Patent Publication Number: US-2021161633-A1

Title: Dental Monitoring System

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 62/444,676 entitled “Dental Monitoring System” filed Jan. 10, 2017, which is hereby incorporated by reference in its entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Disclosure 
     This disclosure relates to a dental monitoring system for monitoring dental parameters of a subject. 
     2. Description of the Related Art 
     The oral cavity of the human body naturally produces saliva to facilitate the breakdown of food during mastication. The saliva produced in the oral cavity may experience significant changes in physical and biochemical properties. Changes in physical and biochemical properties within the oral cavity may significantly affect overall health including causing an increase in tooth decay and the formation of dental cavities. In some cases, pH levels within the oral cavity are of particular interest to health practitioners in order to monitor the oral health of patients. 
     What is needed therefore is a dental monitoring system capable of monitoring the physical and biochemical properties within the oral cavity of a patient. 
     SUMMARY OF THE INVENTION 
     In one embodiment of the disclosure, a dental monitoring system is provided. The dental monitoring system comprises an intra-oral insert configured to be received in the mouth of a subject; one or more sensors connected to the intra-oral insert and in electrical communication with a controller having a non-volatile memory; a transponder coil received in the intra-oral insert and in electrical communication with the controller; and a transceiver coil in selective wireless electrical communication with the transponder coil. The selective wireless communication between the transponder coil and the transceiver coil can be provided by near-field communication. 
     In some embodiments, the dental monitoring system comprises a support frame configured to mount the transceiver coil. The support frame can be structured to loop around at least a portion of an ear of the subject. The support frame can be dimensioned such that the transceiver coil is positioned adjacent to a cheek of the subject. At least one of the one or more sensors can be a pH sensor, a biochemical sensor, or a pressure sensor, and the controller can comprise a microcontroller and a JTAG programming port. Near-field communication can communicate power from the transceiver coil to the transponder coil and it can simultaneously communicate data bi-directionally, for example through impedance modulation. 
     In some embodiments, the dental monitoring system can further comprise an adhesive patch that retains the transceiver coil on the cheek of the subject. The adhesive patch can be worn for an extended period of time thereby providing continuous monitoring over the extended period of time. 
     In some embodiments, at least one of the one or more sensors may be a biochemical sensor and at least one of the one or more sensors is a pressure sensor. In some embodiments, a plurality of the one or more sensors may be positioned on an inner recessed area disposed between a raised outer profile and a raised inner profile of the intra-oral insert. A plurality of the one or more sensors may be positioned on both sides of a raised outer profile that extends from an inner recessed area disposed between a raised inner profile and the raised outer profile of the intra-oral insert. A plurality of the one or more sensors may be positioned on a raised inner profile that extends from an inner recessed area disposed between the raised inner profile and the raised outer profile of the intra-oral insert. 
     In another embodiment, a dental monitoring system is provided. The dental monitoring system may comprise an intra-oral insert configured to be received in the mouth of a subject; a plurality of sensors connected to the intra-oral insert and in electrical communication with a controller having a non-volatile memory, the plurality of sensors configured to monitor one or more parameters of pressure, force, shear force, acceleration, velocity, pH, and temperature; a transponder coil received in the intra-oral insert and in electrical communication with the controller; and a transceiver coil in selective wireless electrical communication with the transponder coil, the transceiver coil selectively powering the transponder coil. The selective wireless communication between the transponder coil and the transceiver coil can be provided by near-field communication. The controller can be configured to communicate a command to the plurality of sensors to generate a data reading. The controller can communicate the data reading to a smart device configured to process, display and log the data reading on a graphical user interface and to a mass storage media, respectively. The NFC communication may be configured to use encryption for data security. 
     In another embodiment, a method of dental monitoring is provided. The method of dental monitoring can include the steps of: (i) inserting the intra-oral insert into the mouth of a subject; (i) energizing the transponder coil by the transceiver coil to power the intra-oral insert circuitry; (ii) sensing a parameter of the subject using a sensor connected to the intra-oral insert; (iii) communicating the sensed parameter to a controller having a non-volatile memory; (iv) communicating the sensed parameter from the controller to a transponder coil received in the intra-oral insert; and (v) communicating the sensed parameter wirelessly from the transponder coil to a transceiver coil using near-field communication. In some embodiments, the parameter of the subject is sensed when the subject initiates a force to the sensor. The parameter of the subject can be a pH level. In other embodiments, the parameter can be temperature, pressure, moisture, light, total dissolved solids, ionic strength, conductivity, dissolved oxygen, oxidation-reduction potential or any combination of parameters. In yet other embodiments, the parameter can be the sensing of a biochemical species, such as with an ion-selective chem-FET (chemical field effect transistor). 
