Sequence generation
orthodontic
Participants were allocated using stratified block randomisation. The participants were stratified based on three prognostic characteristics: gender, age and IBI at baseline. It has been shown that female orthodontic patients report cleaning their teeth more often than male patients (Using three prognostic characteristics resulted in eight blocks into which patients could be placed. These eight blocks are shown in For each block, six sealed opaque envelopes were produced by the author DT. Inside each envelope was a paper slip which read either ‘Intervention’ or ‘Control’. There were three intervention and three control envelopes produced for each block. A folder was produced for each block and labelled with the block number and description. The six envelopes were placed inside each of the eight block folders. These were kept separately and thus concealed the allocation sequence from DT.