System for detecting bruxism or temporomandibular joint disorder

Abstract

A system for detecting bruxism or temporomandibular disorder is provided. The pressure sensor senses external auditory canal air pressure and identifies bruxism or temporomandibular joint disorder based on the sensed auditory canal air pressure. The output signal is indicative of the detected bruxism or temporomandibular disorder so that remedial action can be taken.

Description

Technical Field

[0001] The present invention relates to a system for detecting and differentiating bruxism or temporomandibular joint disorders, in particular in a non-invasive and user-friendly manner. Background Art

[0002] The jawbones (upper, maxilla, and lower, mandible) are components of the oral cavity. These bones are important for the normal function of the oral cavity and are also associated with pathological conditions in the oral cavity. Bruxism is a condition in which a subject grinds, clenches, or clenches their teeth. Temporomandibular joint disorder is another condition related to the jawbones.

[0003] Bruxism can be divided into sleep bruxism and awake bruxism. Sleep bruxism is characterized by rhythmic or arrhythmic muscle activity of the biting mechanism during sleep. Awake bruxism is characterized by repeated or sustained tooth contact and / or tensing or pushing / sliding of the lower jaw. The prevalence of bruxism varies by age group. In the adult population, the prevalence of awake bruxism is estimated to be about 22%-30%, and sleep bruxism in this population is about 1%-15%. In children and adolescents, the prevalence of bruxism is reported to be about 3%-49%.

[0004] Bruxism is associated with a number of short-term and long-term adverse health effects. Short-term effects of bruxism include headaches, limited mouth opening, facial myalgia (pain in the jaw and facial muscles), ear pain, and tight or stiff shoulders. Bruxism can also affect sleep in the form of frequent interruptions. It is also well known that the teeth grinding or knocking noise caused by bruxism may cause disrupted sleep for the bed partner. Oral manifestations of bruxism include excessive tooth mobility and gum inflammation and recession. Long-term effects of bruxism include temporomandibular joint disorder (hereinafter referred to as TJD, discussed further below), tooth wear and fracture.

[0005] Many of the problems associated with bruxism can be avoided if diagnosed and treated early. For example, it has been observed that awake bruxism can be reduced through the use of appropriate reminder techniques.

[0006] The temporomandibular joints (TMJs) are two joints that connect the mandible (jawbone) to the skull. It is estimated that approximately 20%-40% of the population has some degree of TJD. The three classic features of TJD include pain, reduced range of jaw movement, and noises (clicking / popping) in the joint.

[0007] The ear is divided into three parts: the outer ear, the middle ear, and the inner ear. The outer ear canal is about 25 mm long and about 7 mm in diameter. The TMJ is located at the cartilaginous floor of the outer ear canal. Therefore, the movement of the jaw changes the size of the floor of the outer ear canal.

[0008] The pressure in the middle ear is maintained very close to atmospheric pressure by various physiological mechanisms, including airflow through the Eustachian tube. Normally, the Eustachian tube is collapsed, but during swallowing and other oral activities, it opens, creating positive pressure in the nasal cavity. Therefore, movement in the mouth can cause characteristic changes in the pressure in the outer ear.

[0009] It would be desirable to be able to diagnose bruxism or TJD early, for example to enable timely alerts to be provided to the user to stop grinding or clenching the teeth.

[0010] US20150039087A1 describes an in-ear device for managing symptoms related to the temporomandibular joint.

[0011] US2019343452A1 describes a bruxism detection subsystem that is at least partially located in the ear canal and is capable of measuring changes in the size of the patient's ear canal. Summary of the invention

[0012] The invention is defined by the claims.

[0013] According to an example according to one aspect of the present invention, a system for detecting and distinguishing bruxism from temporomandibular joint disorder is provided, the system comprising:

[0014] a pressure sensor device for sensing the pressure in the external auditory canal; and

[0015] A processor for processing the sensed ear canal pressure, wherein the processor is configured to:

[0016] Detecting bruxism or temporomandibular joint disorder based on sensed ear canal pressure; and

[0017] An output signal is generated that is indicative of detected bruxism or temporomandibular joint disorder.