     To accurately assess a variety of dental and oral conditions in a subject, it is beneficial for a dental practitioner to monitor as many physiological, physical and biochemical parameters as possible. Ideally, these parameters are continuously monitored and logged in real-time to show trending over time. To maintain patient comfort, any instrumentation must be designed to be as least invasive as possible while still providing the required parameter readout. To assure safety, any instrumentation placed into the oral cavity must be physically large enough not to risk accidental swallowing. Alternatively, any instrumentation placed into the oral cavity must be provided with a means to securely anchor it to structures such as teeth, gums or other tissue. The presented dental monitoring system concept addresses these requirements. 
     Sensors and associated electronics must be as small as possible to fit into the oral cavity without causing patient discomfort. Many electronic chips available today are as small as a grain of rice, immediately raising the concern of accidental swallowing. Therefore, all instrumentation components will be mounted to a large framework, such as an athletic intra-oral insert or an anti-snore piece. To protect the electronics from bodily fluids and assure materials bio-compatibility, the electronics may be encapsulated into the mouthpiece during the casting or molding process of the mouth piece. 
     The instrumentation inside the oral cavity should be wireless. At todays standard of technology, it would not be acceptable to use cables through the mouth to connect to the data logger or a power supply. Therefore, the electronics should either be battery-operated or be powered by energy-harvesting of external fields. 
     The system properties may feature continuous parameter readout in real-time and smallest possible size of the interior electronics. A patient-worn ear piece is not likely to result in additional discomfort, especially since Bluetooth®-style cell phone attachments are in widespread use and many people are used to wearing them. If an ear piece is present, the size of the interior electronics of the intra-oral insert may be reduced by eliminating the battery and its required charging circuit. Energy may then be harvested with a receiving coil energized by a transmitting coil attached to the ear piece. The receiving coil may be embedded in the intra-oral insert material, thus not requiring any additional space in the oral cavity. The ear piece may be connected to a smart device for continuous data transmission, data logging and display to a remote station. A cable can be connected between the ear piece and the smart device for this connection in order to simplify the electronics of the ear piece whereby minimizing its power consumption and thus its battery size and total physical size and weight. 
     It is therefore an advantage of the disclosure to provide a dental monitoring system capable of monitoring the physical and biochemical properties within the oral cavity of a patient. 
     These and other features, aspects, and advantages of the present disclosure will become better understood upon consideration of the following detailed description, drawings and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of the intra-oral insert of the dental monitoring system. 
         FIG. 2  shows a top view of the intra-oral insert of  FIG. 1 . 
         FIG. 3  shows a perspective side view of the intra-oral insert of  FIG. 1 . 
         FIG. 4  shows a perspective top and side view of another intra-oral insert according to this disclosure. 
         FIG. 5  shows a perspective top and side view of yet another intra-oral insert according to this disclosure. 
         FIG. 6  shows a perspective top and side view of still another intra-oral insert according to this disclosure. 
         FIG. 7  shows, at the bottom, a top view of the controller of the dental monitoring system. 
         FIG. 8  shows an environmental view of the intra-oral insert of the dental monitoring system during insertion into the mouth of a subject. 
         FIG. 9  shows a side view of the dental monitoring system on a subject. 
         FIG. 10  shows a flow diagram that illustrates the application, initialization and operation of the dental monitoring system according to the disclosure. 
         FIG. 11  shows the results of a case study of the dental monitoring system in response to an added acidic buffer. 
         FIG. 12  shows the results of a case study of the dental monitoring system in response to an added neutral buffer. 
         FIG. 13  shows the results of a case study of the dental monitoring system in response to an added basic buffer. 
         FIG. 14  shows the results of a case study of the dental monitoring system of  FIG. 13  in response to an added pH 4 buffer. 
