ABSTRACT

Our study originates from the philosophy of Baiters on etiology of Class II, Div. 1 malocclusion. According to Baiters the etiology of Class II, Div 1 malocclusion is the cervical position of the tonque. The purpose of the study is to determine whether the cervical position of the tonque can be treated functionally by the Bionator. Active treatment group consists of 13 girls and 12 boys (total 25) with Class II, Div. 1 malocclusion. A control group of 6 girls and 4 boys with the same norms was taken to make a healthier comparison between the two groups. The Bionator was used by the treatment group for one year, not to be less than 17 hours a day. Rakosi’s tonque analysis was used to determie the changes that took place in the tonque. The hyoid bone was also evaluated on cephalometric films, to bring forth the changes in the position of the tonque Radiopaque barium sulfate solution, was applied on the tonque ’s upper surface to make the view tonque easier. The cephalometric changes of each case was evaluated by the Steiner Analysis. At the completion of the treatment the N-S-Ar, Ar-Go-Me, 1-FH, 1-SN, H-CV2, H-CV2’, H-S, H-N, values were fouund to be changed statistically important, levels. In the control group the values SNB, ANB, H-CV2, H-N, H-S, H-ANS were significantly changed during the year. The comparison of the treatment and control group showed that Ar-Go-Me, ANB, 1-FH values were significantly different between the two groups. Although there were significant changes in the hyoid valuees of the treatment group, the control group also reflects this changes. This and the fact that the tonque analysis shows the same results, prompts of the conclude that the treatment of the class II, Div. 1 malocclusion with the Bionator, does not change the position of the tonque and the hyoid bone significantly.