Palatal expanders for controlling crown tipping

A series of palatal expanders having a sequence and configured to be sequentially worn by a patient to expand the patient's palate in the sequence while controlling crown tipping, a first palatal expander in the series of palatal expanders comprising:

• a left tooth engagement region configured to be removably worn over the patient's teeth in a left maxillary portion of the patient's upper jaw;
• a right tooth engagement region configured to be removably worn over the patient's teeth in a right maxillary portion of the patient's upper jaw;
• and
• a palatal region between the left tooth engagement region and the right tooth engagement region configured to expand the patient's palate,
• wherein the left tooth engagement region and the right tooth engagement region are configured to add anti-tipping torque to at least one tooth to control tipping of a crown of the at least one tooth during palatal expansion,
• wherein the left tooth engagement region and the right tooth engagement region are configured to add the anti-tipping torque by having buccally rotated cavities for receiving a coronal portion of the at least one tooth therewithin, wherein a coronal portion of the buccally rotated cavities is rotated buccally relative to a current tooth position of the at least one tooth wherein one or more spaces are created between one or more surfaces forming the buccally rotated cavities and the current tooth position of the at least one tooth when the palatal expander is worn by the patient, and
• wherein, in the series of palatal expanders, the palatal region of the first palatal expander has a first distance between the left and right tooth engagement regions, and a second palatal expander has a second palatal region having a second distance between respective second left and right tooth engagement regions, the second palatal expander being later in the series and the second distance being larger than the first distance.