Imad Boustani
Fifth year, Group 13THE PREVALENCE OF BRUXISM AND ITS LINK TO
TEMPOROMANDIBULAR DISORDER AMONG LSMU
ODONTOLOGY STUDENTS
LITHUANIAN UNIVERSITY OF HEALTH SCIENCES MEDICAL ACADEMY FACULTY OF ODONTOLOGY
ORAL AND MAXILOFACIAL CLINIC
The prevalence of bruxism and its link to temporomandibular disorders among LSMU odontology students
Master’s Thesis 2021
The thesis was done
by student ... (signature) ... (name surname, year, group) ... 20.... (day/month) Supervisor ... (signature) ... ... (degree, name, surname)
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CONTENTS
ABBREVIATIONS ... 4
SUMMARY ... 5
1. INTRODUCTION ... 6
2. MATERIALS AND METHODS ... 8
ABBREVIATIONS
LSMU – Lithuanian University of Health SciencesSUMMARY
Aim: To evaluate the prevalence of bruxism and its link to TMD among LSMU Odontology students. Materials and methods: A self-administered structured anonymous questionnaire was distributed through Odontology student groups on social media using Google Forms during the spring semester of 2021. The study enrolled 132 LSMU Odontology students. The questionnaire consisted of demographic characteristics, the prevalence of symptoms of bruxism and TMD, as well as, experienced stress and the self-reported connection between them. The participation was anonymous and voluntary. The data was analysed using IMB SPSS Statistics 27.0. Descriptive statistics was applied and comparison between variables was made by Chi-square, Mann-Whitney and Z tests. Statistical significance was set at p <0.05.
Results: Participants were 43.2% female and 56.8% male. Overall, more than half of LSMU odontology students (54.5%) experienced symptoms of bruxism. 43.9% of surveyed students defined the frequency of experienced stress as “often” and 43.2% as “sometimes”. Statistically significant correlation was found between preserved stress and bruxism (p<0.05). Out of all TMD symptoms, headache was found to be the most prevalent both throughout the day and soon after waking up (44.7% and 40.9%) followed by TMJ pain and jaw discomfort. Moreover, the study concluded that there is a correlation between bruxism and TMD symptoms, as well as, between the duration of bruxism and TMD (p<0.05). Almost half of the respondents (45.9%) stated that they have noticed a connection between bruxism and their symptoms of TMD.
Conclusion: More than half of the dental students experience symptoms of bruxism. A link between bruxism and certain symptoms, such as headache, jaw discomfort or soreness, TMJ clicking or popping, painful chewing, TMJ pain, facial pain was found.
1. INTRODUCTION
1.1.BruxismClenching and grinding of the teeth are involuntary movements that commonly appear as a reaction to stress and/or anxiety. This involuntary action is called bruxism and affects up to 1/3 of the general population with a significantly higher prevalence in younger people [1,3]. Bruxism can happen during night time and day time, therefore, it is classified into awake and sleep bruxism.
The etiology of bruxism is thought to be complex and involving many risk factors, such as stress, anxiety and sleep deprivation. As students are more susceptible to above mentioned psychosocial factors, they often experience bruxism. The prevalence of stress and bruxism have been analysed among students in Italy, Brazil and Vietnam, however, there is no data about bruxism among students in Lithuania [1,9,10]. What is more, bruxism might have serious consequences and might lead to temporomandibular joint disorder (TMD) [4-6].
1.2.Temporomandibular joint disorder (TMD)
TMD is a group of various conditions involving temporomandibular joint (TMJ) and the surrounding structures, such as, muscles and nerves [13]. Typical symptoms include pain in the areas of head, face and neck, as well as other signs and symptoms, such as, painful chewing, TMJ clicking, ringing in the ears (tinnitus). It is a very common condition that affects 60-70% of the people, although, it has been proven to be more common among younger individuals.
Studies have concluded that there is a close correlation of bruxism and TMD. Researchers explain that the symptoms of TMD might be caused by bruxism leading to the overload of the muscles, which then causes blood flow restrictions and, consequently, pain [16].
TMD is the second most frequent cause of pain in the cranial, facial and mouth regions, having a high chance of evolving into chronic pain. Studies show that more than 95% of all cases of headaches might be accounted to TMD [5,12]. It is obvious that TMD might affect one’s everyday life severely, especially that of university students. As a result, it is important to investigate the prevalence of bruxism and its link to TMD among odontology students of LSMU, so further research could be conducted in order to develop treatment methods and strategies to prevent it.
