Abstract: A device includes an antenna, markers disposed inside the device and configured to be movable inside the device to measure positions of a first tooth and a second tooth among teeth in the oral cavity, a sensor module measuring positions of the markers, and at least one of a distance between a reference point set in the device and at least one of the first tooth and the second tooth and a distance between the first tooth and the second tooth based on the measured positions of the plurality of markers. The device further includes a communication module transmitting to an external device at least one of information about the measured distance between the reference point set in the device and the at least one of the first tooth and the second tooth and information about the measured distance between the first tooth and the second tooth through the antenna.

Abstract: Inventions herein include at least mostly optically clear orthodontic braces and feet orthotics (collectively referred to as “appliances”) with backscatter based sensors. These two categories of appliances share a common property requiring that the given appliance must be correctly custom manufactured to fit a patient's own particular geometry and dimensions of their teeth and/or feet in order to perform as intended. Incorporating such appliances with backscatter based sensors enables simple, easy, fast, efficient, and cost effective measurements, in real-time or near real-time, of stresses, forces, structural changes, and/or the like in the given appliance; which in turn can aid in determining if adjustments or re-manufacture of the appliance may be needed or desired; and/or wherein such measurements may aid in evaluating performance of the given appliance. In some embodiments, such measurements may also be taken remotely away from a practitioner; and then communicated to a remotely located practitioner.

Abstract: An orthodontic positioning device including a patient removable orthodontic tooth positioning appliance having teeth receiving cavities shaped to receive and apply a resilient positioning force to a patient's teeth provided in one of an upper jaw and a lower jaw and comprising a cutout operable to expose an orthodontic elastic band receiving member.

Abstract: This invention presents an intraoral device for generation of contact perception between teeth, the device being configured for application to the upper or lower dental arch of a user and comprising a contact means (20, 20?) configured to be associated with at least a portion of one to four posterior teeth (D1) of the upper or lower dental arch, the device (10) being configured to generate a perception of contact to the user upon the contact between the contact means (20, 20?) and at least a portion of the opposing arch to at least a portion of one to four posterior teeth (D1), offering the option of an accessible intraoral device for practical use to the user, and that does not impair the mouth functions of the user during its use in the waking period. This invention further comprises a method of applying the device which allows the user to apply the device without assistance of a skilled professional, and a method for determining the thickness of the aforesaid device.

Abstract: A multilayer sheet for a dental appliance provided in the present disclosure includes a core layer having a tensile modulus greater than about 1400 MPa and an elongation at break greater than about 3%; and a first skin layer and a second skin layer sandwiching the core layer, wherein each of the first skin layer and the second skin layer independently has a water contact angle greater than 72° and/or a surface energy less than about 40 mN/m. The first skin layer and the second skin layer are the outermost layers of the multilayer sheet. A dental appliance made from the multilayer sheet structure is also provided.

Abstract: A bone foundation guide system and method, the system could includes a bone foundation guide including a body forming an open surgical space, the body further having a bottom contoured to reversibly affix to exposed bone of a dental surgical site and a top contoured to match a bottom side of a dental implant surgical guide; at least one anchoring strut that removably attaches to the body with an apex of the anchoring strut further denoting one or more indentations for matching up with and receiving one or more portions of one alveolar ridge that opposes another alveolar ridge supporting the dental surgical site; alternatively to the anchoring struts and a tissue spacing gasket, the dental implant surgical guide that removably connects to the body; and alternatively to the anchoring struts or the dental implant surgical guide, the tissue spacing gasket that removably connects to the body.

Abstract: The present invention discloses a clear orthodontic tray system and methods of making and using the same. The clear orthodontic tray system comprises pre-fabricated attachment device.

Abstract: Embodiments relate to aligners that are capable of immobilizing a patient's jaw after orthognathic surgery while also applying forces to reposition a patient's teeth. In embodiments, a processor determines, for a treatment stage, a dentition for an upper dental arch and a lower dental arch. The processor applies one or more stabilizing features to the upper dental arch and the lower dental arch. The processor determines whether the one or more stabilizing features will prevent jaw movement while the upper dental arch is engaged with the lower dental arch. Responsive to a determination that the one or more stabilizing features will prevent the jaw movement, the processor stores a first digital model comprising the dentition for the upper arch and the one or more stabilizing features for the upper arch and stores a second digital model comprising the planned dentition for the lower arch and the one or more stabilizing features for the lower arch for each increment of treatment.

