tension-type headache - temporomandibular joint disorders - bruxism - surveys and
questionnaires
cefaleia do tipo tensional - transtornos da articulação temporomandibular - bruxismo
- inquéritos e questionários
The serious political, economic and moral crisis that affects Brazil, especially the
state of Rio de Janeiro, with violence and neglect of public institutions, is reflected
in the life and work of our population.
Studies have indicated that the activities of military firefighters have direct correlations
with occupational stress, high risk of back injuries, dangerous working conditions,
complaints of anxiety and depression, irregular work shifts and consequent changes
in sleep patterns[1],[2],[3].
Anxiety symptoms and changes in sleep patterns have been correlated with the presence
of headaches and temporomandibular disorders (TMDs)[4],[5],[6],[7]. Some studies have described associations of this nature in the profession of military
firefighter[1]
-
[3]. Also, in these professionals, deficiencies in sleep quality have been correlated
with work accidents and thus represent a risk to their safety[8].
Frequent episodic tension-type headache (FETTH) is described as frequent episodes
of headache that are typically bilateral, of a pressing or tightening quality and
of mild to moderate intensity. They may last for periods of minutes to days. The pain
does not worsen with routine physical activity and is not associated with nausea,
but photophobia or phonophobia may be present and there may be at least 10 episodes
of headache occurring on 1 to 14 days per month, which are repeated, on average, for
more than three months (≥ 12 days and < 180 days per year)[9].
Pericranial myofascial nociception may be important in the pathophysiology of FETTH,
whereas sensitization of central nociceptive pathways seems to be responsible for
conversion of episodic headache to chronic tension-type headache[10].
In spite of the high frequency of tension-type headaches in the population, a low
demand for medical attention has been registered[9]. For this reason, few articles have discussed associations of symptoms in episodic
cases. Although the interweaving of symptoms makes diagnosis difficult[11], the presence of oral parafunctional habits, that are inappropriate for treatment
by analgesic drugs, suggests that more training in the field of headache and orofacial
pain is required at primary healthcare units[12].
Headache is also a frequent complaint among patients with TMDs[10],[13],[14],[15],[16]. According to the American Academy of Orofacial Pain, TMD is defined as a set of
disorders involving the masticatory muscles, temporomandibular joint and associated
structures[17].
The etiology of TMDs is considered to be multifactorial and its natural course remains
unclear. It is believed that there are risk factors that contribute to its onset or
to the perpetuation of the pain[17]. One of these factors is sleep bruxism, which is defined as repetitive jaw-muscle
activity characterized by clenching or grinding of the teeth and/or by bracing or
thrusting of the mandible[18].
Some studies have found an interaction between the presence of primary headaches and
TMDs[10],[13],[15],[16], but few studies have been conducted on their relationship to frequent episodic
tension-type headache[14]. None have been conducted among military firefighters.
All these symptoms and complaints are common. Patient education, behavioral intervention,
drugs, individually fabricated occlusal splint therapy, physical therapies, postural
training and exercises are examples of available treatment options. Evidence-based
dentistry advocates treatment through multidisciplinary teams (doctors, dentists,
physiotherapists and psychologists) working in their specific areas, with conservative
proposals[17].
The objective of our study was to evaluate associations of painful TMD, sleep bruxism,
subjective sleep quality and anxiety symptoms among military firefighters with and
without FETTH.
This study was approved by the Ethics Committee for Research on Human Beings of the
Medical School of the Fluminense Federal University, and the approval was filed under
number #1341316.
The study was conducted within the Military Firefighters’ Department of the State
of Rio de Janeiro, over the period from December 1, 2015, to April 26, 2016.
