Both rapid and slow maxillary expansion protocols may produce different effects on the palatal suture, on the periodontium, and on alveolar anatomy such as lateral flexion of the alveolar processes, root resorption, bone fenestration and the anchorage teeth can show different degrees of inclination and dislocation. In order to reduce these side effects, maxillary expansion devices anchored to deciduous teeth or miniscrew-supported appliances should beconsidered.