Table 4. Characteristics of the included studies that evaluated accelerated traction.

RCT: randomized clinical trial; M: males; F: females; PDC: palatally displaced canine.

Study/setting	Study design	Sample size, gender, age (years)	Intervention (type of appliance, type of the attachment, mechanism of traction, type of withdrawal technique)	Comparison (type of appliance, attachment, traction mechanism, withdrawal technique)	Outcome measures	Main findings
Fischer (2007) [31], USA	RCT, bilateral PDC	6 (2M + 4F), 12 impacted canines. 11.1-12.9 years	Fixed appliances, corticotomy-assisted, and open surgical technique	Fixed appliances, conventional withdrawal, and open surgical technique	Treatment time, velocity	The reduction in treatment time ranged from 28% to 33%. The corticotomy-assisted canines moved at a rate of 1.06 mm/mo vs. 0.75 mm/mo for the conventional canines
Dehis et al. (2018) [43], Egypt	RCT, unilateral PDC	12 (3M + 9F) 16-34 years	Fixed appliances, intra-epidermic vitamin C injection, power chain, and closed surgical technique	Fixed appliances, power chain, and closed surgical technique	Rate of the orthodontic tooth movement, the width of keratinized tissues, alveolar bone thickness, lateral incisor root resorption	The rate of tooth movement was recorded in the intervention group (2-2.5 mm), compared to the control group (0.5-1.5 mm)