Hawley retainer is a device composed of an acrylic base with built-in hooks and a labial arch wire 0.022 "x0.036" and attached to the teeth. Its metal component consists of two adams hooks positioned from the first permanent molar right to left, a labial bow that progresses from lingual superface to distal of canine to integrate with the acrylic base.

The essix retainer is made in a thermoforming copolyester 0.75mm (0.30 ", it processed gives a thickness of 0.015" approximately. Retainer will be used molar to molar. subjects in this arm will have this retainer for 24 hours a day for 6 months, they won´t have this device for food intake.

Dental stability will be assessed like this, models: rotation of central and lateral incisor, canine, first and second premolar, first molar on each side and each arch; and cephalometric analysis: SN-upper central incisive, FK-upper central incisive, palate plane-upper central incisive, interincisal angle, mandibular plane-lower central incisive; vertical distances: palate plane-upper central incisive, palate plane-first upper molar, mandibular plane-lower central incisive, mandibular plane-first lower molar; horizontal distances: A-Pogonion upper and lower central incisive.

Occlusal stability will be measured at the beginning and end of study through clinic exam and study models.

Clinic exam: canine relations right and left, molar relations left and right, overjet, overbite, presence of anterior open bite, presence of posterior open bite.

Models: upper and lower arch, upper and lower intercanine distance, upper and lower distance interpremolar, upper and lower intermolar distance.