Hypothesis: In this study we expect that symptoms of bruxism are frequent among LSMU
Odontology students due to the stress and lack of sleep experienced by them. Bruxism should have an impact on the prevalence of TMD among LSMU students.
Objectives:
1. To analyse the prevalence of bruxism among LSMU Odontology students.
2. MATERIALS AND METHODS
A cross-sectional study was conducted to evaluate the prevalence of bruxism and its link to TMD among odontology students at the Lithuanian University of Health Science (LSMU) during 2020/2021 study year in Kaunas, Lithuania.
Ethical approval for this study was obtained from the Bioethics Center of LSMU, Kaunas. Nr. BEC-OF-120.
2.1. Subjects
The subjects of the research were LSMU odontology students of 2nd - 5thacademic year. All students were invited to participate by completing an anonymous questionnaire. Overall, 132 odontology students participated in the study. All dental students (2nd – 5th year academic year) were invited to take part in the survey. A total of 132 dental students participated in this study. The response rate of study was 82.5%.
2.2. The questionnaire
A self-administered structured anonymous questionnaire distributed through Odontology student groups on social media using Google Forms during the spring semester of 2021.
The questionnaire included 15 questions in English. It consisted of demographic characteristics (gender, age, academic year) and questions concerning bruxism and TMD prevalence, experienced stress and sleep deprivation, as well as, self-reported connection between bruxism and TMD.
The survey included questions about symptoms of bruxism, time of the day when symptoms were experienced, as well as, the duration of them. Same questions were asked concerning TMD. Then participants were asked to answer how often they experience stress and sleep deprivation and to evaluate, whether stress affected their symptoms of bruxism and/or TMD. Finally, student participants were asked, if they have noticed a link between their experienced symptoms of bruxism and TMD.
The participation of this study was voluntary and anonymous; thus, return of the completed questionnaire was considered as acceptance to participate.
2.3. Data analysis
3. REVIEW OF LITERATURE
3.1. BruxismBruxism is a condition that is characterized by involuntary and repetitive clenching and grinding of the teeth [1]. It can happen during the day and/or night and is therefore classified into awake and sleep bruxism. According to the studies it is a common health condition with approximately 31% of adults experiencing awake bruxism and up to 15.3% experiencing sleep bruxism [2]. However, it is stated that the numbers of bruxism cases might be even higher in the younger populations, with up to 50% being affected [3].
The etiology of bruxism is viewed as unclear and complex, involving many psychological and psychosocial risk factors, such as stress, sleep patterns, and consumption of stimulants, like coffee and alcohol [1,4]. Studies have concluded that there is a relationship between perceived stress and bruxism. One particular study using the Perceived Stress Score discovered that the higher the score, the more prevalent sleep bruxism [5]. What is more, stress might also affect awake bruxism as neurochemicals, such as dopamine and adrenalin, play a role in both sleep and awake bruxism [6]. Lastly, a correlation between insomnia and bruxism was concluded by M. Maluly et al., although, only in middle-aged females [7].
mandibular condyle are the components that form the TMJ. Pain in the craniofacial, orofacial and neck areas, as well as, other signs and symptoms, such as tinnitus and TMJ clicks are characteristic of TMD. In fact, TMD is the most common prevailing cause of pain in the head, face and mouth, following odontogenic pain. In addition, it has a high likelihood of developing into a chronic pain. >95% of cases of headaches originate from TMD [5,12].
TMD affects more than a half of general population, with 60-70% experiencing the above mentioned symptoms. [13]. Also, a peak of TMD cases in 20-40 year olds has been recorded [14]. A study of self-reported bruxism and symptoms of TMD among Finnish university studies stated that TMD was reported by 25.9% female and 11.4% of male student [15].
Previously conducted studies have concluded that there is a close relationship between bruxism and TMD. The cause of this could be due to the muscle overload from teeth clenching, restricting the blood flow to the muscles responsible for the movement of the mandible and leading to ischemia and pain [16].
4. RESULTS
Out of 132 participants 43.2% were female and 56.8% were male. Majority of the students enrolled in the study were under 26 years old, with 22-year-olds making up the biggest part (18.2%). Concerning the academic year of Odontology studies, majority of the students (27.3%) were 2nd year students. 3rd and 5th year students made up approximately 24% of the participants each, while 4th year made up 25%. (Table 1).