METHODS
A total of 285 individuals between the ages of 18 and 55 years were examined and 125
were excluded through the following criteria: loss of more than two posterior teeth,
except third molars (n=11); presence of a total or partial prosthesis (n=24); presence
of toothache or neuropathic pain (n= 3); continuous treatment of psychiatric disorders,
major rheumatological, neurological or chronic pain syndrome (n=31); presence of other
headaches (n=42); diagnosis or signs and symptoms compatible with other sleep disorders
(n=5); and impossibility of regular monitoring because of not attending all assessment
visits (n=9).
The sample was made up through spontaneous demand from the military firefighters who
sought treatment at the Orofacial Pain Clinic at the General Command Headquarters
of the Military Fire Brigade of the State of Rio de Janeiro.Each of the 160 individuals
(mean age 36.9 years; standard deviation ± 9.9 years; 52.5% females and 47.5% males)
who took part in the survey read and signed a free and informed consent form. There
was no external financing source for this study.
A standardized protocol test was applied to all patients, using the following diagnostic
tools: anamnesis, medical and dental history and physical examination in accordance
with standardized clinical records. Through this, the main complaint, pain characteristics
(location, intensity, quality, duration, worsening period, mitigating and aggravating
factors), presence of headache and pain in other parts of the body and the patient’s
medical history were detailed.
The evaluation of FETTHs was performed by a single neurologist through a questionnaire
containing objective questions that were in line with the diagnostic criteria established
through the International Classification of Headache Disorders – III, 3rd edition (beta version)[9].
The individuals diagnosed with FETTH presented with: frequent episodes of headache,
typically bilateral, pressing or tightening in quality and of mild to moderate intensity,
lasting minutes to days. The pain did not worsen with routine physical activity and
was not associated with nausea, but photophobia or phonophobia may have been present[9].
TMD assessment
The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD)[19]Portuguese version[20]; were applied to classify TMDs. The RDC/TMD is a standardized system that can be
used to classify the most common subtypes of TMD through a questionnaire and a physical
examination. Based on Axis I of the RDC/TMD, patients were classified into: group
I (muscle disorders); group II (disc displacements) and group III (arthralgia, arthritis
and arthrosis). Subsequently, they were divided into two groups. Individuals with
complaints of painful TMD (group I: myofascial pain TMD or myofascial pain TMD with
limited opening; and/or group III: temporomandibular joint arthralgia and/or osteoarthritis),
which became the study group; and the control group who had no complaints of painful
TMD (only group II diagnosis: disc displacement with or without reduction or absence
of TMD; no diagnoses of groups I, II or III).
During the evaluation of masticatory muscle sensitivity, the participants of the control
group confirmed that the pain caused was similar to the pain reported by the patients
in the study group[21]. Muscle examination (masseter and temporal) and joint capsules to assess sensitivity
were done manually. A standard pressure of 1 kg was applied to the extra-oral muscles
and 0.5 kg to the joints.[20] The pressure was calibrated using a digital electronic scale. The balance was set
to zero and the digital pressure of 1 kg was placed on the plate. The individuals
who reported sensitivity in masticatory muscles and joint capsules with intensity
of at least 3 in the last month were considered patients with painful TMD.
Assessment of sleep bruxism
The diagnosis of sleep bruxism was made in two stages: application of a questionnaire
consisting of seven objective questions in accordance with the criteria of the International
Classification of Sleep Disorders, 3rd edition[22]; and a physical examination. This assessment consisted of a systematic evaluation
of signs and symptoms of sleep bruxism in terms of the following:
-
Frequency of days of self-reported sleep bruxism, which was evaluated through five
possible choices: (0) none of the time; (1) < 1 night per month; (2) 1–3 nights per
month; (3) 1–3 nights per week; (4) 4–7 nights per week[23].
-
The questionnaire for sleep bruxism, based on the International Classification of
Sleep Disorders, 3rd edition, which included three questions about the presence or absence of transient
morning jaw muscle pain or fatigue, temporal headache, and jaw locking upon awakening[22].
-
Assessment of abnormal tooth wear, which was observed through an ordinal scale of
five points. The incisor, canine and last molar present in the fourth dental quadrant
were inspected. Tooth wear was classified on a tooth-by-tooth basis using an ordinal
scale of five points[24].
