PUL: a New Functional Appliance for class II growing patients. A prospective controlled study.

Objectives: The objective of this prospective controlled study was to evaluate the skeletal, dento-alveolar and soft tissue effects of the PUL appliance in the treatment of Class II malocclusion. Subjects and Methods: This study included 56 skeletal Class II patients (25 boys and 31 girls). The treated group (TG) consisted of 40 patients consecutively treated with the PUL appliance (mean age 10,6 ± 1.2 years). The PUL appliance consists of two different component, the first for the upper jaw and the second for the lower jaw. These parts are fabricated using a thermoforming material from the dental cast; the appliances are connected by two telescoped rods incorporating a stainless steel coil spring activated to enhance the mandibular position; TG was compared with a control group (CG) of 16 untreated class II subjects (T0 mean age 9,4 ± 1,6 years, T1 mean age 10,6 ± 0,8 years). Patients in both groups had the following features: ANB ≥ 5°; overjet > 5 mm; full class II molar relationship; no missing teeth (extracted or agenesis); prepubertal stage (CS1 or CS2); The mean treatment time for the TG was 11,2 ± 0,3 months. Lateral cephalograms were analyzed at the start of treatment (T0) and at the end of the therapy (T1). Customized cephalometrics examination was used. Cephalograms magnifications were normalized. ICC for angular and linear measurements were evaluated (both > 0,91). Blinded statistical analysis with T-test for independent data with difference between T1 and T0 was used for the comparison. Statistical significance was tested at P < 0,05. Results: statistically significant difference between TG and CG were found for SNA°, SNB°, ANB°, WITS, Upper1/SpP°, OJ, Co-Gn, Co-Go, Mx/Mn diff, Pog-OLP, Li-OLP, Mi-OLP, Molar relationship and U lip protraction. Conclusions: The PUL appliance efficiently corrected the class II relationship and significantly produced improvements if compared with the class II non treated patients.