IRCT2013113015598N1.

Trial name or title	Comparision of the effect of three different approaches of retention on reopening of extraction space of fixed orthodontic patients in three different retention phases
Methods	Parallel RCT, single‐blind
Participants	90 males and females, any age Inclusion criteria: the presence of all the permanent teeth irrespective of third molars; the use of a fixed flexible spiral wire retainer or an extended fixed retainer or a fixed flexible spiral wire retainer along with a Hawley plaque Exclusion criteria:missing teeth; the use of other types of retainers
Interventions	Group 1: extended fixed retainer Group 2: flexible spiral wire retainer Group 3: fixed flexible spiral wire retainer along with Hawley plaque
Outcomes	Reopening of extraction space
Starting date	2013
Contact information	Farzaneh Rasouli, rasoulifa@tbzmed.ac.ir
Notes	Faculty of Dentistry, Tabriz University of Medical Sciences, Iran