Clinical interventions
In group 1, the patients were assigned to use the manual orthodontic toothbrush (Systema OD, Lion Company, Tokyo, Japan) for 28 d, followed by using their own non-assigned toothbrush for 28 d (wash-out period), and then used the LED toothbrush for 28 d. In group 2, the patients used the LED toothbrush during the first period (28 d), wash-out for 28 d, and then used the manual toothbrush during the second period (28 d). The patients were instructed by one dentist for 5 min on how to brush with the Bass technique before starting the interventions [