Objectives. In this retrospective clinical study, we assessed skeletal, dental and soft tissue changes after using Bionator or Twin
Block therapy. Materials and methods. Forty nine patients were examined, 25 of them treated with Bionator and 24 with Twin Block.
The two groups were defined in order to assess cephalometric changes at initial stage (T1) and before treatment (T2). Skeletical
changes were defined by two measurements: facial convexity and Ricketts mandibular plane angle. Dental changes were defined by
upper and lower incisor angle, overjet and overbite. Soft tissue changes were defined by nasolabial angle (ANL) and mentolabial
angle (AML). Initial and final mean and standard deviation were analyzed. A comparative analysis of the mean difference was done.
A p value of .01 was considered statistically significant. We used the statistical program SPSS for Windows. Results. Facial convexity
was found decreased in both samples; while the mandibular plane, ANL and AML angles was increased. Both appliances retroclined
the upper incisors and proclined the lower incisors, what helped the correction of overjet and overbite. Conclusion. Although
Bionator and Twin Block therapies improved skeletal Class II, Twin Block effects were slightly greater than Bionator effects. Moreover
there was a proclination of the upper incisors with a better harmony of the facial profile.
(Rev Esp Ortod. 2009;39(3):205-211)