[0018] Such a system monitors pressure changes in the external auditory canal to detect oral pathologies such as bruxism and TJD. The output signal is used, for example, to deliver appropriate notifications or reminders to the user based on the detected pathology.

[0019] The present invention is based on the recognition that the characteristics of the measured outer ear pressure can be used to detect and quantify typical movements involving the jawbone, such as jaw-up movement, jaw-down movement and side-to-side movement of the jaw. This information can then be further used to detect complex movements of the oral cavity, such as swallowing and yawning, which involve different combinations of typical movements of the jawbone.

[0020] Depending on the nature of these movements, it can be detected whether bruxism or TMJ disorder is present, and the system can differentiate between them.

[0021] The pressure sensor may comprise a speaker, which operates in microphone pressure sensing mode. The speaker is, for example, an existing part of an earbud, such as an existing part of an entertainment system or a sleep monitoring system. It may be part of a hearing aid system. A single speaker may be used as a speaker in time division mode and as a pressure sensor. Alternatively, there may be two microphone transducers: one used as a pressure sensor and the other as a speaker. Alternatively, a pressure sensor without an output (e.g. microphone) function may be used.

[0022] The system may include a microphone for audio detection, and the processor is used to perform audio analysis. For example, the processor may be further configured to detect clicks, or pops, or sounds made by teeth grinding, or clicks associated with temporomandibular joint disorder. Thus, analysis of the sounds created and pressure levels may help detect bruxism or temporomandibular joint disorder.

[0023] The pressure sensor arrangement may be used to obtain pressure differential measurements from both ears simultaneously (eg, using two pressure sensing earplugs) or sequentially.

[0024] For example, a constant difference may be associated with an ear / nose / throat / sinus pathology rather than a bruxism signal (which is periodic in nature). Additionally, differences in the arrival time (phase) or amplitude of the signals may enable more reliable identification of the pathology. Thus, the processor may be configured to use the differential pressure measurements to differentiate between (i) bruxism and TMJ disorder and (ii) ear / nose / sinus pathology.

[0025] The processor may be configured to analyze the sensed ear canal pressure to detect characteristic pressure patterns and repetition rates. Thus, both the pressure waveform and the repetition rate over a short period of time (eg, corresponding to a grinding event) may be used.

[0026] The processor may be configured to detect bruxism by:

[0027] Identify the type of jaw movement based on the sensed ear canal pressure;

[0028] Determine if there is grinding or clenching jaw movement; and

[0029] Bruxism is detected based on the frequency of grinding or jaw clenching movements exceeding a threshold.

[0030] Jaw grinding or jaw clenching movements are thus detected and counted in this way.

[0031] The processor may be configured to detect a temporomandibular joint disorder by:

[0032] Identify the type of jaw movement based on the sensed ear canal pressure;

[0033] Determine if there is jaw closure movement;

[0034] Determine the range of jaw movement and the speed of jaw movement according to the pressure change amplitude and the pressure change rate; and

[0035] Detection of temporomandibular joint disorders based on a function of the range of jaw movement and the speed of jaw movement.

[0036] Therefore, the range and speed of jaw movement were analyzed.

[0037] The processor may be configured to analyze the sensed ear canal pressure to detect whether the user is awake or asleep. This may enable, for example, differentiation between sleep bruxism and wakefulness bruxism.

[0038] The system may further comprise an alert system for providing an alert or notification to the user indicating the detected bruxism or TMJ disorder.This is a known way of treating the condition.

[0039] The present invention also provides an oral care system, the oral care system comprising:

[0040] Oral care tips; and

[0041] A system as defined above.

[0042] In such an oral care system, an oral health routine, such as brushing, spraying or flossing, may be used, particularly for measuring TJD. For example, the mouth would be opened at the beginning of a brushing session, and closed at the end of the brushing session. Similarly, the mouth would be opened to insert a toothbrush mouthpiece and additionally to remove the toothbrush mouthpiece, and closed to the toothbrush mouthpiece after it has been inserted. The mouth also needs to be opened to access the back teeth for spraying or flossing, and possible side-to-side movement when spraying or flossing the back teeth.