Abstract: An orthodontic appliance is constructed from shells shaped to receive teeth. The shells can be constructed from one or more polymer materials and stacked and also varyingly affixed to one another, which can include affixing only about the edge of each shell. The orthodontic appliance can be one of a series of similar appliances for incremental orthodontic modification of teeth.

Abstract: The present invention provides methods and systems including orthodontic tooth positioning appliances. An exemplary appliance can include teeth receiving cavities shaped such that, when worn by a patient, repositioning the patient's teeth from a first arrangement toward a subsequent or target arrangement. Appliances can include a cavity having one or more shaped features or protrusions shaped and/or positioned so as to apply a desired force to a patient's tooth received in the cavity and move the tooth along a desired path or direction.

Abstract: The example systems, methods, and/or computer-readable media described herein help with design of highly accurate models of un-erupted or partially erupted teeth and help fabricate of aligners for un-erupted or partially erupted teeth. Automated agents that use machine learning models to parametrically represent three-dimensional (3d) virtual representations of teeth as 3D descriptors in a 3D descriptor space are provided herein. In some implementations, the automated agents described herein provide instructions to fabricate aligners for at least partially un-erupted teeth using representative 3D descriptor(s) of a tooth type.

Abstract: Mouth guard that includes a flexible printed circuit board encapsulated within a base member is provided. The flexible printed circuit board includes multiple separate stiff sections spaced apart from each other within the base member. One or more electronic devices are disposed within the base member. In particular, the one or more electronics are disposed on the base member.

Abstract: A removable dental appliance may include an appliance body configured to at least partially surround a plurality of teeth of a dental arch of a patient. The appliance body may include a unitary material defining a shell shaped to receive at least one tooth of the patient and a spring member integrally formed with the shell. The spring member may be configured to receive an attachment. The attachment may be configured to affix to the at least one tooth. The spring member may be configured to apply a spring force to the attachment to cause at least one of a rotation, a translation, a tipping, a torqueing, an extrusion, or an intrusion of the at least one tooth toward a desired position of the tooth when the removable dental appliance is worn by the patient.

Abstract: A mouth appliance for maintaining effective airflow in a user's airway comprises a frame formed to engage the user's upper and lower teeth to retain the frame in a selected position in the user's mouth in accord with the user's natural bite. A tongue depressor is mounted to the frame and formed to extend to a rear portion of the user's throat and to exert pressure directly on the tongue in the area of the user's soft palate, thereby facilitating comfort and ease in occasional swallowing, while providing airflow effectiveness to prevent the user from snoring and experiencing sleep apnea.

Abstract: A masticatory orthodontic device includes a masticatory unit with a rigid body. The masticatory unit is configured to be removably worn on a dental arch, wherein when worn during mastication, the shape of the masticatory unit is maintained even under a stress from occlusal forces. The masticatory unit includes a teeth-receiving surface with several recesses for accommodating teeth of the dental arch. A shape memory mesh is disposed between the teeth-receiving surface and the dental arch, configured to remember the shape of the teeth in target teeth positions to guide teeth movements from initial teeth positions toward the target teeth positions. A buffering member is disposed between the teeth-receiving surface and the shape memory mesh. Occlusal forces loading on the masticatory unit are transmitted to the shape memory mesh and the teeth through the buffering member, to achieve teeth movements in the recesses.

Abstract: An orthodontic correction device includes a correction unit that is adapted to be removably worn on a dental arch. The correction unit includes at least one first receiving part for receiving at least one first tooth which needs correction. The shape of the first receiving part allows the first tooth to move toward the alveolar bone. At least one elongated opening is formed on the occlusal surface of the correction unit and extends to the lingual surface and the buccal surface of the correction unit. The opening exposes parts of the occlusal surface, the lingual surface and the buccal surface of the first tooth. A force exerting assembly is configured to contact the first tooth through the opening, thereby exerting a force on the first tooth to press the first tooth into the alveolar bone.

Abstract: In one aspect, the present application provides a computer-based method of measuring positional relationship between two teeth, comprising: obtaining a second 3D digital model representing a plurality of teeth under a second tooth arrangement, wherein the plurality of teeth comprise a first tooth and a second tooth; and measuring a value of a collision or a size of a gap between the first tooth and second tooth based on the second 3D digital model and in a predetermined first direction.

