The aim of this study was to evaluate the eventual alteration in the craniocervical position of patients, oriented in the Natural Head Position (NHP), after the rapid maxillary expansion (RME) procedure. We have used lateral radiographs, selected from the documentation file of the Preventive Orthodontics Clinic, School of Dentistry, University of São Paulo. Our sample consisted of 20 patients (7M:13F), with ages ranging from 5.08 up to 11.08 years (mean of 9,0). The cephalometric radiographs were obtained in the beginning of the treatment and immediately after the active phase of the maxilla expansion. All patients showed constrictions of the maxilla, and were treated with modified Biederman appliance. Craniocervical cephalometric analysis was carried out by evaluating the craniovertical (SN.VER), craniocervical (OPT.SN e CVT.SN), cervicohorizontal (OPT.HOR e CVT.HOR) and the cervical curve (OPT. CVT) angles. On the basis of the statistical analysis of the data, we conclude that the head position did not show significant alteration. Statistically significant differences were not detected between the sexes, when the phases pre and post RME were compared for the measurements studied. In the sample studied, the method of obtaining cephalometric radiographs in the Natural Head Orientation showed to be trustworthy and reproducible, even in the presence of orthodontic-orthopedic intervention between the series of radiographs.
Orthodontic; Natural head position; Cephalometric radiographs; Rapid maxillary expansion