. 2020 Feb 10;90(3):442–456. doi: 10.2319/080619-517.1

Table 1. .

Data Extraction of Articles Included in This Systematic Review^a

Author and Year	Sample and Age	Malocclusion Class	Need for Expansion	Expander Device	Activation Protocol	Measurement Type	Interest Outcome
Arat et al. (2008)²²	18 patients	NA	Unilateral or bilateral posterior crossbite	Haas		Magnetic Resonance Imaging	RME promotes remodeling in the head and / or condylar branch.
	(9.75–14.8 years)				2/4 turn/d until overcorrection	•Condylar remodeling
						•At the beginning of the treatment, 6 and 18 weeks after the activations
Arat et al. (2008)²³	18 patients	NA	Unilateral or bilateral posterior crossbite	Haas	2/4 turn/d until overcorrection	Magnetic Resonance Imaging	RME does not change the position of the articular disc.
	(9.75–14.8 years)					•Positioning of the articular disc
						•At the beginning of the treatment and 18 weeks after the activations
Masi et al. (2009)²⁴	30 patients	I, II, or III	FUPC	Haas	1 turn/d until overcorrection	Magnetic Resonance Imaging	RME does not change the position of the articular disc.
	(6.8–14.2 years)					•Positioning and shape of the articular disc
						•At the beginning of the treatment, 12 and 18 weeks after the activations
Matta et al. (2009)²⁵	10 patients	I	FUPC	Haas	2/4 turn/d until overcorrection		RME altered the condylar position and joint space, promoting greater spatial symmetry between the crossed and non-crossed sides.
	(7.2–11.2 years)					Conventional tomography
						•Condylar position and joint space
						•At the beginning of the treatment and 12 weeks after the activations
Leonardi et al. (2012)²⁶	39 patients	I	Group 1: 26 patients	Hyrax	3/4 turn for up to 18 days	Conventional tomography	RME promoted an increase of the joint spaces maintaining the symmetry of the condyle-fossa joint relationship.
	(8.2–11.6 years)		26 patients			•Conventional tomography
			Maxillary constriction with FUPC			•At the beginning of treatment and at the end of activations
			Group 2:
			13 patients
			Palatine displaced canine without FUPC
Melgaço et al. (2014)²⁷	34 patients	I	Maxillary constriction without posterior crossbite	Haas and Hyrax		Cone-beam tomography	RME induces a change in condylar position, down and forward symmetrically on both sides, without generating asymmetry.
	(average age of 12 years and 10 months for girls and 13 years for boys)				1 full turn on the first day and 2/4 turn in the next 6 days	•Condilar position
						•At the beginning of treatment and 12 weeks after activations
Mcleod et al. (2016)²⁸	37 patients	NA	Group 1:	Hyrax	2/4 turn/d until overcorrection	Cone-beam tomography	RME does not alter the condylar position in the glenoid cavity.
	(11–17 years)		19 patients			•Glenoid fossa and joint space
			Maxillary constriction with FUPC			•At the beginning of treatment and 24 weeks after activations
			Group 2:
			18 patients
			With delayed treatment
Ghoussoub et al. (2018)²⁹	27 patients	NA	Group 1:	Hyrax	2/4 turn/d until overcorrection	Cone-beam tomography	RME is effective during growth, widening the interglenoid fossa distance and the lateral positions of the condyles.
	(8–13 years)		18 patients			•Condyllar position and glenoid fossa
			Maxillary constriction with BPC			•At the beginning of treatment and 24 weeks after activations
			Group 2:
			9 patients
			With delayed treatment

NA indicates not available; FUPC, functional unilateral posterior crossbite; BPC, bilateral posterior crossbite; RME, rapid maxillary expansion.