[0043] The present invention also provides a computer program, the computer program comprising computer program code means, which, when said program is run on a computer, is adapted to implement a method comprising:

[0044] receiving the sensed external auditory canal pressure; and

[0045] processing the sensed ear canal pressure to detect bruxism or temporomandibular joint disorder based on the sensed ear canal pressure; and

[0046] An output signal is generated that is indicative of detected bruxism or temporomandibular joint disorder.

[0047] The implemented method may include detecting bruxism by:

[0048] Identify the type of jaw movement based on the sensed ear canal pressure;

[0049] Determine if there is grinding or clenching jaw movement; and

[0050] Bruxism is detected based on the frequency of grinding or jaw clenching movements exceeding a threshold.

[0051] The implemented method may include detecting a temporomandibular joint disorder by:

[0052] Identify the type of jaw movement based on the sensed ear canal pressure;

[0053] Determine if there is jaw closure movement;

[0054] Determine the range of jaw movement and the speed of jaw movement according to the pressure change amplitude and the pressure change rate; and

[0055] Detection of temporomandibular joint disorders based on a function of the range of jaw movement and the speed of jaw movement.

[0056] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] For a better understanding of the invention, and in order to more clearly show how the invention may be put into practice, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0058] Figure 1 A system for sensing bruxism or temporomandibular joint disorder is shown;

[0059] Figure 2 An example of pressure changes in the external auditory canal during yawning is shown;

[0060] Figure 3a and Figure 3b An example of a method 200 for detecting TJD and bruxism is shown;

[0061] Figure 4 shows the change in pressure in the external auditory canal during jaw movement, during slow jaw movement and during fast jaw movement; and

[0062] Figure 5 Duty cycle control for microphone and speaker modes is shown. DETAILED DESCRIPTION

[0063] The present invention will be described with reference to the accompanying drawings.

[0064] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, system, and method, are intended for illustrative purposes only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, system, and method of the invention will be better understood through the following description, the appended claims, and the accompanying drawings. It should be understood that the drawings are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the drawings to indicate the same or similar components.

[0065] The present invention provides a system for detecting bruxism or temporomandibular joint disorder. A pressure sensor senses the pressure of the external auditory canal, and identifies bruxism or temporomandibular joint disorder based on the sensed auditory canal pressure. An output signal indicates the detected bruxism or temporomandibular joint disorder so that remedial measures can be taken.

[0066] Figure 1 A system 100 is shown that includes a pressure sensor 102 for sensing external ear canal pressure and a processor 104 for processing the sensed external ear canal pressure. Bruxism or temporomandibular joint disorder is detected based on the sensed ear canal pressure and an output signal ("bruxism" or "TJD") is generated.

[0067] The pressure sensor 102 is, for example, in the form of an earplug. The outer ear pressure is the pressure between the eardrum and the inserted earplug. In use, the earplug seals the ear canal from the outside atmosphere. This essentially forms a closed chamber. The pressure sensor 102 is on one side of the chamber and the eardrum is on the other side. The earplug can also be used for other purposes, such as entertainment purposes or communication purposes. The user wears the earplug during daily life and during sleep, for example in the form of a so-called sleep band or snooze band.

[0068] There may be a single earbud, or more likely two earbuds in each ear. Figure 1 A second earbud 106 is shown, which is represented as a speaker rather than a pressure sensor.

[0069] Thus, there may be a single pressure sensing earbud 102, or two pressure sensing earbuds, or one pressure sensing earbud and one loudspeaker earbud. In some embodiments discussed below, the earbud or each earbud may perform both pressure sensing and loudspeaker functions, and the same structure may be used for both functions (i.e., the speaker is in either output mode or sensing mode). However, the system may be implemented using a pressure sensor without any loudspeaker function.

[0070] It is possible to measure oral lesions with a single earplug in a single ear, but the specificity of the measurement will be improved if both ears are measured. If both ears are monitored, a single earplug may be applied to both ears consecutively or two earplugs may be applied to both ears simultaneously for examination. Most preferably, both earplugs are applied simultaneously.

[0071] However, all of these possible sensor combinations may generally be considered to constitute a "pressure sensing device" and are intended to fall within the general concept of the present invention.A pressure sensing device is used to measure air pressure, ie atmospheric pressure.

