Summary Introduction: Routine brushing protocols might not suffice to reduce the increased plaque accumulation in orthodontic patients. Antimicrobial mouth rinses are favorable in this regard. This two-phase study evaluated the effects of orthodon- tic treatment and the application of two mouthwashes not stud- ied before on oral health indices. R  esum  e Introduction : Les techniques de brossage conventionnelles peuvent s’av  erer insuffisantes pour r  eduire l’accumulation de plaque accrue chez les patients porteurs d’appareil orthodon- tique fixe. Pour cela, les bains de bouche antimicrobiens pr  esentent un int  er ^ et non n  egligeable. Cette  etude en deux phases a  evalu  e les effets du traitement orthodontique et de l’application de deux bains de bouche encore non valid  es a`ce jour sur les indices de sant  e buccale. Original Article Article original Ó 2018 CEO Published by / E ´ dite ´ par Elsevier Masson SAS All rights reserved / Tous droits re ´serve ´s Effects of fixed orthodontic treatment and two new mouth rinses on gingival health: A prospective cohort followed by a single-blind placebo-controlled randomized clinical trial § Effets d’un traitement orthodontique fixe et de deux bains de bouche sur la sant  e gingivale : cohorte prospective suivie d’un essai clinique randomis  e, contr ^ ol  e par placebo, en simple insu Farhad Sobouti a,* , Vahid Rakhshan b,c , Mohaddeseh Heydari d , Shohreh Keikavusi e , Sepideh Dadgar a,* , Mahsa Shariati f a Orthodontics department, dental faculty, Mazandaran university of medical sciences, Sari, Iran b Iranian tissue engineering and graft bank and research center, Tehran university of medical sciences, Tehran, Iran c Department of dental anatomy and morphology, dental school, Azad university, Tehran, Iran d Dental implant research center, dentistry research institute, Tehran university of medical sciences, Tehran, Iran e Faculty of dentistry, student research committee, Mazandaran university of medical sciences, Sari, Iran f Craniomaxillofacial surgery research center, Tehran university of medical sciences, Tehran, Iran Available online: 23 February 2018 / Disponible en ligne : 23 f evrier 2018 § The RCT is registered in an international center for evaluation and approval of RCTs (the IRCT database) as IRCT2016033024573N2. * Correspondence and reprints / Correspondance et tir es a ` part : Sepideh Dadgar, Department of orthodontics, faculty of dentistry, Mazandaran university of medical sciences, Sari, Iran. e-mail address / Adresse e-mail : dadgar_sepideh@yahoo.com (Sepideh Dadgar) 12 International Orthodontics 2018 ; 16 : 12-30 http://dx.doi.org/10.1016/j.ortho.2018.01.027