Table 1. Characteristics of participants by gender and academic year of studies (N=132)
Academic year: mean 3.46, median 3, mode 2, std. deviation 1.135
54.5% of the participants answered “yes” when asked if they were self-aware of grinding and/or clenching their teeth. A statistical analysis was conducted. There was no correlation found between gender and bruxism – χ2 = 2,696, df = 1, p>0,05 (p=0,101), as well as, age and bruxism - Mann-Whitney U test, p>0,05 (p=0,115). Variables N (%) Gender Male 75 (57) Female 57 (43) Total N (%) 132 (100)
Academic year of study
2nd 36 (27)
3rd 31 (24)
4th 33 (25)
5th 32 (24)
Chart 1. Participant answers on the duration of their bruxism.
28.0% of respondents stated that they experience symptoms of bruxism at night, 8.3% - during the day and 20.5% stated they experience it both at night and during the day.
We then asked surveyed students how often they experience stress. 43.9% responded “often” and 43.2% - “sometimes”. Only 3.8% responded never. The correlation between stress and bruxism was found statistically significant - χ2 = 10,048, df = 3, p<0,05 (p=0,018) (Chart 2). Also, 38.6% participants themselves responded that they believe their symptoms of bruxism get worse when they experience stress.
Chart 2. Correlation between bruxism and experienced stress.
It was found that 46.2% of the participants sometimes and 34.1% often suffered from lack of sleep, however there was no correlation found χ2 = 6,397, df = 3, p>0,05 (p=0,094).
15% 16%
18% 24%
27%
How long have you had bruxism?
≤1 month 1-6 months 6 months - 1 year 1-3 years ≥3 years
32 35 4 25 22 9 5 0 5 10 15 20 25 30 35 40 Often Sometimes Rarely Never
Bruxism and stress
The information on the prevalence of TMD was collected by asking about the occurrence of typical TMD symptoms during the day and soon after waking up. Headache was the most prevalent symptom both throughout the day and in the morning (44.7% and 40.9%). More students responded to having no symptoms of TMD in the morning than during the day (49.2% vs. 39.4%). The prevalence of other symptoms is shown in Chart 3.
When asked about the duration of TMD symptoms experienced during the day 26.9% answered less than 1 month and 25.8% 6 months to one year (Chart 4). 34.1% stated that they have been experiencing TMD symptoms in the morning for less than a month and the same percentage of participants chose the duration of 1-6 months for the duration of their morning TMD symptoms (Chart 5).
The statistical analysis of Chi square test and Z-test for the link between bruxism and TMD symptoms experienced during the day concluded that the correlation is relevant for symptoms marked “*”. All symptoms except for earaches or ringing in the ears and neck pain were correlated with bruxism (p<0.05 for symptoms marked “*”) (Chart 6). The correlation was also found between bruxism and the same symptoms of TMD experienced in the morning as during the day (Chart 7).
Chart 3. TMD symptoms experienced in the morning and during the day
0 10 20 30 40 50 60 70
Headache Jaw discomfort or soreness Facial pain Neck pain TMJ pain TMJ clicking or popping Painful chewing Earaches or ringing in the years None
TMD symptoms in the morning and during the day
Chart 4. Participant answers on the duration of TMD symptoms experienced during the day
Chart 5. Participant answers on the duration of TMD symptoms experienced in the morning
How long have you been suffering from the symptoms of TMD during days?
Less than 1 month 1 to 6 months 6 months to 1 year 1 to 3 years More than 3 years
27%
20% 15%
26% 13%
How long have you been experiencing the TMD symptoms soon after waking up?
Less than 1 month 1 to 6 months 6 months to 1 year 1 to 3 years More than 3 years
34% 17%
10% 6%
Chart 6. Correlation between bruxism and TMD symptoms during the day. Symptoms marked * have correlation.
Chart 7. Correlation between bruxism and TMD symptoms in the morning. Symptoms marked * have correlation.
42 34 7 19 26 18 23 10 13 17 3 1 9 1 6 0 5 39 0 10 20 30 40 50 Headache* Jaw discomfort or soreness* Facial pain* Neck pain TMJ pain* TMJ clicking or popping* Painful chewing* Earaches or ringing in the ears None*
Bruxism and TMD (symptoms during day)
No bruxism Bruxism 42 28 8 13 20 14 20 6 19 12 2 1 5 0 2 0 3 46 Headache* Jaw discomfort or soreness* Facial pain* Neck pain TMJ pain* TMJ clicking or popping* Painful chewing* Earaches or ringing in the ears None*
Same correlations were discovered with symptoms of headache, TMJ clicking and jaw discomfort experienced in the morning (Chart 9).
Lastly, 45.9% of the respondents stated that they have noticed a connection between bruxism and symptoms of TMD that they experienced and 41.2% chose “maybe” as their response when asked about the connection.