[0072] The pressure sensing device is used to measure pressure changes in the outer ear. The earplugs can optionally be integrated with an infrared measurement unit sensor or an inertial measurement unit (IMU) sensor to detect whether they are tightly inserted in the ear canal.

[0073] The processor 104 receives pressure information from the external auditory canal. The pressure information from the pressure sensing device is then evaluated to establish jaw movement.

[0074] The simplest implementation is a pressure sensor 102 in the form of an earplug or earplug (both are intended to be considered "earplugs") integrated with a pressure sensor. The pressure sensor can be a barometric MEMS pressure sensor, or indeed any other pressure sensor. The earplug is used to continuously monitor pressure changes in the outer ear.

[0075] Bruxism is characterized by frequent grinding or clenching of the teeth, which involves side-to-side lateral movement of the jaw (grinding) or tight closing of the jaw (clenching). In some cases, bruxism activity is rhythmic, with bite force pulses of one-tenth of a second (similar to chewing), and in some cases it has longer bite force pulses of 1 to 30 seconds (clenching).

[0076] Grinding movements involve the TMJs on both sides of the jaw; during grinding, one half of the jaw (with the corresponding TMJ) moves inwards, while the other half moves outwards. Due to the close anatomical relationship between the jawbone and the external auditory canal, these movements result in changes in the dimensions of the external auditory canal of both ears, resulting in characteristic changes in ear pressure.

[0077] Using the experimental and simulation data, a database of typical patterns of external auditory canal pressure associated with teeth grinding or clenching due to bruxism can be established.

[0078] Bruxism also involves frequent repetition of these grinding or clenching activities. Therefore, it is also valuable to monitor the frequency of bruxism or clenching episodes. Based on clinical data, a certain threshold value (such as T1) for the duration of bruxism or clenching episodes can be derived to distinguish bruxism-related bruxism or clenching from other activities such as eating. Such a threshold value can also be modified based on important demographic characteristics such as the subject's age, gender, etc. Alternatively, the data can be used to train a machine learning algorithm to classify bruxism.

[0079] Changes in ear pressure can also be used to detect whether a person is awake or asleep. Sleep is characterized by long periods of inactivity or minimal activity in the mouth. Significant oral activity, such as vocalization and swallowing (both of which produce known pressure signals in the earbuds), is notably absent during sleep. Drowsiness before bed is characterized by frequent yawning. Yawning also causes characteristic changes in ear pressure. Therefore, yawning after long periods of inactivity or minimal activity in the mouth can be used to distinguish between an individual's wakefulness and sleep. This information can then be used to classify bruxism episodes in sleep bruxism and wakefulness bruxism.

[0080] Figure 2 An example of pressure changes in the external auditory canal during yawning is shown (as pressure versus time).

[0081] It is well known that bruxism can be reduced in many cases by using appropriate reminder techniques. The effectiveness of such techniques can be further enhanced if such reminders or notifications are provided to the user in near real time and on a continuous basis during or immediately after an episode of bruxism.

[0082] Thus, once bruxism is detected based on the ear pressure analysis as described above, an appropriate notification can be generated (outputting "bruxism") and delivered to the user. For awake bruxism, an earplug including a speaker (i.e., an earplug with pressure sensing capability and loudspeaker functionality) can be used to deliver appropriate audio notifications to the user in real time. User compliance with such reminders can also be monitored and can be used for user education. User responses to such notifications can be used to adjust the nature of future notifications to improve effectiveness.

[0083] Figure 3a and Figure 3b An example of a method 200 for detecting TMD and bruxism is shown.

[0084] In step 202, pressure variations in the outer ear are analyzed. These are called "PEEs." In step 204, different types of jaw movements "JM" are detected from the analysis of the pressure variations.

[0085] In step 206, it is detected whether complex oral movements are detected. Complex movements include swallowing and yawning, for example.

[0086] The presence of complex movements may indicate TJD, whereas the absence of complex movements may indicate bruxism.

[0087] Basic jaw movements, such as moving the jaw up and down (clenching) and moving the jaw side to side (grinding) can be considered simple movements.

[0088] More complex movements include, for example, yawning, eating, and swallowing, and they include different combinations and sequences of these simple movements. These can be considered complex movements.

