Cossellu G, et al. - Researchers assessed the impacts of ketoprofen lysine salt (KLS) vs paracetamol/acetaminophen (P) on pain perception during rapid maxillary expansion (RME). They included 151 patients in this study. During the second and third day of expansion, perceived pain was higher. Findings suggested a greater efficacy in terms of analgesic effect of KLS vs P during the fourth, fifth, and sixth day. Seemingly, the use of KLS during the first 3 days of activation was able to reduce pain during the whole active phase.