The Complete Guide to Biofeedback and How It Can Help with Bruxism

Introduction: What is Biofeedback?

Biofeedback is a technique used in medicine to describe a process of self-regulation to improve health or performance. The idea is that by giving people information about the current state of their body, they can become more aware and better control their bodily functions.

This technique is used for a variety of conditions, including asthma, attention deficit hyperactivity disorder (ADHD), chronic pain, high blood pressure, stroke, incontinence, headaches and gait training. Although in the past biofeedback was usually done in a professional setting under the supervision of a doctor or physiotherapist, there are now several home biofeedback devices designed for general well-being and performance enhancement. For example, there’s now a biofeedback device in the form of a headband that helps people meditate or concentrate. It uses EEG to monitor your brain waves and tells you when you’re getting distracted during your meditation practice.

How Does Biofeedback Work?

The basic idea of biofeedback is that we can better control processes that we can sense, track and measure.

It generally consists of the following steps:

1. some type of sensors is used to electronically monitor a specific physiological function. This can be muscle activity, brain activity, limb movement, heart rate, etc.
   
   
2. feedback is given when the signal reaches a certain threshold or indicates that a certain activity is taking place. Feedback to the person is provided either by sensory input (sounds, smells, touch, vibration, warm/cold sensations) or by display of visual information.
   
   
3. feedback prompts the person to take action.
   
   
4. monitoring continues to ensure that the target behavior is maintained.
   
   
5. this feedback loop is performed repeatedly to produce a learning response that persists even after the biofeedback is no longer used.
   

It’s important to note that the goal of the feedback stimulus isn’t to “punish,” but to help individuals understand how their actions affect their bodies. In this way, they can learn to self-regulate their physiological functions.

For example, a stress/anxiety biofeedback device can alert you when your heart rate spikes (a first sign of stress) and encourage you to slow your breathing, relax your muscles, and use other relaxation methods long before your stress level gets out of control. Without biofeedback, you might’ve ignored the first signs of stress and not realized you needed a break until you were already overwhelmed. Even more encouraging, research has shown that through repetition, these devices can help train your ability to manage stressful situations and create a greater sense of calm and well-being.

Another area where biofeedback has been used successfully is in the treatment of pelvic floor dysfunction in women. Similar to how a yoga instructor can help correct your posture and point out the muscles you need to engage, patients use biofeedback devices while performing muscle training exercises for pelvic floor dysfunction to see if they’re exercising properly. They receive a confirmation via the device (positive reinforcement) when they tighten the correct muscles, which leads to better performance of the exercises and greater effectiveness of the muscle training.

These examples illustrate how biofeedback can be very helpful and beneficial in many situations. By providing real-time data, people learn to bring certain physiological processes under control. Not only is biofeedback applicable to a wide range of conditions, it’s also non-invasive and can help people feel more empowered about their health. It encourages positive behavioral changes that can ultimately lead to better health or performance.

How Does Biofeedback Apply to Bruxism?

Since experts began referring to bruxism as a behavior rather than a disorder, there’s been increased interest in cognitive and psychological interventions that directly target teeth grinding/clenching behaviors. This is where biofeedback comes in.

Until now, biofeedback was thought to be effective only as a training tool for conditions that occur while awake. It requires that the person be aware of the feedback and act voluntarily when receiving it. This led to the assumption that biofeedback is only effective for awake bruxism (subconscious clenching while awake), but not for sleep bruxism (involuntary grinding and clenching while asleep).

However, a few exploratory studies in the early 1980s were able to show that EMG-based biofeedback for sleep bruxism resulted in a “uniformly clear reductions in bruxing durations.” It turned out that our brains are still capable of processing sensory information while we sleep, and it appeared that the person didn’t need to be awakened by the stimulus for the biofeedback to work. Since then, there have been several attempts to develop biofeedback devices for bruxism.

In general, these are the mechanisms of action for bruxism biofeedback devices:

1. Detection
   
   Mechanical sensors are incorporated into splints, headbands, or patches on the face to detect grinding/clenching based on bite pressure, muscle activity, or anatomical measurements that correspond to grinding/clenching activity. Two of the most commonly used detection methods are electromyography (EMG), which measures activity of the masseter or temporalis muscles (the ones responsible for chewing action), and a pressure sensor embedded in the nightguard/mouthguard/splint. More recent approaches use measurements of interocclusal space (the distance between our teeth) and the shape of the ear canal to detect whether a person is clenching or grinding.
   
