Rapid palatal expanders (RPEs) are a commonly used orthodontic adjunct for the treatment of posterior crossbites. RPEs are cemented to bilateral posterior teeth across the palate and thus may interfere with proper tongue movement and linguopalatal contact. It is important to identify what specific role RPEs have on speech sound production for the child and early adolescent orthodontic patient. Numerous phonemes were distorted upon RPE placement which indicated altered speech sound production. For most phonemes, it takes longer than two weeks for speech to return to baseline, if at all. Clinically pre-treatment and interdisciplinary counseling for orthodontic patients receiving palatal expanders is important
Keywords: Palatal Expanders, Rapid Palatal Expanders, Posterior Crossbite, Orthodontic movement, Speech.