approve of the significant role of CNS factors in developing bruxism; among these, an interesting issue is represented by the study of the psychic component, whose abnormalities can contribute to determine poor sleep quality and high emotional tension, which are key risk factors for sleep and awake bruxism, respectively.
One of the complications in the study of the relation between bruxism and psychopathology is presented by the possible presence of temporomandibular disorders in bruxers. TMD are a number of conditions for which an association with psychopathological symptoms has been described. Also, bruxism is considered a major risk factor for temporomandibular disorders. In particular, both bruxism and some forms of psychopathology appear to be somehow related to painful TMD and in particular to muscular forms. For these reasons, patients with signs of TMJ disorders were excluded from this study.
Many attempts have been made to find special personality characteristics for bruxists and a variety of psychological questionnaires have been used accordingly. The use of YSR questionnaire, which is based on a newly validated concept of spectrum of psychosocial disorders in adolescents, allowed identifying the presence of a wide range of symptoms belonging to experience based and DSM IV disorders.
Bruxers seem to be characterized by thought disorders, conduct disorders and antisocial behaviors. Abnormalities in the study sample were mostly sub-threshold, even though differences between bruxers and non bruxers were significant as for the prevalence of over-threshold psychopathology as well.
Findings from a study by Kampe et al. pointed out that, compared to a normal material, chronic bruxers had statistically significantly higher values at the somatic anxiety scale, and lower values at the socialization scale, which means that bruxers were more anxiety prone, tenser, and more vulnerable to psychosomatic disorders. These findings are in line with our findings of thought and conduct disorders.
In another study, Fischer and O'Toole found chronic bruxers to be shy, stiff, cautious, and aloof, preferring things rather than people, avoiding compromises, rigid in their ways, affected by the feelings of inferiority, impeded in expressing themselves, apprehensive, and given to worrying. These findings were also in line with our findings of thought disorders.
Our findings are also in line with the findings of another study conducted on children, using Conner's questionnaires, which showed more incapability to adapt and more likeliness to behavioral disorders in bruxers.
In another study by Manfredini et al., on 20 to 30 year olds using PAS-SR no correlation was found between bruxism and social disorders. Different findings may be due to different age group and/or psychological questionnaire used.
Although aggressive behavior was found to be more prevalent in bruxers, we found no significant difference between the two groups in this regard, which was in line with Kampe et al. and Watanabe et al. findings on bruxism, aggressive behavior and anger during the day.
Although anxiety disorders were more prevalent in bruxers, there was no significant difference between the two groups in this regard. This can be due to bruxing manifestation of anxiety in subjects, which can also be confirmed by findings of more prevalent non syndromic anxiety disorders, comparing with DSM IV, in bruxers.
Accordingly Manfredini et al., using PAS-SR test on 98, 20-30 year old subjects, found more sub clinical anxiety disorders in bruxers.
On the other hand, Restrepo et al., in a study on 3 to 6 year-old children, using Conner's questionnaires, found that bruxism levels and anxiety symptoms (using CTRS and CPRS tests) reduced after a six month application of psychological techniques, which showed a correlation between bruxism and anxiety disorders in this age group. Different findings may be the result of different age groups evaluated, sample size, and bruxism diagnosing criteria.
In a study conducted by Pierce et al., the relationship between each individual subject's stress and EMG-measured sleep bruxing activity was evaluated. Only a few subjects had an increased bruxism response related to high same day stress. Thus, these data supported only a very weak link between perceived stress and bruxing activity. The high denial/low stress relationship was rather weak, and since subject belief in a stress-bruxism relationship was also only very weakly related to subsequent self report of daily stress and because only a few individuals had a demonstrable stress-bruxism relationship, it appeared unlikely that self perceived daily stress is a major factor in sleep bruxing behavior. This is not to say that bruxing activity was not related to stress, but it might indicate that bruxers were not very aware of the stressful nature of daily events and/or they minimized the personal impact of life events.
This outcome appears to be consistent with the finding of Weideman et al., that high bruxing activity is likely to be related to a lack of awareness regarding stressful life events. In this context, it is interesting that those bruxers who reported less stress were also somewhat more likely to report higher levels of denial. While it is generally accepted that sleep bruxism is mediated via the central nervous system, the role played in the mediation process by psychological variables such as experienced life stress remains unclear based on that study and those of others.
Findings from another study by Manfredini et al. suggested that a number of both depressive and manic symptoms of the mood spectrum seem to characterize bruxers.
In the present investigation, although depression was more common in bruxers, no significant difference was found between the two groups in this regard. However Manfredini et al. suggest that bruxers seem to be characterized by disturbances in mood phenomenology, levels of activity, and cognitive functions, and such disturbances manifest themselves with alternating periods of reduced (i.e. depressed) and increased (i.e. manic) functions. Different findings may be due to age difference, bruxism diagnosing criteria, sample size and psychological questionnaire.
Findings from the present study suggest that bruxers, compared to non-bruxers, are characterized by different personality traits. They seem unable to get rid of specific thoughts, hurt themselves, hear sounds and/or see images that do not exist, exhibit tics and muscular tensions, sleep less, exhibit sleep parasomnia and strange thoughts and behaviors, treat others meanly, destroy people's properties, don't feel sorry for committing sins, move around in bad circles, initiate fights, escape from home and/or school, tend to catch fire, steal objects from home or outside, are abusive, threaten others, lie and cheat, use tobacco products and misuse drugs.
When approaching the study of such a complex issue, some methodological problems occur. The first problem is represented by the assessment and diagnosis of bruxism itself. Many clinical methods, such as interviews, questionnaires, tooth wear evaluation, electromyography recordings and muscle palpation were proposed to assess bruxism. However a clinical approach still presents some shortcomings, not allowing a distinction between nocturnal and diurnal bruxism, a gradation of bruxism severity, so limiting generalizibility of results. Nevertheless, it is probably the simplest approach to a complex disorder in phase of preliminary data gatherings.
The validity of recording of oral parafunctions has been questioned since some parafunctions are unconscious and thus it is possible that even non-bruxers did brux but were not aware of it because of low symptomatology.
The clinical significance of this study's findings is difficult to establish since the importance of sub clinical symptoms in a non-psychiatric population has yet to be defined.
In conclusion, the descriptive nature of the present study does not allow drawing conclusions about anxiety and bruxism, but it suggests that certain sub threshold manifestations of psychosocial disorders could distinguish bruxers from non-bruxers.
A few investigations have explored neuro-biological factors of such disorders in relation to bruxism, and findings suggest that in subjects with conduct disorders, dopamine b hydroxilase enzyme, transforming dopamine to neuroepinephrine, is considerably lower and in some subjects serotonin is higher in plasma.
When developing a treatment plan for bruxers, it is recommended that dentists be aware of the patient's psychosocial health, so that if after treating local and systemic factors, patients continue to brux, finding the underlying psychosocial disorders is more efficient and in time. It is also recommended that consequences of bruxing activities be shown to the patient by means of audiovisual programs.
It is highly recommended that further studies investigate the effect of psychosocial treatments on prevention and treatment of bruxism, and patients' susceptibility to such disorders be taken into account. In particular, future studies should try to describe deficits or pathogenesis pathways between these disorders and bruxism. In this sense, there is a strong need to clarify the role of neurotransmitters.
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[Table 1], [Table 2]