A method usable in creating a subsequent dental appliance comprising: receiving a current digital dental model that includes a first representation of the set of physical teeth for the patient with a current dental appliance attached to the physical teeth or oral cavity, wherein the current digital dental model is a direct digital scan of the set of physical teeth and the current dental appliance prior to removal of all or a part of the current dental appliance; creating, based on the current digital dental model, a new digital dental model that includes the first representation of the set of physical teeth without the current dental appliance by either; i) Superimposing each of segmented digital teeth of the patient on corresponding digital teeth associated with the current digital dental model, wherein the segmented digital teeth are derived from the set of physical teeth without any dental appliance applied to the set of physical teeth, determining a non-superimposed portion of the current digital dental model based on the superimposing, and creating the new digital dental model by removing the non-superimposed portion of the current digital dental model; or ii) Superimposing a second representation of all or a portion of the current dental appliance on the current dental appliance associated with the first representation, determining a superimposed portion of the first representation based on the superimposing, and creating the new digital dental model by removing the superimposed portion of the first representation; and providing digital data suitable for use in manufacturing the subsequent dental appliance based on electronic data included in the new digital dental model; wherein the receiving and the creating are performed by one or more computer processors receiving a current digital dental model that includes a first representation of the set of physical teeth for the patient with a current dental appliance attached to the physical teeth or oral cavity, wherein the current digital dental model is a direct digital scan of the set of physical teeth and the current dental appliance prior to removal of all or a part of the current dental appliance; creating, based on the current digital dental model, a new digital dental model that includes the first representation of the set of physical teeth without the current dental appliance by either; i) Superimposing each of segmented digital teeth of the patient on corresponding digital teeth associated with the current digital dental model, wherein the segmented digital teeth are derived from the set of physical teeth without any dental appliance applied to the set of physical teeth, determining a non-superimposed portion of the current digital dental model based on the superimposing, and creating the new digital dental model by removing the non-superimposed portion of the current digital dental model; or ii) Superimposing a second representation of all or a portion of the current dental appliance on the current dental appliance associated with the first representation, determining a superimposed portion of the first representation based on the superimposing, and creating the new digital dental model by removing the superimposed portion of the first representation; and i) Superimposing each of segmented digital teeth of the patient on corresponding digital teeth associated with the current digital dental model, wherein the segmented digital teeth are derived from the set of physical teeth without any dental appliance applied to the set of physical teeth, determining a non-superimposed portion of the current digital dental model based on the superimposing, and creating the new digital dental model by removing the non-superimposed portion of the current digital dental model; or ii) Superimposing a second representation of all or a portion of the current dental appliance on the current dental appliance associated with the first representation, determining a superimposed portion of the first representation based on the superimposing, and creating the new digital dental model by removing the superimposed portion of the first representation; and providing digital data suitable for use in manufacturing the subsequent dental appliance based on electronic data included in the new digital dental model; wherein the receiving and the creating are performed by one or more computer processors