Evaluation of cervical spine posture after functional therapy with FR-2: a longitudinal study

The authors compared postural changes produced in 20 Caucasian female children treated with the Frankel Functional Regulator appliance (FR-2) (Frankel Industries, Morangis Cedex, France) using cephalometric tracings and comparing the tracings to 20 untreated Class II controls from the University of Chieti. Each patient in the study group was treated for exactly two years by the same operator using the FR-2 appliance and a standardized design and clinical technique, including prefunctional orthodontics where indicated. The average starting age was 8.4 yrs. (SD+/-2.1). At the end of the therapy, the average age was 10.3 yrs. (SD+/-2.4). Two teleradiographs were made of each patient: the first one at the beginning of treatment and the second one after six months. The radiographs were taken with the subjects standing in the ortho-position with no ear rods in the cephalostat; mirror position was carried out. In order to detect errors due to landmark identification, duplicate measurements were made using ten radiographs, and the error variance was calculated using Dahlberg's formula. Thirty-seven variables were studied. The cervical lordosis angle (CVT/EVT) was significantly higher in the study group as compared to the control group (p<0.05) at the end of treatment, probably due to a significant backward inclination of the upper segment of the cervical column (OPTNer and CVTNer) in the treated group (p<0.001 and p<0.01) from pre- to posttreatment. There was no significant change in the lower segment of the cervical column inclination (EVT/Ver). The changes resulted in a weak association in the multiple regression model to an increasing of maxillary base length and mandibular protrusion (R2=0.272; p<0.05). Other variables in the multiple regression were not significant.