[0089] The pressure signal pattern can be used to classify and identify the movement. For example, Figure 2 The pressure changes in the external auditory canal during yawning as explained above are shown. This pattern consists of a series of simple jaw movements. In contrast, bruxism will only have a simple isolated movement, which can be used for the identification of bruxism.

[0090] Bruxism movements may cause a smoother, somewhat sinus-like increase and decrease in pressure, whereas TMJ has more characteristic patterns.

[0091] Figure 3a The steps are shown when a complex jaw movement has been detected.

[0092] In step 208, it is determined whether the movements include jaw closing movements.

[0093] In step 210, for the jaw closing movement, a jaw movement range "JM-range" is identified. The JM-range is the maximum distance between the two jaws.

[0094] To determine jaw movement, the amplitude of the pressure change can be measured. Generally, the greater the range of jaw movement, the greater the amplitude of the pressure change. Additionally, the rate of change of the pressure change can be measured. For example, the rate of change of pressure can be used in conjunction with the total amplitude to establish the total jaw movement.

[0095] The relationship between pressure changes in the outer ear and jaw movement (extent and speed) can be expressed mathematically as:

[0096] PEE = f(JM-range, JM-speed, IC) (Formula 1)

[0097] Where PEE = pressure in the outer ear,

[0098] JM-Range = Range of jaw movement,

[0099] JM-speed = jaw movement speed,

[0100] IC = characteristics of the individual (age, sex, height, etc.).

[0101] Based on empirical or experimental data, a mathematical model can be derived to derive the range of jaw movement based on the measured PEE. In this case, Equation 1 can be modified to:

[0102] JM-Range = f(PEE, JM-Speed, IC) (Formula 2)

[0103] Any changes in the amplitude, rate, or smoothness of jaw movement are used to assess the development of TJD.

[0104] In particular, in step 212, it is determined whether the range of joint movement is below a threshold. If so, in step 214, it is additionally determined whether the magnitude of the pressure change is below a threshold.

[0105] If both threshold comparisons are satisfied, then the TJD is determined in step 216 .

[0106] Figure 4 The change in pressure in the external auditory canal during jaw movement for the same individual in two different settings is shown; segment A represents slow jaw movement (fast jaw descent and slow jaw closure); segment B represents fast jaw movement (fast jaw descent and fast jaw closure). It is clear that the magnitude of the pressure change depends on both the extent of the jaw movement and the speed of the jaw movement.

[0107] Generally speaking, greater and faster jaw movements will result in higher peak pressures.

[0108] exist Figure 4 The distance between points k and r in the two examples represents the total time taken for a sequence of jaw up and down movements. This time can be used to calculate the speed of jaw movement.

[0109] In the case of TJD, the range and speed of jaw movement are limited due to muscle protection and associated pain. Therefore, pressure changes in TJD will have a slow rate of pressure change (resulting in Figure 4 The slopes of the kl and pq segments shown in segment A are gentler) and the amplitudes of the kl and pq segments are reduced.

[0110] The muscles involved in lowering the jaw are smaller, slower, and much less powerful than those involved in pulling the jaw up. The speed of the jaw movement changes the pressure changes less significantly during jaw lowering than during jaw closing. In segment B, the small notch in segment lq indicates the sudden change in pressure due to the faster movement.

[0111] A large database of pressure variations under different TJD conditions can be used to derive certain thresholds (e.g., if the JM-range is below a certain threshold) or to train a machine learning algorithm to detect TJD problems.

[0112] TJD measurements can be made using earbuds with integrated pressure sensors and microphones. The earbuds are used to monitor pressure changes in the outer ear during jaw movement as described above, and the microphone is additionally used to detect any clicks during jaw movement. The pressure signal and audio signal are then analyzed together to find TJD.

[0113] The system can be enhanced with pain sensors to detect pain during jaw movement, allowing detection of TJD covering all three classic features of TJD.

[0114] Figure 3b The steps are shown when complex oral movements have not yet been detected.

[0115] In step 300 ( Figure 3a In step 206 after), determine whether only grinding or clenching movement is detected. If so, then in step 302, analyze the signal properties.

