Post on 16-Oct-2021
The American Academy of Orofacial Paindefines bruxism as a diurnal or nocturnal
parafunctional activity including clenching, bracing,gnashing, and grinding of the teeth1.
The prevalence of oral parafunction in the generalpopulation is very variable, different studies reportdifferent results also according to the method used toassess the pathology. Generally, awareness of bruxismranges from 6% to 27.2%2-6, but EMG nocturnalrecordings during sleep show masticatory musclesactivity in 100% of the subjects2. The most commonway of evaluating the presence of tooth grinding indental patients is to look at dental wear, and data showthat using such analysis we can find positive results in
about 50% of them2.To date, what causes bruxism is not clear. Although
many theories have been proposed none of them hasproved a cause-and-effect relationship with the onsetof oral parafunctions.
Occlusion has been anecdotally correlated to toothgrinding, yet clinical studies give controversialresults7-13. Interesting is the role of stress indetermining increase of bruxism, in fact some studiesshow a clear temporal association between the twovariables7,14, but others fail to confirm such data15,16.
A different issue is the presence of neurologicaldisorders that can be associated with involuntarymuscular movements involving the oral structures,such as extrapyramidal disorders17-19, or chronic use ofmedications that can elicit bruxism as side effect:SSRIs20-24, amphetamines25, fenfluramine25,26,L-dopa25,27, phenothiazine25, and other neuroleptics28.
Damage to the oral structures caused by oral
TMD and Orofacial Pain
Journal of the Lebanese Dental Association
Bruxism Prevalence in a Selective Lebanese Population
31
Statement of the problem: In recent years, many Lebanese dentists reported an increase in night-time parafunctional activity
of their patients.
Purpose of the study: To investigate night bruxism awareness in a selective Lebanese population.
Materials and Methods: 868 visitors of a shopping mall in the city of Beirut (Lebanon) were interviewed about their habit
of clenching and grinding their teeth at night, and about their age and gender. Gender distribution was as follows: 530
females and 338 males, mean age was 34.9 (±11.6 SD) and 37.8 (±14.6 SD) respectively.
Results: Overall prevalence of bruxism was 35.8% for males and 32.6% for females with no statistically significant
difference between the two groups. Bruxism was found to increase with age for both genders. Bruxism awareness per
age and gender was as follows: <26 years (F: 24.1%; M: 19.4%), 26-35 years (F: 26.1%; M: 27.2%), 36-45 years (F:
41.1%; M: 41.6%), 46-55 years (F: 41.5%; M: 50%) and >55 years (F: 63.6%; M: 53.5%).
Conclusion: Night bruxism prevalence in this Lebanese group seems to be higher than in reported western studies and a
deeper socio-economical investigation is needed. Future larger scale studies might be needed to confirm if bruxism
awareness increases with age.
* Private Practice, Beirut, Lebanon.
† Private Practice, Cagliani, Italy.
§ PhD Candidate, Boston University, Goldman School of
Dental Medecin, Boston, USA
Youssef S. Abou-Atme, DDS, MS* Marcello Melis, DMD, RPharm† Khalid H. Zawawi, BDS.§
parafunctions includes teeth (attrition, fractures)29-31,periodontium (tooth mobility, abfractions)30,temporomandibular joints (noises, pain, boneremodeling)32,33 and masticatory muscles (pain,fatigue, stiffness)32-36, that can be variably affected37.
Since etiology of bruxism is unknown, treatment isdesigned to prevent its effects on the masticatorysystem. Use of occlusal appliances38-43 limits thedamage to the teeth, periodontium,temporomandibular joints and the masticatorymuscles; in addition to that, other procedures can beeffective reducing overall parafunctions. Mostreported are stress management44, biofeedbackmodalities42,44,45 and eventually medications44,46,47.
PURPOSE OF THE STUDYThe purpose of this study was to detect the
prevalence of night bruxism awareness in shopping
mall visitors in the Lebanese capital Beirut, exploring
the relationship between bruxism and two factors: age
and gender.
MATERIALS AND METHODSDuring the summer of 2001, a total of 868 adult
subjects among the visitors of a shopping mall in thecity of Beirut (population 1.1 million) the capital ofLebanon (population 4.3 million mid 2001)48 wereinterviewed regarding their age and gender, as well asany habit of teeth clenching or grinding at night.Questions regarding oral parafunctions were thefollowing:
1- Do you clench your teeth at night?2- Do you wake up in the morning with your jaws
braced together?3- Were you told that you make noises with your
teeth while asleep?
No effort was made to verify the data and to
distinguish symptomatic from asymptomatic people.
Two investigators in a shopping mall area, but without
standardized randomization, recruited the subjects.
Answering positively to one question was interpreted
as presence of nocturnal oral parafunctions. The
response rate was not recorded by the investigators.