Patients were considered to have sleep bruxism when it was self-reported on more than
four nights a week and, in addition, these patients presented with: 1) incidences
of abnormal tooth wear; or 2) incidences of transient morning jaw muscle pain or fatigue.
For a diagnosis of sleep bruxism to be made, it would need to be impossible to explain
the jaw muscle activity in terms of any other current sleep disorder, medical or neurological
disorder, medication use, substance use disorder, or use of selective serotonin reuptake
inhibitors[25].
Assessment of anxiety symptoms
Anxiety symptoms were assessed using the Beck Anxiety Inventory. This instrument features
21 items that somatically, emotionally and cognitively reflect anxietysymptoms[26]. It is used to measure the severity of an individual’s anxiety. The instrument consists
of a self-report questionnaire with 21 multiple-choice questions about how the individual
has felt over the last week, expressed in terms of common anxiety symptoms. Each symptom
item has four possible response options, as follows, with the corresponding scores:
not at all (0); mildly but it didn’t bother me much (1); moderately, and it wasn’t
pleasant at times (2); and severely, and it bothered me a lot (3). The values for
each item are summed to produce a total score for all 21 symptoms that can range from
0-63 points, and higher values mean higher levels of anxiety symptoms.
Assessment using the Pittsburgh Sleep Quality Index
The Pittsburgh Sleep Quality Index (PSQI) provides a combination of quantitative and
qualitative information on sleep[27]. There are 19 items in the PSQI, and these provide estimates of the quality and
duration of sleep, sleep onset, frequencies of various sleep-related disturbances
and daytime sequelae. It yields seven “components”, which can be summed to give an
overall score ranging from 0-21, in which higher values represent a greater disturbance
of sleep. Individuals can thus be classified as having the following: good sleep (scores
of 0–4), bad sleep (scores of 5-10) and the presence of a sleep disturbance (scores
> 10).
The statistical analysis was conducted using the SPSS version 19. A logistic regression
model was used to calculate the odds ratios (OR) as a relative measurement of risk.
Descriptive statistics and frequency counts were used to characterize the sample.
Quantitative outcomes (age, Beck Anxiety Inventory and PSQI) are presented as means
and standard deviations (SD), along with the distribution according to sex. For the
ORs, and in correlations and tables, a significance level of 95% was used.
RESULTS
Two groups were formed, divided according to the presence of FETTH complaints, with
80 individuals in each group. The control group (FETTH-free) comprised 44 men (55%)
and 36 women (45%), mean age 35.2 years (range 19–55 years); the majority (54% n =
43) had completed high school. The study group (FETTH patients) comprised 48 women
(60%) and 32 men (40%), mean age 38.5 years (range 18–55 years); 58.8% (n = 47) had
completed undergraduate education ([Table 1]).
Table 1
Distribution of the sample by the presence of FETTH n (%).
|
Variables
|
Total
|
Absence of FETTH
|
Presence of FETTH
|
|
|
|
|
|
160 (100)
|
80 (100)
|
80 (100)
|
|
Mean ± SD (range)
|
36.8 ± 9.9 (18–55)
|
35.2 ± 10.0 (19–55)
|
38.5 ± 9.7 (18–55)
|
|
Gender
|
|
Female
|
84 (52.5)
|
36 (45.0)
|
48 (60.0)
|
|
Male
|
76 (47.5)
|
44 (55.0)
|
32 (40.0)
|
|
Educational level
|
|
Undergraduate level
|
84 (52.5)
|
37 (46.3)
|
47 (58.8)
|
|
High School
|
76 (47.5)
|
43 (53.7)
|
33 (41.2)
|
|
Sleep Bruxism
|
26 (16.0)
|
10 (12.5)
|
16 (20)
|
|
Painful TMD
|
70 (100)
|
9(11.25)
|
61 (76.25)
|
FETTH: frequent episodic tension-type headache.