     
    
    
     Like reference numerals will be used to refer to like parts from Figure to Figure in the following description of the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     A dental monitoring system  20  for monitoring a variety of subject parameters is provided.  FIGS. 1-3  show an intra-oral insert  24  for insertion into the mouth of a subject, which in some embodiments may be a mouth guard or similar device. According to one embodiment, the intra-oral insert  24  may be configured to contain internal components of the dental monitoring system  20 . A sensor  28  is connected to and at least partially received in the intra-oral insert  24 . The intra-oral insert  24  also contains a controller  32  and a transponder coil  36  within the intra-oral insert  24  such that the controller  32  and the transponder coil  36  are interior to the intra-oral insert  24 . 
     In some embodiments, the intra-oral insert  24  may be configured to be received in the mouth of a subject and contain components of the dental monitoring system  20 . As depicted in  FIGS. 1-3 , the intra-oral insert  24  may be U-shaped having an inner recessed area  40  disposed between a raised outer profile  44  and a raised inner profile  48 . In some embodiments, the raised outer profile  44  can be larger than the raised inner profile  48 . The raised outer profile  44  and the raised inner profile  48  may be tapered such that an anterior end of the intra-oral insert  24  has a larger raised outer profile  44  and raised inner profile  48  than a posterior end of the intra-oral insert  24 . The intra-oral insert  24  may be dimensioned in order to facilitate a comfortable fit around the maxillary teeth of the subject. In other embodiments, the intra-oral insert  24  may be dimensioned in order to facilitate a comfortable fit around the mandibular teeth of the subject. The intra-oral insert  24  is configured to contain the controller  32  and a transponder coil  36  within the intra-oral insert  24  such that the controller  32  and the transponder coil  36  are interior to the intra-oral insert  24 . 
     The intra oral insert  24  can be received or implanted on the Mandibular or Maxillary levels of the subject. Additionally, attachments and inserts can be positioned on the buccal (cheek) or lingual (tongue) side of the alveolar margin. 
     In some embodiments, the sensor  28  is configured to monitor at least one dental parameter of the subject. The sensor  28  may be fixed to the intra-oral insert  24  such that the sensor is positioned near a bottom curved portion of the U-shaped intra-oral insert  24  over a top surface of the inner recessed area  40  of the intra-oral insert  24 . The sensor  28  can at least partially extend outside of the intra-oral insert  24  such that the sensor  28  can directly interface with the environment of the oral cavity of the subject and come in contact with bodily fluids or gases therein or come in contact with teeth, for example to measure bite pressure and teeth grinding. The sensor  28  may be generally cylindrical in shape with a conical end structure positioned such that the conical end surface directly interfaces with the oral cavity of the subject. The sensor  28  may be in direct or wireless electrical communication with at least one of the controller  32  or the transponder coil  36 . In one embodiment, the sensor may be a pH sensor configured to measure the pH level in the subject&#39;s oral cavity. In other embodiments, the sensor  28  can be a temperature sensor, a pressure sensor, a moisture sensor, a light sensor, total dissolved solids, ionic strength, conductivity, dissolved oxygen, oxidation-reduction potential or any combination of sensors. In yet other embodiments, the parameter can be the sensing of a biochemical species, such as with an ion-selective chem-FET (chemical field effect transistor). Additional non-limiting examples of parameters that can be measured by sensor  28  include: normal force, shear force, pressure, acceleration, velocity, and temperature. 
     The transponder coil  36  may be positioned near an exterior surface of the intra-oral insert  24  in order to facilitate wireless communication in the dental monitoring system  20 . The transponder coil  36  may be embedded in a side wall of the raised outer profile  44  of the intra-oral insert  24  such that when the intra-oral insert  24  is inserted into a subject&#39;s mouth, the transceiver coil is positioned adjacent to an inner surface of the subject&#39;s cheek. In some embodiments, the transponder coil  36  may be triangular in shape and may extend along the length of the side wall of the intra-oral insert  24 . The transponder coil may be wound from litz wire, which makes the coil flexible to make the intra-oral insert more pliable so it may conform better to the oral cavity and mouth movements for increased wearing comfort for the subject. The transponder coil  36  may be in direct or wireless electrical communication with at least one of the sensor  28  or the controller  32 . 