Abstract: The present invention refers to a hybrid photopolymer composition for additive manufacturing, —comprising 50-95% by weight of a free radically curable-component, farther comprising at least one (meth)acrylate monomer or oligomer, 5-49% by weight of a cationically curable component, further comprising a cycloaliphatic epoxide, an oxetane mixture, containing a monooxetane compound and a polyoxetane compound, and a thermoplastic polycaprolactone with a molecular weight of 20,000-100,000 g/mol, a free radical photoinitiator, a UV blocker, a cationic photoinitiator, optionally a cationic photosensitiser, and optionally a thermal initiator, wherein the percent by weight is based on the total weight of the photopolymer' composition.

Abstract: Disclosed is a method for producing an orthodontic appliance for securing to a user's teeth in order to carry out an orthodontic treatment, the appliance having an element. The method includes a) gathering information relating to the user's set of teeth; b) using the information to determine at least first and second stable shapes of the element towards which the element should tend to deform during the first and second periods of treatment, respectively; and c) producing and programming the element in such a way that the application of a stimulus during the first period of the treatment renders the second stable shape operational. In certain aspects in step c), a retractable or expansible material is incorporated into the element.

Abstract: An oral weight control device that inhibits the mastication and swallowing of food is provided. The oral weight control device is a dental appliance that includes upper and lower retainers, where each retainer covers the lingual, palatal and buccal side of the teeth to inhibit mastication of food. The dental appliance further includes left and right flexible food barriers extending from the upper retainer to the lower retainer on the lingual side of the teeth to prevent food that a user may attempt to masticate between the upper and lower retainers from being passed to the tongue of the user to ingest. The upper and lower retainers may be customized to fit on each user and may cover all the upper and lower teeth of the wearer on the lingual, palatal and buccal sides of the teeth. The retainers may be removable or semi-permanently secured to the teeth.

Abstract: A removable dental appliance configured to reposition one or more teeth of a patient includes an appliance body forming an active band configured to surround two or more teeth of the patient. The appliance body includes a facial portion configured to register with facial sides of the surrounded teeth, a lingual portion configured to register with lingual sides of the surrounded teeth. The facial portion of the appliance body and the lingual portion of the appliance body form receptacles. Each receptacle is configured to accept at least one of the surrounded teeth. The receptacles separate the facial portion from the lingual portion at least along an anterior portion of the appliance body. The active band is configured such that occlusal surfaces of the surrounded teeth of the patient are exposed when the removable dental appliance is worn by the patient with the surrounded teeth positioned within the active band.

Abstract: An orthodontic correction device is provided, including a shell having a number of teeth receiving cavities configured to receive teeth of a dental arch of a patient. A first elastic member holding feature is formed on one side of the shell and corresponds to an undercut region of a tooth of the dental arch. A first orthodontic elastic member is coupled to the first elastic member holding feature and extends to the interior of the shell to engage with the undercut region of the tooth, thereby enhancing the retention of the orthodontic correction device on the dental arch.

Abstract: Tooth-positioning appliances and apparatuses, components, methods, and techniques for producing and using tooth-positioning appliances are provided. An example tooth-positioning appliance for adjusting the position of teeth of a patient includes a tooth-clasping arrangement shaped to secure the orthodontic appliance to at least one tooth and a flexible arrangement connected to the tooth-clasping arrangement. The flexible arrangement is less rigid than the tooth-clasping arrangement.

Abstract: Polymeric shell appliances are provided in which the polymeric shell appliances are configured to provide one or more activation forces to facilitate tooth movement. In many embodiments, the appliances comprise interproximal engagement structures to provide activation forces to interproximal tooth surfaces. In many embodiments, the activation forces are arranged to provide a plurality of forces, including a force in a direction opposite to an intended direction of tooth movement. The polymeric shell appliances may comprise one or more tooth receiving cavities, in which each of the plurality of tooth receiving cavities is shaped and arranged to provide a counter moment of each of the plurality of teeth.

Abstract: Methods, systems, and apparatuses for dental appliance reinforcement are provided. One dental appliance includes a number of tooth apertures for the placement of teeth therein wherein the number of tooth apertures include an interior surface and an exterior surface, and a reinforcement rib positioned along the exterior surface.