The presence of painful TMD was higher in the study group (76.25%; n = 61). Headache
complaints were more common among women (60.0%; n = 48). The prevalence of sleep bruxism
was 16.0% (n = 26) and the activity level was higher in the study group (n = 16).
[Table 2] shows the interaction between painful TMD and FETTH (OR = 26.4; 95% confidence interval,
CI: 10.4-64.6; p < 0.001). The presence of sleep bruxism did not represent a risk
of occurrence of FETTH (OR = 0.7; 95% CI: 2.0-2.5; p = 0.670).
Table 2
Analysis of results.
|
Variables
|
Study Group
|
Control Group
|
Total
|
Odds Ratio
|
|
Painful TMD diagnoses
|
Presence of FETTH n (%)
|
Absence FETTH n (%)
|
Total n = 160
|
OR (95%CI)
|
|
Absence of TMD
|
19 (21.0%)
|
71 (79.0%)
|
90
|
Reference
|
|
Presence of TMD
|
61 (87.0%)
|
9 (13.0%)
|
70
|
26.4 (10.4; 64.6)
|
|
|
|
|
|
p < 0.001
|
|
Sleep bruxism
|
|
Absence
|
64 (48.0%)
|
70 (52.0%)
|
134
|
Reference
|
|
Presence
|
16 (62.0%)
|
10 (38.0%)
|
26
|
0.7 (0.2; 2.5)
|
|
|
|
|
|
p = 0.670
|
|
Mean PSQI
|
|
Good sleepers
|
33 (41.5%)
|
31 (38.5%)
|
64
|
Reference
|
|
Bad sleepers
|
42 (52.5%)
|
46 (57.5%)
|
88
|
1.8 (0.41; 8.1)
|
|
Sleep disturbance
|
5 (6.0%)
|
3 (4.0%)
|
8
|
|
|
|
|
|
|
p = 0.687
|
|
|
Mean PSQI = 5.3
|
Mean PSQI = 4.5
|
|
|
|
Beck anxiety inventory
|
|
Minimum
|
33 (41.3%)
|
61 (76.3%)
|
94
|
Reference
|
|
Light
|
32 (40.0%)
|
16 (20.0%)
|
48
|
1.000 (0.1;1.9)
|
|
Moderate
|
13 (16.2%)
|
2 (2.5%)
|
15
|
0.3 (0.0;5.1)
|
|
Severe
|
2 (2.5%)
|
1 (1.2%)
|
3
|
|
|
|
|
|
|
p = 0.002
|
FETTH: frequent episodic tension-type headache; TMD: temporomandibular disorders;
PSQI: Pittsburgh Sleep Quality Index; CI: confidence interval.
The mean PSQI components were slightly higher in the study group (PSQI = 5.3) than
among the controls (PSQI = 4.5). However, we did not find any significance in these
data (p = 0.687), indicating that sleep quality assessments did not show increased
risk of FETTH.
The individuals in the study group had more anxiety symptoms (p = 0.002).
Individuals with sleep bruxism ([Table 3]) had more complaints of painful TMD (p = 0.012).
Table 3
Association of painful TMD diagnoses with sleep bruxism.
|
TMD Diagnoses n (%)
|
Presence of SB
|
Absence of SB
|
Odds ratio (95% CI)
|
|
Painful TMD n (%)
|
17 (66.4)
|
53 (39.6)
|
Reference
|
|
No Painful TMD n (%)
|
9 (34.6)
|
81 (60.4)
|
2.9 (1.2–6.9)
|
|
|
|
|
p = 0.012
|
TMD: temporomandibular disorders; SB: sleep bruxism; CI: confidence interval.
DISCUSSION
This study is the first to assess the presence of painful TMD, sleep bruxism, anxiety
symptoms and subjective sleep quality among military firefighters with FETTH.
