“…4,5,6,7,8,9,12,13,14,15,16,17 The most commonly used maxillary orthodontic retainers are removable, especially the Hawley plate, the WA, and the CT, whose preferences vary according to country or region. 2,3,16,18,19,20,21,22,23 The WA was selected for this study in relation to the Hawley plate, because the aim was to evaluate the influence of the different palatal acrylic designs, and the occlusal interference generated by the Hawley retaining clasps could impair this evaluation. Thinner maxillary removable retainers appear to generate less interference in speech.…”