[0116] In step 304 it is determined whether the signal properties match a bruxism pattern. If so, the frequency of these patterns is additionally determined in step 306 and compared with a threshold value T1. If the frequency is greater than T1, bruxism is concluded in step 308.

[0117] Then, the method further optionally distinguishes sleep bruxism from wakefulness bruxism by detecting a sleep state or a wakefulness state based on the pressure signal in step 310 .

[0118] If awake bruxism is concluded in step 312 , an audio notification or a vibration notification / haptic notification is delivered in step 314 , and it is monitored in step 316 whether the notification results in the bruxism ending.

[0119] If sleep bruxism is concluded in step 318 , a notification is delivered in step 320 , and it is monitored in step 322 whether the notification leads to an end to the bruxism.

[0120] For example, this notification is a report to the user the next morning.

[0121] The pressure sensing used in the system of the present invention can be based on the reuse of the acoustic transducer in the earplug. The microphone can be reversed to function as a microphone. Thus, the microphone can be reconfigured as a microphone, thereby acting as an air pressure sensor. The displacement of the diaphragm can be used as the air pressure sensor signal.

[0122] A single acoustic transducer can be operated in microphone mode (mode 1 - recording, ear pressure measurement) and in loudspeaker mode (mode 2 - sound generator). This can be done using e.g. Figure 5 The duty cycle control shown is implemented. A controller is then used to switch modes and control the sensitivity and duty cycle length / mode of the two modes. The reconfigured speaker can be used to measure ear canal pressure and can also be used as a microphone to record teeth grinding or joint clicking sounds.

[0123] Alternatively, a system might have two acoustic transducers, as are typically already present in a single headset, but reconfigured to function as one microphone and one speaker.

[0124] When a system has two earbuds, differential measurements can be made. Differential signal analysis can enable improved specificity of diagnosis. Considering the pressure signal, a constant difference between the pressure signal in the left or right ear, or a difference that lasts for several days, can be interpreted as being related to ear / nose / throat / sinus pathology. These fairly constant differences can be used to distinguish pathology signals from bruxism signals, which are periodic in nature with a frequency of seconds or minutes. In addition, any of these fairly constant differential signals can be used to distinguish ear / nose / throat / sinus pathology signals from TJD signals, which, if present, would not show such a strong differential signal. Considering the audio signal, differences in the arrival time (phase) or amplitude of the sound signal can enable better elucidation (or even locating using arrival time offsets) of dental pathologies, such as which teeth are grinding.

[0125] Oral hygiene routines, such as brushing teeth, can be used as a stimulus for TJD measurement. In particular, jaw movements during brushing teeth, spraying, air flossing, inserting or removing a toothbrush mouthpiece, etc. can be used as a stimulus for measuring TJD.

[0126] Specific conditions that induce controlled jaw movement include:

[0127] Open your mouth at the beginning of your brushing session;

[0128] Close your mouth at the end of your brushing session;

[0129] Open the mouth to insert the mouthpiece and also to remove the mouthpiece;

[0130] After the toothbrush mouthpiece has been inserted, close your mouth onto the toothbrush mouthpiece;

[0131] Open mouth to access back teeth for jetting or flossing;

[0132] Side-to-side movement possible when jetting or flossing the back teeth.

[0133] Jaw movement during speech can also be used as a stimulus for measuring TJD. When using earbuds (with a microphone) as a communication device, there may be speech. For example, the measured speech (intensity, spectrum) can be used to infer what kind of movement is taking place, and this can be compared over time to check for any changes in the associated amount of jaw movement.

[0134] For example, the system can be calibrated by asking the patient to perform controlled jaw movements while pressure (and optionally sound) measurements are being taken. For example, the patient may be asked to perform some simple manipulative actions such as swallowing, yawning, and jaw dropping. These actions produce pressure changes in the outer ear, and the pressure changes can be analyzed and used as a baseline for subsequent processing.

[0135] The system of the present invention can be configured to detect bruxism or TJD or both. Figure 3a and Figure 3b ) is shown to be able to detect both conditions, but the present invention can only be applied to one of the two conditions.

