Table 2 Overview of included studies

Miles (2012) [16]

RCT

Australia

n = 66; F:40; M:26;

Age:11–15

E:M:12;F:21;Age:13.0 ± 0.18y;

C:M:14; F:19;Age:13.1 ± 0.18y

Tooth Masseuse (111 Hz, 0.06 N)

Alignment of the 6 mandibular anterior teeth (3–3)

Pavlin (2015) [23]

RCT

USA

n = 45; Age:12–40

E:n = 23; C:n = 22

AcceleDent (30 Hz, 0.25 N)

Retraction of maxillary canine or maxillary anterior teeth (3–3).

Woodhouse

(2015a) [18]^a

RCT

UK and Germany

n = 81; M:40, F:41.

Age: 14.06 ± 1.7y

E:n = 29; Age: 13.9 ± 1.6y

Sham: n = 25; Age: 14.1 ± 1.9y

C: n = 27; Age: 14.4 ± 1.8y

AcceleDent (30 Hz, 0.25 N)

Alignment of the mandibular arch in comprehensive treatment

Woodhouse

(2015b) [17]^a

RCT

UK and Germany

n = 81; M:40, F:41.

Age: 14.1 ± 1.7y

E:n = 29;M:15, F:14; Age: 13.9 ± 1.6y

Sham: n = 25; M: 13, F:12 Age:13.8 ± 1.7y

C: n = 27; M:12, F:15; Age: 14.4 ± 1.9y

AcceleDent (30 Hz, 0.25 N)

Alignment of the mandibular arch in comprehensive treatment

Leethanakul (2016) [20]

CCT

Thailand

n = 15; M:4; F:11

Age:19-25y

Split-mouth design, the experimental tooth (right or left) was determined randomly.

A electronic toothbrush (Colgate) with a vibrating head (125 Hz)

Retraction of maxillary canines after complete alignment.

Lobre

(2016) [21]

RCT

USA

N = 58

E:n = 29

C:n = 29

AcceleDent(30 Hz, 0.25 N)

Alignment in comprehensive treatment

Miles

(2016) [22]

RCT

Australia

n = 40; M:14; F:26

Age:12.8 ± 1.3y

E:M:6; F:14; Age: 12.7 ± 1.2y

C:M:8; F:12; Age: 13.0 ± 1.5y

AcceleDent(30 Hz, 0.25 N)

Alignment of the 6 mandibular anterior teeth (3–3)

DiBiase

(2016) [19]^a

RCT

UK and Germany

n = 81;

E:n = 29

Sham: n = 25

C: n = 27

AcceleDent (30 Hz, 0.25 N)

Alignment in comprehensi9ve treatment