STATISTICAL ANALYSISSubjects were divided by gender and grouped in
four age categories for each gender. Age categories are
similar to those used previously5; i.e., less than 26
years, 26-35, 36-45, 46-55 and more than 55 years. Chi
square (χ2) test was performed to study the
relationship between gender and bruxism, and age and
bruxism. The level of significance was accepted for
p<0.01.
RESULTSA total of 868 subjects participated in the study,
530 females and 338 males, mean age was 34.9 (±11.6
SD) and 37.8 (±14.6 SD) respectively. 294 (33.9%)
reported being aware of night bruxism.
No significant association was found between
gender and reported bruxism, χ2df=1
= 0.4, p>0.1,
(35,8% for males and 32.6% for females). On the other
hand, there was a significant association between age
groups and bruxism, χ2df=4
= 45.8, p<0.0001.
Table 1 shows the distribution of Bruxism by age
and gender.
Table 1. Bruxism by age and gender
Age Range Gender Bruxism No Bruxism Total
< 26 years Females 28 (24.1%) 88 (75.9%) 116
Males 14 (19.4%) 58 (80.6%) 72
26-35 years Females 53 (26.1%) 150 (73.9%) 203
Males 25 (27.2%) 67 (72.8%) 92
36-45 years Females 51 (41.1%) 73 (58.9%) 124
Males 32 (41.6%) 45 (58.4%) 77
46-55 years Females 27 (41.5%) 38 (58.5%) 65
Males 27 (50.0%) 27 (50.0%) 54
> 55 years Females 14 (63.6%) 8 (36.4%) 22
Males 23 (53.5%) 20 (46.5%) 43
Total 294 574 868
Abou-Atmé YS, Melis M, Zawawi KH
Volume 41 - Nº 2 - 200432
DISCUSSIONIn the population we examined 294 subjects
reported nocturnal bruxism, which is 33.9% of the
individuals. This result is higher than the percentages
that are usually reported in the literature, even though
the studies show very different values according
probably to different populations examined and
different ways to evaluate bruxism awareness.
Prevalence ranges from 6 to 27.2%2-6. The results are
even more evident considering the fact that our
questions were asked to detect only nocturnal
parafunction, which usually occurs without the
subjects being aware of it. We cannot exclude and we
can even expect that adding to our results overall
bruxism occurring day and night, or bruxism
occurring during the day only, the percentage of
people that reported parafunction would increase
further.
The reason for this high percentage of individuals
affected by night bruxism is unknown, but one might
suspect the effect of the worsening socio-economical
crisis in Lebanon at the time of the survey. We should
say that our study was performed without any attempt
to reach a population that was a representative sample
of the entire Lebanese population: subjects were
interviewed casually and we cannot exclude bias
coming from involuntary selection of the individuals.
The shopping mall itself where the subjects were
recruited is geographically situated in the middle of
Beirut, and is routinely visited by middle and high
social and economical classes of shoppers. The actual
study may be used as a pilot for future nation-wide
bruxism surveys in Lebanon.
Referring to the theories on the etiology of
bruxism10 we should say that we do not have elements
to assess the factors eventually playing a role in the
pathogenesis of bruxism in the population surveyed.
We did not gain any information regarding occlusion,
neurological diseases and medications, and
psychological factors of the subjects we examined,
because finding the cause of parafunction was not the
purpose of the study. Yet, these conditions might have
altered our results.
Based on the outcome of this study, gender seems
not to make a difference in the overall awareness of
nocturnal bruxism, and the same results were found
by Glaros4 in a study where overall parafunctions
where equal in men and women. On the other hand,
age was found to correlate with bruxism: whether
genders were combined or separate, bruxism
awareness tended to increase with age (Table 1). This
is the first time such age related parafunctional
awareness is reported. It might be due to life
experience, including an increase of responsibility
with age, exposure to stressful events and pain
experiences, along with increase of general health
awareness because of great availability of new means
of divulgation such as television, radio and internet.
Life experience would also mean a great contribution
from psychological factors in the etiopathogenesis of
bruxism, but that is still controversial34,35,40,41.
CONCLUSIONSThe present study seems to show a higher
prevalence of nocturnal bruxism in the Lebanese
population compared to other previous studies in
western populations. Awareness of nocturnal
parafunction was found to increase with age for both
genders. This new finding should be investigated in
future studies. Larger surveys are needed to find out
the relationship between the Lebanese socio-economic
situation and bruxism.
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Dr. Youssef Abou-AtmeMedawar St, Akar Bldg, Badaro, Beirut, Lebanon 2058-7017Email: youssefaa@yahoo.comPhone: +961-3-853556 - +961-1-612761Phone/Fax: +961-1-612762E-Fax: +1-509-351-3240
Journal of the Lebanese Dental Association 35
Abou-Atmé YS, Melis M, Zawawi KH