تقييم فعالية القطعة التوامية بالمقارنة بصفيحة شفارتز المضاعفة في تصحيح الصنف الثاني الهيكلي: دراسة سيفالومترية جانبية

Background & Objective: functional treatment of skeletal class II malocclusion is one of the most important treatment options in mixed dentition. The aim of this research is to evaluate the effectiveness of two of the most popular functional appliances in daily orthodontic practice which are: Schwarz double plate and twin block, and to compare the effectiveness of these appliances. Methods & Materials: Forty patients (22 Male and 18 female), aged (11.6±0.9 year), ranged 10-13 year, were selected from orthodontic clinic in Albaath university. These patients were divided randomly into two equal groups. The subjects in the first group were treated with Schwarz double plate appliance, and the subjects in the other group were treated with twin block appliance. Lateral cephalometric radiographs were obtained before treatment and after six months of treatment. Paired sample t-test was used to determine the significant changes obtained from the use of each appliance, and two sample t-test was used to compare between the two groups, decisions were judged at significance level of 0.05. Results: The results indicated that both appliances could correct sagittal disorders. ANB Angle decreased by (-3.51± 1.28 degrees) in a Schwarz double plate group, and by (-3.95± 0.97 degrees) in a twin block group, with no significant differences between the groups. It was noted that a Schwarz double plate stimulated vertical growth, while a twin block stimulated horizontal growth as many variables indicated. Conclusions: Each one of the two studied appliances is indicated for the functional treatment of skeletal class II malocclusion, it is recommended to use the Schwartz double plate when the vertical growth is desired, while it is recommended to use the twin block when the horizontal growth is desired