Introduction

Surveys have shown that about 8% of the population exhibit nocturnal bruxing behavior, or sleep bruxism (SB). Symptoms include severe tooth wear, temporomandibular joint disorder (TMD), morning headaches, disturbed sleep and daytime sleepiness. Few of these individuals are aware of, or seek treatment for SB, while others suffer the consequences indefinitely.

SB is characterized by the involuntary, nonfunctional grinding and/or clenching of the teeth during sleep. Patients are usually unaware of the condition, however others in the proximity may complain of loud grinding sounds produced by the friction of the teeth. SB is often related to malocclusion, mental anxiety, and neurological disorders; it may subside and reappear spontaneously.

Diagnosis of SB is best achieved by conducting an overnight sleep study that includes continuous monitoring of the electrical activity of the masseter muscles (EMG), which may show repeated bursts of activity that are not present in non-bruxers.

S.L.P.’s BiteStrip® is a low-cost, single use assessment and follow-up tool for SB. The device is used for determining the existence and severity of SB, for evaluating the short- and long-term efficacy of a treatment (such as a dental splint), and for titrating drug dosages.

Description

The BiteStrip is a single-use disposable device designed as a front line screener for SB. It is a miniature electronic system comprising:

• Two pre-gelled skin EMG electrodes and an EMG amplifier, for acquiring nocturnal EMG signals from the masticatory muscles.

• A CPU for running real-time software that analyzes EMG strength patterns and for detecting and counting each bruxing episode.

• A permanent chemical display for presenting the study outcome in the morning.

• A lithium battery

• All the elements are integrated onto a single flexible substrate.

 Operation

The patient cleans the BiteStrip’s display with the alcohol pad provided and applies the green sticker over the display area to activate the BiteStrip. The unit’s red light starts blinking, and then stops again a few seconds after the device is applied to the skin. The light will then blink with every EMG peak significantly stronger than the background signal.

Instruct the patient to perform at least two maximal voluntary clenches (MVCs) during the first 20 minutes. The two strongest EMG peaks detected during this period are used to establish the threshold, which is set at 30% of their average amplitude. It is therefore very important to make sure the patient performs this maneuver shortly after applying the device on the face in order to avoid picking up every small twitch during the night.

The BiteStrip counts each EMG peak stronger than the threshold for a period of up to six hours. Removing the BiteStrip in under four hours results in an error because four hours is considered the minimum period for a significant indication.

The counting stops after six hours, but the device may remain in place for up to 12 hours. A study longer than 12 hours is also considered to be in error because it probably indicates a technical problem in the device.

The study ends once the BiteStrip is removed from the face. The red light turns on within two minutes after removal. The display is ready for reading 30 minutes later. The green sticker should not be removed sooner, or the display will be difficult to read.

The display presents a number that indicates the severity of bruxism during the study.

Reading the BiteStrip display

The display consists of a single digit or letter, which appears in black over the bright silver background at the end of the study.

The final score represents five possible test outcomes, based on the severity of the bruxism:

0 – no bruxism:  comparable to a sleep lab brux count of up to 39 over 5 hours

1 – mild:  comparable to a sleep lab brux count between 40 and 74 over 5 hours

2 – moderate:  comparable to a sleep lab brux count between 75 and 124 over 5 hours

3 – severe: comparable to a sleep lab brux count of more than 125 over 5 hours

E – error in study

Blank – bad sensor

           No significant bruxism was detected                    Severe bruxism was found –

                                                                                            more than 125 episodes in 5 hours.

Notes

Bad sensor indicates technical malfunction of the sensor, which results in no segments changing color. The device will be replaced under warranty.

Bad study indicates a short (less than 4 hours) or long study (more than 12 hours). A short study may occur when the sensor is inadvertently dislocated from place during the night, or the patient removed it in his sleep. The test is considered invalid due to insufficient recording time.

Precautions and miscellaneous  

• Touching the display may cause the red light to turn on momentarily. This is not a problem, and the device can still be used.
• The patient must leave the green sticker in place in the morning.
• The BiteStrip should be stored in a cool dry place until it is ready to be used.
• Review with the patient the correct way to apply the BiteStrip.
• Make sure the patient knows to remove the sensor in the morning.
• Should the patient develop anything more than a mild skin rash or reaction at the site of attachment, instruct him or her to consult a dermatologist.