Palatal expanders with breach regions

Palatal expander systems and methods. A palatal expander includes a palatal region connecting tooth engagement regions, where the palatal region is configured to apply a lateral force across a patient's palate when the tooth engagement regions are worn over the patient's teeth. Attachment regions on buccal sides of the tooth engagement regions are shaped and sized to engage with dental attachments bonded to the patient's teeth. At least one breach region corresponding to a thinned region of the palatal expander extends anteriorly to posteriorly in the palatal region or an occlusal portion of one or both of the tooth engagement regions. The at least one breach region is configured to breach or bend when a pulling force is applied to one or both of the tooth engagement regions such that one or both of the attachment regions are detached from respective attachments.