     Referring now to  FIGS. 1-4 and 8 , one embodiment of the controller may be configured to control wireless communication within the dental monitoring system  20 . In some embodiments, the controller can be embedded below the inner recessed area  40  and positioned on the same side of the intra-oral insert  24  as the transponder coil  36 . The controller may be in direct or wireless electrical communication with at least one of the sensor  28  or the transponder coil  36 . In some embodiments, the controller  32  comprises a microcontroller chip  52  and a programming port  56 . The programming port may be a JTAG programming port. The controller  32  may feature a non-volatile memory configured to allow for storage of data acquired by the sensor  28  or transmission of data acquired by the sensor  28  to the transponder coil  36 . The controller  32  provides the intra-oral insert  24  the ability to transmit data from the intra-oral insert through the dental monitoring system  20  using near-field communication. The electronic circuit may incorporate a supercapacitor or a small primary or re-chargeable battery to store a certain amount of energy to operate temporarily without being energized through the transceiver coil. A non-limiting example of the size of the controller  32  is shown in  FIG. 7  where the controller  32  is compared to the size of a United States penny. 
       FIG. 4  shows a perspective top and side view of another intra-oral insert  24 A according to this disclosure. The intra oral insert  24 A shown in  FIG. 4  includes a plurality of pressure sensors  100  positioned on or in the inner recessed area  40  disposed between the raised outer profile  44  and the raised inner profile  48 . 
     One non-limiting example of pressure sensors  100  that could be implemented into the intra-oral insert  24 A to measure teeth grinding pressure and timing during sleep of a subject. Since the pressure sensors  100  are placed in the bite area of a subject, which generally corresponds with the inner recessed area  40  disposed between the raised outer profile  44  and the raised inner profile  48 , when the subject grinds their teeth, pressure is exerted on the pressure sensors  100  and the signals change. By having a plurality of pressure sensors  100 , it is possible to determine the distribution of teeth grinding load and thus recommend an intervention. The pressure sensors  100  can be embedded in the substrate of the intra-oral insert  24 A which holds the components of the oral sensor. The pressure sensors  100  can be embedded in such a way as to be flush with a surface of the inner recessed area  40  of the intra-oral insert  24 A which increases the wear comfort for the subject. The pressure sensors  100  can be made from elastomeric material such that while pressure sensing the pressure sensors  100  can conform to the crowns of the teeth, minimizing discomfort for the subject and providing a more accurate pressure measurement. The sensors may be configured to measure lateral movement of the teeth in addition to axial movement for a more complete, possibly 3-dimensional, analysis of the teeth grinding movement. 
       FIG. 5  shows a perspective top and side view of another intra-oral insert  24 B according to this disclosure. A plurality of biochemical sensors  110  are shown to be placed on both sides of the raised outer profile  44  of the intra-oral insert  24 B. By placing the biochemical sensors  110  on both sides of the raised outer profile  44  of the H-profile of the intra-oral insert  24 B, the sensors are predominantly exposed to either the gum side or the mouth cavity wall. It is advantageous to measure for biochemical species in a variety of locations inside the mouth cavity because the biochemical species are not always evenly distributed. Moreover, the distribution itself is helpful in diagnosing the health status of the oral cavity. 
     The biochemical sensors  110  are capable of generating a signal according to the presence of certain chemicals in the saliva of the subject. One non-limiting example of biochemical sensors that can be used are ISFET (ion-sensitive field-effect transistor) sensors, which comprise a preferred configuration where there is a functional boundary between the wet biochemical side of the saliva media and the dry semiconductor electronic side that generates the electrical signal. The functional boundary may be an inert layer of insulating gate material, such as silicon dioxide. This configuration yields a dimensionally small and mechanically and biochemically rugged sensor. Moreover, it operates with minimal current, making it ideal for ultra-low power applications such as desirable and advantageous for the oral sensor. 
       FIG. 6  shows a perspective top and side view of another intra-oral insert  24 C according to this disclosure having biochemical sensors  120  placed around the raised inner profile  48  of the intra-oral insert. The placement of biochemical sensors  120  provides access to the saliva area near the tongue so that the biochemical content of that area may be measured. By placing the biochemical sensors  120  on the inner side of the inner raised inner profile  48  of the H-profile of the intra-oral insert  24 C, the biochemical sensors  120  will be exposed to the surface of the tongue of the subject. Since the tongue&#39;s surface carries a wealth of medically relevant information, these sensors will yield valuable information for medical diagnoses. In one example, the biochemical sensors  120  can analyze biomarkers or other proteins and protein derivatives of the subject. 