   
2. Feedback
   
   A feedback is provided when we grind /clench. The type of feedback used should not be unpleasant, but merely noticeable enough to alert the person and prompt them to relax their jaw muscles. In sleep bruxism, it has been found that the signal does not have to wake the person, as the brain can still process sensory information while asleep. The signal only needs to be “registered” (or perceived) by the sleeping brain.
   
   Auditory: Acoustic alarm in the form of a beep/sound.
   
   Electrical: Electrical stimulation of the lips, mouth, temple to trigger the Masseter Inhibitory Reflex (MIR, a natural reflex that prevents us from closing the jaw)
   
   Haptic: Vibration motor in pressure-sensitive mouthguard or vibration on wrist via connected wristband or on other body parts, sensation (pressure or touch) to other body parts
   
   
3. Action
   
   The feedback alerts and prompts the person to relax their jaw muscles, reduce the duration and frequency of the behavior, and thus minimize the stress on the teeth, masticatory muscles, and jaw joints. The hope is that symptom relief (reduction or elimination of pain and headaches) can be achieved. The immediate behavioral reduction that biofeedback produces can also give our nervous system a “break” and prevent over-sensitization of certain pain receptors caused by a persistently over-reactive nervous system (“central sensitization”).
   
   In sleep bruxism, it is also possible that the sensory feedback causes an attentional distraction to the semi-awake brain, leading to the cessation of the grinding / clenching movement. This would explain why individual need not be awake or consciously act on the stimulus for the method to work.
   
   
4. Learning
   
   For awake bruxism, repeated biofeedback sessions can equip individuals with better habits (i.e., learning to pay close attention to the sensation of tension in their body), learn better coping skills, and become aware of situations or thought processes that contribute to the subconscious clenching. By learning these skills, they can continue to reduce and control their subconscious clenching habit even after biofeedback is discontinued.
   
   In the case of sleep bruxism, it is still unclear whether the repetitive subconscious response to the stimulus during sleep can produce a lasting learning effect, similar to what is observed with other awake behaviors.
   
   

Examples of biofeedback devices for bruxism

Effectiveness of Biofeedback Devices for Bruxism

One question remains: does biofeedback actually work for bruxism?

The current scientific conclusion is, unfortunately, ambiguous. While there’s some research indicating that biofeedback therapy is effective in reducing bruxism, the number and quality of available studies have been quite limited. These studies use different study designs, controls, diagnostic criteria and outcome measures, making it difficult to summarize the results and draw a definite conclusion.

In addition, since not all studies use the same biofeedback device and each device uses a different detection and feedback method, they show wide variations in effect. These differences are probably related to the accuracy of the detection method and the effectiveness of the feedback in interrupting the episode. The more accurate the detection and the more effective the feedback stimuli, the more likely it is that we see a reduction in bruxism episodes. It is also unfortunate that most of these devices have never become widely used, such that none of the devices ever gather enough body of evidence to justify their clinical utility.

Yet, despite these differences in how the devices work and in the study designs, we can observe a consistent trend: the use of biofeedback leads to an immediate reduction in the duration (and sometimes the frequency) of bruxism episodes.

In studies that have investigated the effects of biofeedback on sleep, no impairment in sleep quality, total sleep time or sleep architecture were observed. This is probably due to the particular nature of bruxism, which usually occurs as part of the microarousal response during light sleep (phase 1 / 2, non-REM sleep) when individuals are briefly awake.

Although we’d expect that a reduction in activity would also lead to a reduction in symptoms, the effect of biofeedback on symptom reduction is inconsistent to say the least. Not all studies measure symptom reduction (pain, headache), and of those which do, not all report a statistically significant reduction in symptoms. However, this could be related to differences in the duration of the intervention and the inclusion criteria of the study participants. It’s possible that the reduction in symptoms is only observed after a certain period of time and only in patients with more severe pain.

It remains to be seen whether biofeedback can produce a lasting learning effect and a permanent reduction in bruxism behavior. Not all studies have shown a post-treatment effect. One study showed that subjects had a statistically significant reduction in the average and maximum duration of their bruxism episodes even after biofeedback treatment ended. Most studies, however, showed a return to baseline levels after biofeedback was discontinued.

Some researchers have theorized that biofeedback is a training process that requires patients to “unlearn” their behavior, therefore a longer duration of treatment is required for a greater and lasting learning effect. It would be interesting to see if there’s a correlation between how long an individual has been grinding his / her teeth and the duration of biofeedback treatment needed to achieve lasting results.

