Efficacy of ketoprofen lysine salt and paracetamol/acetaminophen to reduce pain during rapid maxillary expansion : a randomized controlled clinical trial

Background: Rapid maxillary expansion (RME) is an orthopaedic procedure indicated for a wide variety of clinical conditions. Aim: The aim of the study was to compare the effects of ketoprofen lysine salt (KLS) vs paracetamol/acetaminophen (P) on pain perception during RME. Design: One hundred and fifty-one subjects (mean age 8.6 year) were enrolled in this prospective controlled clinical trial according to inclusion criteria: prepuberal stage of development, negative posterior transverse interarch discrepancy, non-concurrent use of other drugs. First phase: n.40 allocated to Group 1 used 40 mg of KLS, n.40 to Group 2 used 250 mg of P, n.36 to Group 3 as control group. Second phase: n.35 allocated to Group 4 used 40 mg ketoprofen lysine salt once a day for the first 3 days of activation. Pain experience was reported on a numeric rating scale (0-4) and a 100-mm visual analogue scale. Pain perception was tested with the Mann-Whitney test (P < 0.05). Results: Pain perception was higher during the first 3 days of activation and it was described as mild to moderate. Group 1 experienced significantly less pain during the fourth, fifth, and sixth day (P < 0.05) compared with Group 2. Patients of the Group 4 reported significantly lower pain during the whole period of RME activation (P < 0.05). Conclusions: The perceived higher pain was reported during the second and third day of expansion. The analgesic effect of KLS is more effective than P during the fourth, fifth, and sixth day. The use of KLS during the first 3 days of activation seems to be able reducing pain during the whole active phase.