Table 1.

Framework for elaborating the question, PICO.

Population	Pre-adolescents (mean age 12 years, maximum age 14 years) with obstructive respiratory disorders
Intervention	Rapid maxillary expansion
Comparative group	Without rapid maxillary expansion intervention
Outcomes	Restoration of the normal breathing pattern, analyzed clinically, by report and/or by measurements.
	1. Cephalometric radiographic exams, which are: Intermolar distance; Intercanine distance; Internasal distance; and interzygomatic distance
	2. Volumes: Nasal volume and pharyngeal volume
	3. Clinical report of mouth, nasal or mixed breathing before and after RME.