       FIGS. 9 and 10  show the dental monitoring system  20  where the intra-oral insert  24  may wirelessly communicate with a transceiver coil  60  positioned outside of the subject&#39;s mouth. In some embodiments, the intra-oral insert  24  is inserted in the mouth of a subject and may be secured around the maxillary teeth of the subject. Once inserted into the mouth of the subject, the sensor  28  may directly interface with the environment inside the mouth of the subject and any fluids or gases that may be present in the mouth of the subject. The sensor  28  may electrically communicate the data monitored by the sensor  28  with the controller  32 . The data may be electrically communicated between the sensor  28  and the controller  32  via wired connection or wireless connection. The controller  32  can temporarily store or automatically transmit the data received from the sensor  28  to the transponder coil  36 . The transponder coil  36  may communicate the data received from the controller  32  wirelessly with the transceiver coil  60 . The wireless communication may be encrypted for data security. While  FIG. 9  illustrates use of the intra-oral insert  24  in the dental monitoring system  20 , any of the intra-oral inserts  24 A,  24 B,  24 C may be used in the dental monitoring system  20 . 
     The transceiver coil  60  may be positioned outside of the subject&#39;s mouth adjacent to an outer surface of the subject&#39;s cheek. In some embodiments, the transceiver coil  60  may be positioned to oppose the transponder coil  36  such that the transceiver coil  60  and the transponder coil  36  are directly across the subject&#39;s cheek. In some embodiments, the transceiver coil  60  may be circular in shape and may feature a central opening. One skilled in the art would appreciate that the transceiver coil can take any appropriate shape in order to facilitate wireless communication between the transceiver coil  60  and the transponder coil  36 . 
     The transceiver coil  60  may be mounted to a support frame  64  that is dimensioned to position the transceiver coil  60  such that it can wirelessly communicate with the transponder coil  36 . In some embodiments, the support frame may extend from an ear hook  68  to the transceiver coil  60  along an outer surface of the subject&#39;s cheek. The ear hook  68  can loop around at least a portion of an ear of the subject to secure the position of the support frame  64  and consequently the transceiver coil  60 . The ear hook  68  may have a central body  72  that the support frame  64  can extend from. In some embodiments, the central body  72  can be a wirelessly connected device such as a Bluetooth™ connected device or a Wi-Fi™ connected device, Another non-limiting example of the wireless protocol for transmitting data from the transceiver coil includes using a wireless medical band signal (MICS—Medical Implant Communication Service) at 402-405 MHz. The wireless communication may be encrypted for data security. 
     In other embodiments, the central body  72  can be connected via a wire  76  to a smart device  80 . The smart device  80  can store, process, analyze, transmit and display the data acquired by the dental monitoring system  20 . 
     In still other embodiments, the external transceiver, instead of an earpiece can be a padded patch-like embodiment, which can be attached to the cheek with an adhesive. This enables a longer term (such as overnight) data logging from the oral cavity, bring the transceiver coil closer to the transponder coil and fix it in an optimal location for maximum energy transfer. 
     The dental monitoring system  20  can wirelessly communicate from the transponder coil  36  to the transceiver coil  60  using near-field communication. Near-field communication (NFC) between the transponder coil  36  and the transceiver coil  60  requires the transponder coil  36  and the transceiver coil  60  to be positioned near each other on opposing sides of the subject&#39;s cheek. 
     NFC is a short-range radio frequency (RF) communication technology that can operate at a distance of up to 10 cm or less between two communicating devices. Communication via NFC involves an initiator device (often referred to as a “reader”) and a target device. The initiator device may be the transceiver coil  60  and the target device can be the transponder coil  36 . 
     In some embodiments, the transceiver coil  60  can generate an RF field that can power the transponder coil  36 , which in turn supplies the controller  32  with sufficient power such that it does not require batteries or a power source embedded in the intra-oral insert  24 . In this configuration, the transponder coil  36  may be read-only and directed to a single application, for example, identification of the transceiver coil  60  and transmission of data associated with the sensor  28 , for example through impedance modulation. In this configuration, the intra-oral insert  24  may be operable to communicate via NFC without onboard power thereby reducing the size of the electronics required in the intra-oral insert  24  as well as increasing the amount of time the intra-oral insert  24  can remain in the subject. 
