A comparison of Class II treatment changes noted with the light wire, edgewise, and Fränkel appliances

The purpose of this study was to determine if selected cephalometric changes noted in groups of growing patients with Class II, Division 1 malocclusions treated with the Fränkel function regulator (FR-2), the edgewise technique, and the light-wire (Begg) mechanism were different and characteristic of a specific technique. To this end, the changes in the SNA, SNB, N-S-Gn, and the SN-GoGn angles, face height (N-M), the anterior movement of pogonion, and the annualized mandibular growth increment (AR-Gn) in a group of patients treated with the FR-2 were compared to the changes noted in similar groups of patients treated by the edgewise technique and the light-wire mechanism. The methods used to compare the groups were an analysis of variance and a discriminant analysis. A reduction in the SNA angle was observed in all groups. It was -0.37 degrees with light wire treatment, -0.60 degrees with Fränkel appliance use, and -1.47 degrees with edgewise therapy. The SNB angle increased in all three groups, ranging from 0.29 degrees in the edgewise group to 0.56 degrees in the Fränkel group. In the light-wire group it was 0.34 degrees. The N-S-Gn angle in the Fränkel group remained essentially the same (0.06 degrees), while in the light-wire and edgewise groups it increased 0.81 degrees and 0.82 degrees. The SN-GoGn angle opened slightly in all groups, ranging from a low of 0.46 degrees with Fränkel therapy to 0.58 degrees with edgewise treatment to 1.25 degrees with the use of the light-wire appliance.(ABSTRACT TRUNCATED AT 250 WORDS)