Customized aligner change indicator

Abstract

According to the techniques herein, one or more sensors coupled to an aligner are used to sense one or more physical qualities of the aligner to determine whether the physical qualities indicate that the aligner material has relaxed and has, e.g., reduced the force systems applied to teeth and/or that the teeth movement for the stage has slowed down. The sensors may provide a signal that represents whether or not the physical qualities fall below a threshold value. A treatment plan may be modified if needed. These techniques have the potential to make treatment plans faster and more effective by speeding up some stages while making sure some, perhaps other, stages are implemented only after the teeth are near the appropriate position.

What is claimed: 
     
         1 . A dental repositioning appliance comprising:
 a polymeric shell having a plurality of cavities shaped to fit over a patient's teeth and configured to reposition the patient's teeth in accordance with an orthodontic treatment plan;   an intersecting array of microfluidic channels embedded within the polymer shell; and   one or more sensors configured to measure a spatially distributed strain in the polymeric shell based at least in part on a distance between two or more channels of the intersecting array of microfluidic channels.   
     
     
         2 . The dental repositioning appliance of  claim 1 , wherein the intersecting array of microfluidic channels are filled with a conductive fluid. 
     
     
         3 . The dental repositioning appliance of  claim 2 , wherein the conductive fluid comprises a liquid metal alloy. 
     
     
         4 . The dental repositioning appliance of  claim 3 , wherein the metal alloy comprises eutectic Gallium-Indium. 
     
     
         5 . The dental repositioning appliance of  claim 1 , wherein the one or more sensors are selected from the group consisting of a magnetic stress/strain sensor, a piezoelectric strain sensor, a piezoresistive sensor, an inductive stress/strain gauge, a metal foil strain gauge, a nanoparticle-based strain sensor, an optical strain sensor, and a capacitive sensor. 
     
     
         6 . The dental repositioning appliance of  claim 1 , further comprising a wireless transmitter configured to wirelessly transmit one or more signals corresponding to the spatially distributed strain to an external signal processing device. 
     
     
         7 . The dental repositioning appliance of  claim 6 , wherein the one or more signals comprise stress data, strain data, displacement data, or any combination thereof. 
     
     
         8 . The dental repositioning appliance of  claim 6 , wherein the external signal processing device is configured to calculate a corrective force vector from the one or more signals and positions of the one or more sensors. 
     
     
         9 . The dental repositioning appliance of  claim 6 , wherein the external signal processing device is configured to calculate a rate of movement for the one or more teeth based on the one or more signals and positions of the one or more sensors. 
     
     
         10 . The dental repositioning appliance of  claim 6 , wherein the external signal processing device is configured to calculate a value of the spatially distributed strain based at least on the measured capacitance. 
     
     
         11 . The dental repositioning appliance of  claim 10 , wherein the external signal processing device is configured to determine whether the value of the first physical quality is less than a threshold value, the threshold value corresponding to a specified reduction in a force applied by the polymeric shell to the one or more teeth in accordance with a first stage of the orthodontic treatment plan. 
     
     
         12 . A system comprising:
 a) one or more dental repositioning appliances comprising:
 i) a polymeric shell having a plurality of cavities shaped to fit over a patient's teeth and configured to reposition the patient's teeth in accordance with an orthodontic treatment plan, 
 ii) an intersecting array of microfluidic channels embedded within the polymer shell, and 
 iii) one or more sensors configured to measure a spatially distributed strain in the polymeric shell based at least in part on a distance between two or more channels of the intersecting array of microfluidic channels; and 
   b) an external signal processing device configured to receive and process the one or more signals from the one or more dental repositioning appliances.   
     
     
         13 . The system of  claim 12 , wherein the one or more sensors are selected from the group consisting of a magnetic stress/strain sensor, a piezoelectric strain sensor, a piezoresistive sensor, an inductive stress/strain gauge, a metal foil strain gauge, a nanoparticle-based strain sensor, an optical strain sensor, and a capacitive sensor. 
     
     
         14 . The system of  claim 12 , wherein the one or more signals generated by the one or more sensors comprise stress data, strain data, displacement data, or any combination thereof. 
     
     
         15 . The system of  claim 12 , wherein the external signal processor is further configured to calculate a corrective force vector or a rate of movement for the one or more teeth based at least in part on the one or more signals. 
     
     
         16 . The system of  claim 12 , wherein data for the one or more signals is stored locally on a cell phone, a laptop computer, a personal computer, or a computer system or in a cloud-based database. 
     
     
         17 . The system of  claim 12 , wherein the one or more dental repositioning appliances further comprise a wireless transmitter configured to wirelessly transmit one or more signals corresponding to the spatially distributed strain to the external signal processing device. 
     
     
         18 . The system of  claim 12 , wherein the external signal processing device is configured to calculate a value of the spatially distributed strain based at least on the measured capacitance. 
     
     
         19 . The system of  claim 12 , wherein the external signal processing device is configured to determine whether the value of the first physical quality is less than a threshold value, the threshold value corresponding to a specified reduction in a force applied by the polymeric shell to the one or more teeth in accordance with a first stage of the orthodontic treatment plan. 
     
     
         20 . The system of  claim 12 , wherein the intersecting array of microfluidic channels are filled with a conductive fluid.