Chart 8. The correlation between the duration of bruxism and TMD symptoms experienced during the day.
Chart 9. The correlation between the duration of bruxism and TMD symptoms experienced in the morning. 28,8* 8,1* 25 28,6 3,7* 20,8* 33,3 71,2* 3,4 2,7 4,3 15,4* 10,2 8,1 12,5 10,7 11,1 4,2 17,4 20 3,8* 18,6* 24,3* 14,3 18,5 20,8* 21,7* 13,3 20,3* 32,4* 25 21,4 44,4* 29,2* 39,1* 13,3 3,8* 18,6 24,3 37,5 25 22,2 25 17,4 20 5,8* 0 10 20 30 40 50 60 70 80 90 100 Headache
Jaw discomfort or soreness Facial pain Neck pain TMJ pain TMJ clicking or popping Painful chewing Earaches or ringing in the ears None
Duration of bruxism and TMD (symptoms during the day)
I don't have bruxism ≤1 month 1-6 months 6 months - 1 year 1-3 years ≥3 years
22,2* 3,3* 11,1* 27,8 12,5* 33,3 67,7* 11,1 3,3 7,7 11,1 13,3 11,1 22,2 5 5 11,1 4,6 24,1* 30* 11,1* 16,7* 40* 31,3* 30* 22,2 22,2* 26,7* 16,7 45* 37,5* 30* 11,1 6,2* 9,3 23,3 66,7* 16,7 10 18,8 35* 22,2 13,8 0 10 20 30 40 50 60 70 80 90 100 Headache
Jaw discomfort or soreness Facial pain Neck pain TMJ pain TMJ clicking or popping Painful chewing Earaches or ringing in the ears None
Duration of bruxism and TMD symptoms (in the morning)
5. DISCUSSION
This study revealed that out of 132 surveyed LSMU Odontology students more than half of them have bruxism. More males than females answered the questionnaire of the study, however no connection was found between gender and bruxism. Sleep bruxism was reported by more surveyed students, than awake bruxism. The results conducted in this study showed that the prevalence of bruxism is higher among LSMU Odontology students when compared with that of Italian and Brazilian students (54.5% vs. 37.9% and 31.6%) [1,9]. However, a study analyzing the prevalence of bruxism among Vietnamese medical students showed similar results to this study (51.2%) [10]. All in all, a conclusion of bruxism being a prevalent health condition among students could be easily drawn.
The levels of stress experienced by participated students seem alarming. The vast majority of students defined the frequency of stress they experience as “sometimes” or “often”. The results are consistent with the previously conducted studies, as well as, common societal beliefs. Meaning that university students are at a high risk for stress related conditions, such as bruxism and TMD. In fact, in this study a statistically relevant correlation was found between perceived stress and bruxism proving the effect of stress. Also, more than 1/3 of the respondents have noticed that there is a connection between bruxism and the TMD symptoms that they experience.
6. CONCLUSIONS
1. More than half (54.5%) of surveyed odontology students have symptoms of bruxism.
2. A link between bruxism and certain symptoms, such as headache, jaw discomfort or soreness, TMJ clicking or popping, painful chewing, TMJ pain, facial pain was found.
7. ACKNOWLEDGEMENT
A special thank you is extended to the supervisor of the study, Dr. Marijus Leketas, for his collaboration in the process of the work. As well as, to the odontology students who have participated in the questionnaire for making this study possible.
8. CONFLICT OF INTEREST
The author has not encountered any conflict of interests during this study.9. ENSURING OF CONFIDENTIALITY
Confidentiality of participants was ensured as the conducted survey was anonymous and no personal data was shared. The name, surname and address were not included.
10. PRACTICAL RECOMMENDATIONS
11. REFERENCES
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2. Manfredini D, Winocur E, Pain O, Guarda-Nardini L, Paesani D, Physiology S, et al. Epidemiology of Bruxism in Adults: A Systematic Review of the Literature. J OrOfac Pain. 2013;27:99–110.
3. Melo G, Duarte J, Pauletto P, Porporatti AL, Stuginski-Barbosa J, Winocur E, et al. Bruxism: An umbrella review of systematic reviews. J Oral Rehabil. 2019;(October 2018):666–90. 4. Renato Paranhos L, Sazci A, Rodrigues Lima R, dos Santos Chemelo V, Gecy de Sousa Né
Y, Ribeiro Frazão D, et al. Is There Association Between Stress and Bruxism? A Systematic Review and Meta-Analysis. Front Neurol | www.frontiersin.org [Internet]. 2020 [cited 2021 Apr 11];11:590779. Available from: www.frontiersin.org
5. Saczuk K, Lapinska B, Wilmont P, Pawlak L, Lukomska-Szymanska M. Relationship between sleep bruxism, perceived stress, and coping strategies. Int J Environ Res Public Health. 2019;16(17).
