Arch expanding appliance

1. An appliance comprising:

a removable shell formed of a first material having a number of cavities formed therein, wherein the number of cavities are shaped to receive teeth of a patient; and

an arch element extending from the removable shell in a lingual direction and continuing uninterrupted across the arch width of the removable shell from a first side of the removable shell to a second side of the removable shell, wherein the arch element is formed of the first material and a second material that is different in at least one material property than the first material, and designed to expand an arch of the teeth of the patient, wherein the arch element has a width specific to a stage of a treatment plan.

2. The appliance of claim 1 , wherein the width of the arch element is wider than an arch width of the teeth of the patient.

3. The appliance of claim 2 , wherein the width is 0.25 millimeters wider than the arch width of the teeth of the patient.

4. The appliance of claim 1 , wherein the second material is more rigid than the first material.

5. The appliance of claim 1 , wherein the second material substantially follows contours of a surface of the mouth of the patient when the appliance is placed over the teeth of the patient.

6. The appliance of claim 1 , wherein the appliance is designed to reposition the number of the teeth of the patient and wherein the arch element is designed to expand the arch of teeth of the patient.

7. The appliance of claim 1 , wherein the arch element applies a force to at least a portion of the number of teeth in a transverse direction to expand the arch of teeth of the patient.

8. The appliance of claim 1 , wherein the arch element has a surface that is offset from a palatal surface of the patient.

9. A system, comprising:

a first appliance, of a series of appliances designed to incrementally implement a treatment plan, comprising a first shell formed of a first material having a plurality of cavities therein designed to receive teeth of a first jaw, wherein the first appliance includes a first arch element formed of a first layer of the first material and a second layer of a second material different than the first material, extending therefrom in a lingual direction and continuing uninterrupted across an arch width of the first shell from a first side of the first shell to a second side of the first shell, and designed to expand an arch of the teeth of a patient, and wherein the first arch element has a first width specific to a first stage of the treatment plan; and

a second appliance, of the series of appliances, comprising a second shell having a plurality of cavities therein designed to receive teeth of the first jaw, wherein the second appliance includes a second arch element, wherein second arch element has a second width specific to a second stage of the treatment plan.

10. The system of claim 9 , wherein the series of appliances includes a third appliance including a third shell having a plurality of cavities therein designed to receive teeth of the second jaw, wherein the third appliance includes a third arch element designed to expand the arch of teeth of the patient, and wherein the third arch element has a third width specific to the first stage of the treatment plan.

11. The system of claim 10 , wherein the first arch element and the third arch element are designed to expand the arch of the teeth of the first jaw and the arch of the teeth of the second jaw to a same degree based on the first width and the second width.

12. The system of claim 9 , wherein the series of appliances includes a third appliance including a third shell having a plurality of cavities therein designed to receive teeth of the first jaw and to reposition a number of the teeth of the first jaw, wherein the third appliance does not include an arch element.

13. The system of claim 9 , wherein the first appliance is designed to reposition a number of the teeth of the first jaw concurrently as the first arch element expands the arch of teeth of the first jaw.

14. The system of claim 9 , wherein a surface of the first arch element and a surface of the second arch element are shaped to substantially follow contours of a palate of the patient.

15. The system of claim 9 , wherein the second width is wider than the first width.

16. A method of forming a dental appliance, comprising:

forming a first portion of an arch element of a material using a virtual model of a palate of a patient and a virtual model of a number of teeth of the patient, wherein the first portion of the arch element is wider than an arch width of the number of teeth of a first jaw of the patient, specific to a stage of a treatment plan, and is shaped to substantially follow contours of the palate of the patient;

forming a removable shell over a set of molded teeth, wherein the removable shell includes:

a number of cavities formed therein, wherein the number of cavities are shaped to receive the number of teeth of the patient; and

a second portion of the arch element extending from the first portion of the arch element, continuing uninterrupted across the arch width of the removable shell from a first side of the removable shell to a second side of the removable shell, and formed of the same material as the number of cavities, wherein the material forming the first portion of the arch element is more rigid than the material forming the second portion of the arch element and wherein the second portion is the same width as the first portion of the arch element; and

connecting the first portion of the arch element to the second portion of the arch element to form the dental appliance, wherein the arch element is designed to provide a force to at least a portion of the number of teeth in a transverse direction to expand the arch of teeth of the first jaw of the patient.

17. The method of claim 16 , wherein connecting the first portion of the arch element to the second portion of the arch element includes thermoforming the removable shell over the set of molded teeth with the first portion of the arch element placed within the set of molded teeth.

18. The method of claim 17 , including adding an agent to connect the first portion of the arch element to the second portion created by thermoforming the removable shell.

19. The method of claim 16 , wherein connecting the first portion of the arch element to the second portion of the arch element includes adhering the first portion and the second portion subsequent to forming the first portion of the arch element and the removable shell.

20. The method of claim 16 , wherein forming the first portion of the arch element includes creating a number of features.

21. The method of claim 20 , wherein forming the first portion of the arch element includes creating at least one raised element.

22. The method of claim 21 , wherein creating at least one raised element includes creating an elongated element that is straight in the direction of elongation.

23. The method of claim 21 , wherein creating at least one raised element includes creating an elongated element that contains at least one portion that is transverse to the direction of elongation.

24. The method of claim 20 , wherein connecting the first portion of the arch element to the second portion of the arch element includes thermoforming the removable shell over the set of molded teeth with the first portion of the arch element placed within the set of molded teeth, wherein a thermoformed material surrounds the number of features.