Abstract: The present invention provides orthodontic appliances and systems, and related methods, for applying a force to a target tooth as an appliances is worn by the patient. One positioning appliance includes a tooth positioning appliance having teeth receiving cavities shaped to apply a positioning force to the patient's teeth. The appliance includes a spring-loaded tooth movement device disposed in the appliance so as to engage an attachment mounted on a surface of a patient's tooth and apply a force to the tooth.

Abstract: A bruxism mouth guard device is disclosed herein. The bruxism mouth guard device includes a mouth guard body portion with a channel formed therein for receiving one or more teeth of a user; one or more pressure sensing devices for sensing a grinding or clenching of the one or more teeth of the user; a vibration device for vibrating one or more portions of the mouth of the user; and a control device operatively coupled to the one or more pressure sensing devices and the vibration device, the control device activating the vibration device so as to vibrate the one or more portions of the mouth of the user when the one or more pressure sensing devices sense the grinding or clenching of the one or more teeth by the user. A bruxism mouth guard system including the device is also disclosed herein.

Abstract: A method includes forming a plastic orthodontic aligner having a plurality of cavities shaped to receive at least portions of a plurality of teeth of a patient. A first segment of the plastic orthodontic aligner corresponds to a first subset of the plurality of cavities for moving a first subset of the plurality of teeth of the patient. A second segment of the plastic orthodontic aligner corresponds to a second subset of the plurality of cavities. The method further includes removing a first portion of the plastic orthodontic aligner between the first and second segments of the plastic orthodontic aligner to form a connector to minimize force transmission between the first and second segments. The connector is configured to be disposed along one or more additional teeth to span a gap between the first and second segments without exerting a clinically significant force on the one or more additional teeth.

Abstract: An appliance for correcting a malocclusion in a mouth of a user, the appliance including a generally U-shaped upper body having an anterior portion configured to be adjacent to upper incisors and a posterior portion located rearward to the anterior portion, the upper body having an outer perimeter and an inner perimeter that is located interior to the outer perimeter; a generally U-shaped lower body having an outer perimeter, the outer perimeter of the lower body having an anterior portion adjacent to lower incisors and a posterior portion located rearward to the anterior portion of the lower body, wherein the lower body has a lower labial shield extending along the outer perimeter of the lower body; and lingual protrusions extending generally upward from the posterior portion of the inner perimeter of the upper body, the lingual protrusions being configured to contact a palate of the user as the appliance is worn within the mouth of the user.

Abstract: The present disclosure provides methods, computing device readable medium, devices, and systems having a dental appliance binding structure. One method can include to create a treatment plan based on a virtual model of a jaw of a patient, wherein the treatment plan includes use of a dental appliance having a first surface that defines a plurality of cavities shaped to receive a plurality of teeth, modify the virtual model of the jaw in a first configuration to include a virtual binding structure on a second surface, the platform shaped to receive a specialized feature that provides one or more force characteristics, select a particular specialized feature as an attachment to the dental appliance, and adjust the virtual model of the jaw from a first configuration to a second configuration, based at least in part on a modeled force provided by the virtual binding structure and the particular specialized feature.

Abstract: A method for altering an orthodontic archwire of a unitary piece of shape memory alloy having a composition and generally uniformly formed properties along its length to different stiffness profiles along the length of the archwire. In one embodiment, the method includes determining a stress profile for teeth at a location. The method may include calculating a force the archwire is to produce on the teeth to satisfy the determined stress profile and determining an altered stiffness of a section of the archwire based on the calculated force. The method may include changing the composition of the section based on the determined altered stiffness. The method may include determining a load for teeth and calculating a force the archwire is to produce on the teeth to satisfy the determined load.

Abstract: Orthodontic positioning devices, and related methods and systems, are disclosed for use with one or more orthodontic elastic members. The disclosed devices are configured to couple with an orthodontic elastic member so as to react a force from the elastic member into the appliance to, for example, generate traction forces on the patient's teeth to produce a desired occlusion. A positioning device includes a patient removable tooth positioning appliance having teeth receiving cavities shaped to receive and apply a resilient positioning force to a patient's teeth. The appliance includes a hook configured to interface with an orthodontic elastic member. The hook can be configured to be offset from a surface of a tooth when the appliance is coupled with the patient's teeth and no elastic member is coupled with the tooth. The hook can be curved so that the hook is more retentive on the aligner. The hook can be reinforced so that the reinforcement resists deformation when the elastic is in place.

