Methods of forming dental appliances with reinforcement ribs

A method forming a dental appliance, the method comprising:

• forming a composite virtual model that includes a virtual shell placed on a virtual teeth model, wherein the virtual teeth model represents a patient's teeth and the virtual shell has a shape based upon information from the virtual teeth model;
• forming virtual ribs on the virtual shell, wherein the virtual ribs are formed laterally across at least a portion of a lingual surface and a labial surface of the virtual shell and each has an arch shape in accordance with the at least a portion of the lingual surface and the labial surface of the virtual shell, wherein a thickness from rib to rib of the virtual ribs varies, such that thicker one or more ribs are arranged to apply greater force in one or more desired directions;
• confirming that a displacement of one or more teeth of the virtual teeth model based on forces applied by the virtual shell on the virtual teeth model having the virtual ribs is sufficient according to predetermined conditions;
• and
• forming the dental appliance including a shell comprising a polymeric material based on the virtual shell, wherein the dental appliance includes ribs integrally formed with the dental appliance from the polymeric material and laterally across a lingual surface and a labial surface of the shell based on the virtual ribs.

A method forming a dental appliance, the method comprising:

• forming a virtual shell based upon information from a virtual teeth model of a patient's teeth;
• forming virtual ribs on the virtual shell, wherein the virtual ribs are formed laterally across at least a portion of a lingual surface and a labial surface of the virtual shell and each has an arch shape in accordance with the at least a portion of the lingual surface and the labial surface of the virtual shell, wherein a thickness from rib to rib of the virtual ribs varies, such that thicker one or more ribs are arranged to apply greater force in one or more desired directions;
• calculating a displacement of one or more teeth of the virtual teeth model based on forces applied to the one or more teeth by the virtual shell with the virtual ribs;
• and
• forming the dental appliance including a shell comprising a polymeric material based on the virtual shell, wherein the dental appliance includes ribs integrally formed with the dental appliance from the polymeric material and laterally across a lingual surface and a labial surface of the shell based on the virtual ribs.