The presence of FETTH was shown to be directly linked to the presence of painful TMD
symptoms (p < 0.001).
Some studies on the interactions between primary headache and the presence of TMD
symptoms[10],[14],[15],[16],[1]
[7] have shown that despite methodological differences (sample, headache classification
and use of non-standardized questionnaires), this association was greater when there
was pain in the masticatory muscles.
The conditions relating to primary headaches have been little studied among military
firefighters. In this specific group, symptoms relating to insomnia, anxiety, depression
and low back pain were directly associated with loss of quality of life and occurrences
of work accidents[1],[2],[3],[8].
There are significant clinical overlaps between some painful TMDs and headache conditions
that may hamper the diagnostic process and treatment. The important pain mechanisms
contributing to the close association and complex relationship between TMDs and headache
disorders include the following: processes of peripheral and central sensitization
that take place in similar anatomical areas; possible impairment of the descending
modulatory pain pathways; and the processes of reporting pain. In addition, clinical
examinations do not always provide distinguishing information to differentiate between
headaches and TMD[11].
When peripheral alterations persist and other external factors such as emotional disturbances,
stress and parafunctional habits are associated, changes to the central nervous system
may occur. These changes to the conduction system and pain processing are called central
sensitization[28].
The presence of sleep bruxism ([Table 3]) was higher among individuals with complaints of painful TMD (p = 0.012). This probably
occurred because of the concomitant presence of sleep bruxism and clenching of teeth
during wakefulness, although ascertaining this relationship was not an objective of
the present study.
When sleep bruxism and daytime tooth clenching occur separately, they increase the
risk of painful TMD symptoms. When they act simultaneously, the risk is even greater[29]. A systematic review has shown that sleep bruxism may be associated with myofascial
pain, arthralgia and pathological conditions of joints, such as disc displacement
and joint noises. Although the evidence is currently not conclusive and does not provide
information according to the type of bruxism (sleep and/or waking bruxism), it is
possible to suggest that bruxism would be associated with TMDs[30].
It was found that sleep bruxism alone did not increase the risk of any primary headache,
but when it was associated with a painful TMD, the odds of having chronic migraine,
episodic migraine and episodic tension-type headache were significantly increased[16].
Sleep and headache are closely related. Insufficient sleep may increase the risk of
headache in a general manner; it may trigger headache and may also reduce pain thresholds[31].
The anxiety symptoms observed increased the risk of FETTH (p = 0.002), while the subjective
quality of sleep measured by the PSQI was not shown to be a risk factor (p = 0.687).
The anxiety symptoms observed in individuals with FETTH and TMD are in agreement with
other studies[4],[5],[6],[31].
Sleep and pain perception are two phylogenetically well-conserved functions, strictly
influenced by environmental and psychological factors, and are able to interact reciprocally
both in physiological and pathological situations[32].
In a study on sleep among tension-type headache patients, it was observed that these
patients presented with more anxiety, insomnia and fatigue during the day and lower
subjective quality of sleep than did healthy controls, despite presenting with a normal
duration of sleep in diaries and in polysomnographic examinations. It has been proposed
that, on average, these individuals need more sleep time than required by healthy
controls[33].
There was a significant association between severe sleep disturbances and primary
headache, and this was most pronounced for those with chronic headache[4].
The study had some limitations. The sample consisted of patients who sought treatment
for TMD and the results are not representative of the general population. Laboratory
sleep assessment is required to establish a definitive diagnosis of sleep bruxism;
but for large samples it is expensive and inaccessible.
The study’s methodology had important strengths. Headache and TMD were diagnosed and
classified following the “gold standard” of the RDC/TMD[19] and International Classification of Headache Disorders – III[9].
In conclusion, based on the data of this study, an association between the presence
of painful TMD complaints and subjective anxiety symptoms was found among individuals
with FETTH.
Sleep quality assessments and the presence of sleep bruxism without painful TMD complaints
did not increase the risk of FETTH.