Abstract: A method of making a dental appliance for repositioning a patient's teeth includes forming a rigid shell that is configured to receive the patient's teeth of a dental arch. The rigid shell has at least one first cavity with a space for accommodating at least one first tooth of the dental arch needing orthodontic correction and allowing the first tooth to move from an initial tooth arrangement to a target tooth arrangement. The method also includes forming at least one resilient member in the first cavity of the rigid shell. The resilient member has a receiving shape fitting the first tooth in the target tooth arrangement.

Abstract: A system and method for repositioning teeth in a patient jaw includes an attachment bonded to a tooth. The attachment has at least one force receiving component for receiving a force. A polymeric shell repositioning appliance is positioned over at least some of the teeth in the patient jaw. The polymeric shell has at least one force transmitting component for engaging the force receiving component to form a locus of engagement. The locus of engagement transmits the force and moves but is maintained as the tooth is repositioned. In specific embodiments the locus of engagement is maintained over a substantial range of motion. The force transmitted at the locus of engagement increases in response to the tooth lagging an intended position. A space between the positioned appliance and the tooth permits the tooth to move into an intended position.

Abstract: A jaw function measurement apparatus comprises a mastication measurement device having a pliable body, the pliable body defining at least one bite location having at least one force sensor therein. A data collection device is in data communication with the mastication measurement device. Also, a data analysis device is in data communication with the data collection device, which converts data collected by the data collection device into a format suitable for output. Moreover, an input output device is in data communication with the data analysis device 106 that outputs measured bite force.

Abstract: Embodiments of the present invention are directed to a system for automated intra-oral delivery of therapeutic agents. A non-limiting example of the system includes a delivery vessel including a control unit and a reservoir. The system can also include a connector tube including a channel coupled to the delivery vessel. The system can also include a sensor coupled to connector tube.

Abstract: Methods, systems, and apparatus's for improving orthodontic treatments. In an embodiment, an orthodontic system including a tactile object is provided for modulating an engagement between a tooth attachment and an orthodontic appliance.

Abstract: A dental retainer including one or more of a retaining body having a plurality of dental impressions to receive teeth, a pair of passthrough openings to allow passage of one or more molars, premolars, and canines, and an aperture disposed adjacent the lingual surface of the incisors.

Abstract: A dual aligner assembly including a plurality of aligners, including a first aligner and a second aligner. The first aligner has a first shape corresponding to a set of target tooth positions and applies an orthodontic force against a set of target teeth. The first orthodontic force generates movement of the set of target teeth to the set of target tooth positions. The second aligner has a second shape corresponding to a combination of current tooth positions of the set of target teeth, the set of target tooth positions, and a thickness of the first aligner. The second aligner partially encloses the first aligner and provides an anchor for at least a portion of the first aligner. Via the anchor, a combination of the first aligner and the second aligner provides an orthodontic force that prevents the set of target teeth from moving to unwanted tooth positions during orthodontic treatment.

Abstract: The present invention relates to orthodontic positioning appliances and related methods. An appliance in accordance with the present invention has teeth receiving cavities shaped to receive and apply a resilient positioning force to the patient's teeth. At least one of the cavities of the appliance includes a portion shaped to compensate for non-elastic deformation due to use of the appliance.

Abstract: Orthodontic positioning devices, and related methods and systems, are disclosed for use with one or more orthodontic elastic members. The disclosed devices are configured to couple with an orthodontic elastic member so as to react a force from the elastic member into the appliance to, for example, generate traction forces on the patient's teeth to produce a desired occlusion. A positioning device includes a patient removable tooth positioning appliance having teeth receiving cavities shaped to receive and apply a resilient positioning force to a patient's teeth. The appliance includes a hook configured to interface with an orthodontic elastic member. The hook can be configured to be offset from a surface of a tooth when the appliance is coupled with the patient's teeth and no elastic member is coupled with the tooth. The hook can be curved so that the hook is more retentive on the aligner. The hook can be reinforced so that the reinforcement resists deformation when the elastic is in place.

Abstract: The invention provides a sensor assembly embeddable within an oral appliance comprising a sensing means; and a data processing means coupled to the sensing means for processing data obtained by the sensing means; wherein the sensing means and the data processing means are sealed within a deformable layer.