[0136] Variations to the disclosed embodiments may be understood and effected by those skilled in the art in practicing the claimed invention, through a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0137] The functions implemented by a processor may be implemented by a single processor or by multiple separate processing units, which may be collectively considered to constitute a “processor.” In some cases, such processing units may be remote from each other and communicate with each other in a wired or wireless manner.

[0138] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0139] The computer program may be stored / distributed on a suitable medium, such as an optical storage medium or solid-state medium provided with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

[0140] If the term "suitable for" is used in the claims or the description, it should be noted that the term "suitable for" is intended to be equivalent to the term "configured to". If the term "device" is used in the claims or the description, it should be noted that the term "device" is intended to be equivalent to the term "system" and vice versa.

[0141] Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A system (100) for detecting and distinguishing bruxism from temporomandibular joint disorder, comprising: An air pressure sensor device (102) for sensing the pressure in the external auditory canal; as well as A processor (104) for processing the sensed ear canal pressure, wherein the processor is configured to: Detecting bruxism or temporomandibular joint disorder based on the sensed ear canal pressure; and An output signal is generated that is indicative of detected bruxism or temporomandibular joint disorder.

2. The system of claim 1, comprising a microphone for audio detection, and the processor is configured to perform audio analysis.

3. The system of claim 2, wherein the processor is further configured to detect a click, or a pop, or a sound made by teeth grinding, or a click associated with temporomandibular joint disorder.

4. The system according to any one of claims 1 to 3, wherein the air pressure sensor device comprises a speaker, the speaker operating in a microphone pressure sensing mode.

5. The system according to any one of claims 1 to 4, wherein the air pressure sensor device is part of a pressure sensing earplug or a pair of pressure sensing earplugs.

6. A system according to any one of claims 1 to 5, wherein the air pressure sensor arrangement is used to obtain pressure difference measurements from both ears simultaneously or sequentially.

7. The system of claim 6, wherein the processor is configured to use the pressure differential measurements to differentiate between (i) bruxism and temporomandibular joint disorder and (ii) ear / nose / sinus pathology.

8. The system of any one of claims 1 to 7, wherein the processor is configured to analyze the sensed ear canal pressure to detect characteristic pressure patterns and repetition rates.

9. The system of any one of claims 1 to 8, wherein the processor is configured to detect bruxism by: identifying a type of jaw movement based on the sensed ear canal pressure; Determine if there is grinding or clenching jaw movement; and Bruxism is detected based on the frequency of grinding or jaw clenching movements exceeding a threshold.

10. The system of any one of claims 1 to 9, wherein the processor is configured to detect a temporomandibular joint disorder by: identifying a type of jaw movement based on the sensed ear canal pressure; Determine if there is jaw closure movement; Determine the range of jaw movement and the speed of jaw movement according to the pressure change amplitude and the pressure change rate; and Detection of temporomandibular joint disorders based on a function of the range of jaw movement and the speed of jaw movement.

11. The system according to any one of claims 1 to 10, wherein the processor is configured to analyse the sensed ear canal pressure to detect whether the user is awake or asleep, and thereby be able to distinguish between awake bruxism and sleep bruxism.

12. An oral care system comprising: Oral care equipment; as well as A system according to any one of claims 1 to 11.

13. A computer program comprising computer program code means adapted to implement a method when said program is run on a computer, said method comprising: receiving the sensed external auditory canal air pressure; as well as processing the sensed ear canal air pressure to detect bruxism or temporomandibular joint disorder according to the sensed ear canal air pressure; as well as An output signal is generated that is indicative of detected bruxism or temporomandibular joint disorder.

14. The computer program of claim 13, wherein the method implemented comprises detecting bruxism by: identifying a type of jaw movement based on the sensed ear canal air pressure; Determine if there is grinding or clenching jaw movement; and Bruxism is detected based on the frequency of grinding or jaw clenching movements exceeding a threshold.

15. A computer program according to claim 13 or 14, wherein the method implemented comprises detecting a temporomandibular joint disorder by: identifying a type of jaw movement based on the sensed ear canal air pressure; Determine if there is jaw closure movement; Determine the range of jaw movement and the speed of jaw movement according to the pressure change amplitude and the pressure change rate; and Detection of temporomandibular joint disorders based on a function of the range of jaw movement and the speed of jaw movement.

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