     In some embodiments, processing electronics inside the patient&#39;s body must transmit data wirelessly to suitable readout electronics outside the body to display, analyze or log the signals acquired by the sensor  28 . In order to minimize the size of the interior electronics of the intra-oral insert  24 , the available power, either through a battery, a supercapacitor or through an energy-harvesting element, can be small, necessitating low-power or even ultralow-power devices. In a non-limiting example, these devices can transmit at very low power such that their range will be short as well, possibly 0.5 to 10 inches. As a result, an “interrogating” or “listening” device such as the transceiver coil  60  must be placed within 0.5 to 10 inches of the transponder coil  36  in the intra-oral insert  24 , preferably on or near the cheek of the subject. The short communication distance may inherently serve data security, even without encryption, because any intercepting device would have to be brought within close range to the subject. 
     Two non-limiting embodiments of data readout that may be accomplished, continuous readout and batch readout, each having its distinct advantages as explained below. 
     Continuous data readout can require the transceiver coil  60  to be “listening” at all times to receive data from the transponder coil  36  in real-time. Since the transceiver coil  60  must be physically close to the transponder coil  36  at all times, it would have to be worn by the subject for the duration of the data collection. Such a receiver could be built in the form of the ear hook  68  with the transceiver coil  60  receiving element mounted to a support frame  64  extending to the cheek near the transponder coil  36 . The ear hook  68  may have much less stringent space limitations and can therefore incorporate a large enough battery, super capacitor or other power source to either relay the data in real-time to a nearby data display/logger or store the data for batch download at a later time. Continuous data readout may allow the data to be read by a dental practitioner in real-time, intervening quickly as certain situations arise. Alarms may be programmed in case certain parameters go out of range. The interior circuits may be powered by energy-harvesting techniques, thereby eliminating the need for a battery and reducing the size of interior electronics required in the intra-oral insert  24 . 
     Batch data readout can allow the interior electronics of the intra-oral insert  24  to store the acquired data in an on-board flash memory to be retrieved at a later time. In this configuration, the interior electronics may be fitted with a battery or super capacitor because the circuits can operate without an external energy source. The interior electronics can be programmed to mostly stay in an ultra-low power sleep state, wake up briefly at periodic times, measure sensor signals, store the data in its memory and return to the ultra-low power sleep state. This scheme may significantly increase the time the interior electronics could monitor sensor signals autonomously. In some embodiments the wake-up may be triggered by certain conditions arising from certain sensor signals. Readout can be accomplished periodically with the transceiver coil  60  being briefly placed near the cheek of the patient during data download and simultaneous recharging of the battery or super capacitor. In this embodiment of batch data readout, the subject is not required to wear an ear hook  68  in order to maintain communication between the transponder coil  36  and the transceiver coil  60 . 
       FIG. 10  shows a flow diagram that illustrates the application, initialization and operation of the dental monitoring system according to the disclosure.  FIG. 10  begins with the subject inserting the intra-oral insert  24  (or any of the intra-oral inserts  24 A,  24 B,  24 C) and attaching the ear hook  68 . The subject then connects the ear hook  68  and/or the central body  72  to the smart device  80 . On the smart device  80  an application is launched, which initiates the communication via the near-field communication (NFC) protocol. Once communication is established, instruction commands are sent to the intra oral insert  24  and data is read from it. Status messages, error messages and data are processed and displayed on a graphical user interface with which the subject can interact. The controller may be configured to communicate a command to the plurality of sensors to generate a data reading, the controller communicates the data reading to a smart device configured to process and display the data reading on a graphical user interface. 
     The dental monitoring system  20  may have an associated method of use. The method of dental monitoring can include the steps of: (i) inserting the intra-oral insert  24  (or any of the intra-oral inserts  24 A,  24 B,  24 C) into the mouth of a subject; (ii) sensing a parameter of the subject using a sensor  28  connected to the intra-oral insert  24 ; (iii) communicating the sensed parameter to a controller  32  having a non-volatile memory; (iv) communicating the sensed parameter from the controller  32  to a transponder coil  36  received in the intra-oral insert  24 ; and (v) communicating the sensed parameter wirelessly from the transponder coil  36  to a transceiver coil  60  using near-field communication. In some embodiments, the parameter of the subject is sensed when the subject initiates a force to the sensor  28 . The parameter of the subject can be a pH. In other embodiments, the parameter can be a temperature, pressure, moisture, light, total dissolved solids, ionic strength, conductivity, dissolved oxygen, oxidation-reduction potential or any combination of parameters. In still other embodiments, the parameter can be the sensing of the presence and concentration of a chemical species with, for example, a chem-FET (chemical field-effect transistor). 