Abstract: A masticatory orthodontic correction device adapted to use occlusal loads generated during mastication as a correction force to achieve orthodontic correction, includes at least one correction unit with a rigid body. The correction unit is worn on a maxillary or mandibular dental arch of a patient during mastication, and the shape of the correction unit is maintained without deformation when accommodating teeth. At least one first recess is formed in the correction unit and has a shape which allows a first tooth of the maxillary or mandibular dental arch in malposition to move to the envisioned finish position. At least one buffering member is formed in the first recess configured to transmit and buffer the occlusal loads generated during mastication-between the first recess and the first tooth, wherein when the correction unit is worn during mastication, the buffering member deforms and contacts the first tooth over an area.

Abstract: A method for analyzing a quality of a dental aligner includes receiving, by a processor, a digital dental aligner generated based on a fabricated dental aligner, analyzing, by the processor, the digital dental aligner to identify a quality characteristic of the fabricated dental aligner, determining, by the processor, that the quality characteristic is anomalous, and flagging, by the processor, the fabricated dental aligner indicating that the fabricated dental aligner is rejected in response to determining that the quality characteristic is anomalous.

Abstract: A method includes receiving one or more images of an organ of a patient. A physical model of at least a target region of the organ is manufactured based on the images. A distal tip of a medical probe is pre-shaped to fit a surface of the physical model corresponding to the target region.

Abstract: A method of automatically producing or reproducing a customized AGP (Anterior Guidance Package) equipped splint for a patient with or without a severe malocclusion is provided. The method of automatically producing or reproducing an AGP equipped splint according to current invention comprises of combining Virtual Articulation, CAD (Computer Aided Design)-CAM (Computer Aided Manufacturing) method with AGP and special retentive piece technology. The method of the current invention enables a patient with or without a severe malocclusion to receive his/her customized AGP equipped splint or a replacement thereof automatically without visiting the dentist again and again.

Abstract: The present disclosure includes computing device related, systems, and methods for IPR planning as described herein. One method includes identifying a first tooth and a second tooth in a digital dental model with an overlap in a target final position in a treatment plan and identifying a reference line on each of the first tooth and the second tooth; revising the treatment plan wherein a position of each of the first tooth and the second tooth is determined in which the reference line of each of the first tooth and the second tooth are aligned and the first tooth and second tooth are not overlapping; and prescribing IPR based on the determined position of each of the first tooth and the second tooth.

Abstract: A detachable orthodontic bracket and wire system includes bracket bases, brackets, and an arch wire for guiding alignment of teeth. The bracket bases are positioned on a lingual surface and/or a facial surface of the teeth. Each bracket base includes a first surface, a second surface, and at least one first interlocking element. The first surface is rigidly attached to the lingual surface and/or the facial surface of the teeth. The second surface opposes the lingual surface and/or the facial surface of the teeth. The first interlocking element is attached to and positioned in a direction substantially perpendicular to or parallel to the second surface of each bracket base. The brackets include at least second interlocking element that interlocks with the first interlocking element. The arch wire is inserted through a slot channel of each bracket. The bracket and the arch wire are infused and rigidly anchored within enclosing layers.

Abstract: An oral hygiene device is provided. The oral hygiene device includes a body having a base and first and second opposing sides extending from the base and defining a gap therebetween. The device may further include a plurality of corresponding notch pairs, wherein each corresponding notch pair has a first notch positioned in the first opposing side and a second notch positioned in the second opposing side. The location of the notch pairs may coincide with a user's mouth and in particular to the position of the user's teeth within the mouth. As such, a fibrous material, such as floss, may be coupled to the device such that the material spans the gap between at least one of the corresponding notch pairs so that the material may be inserted into the spaces between the user's teeth when the device is placed into the user's mouth.

Abstract: Improved orthodontic appliances, along with related systems and methods, are provided. In one aspect, an appliance includes a shell having a plurality of cavities shaped to receive teeth, a discontinuity formed in the shell, and an elastic member positioned to interact with the discontinuity. In another aspect, an appliance includes a plurality of discrete shell segments joined by an elastic material to form a single appliance shell. In another aspect, an appliance includes a shell having an exterior layer and an interior layer having a stiffness less than a stiffness of the exterior layer, and a discontinuity formed in the exterior layer. In another aspect, an appliance includes a shell comprising an interior surface and an exterior surface, and an elastic coating covering at least a portion of one or more of the interior surface or exterior surface of the shell.