Overall, there’s a need for more scientifically-robust longitudinal studies with larger samples to determine the long-term effects (including possible side effects) and the clinical benefits of biofeedback intervention, as well as the most effective biofeedback modality. In addition, future studies need to identify which sub-populations benefit most from the method in order to determine the exact role of biofeedback in the management of bruxism.

What are the Benefits & Disadvantages of Using Biofeedback for Bruxism

Despite the potential efficacy of the various biofeedback methods, none of them has gained acceptance in clinical practice because the available evidence is sparse, limited to research projects with a small group of participants, and the study designs are sometimes poor.

Nevertheless, the hasty dismissal of biofeedback as a potential treatment for bruxism needs to be reconsidered. Most innovations have to start somewhere before they become standard care. Furthermore, even mouth guards (bite splints), which are currently the predominant treatment for bruxism, lack conclusive evidence of their benefits, which has not deterred its use in clinical practice. Considering that millions of people continue to suffer from chronic pain, migraines and severe dental problems due to bruxism, it’s definitely worth looking for alternative interventions that could provide some benefit, especially if they don’t cause unwanted side effects.

This brings us to the point: what are some of the negative side effects of biofeedback?

Actually, not many. Inaccurate detection of the bruxism episode could result in the stimulus being delivered at the wrong time, leading to sleep disturbance, fatigue in the morning (from poor sleep quality) and subsequent daytime sleepiness. Devices that are uncomfortable for the user can also affect sleep quality. For example, most biofeedback mouthguards currently in the market today are bulky and uncomfortable due to the microprocessor and battery within.

And some types of biofeedback that use electrical stimuli can cause uncomfortable pain sensations if not properly adjusted. However, available studies point that such cases are rare and no significant sleep disturbances or other problems have been reported. It’s likely that any potential negative effects will quickly disappear once the intervention is stopped.

Is Biofeedback a Bruxism Cure?

Much of the enthusiasm for biofeedback stems from the fact that it could elicit a learned response that might lead to a lasting reduction or elimination in grinding or clenching episodes. Preliminary data from several studies suggest that this is unlikely: the reduction in behavior lasts only as long as biofeedback is applied, making it more of a condition management tool than a one-time intervention that leads to a permanent cure.

However our new understanding of bruxism as a behavior rather than a disorder should also change our approach to treatment. Scientists now view bruxism as a part of normal physiology that is not always harmful. In some cases, the act of teeth grinding can even have beneficial effects (e.g., it opens the airway in sleep apnea and increases salivation which reduces acidity in GERD).

The objective of any bruxism treatment should therefore be not to eliminate the behavior completely, but to reduce and control it to the point where it no longer causes health issues.

Within this paradigm, a biofeedback device that can alleviate symptoms while non-invasively measuring and tracking episodes can be a tremendous help to the millions of people who suffer significant pain, headaches, and other problems associated with their excessive teeth grinding or clenching. Such a device can help individuals identify the factors (e.g., caffeine consumption, stress levels, sleep position, diet, medications, habits, etc.) that trigger their bruxism and adjust accordingly. It will not magically cure nor stop individual from ever grinding or clenching again, but it can give them helpful strategies to control their grinding/clenching to the point where it no longer causes health problems and improves their overall quality of life. And in that sense, the data and insights provided by the device are exactly the feedback that will lead to behavior change and a lasting learning effect we hope to achieve.

Conclusion

In summary, biofeedback is a promising behavioral intervention that has been shown in numerous studies to reduce teeth grinding or clenching without affecting sleep quality.

Although there is not yet conclusive evidence of its efficacy, it may be worthwhile to explore how biofeedback can be integrated into the bruxism treatment protocol, as it is noninvasive, reversible, and has few known side effects. It can also be used to maximize the impact of a multi-modal approach, which is consistent with the multi-factorial nature of bruxism itself.

Recent technological advances in this area have focused on the development of devices with a comfortable form factor (something that can be worn all night or all day without discomfort or stigma), more accurate detection, and feedback signals that prevent long-term adaptation. These advances could lead to more widespread use of biofeedback for bruxism in the future.

In addition, since biofeedback is largely considered “training not treatment”, biofeedback devices need to also provide individual with data and insights about exogenous factors that affect their grinding / clenching. By doing so, individual can take an active role instead of passively receiving treatment, and implement what is learned to get their bruxism under control. Finally, the interactive nature of biofeedback could provide individual with greater sense of control over their condition and improve their well-being as a result.

Any more questions about biofeedback? Leave a comment and we’ll answer it in our next post!

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