     A non-limiting example of prototype development involved Texas Instruments&#39; semiconductors for NFC. The prototype can use the international NFC protocol ISO/IEC 15693 operating at a frequency of 13.56 MHz. The interior electronics can use a transponder that operates without a battery and is powered only by RF energy harvested by a small transponder coil from a small transceiver coil. The transceiver coil is mounted near the cheek of a subject and is driven by an NFC transceiver. Communication to the transponder coil can be facilitated by modulation of the carrier frequency and communication back to the transceiver coil can be facilitated by the transponder changing the impedance of the transponder coil by partially shorting it out. This requires a low amount of energy on the transponder coil side but the impedance changes can be sensed by the transceiver circuit. Thus a bi-directional communication is possible without the transponder having to actively transmit energy and thereby minimizing energy requirements to the point where not even a battery is required and all needed energy is harvested by the transponder coil energized by the transceiver coil. 
     The coils and hardware used in the prototype were manufactured by Texas Instruments and belong to the RF430 family of NFC devices. An evaluation development kit was purchased containing the TRF7970A NFC Reader (transceiver coil) and the RF430FRL15EVM tag (transponder coil). Initial tests showed that the system and their devices were suitable for the prototype. While the NFC Reader (transceiver coil) was kept as is, the NFC tag (transponder coil) was designed from scratch to be fitted into an intra-oral insert and connected to sensors relevant for oral cavity monitoring. The NFC tag is a transponder coil and is energized by the RF energy transmitted by the NFC Reader which energizes the transceiver coil. Data transfer is bi-directional. The NFC tag (transponder coil) does not need a battery. 
     A non-limiting proof of concept was performed by placing the intra-oral insert  24  prototype in a water beaker, simulating the wet environment of the oral cavity, and placing the prototype reader board just outside the beaker. In this prototype configuration, the reader board is part of the Texas Instruments development kit and is meant as a demonstration of the system. The reader coil may be as far as two inches from the receiver coil, although improved communication was achieved at a distance of one inch. The mouth piece was immersed under water in the beaker and held down by a weight to prevent it from floating. The reader coil is approximately 1 inch from the receiver coil of the tag. Since the radio frequency had to penetrate at least ¼″ of water, the system demonstrated that the soft tissue of a cheek would not be an impediment to the operation. 
     To demonstrate the proof-of-concept, a single pH sensor was chosen. The sensor was an electrochemical cell made from dissimilar metals that act as a weak electro-motive force generator outputting a small current proportional to the number of ions and their polarity in the water, which can correlate to a measure of the pH value.  FIG. 11  through  FIG. 14  show data acquired in real-time, one data point per second, with the abscissa being the time axis and the ordinate plotting the sensor response in arbitrary units. As can be seen, when starting with tap water, which is roughly neutral, the graph jumps up when acidic buffer is added ( FIG. 11 ), stays approximately the same when neutral buffer is added ( FIG. 12 ), and drops when basic buffer is added ( FIG. 13 ). Adding basic buffer resulted in reaching the lower end of the scale at “0”. The “un-pegging” of the sensor response through the addition of acidic buffer is shown in  FIG. 13 . This data is the only one that did not start with fresh tap water.  FIG. 14  shows the pH sensor response to tap water from  FIG. 13  and a squirt of pH-10 buffer from the previous Figure and then after a squirt of pH-4 buffer was added at the “28” mark to bring the sensor response up from its peg. 
     Thus, the disclosure provides a dental monitoring system capable of monitoring the physical and biochemical properties within the oral cavity of a patient. 
     Although the disclosure has been described in considerable detail with reference to certain embodiments, one skilled in the art will appreciate that the present disclosure can be practiced by other than the described embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the scope of the appended claims should not be limited to the description of the embodiments contained herein.