6 . Manfredini D, Serra-Negra J, Carboncini F, Lobbezoo F. Current Concepts of Bruxism. Int J Prosthodont. 2017;30(5):437–8.
7. Polmann H, Domingos FL, Melo G, Stuginski-Barbosa J, Guerra EN da S, Porporatti AL, et al. Association between sleep bruxism and anxiety symptoms in adults: A systematic review. J Oral Rehabil. 2019;46(5):482–91
8. Maluly M, Dal Fabbro C, Andersen ML, Herrero Babiloni A, Lavigne GJ, Tufik S. Sleep bruxism and its associations with insomnia and OSA in the general population of Sao Paulo. Sleep Med. 2020;75:141–8.
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https://www.tandfonline.com/doi/full/10.1080/00016357.2016.1247465
12. Commisso MS, Martínez-Reina J, Mayo J. A study of the temporomandibular joint during bruxism. Int J Oral Sci [Internet]. 2014 [cited 2021 Apr 11];6(2):116–23. Available from: /pmc/articles/PMC5490738/
13. Manfredini D, Guarda-Nardini L, Winocur E, Piccotti F, Ahlberg J, Lobbezoo F. Research diagnostic criteria for temporomandibular disorders: A systematic review of axis i
epidemiologic findings. Oral Surgery, Oral Med Oral Pathol Oral Radiol Endodontology [Internet]. 2011;112(4):453–62. Available from:
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14. Gauer RL, Semidey MJ. Diagnosis and Treatment of Temporomandibular Disorders [Internet]. Vol. 91, American Family Physician. 2015 Mar [cited 2021 Apr 11]. Available from: www.aafp.org/afp.
15. Huhtela O, Näpänkangas R, Joensuu T, Raustia A, Kunttu K, Sipilä K. Self-Reported Bruxism and Symptoms of Temporomandibular Disorders in Finnish University Students. J Oral Facial Pain Headache. 2016;311–7.
16. Durham J, Newton-John TRO, Zakrzewska JM. Temporomandibular disorders. BMJ. 2015;350(March):1–9.8.
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12. ANNEXES
12.1 Questionnaire in EnglishOnline link: https://forms.gle/Tu6hWugNKknwU5MQ7
The Prevalence of Bruxism and its link to Temporomandibular Disorder amongst LSMU Odontology Students – Survey
Your participation in this study is completely voluntary, if you feel uncomfortable answering any questions, you can withdraw from the survey at any point.
The questionnaire is completely anonymous. The data gathered will only be used for scientific purposes. Only summarised data will be publicized.
*TMD - Temporomandibular disorder Thank you for your participation.
Please choose sincerely, THE most honest & suitable ANSWER of these following questions. 1. Gender: Male Female
2. Age: __________
3. Academic year: II III IV V
4. Do you clench and/or grind your teeth? Yes No
5. Has anyone ever told you that you grind and/or clench your teeth during sleep? Yes No
6. How long have you had symptoms of teeth clenching and/or grinding (bruxism)? £ 1 month
1 - 6 months 6 months – 1 year 1 – 3 years
³ 3 years
10. Do you think your teeth grinding and/or clenching (bruxism) gets worse when experiencing stress and/or lack of sleep?
Yes No Sometimes I don’t know I don’t have bruxism 11. Do you experience any of the following symptoms of TMD during the day?
Headache
Jaw discomfort or soreness Facial pain
Neck pain TMJ pain
TMJ clicking or popping Painful chewing
Earaches or ringing in the ears None (skip to question 13)
12. How long have you been suffering from the symptoms of TMD during days? £ 1 month
1 - 6 months 6 months – 1 year 1 – 3 years
³ 3 years
13. Do you experience any of the TMD symptoms soon after waking up? Headache
Jaw discomfort or soreness Facial pain
Neck pain TMJ pain
TMJ clicking or popping Painful chewing
Earaches or ringing in the ears None (skip to question 15)
14. How long have you been experiencing the TMD symptoms soon after waking up? £ 1 month
1 - 6 months 6 months – 1 year 1 – 3 years
³ 3 years
15. Have you noticed a connection between the TMD symptoms you experience and teeth grinding and/or clenching?
Yes No Maybe
