The purpose of this investigation is to determine the treatment effect mechanism of the Nonextraction Edgewise Treatment Technique with Class II Intermaxillary Elastics on the dentofacial System of Class II Division 1 cases. The material of this investigation consisted of 96 lateral cephalograms taken from 48 cases, at the beginning and the end of treatment and control periods. The treatment group consisted of 24 individuals (12 Girls, 12 Boys) with a mean age of 12.67±0.95 years at the beginning of treatment while the control group consisted of 11.41+0.87 years at the beginning of the control period. The mean treatment time in the treatment group is 1.01+0.07 years, the mean observation period in the control group is 1.03±0.07 years. Statistically significant changes that were assessed by the treatment can be summarize as follows: The overjet and overbite decreased. Retrusion and extrusion of the upper incisors were obtained. Protrusion of the lower incisors occured. Extrusion of the lower incisors were inhibited. The vertical alveolar development of upper molars decreased. The vertical alveolar development of lower molars increased. The inclination of occlusal plane increased. SNA angle decreased. Y angle (Parameter 8. N-S-Gn angle) increased.

Keywords: Class II, Division 1 Malocclusion, Class II Inter-maxillary Elastics, Edgewise Treatment Technique, Non-extraction Treatment