Comparison of the effects of monoblock and twin-block appliances on the skeletal and dentoalveolar structures.

Functional appliances, which are used in the early treatment period of skeletal Class II malocclusions, induce the forward displacement of the mandible by altering the postural activity of the muscles and causing some changes in both skeletal and dentoalveolar structures. The purpose of this investigation was to evaluate the differences between monoblock and twin-block appliances. Two treatment groups composed of 26 growing patients with skeletal and dental Class II, Division 1, malocclusions, were compared to an untreated control group of 13 patients with the same morphologic characteristics and growth rate. These groups were matched according to their age, sex, and vertical and sagittal skeletal cephalometric and dental characteristics. Monoblock was worn by the subjects for 16 hours/day, whereas twin-block was worn 24 hours/day, even while eating. Patients of the control group were followed without any intervention. Treatment effects were identified with a conventional cephalometric analysis. The findings of this study revealed that by using these different functional appliances, the stimulation of the growth of the lower jaw and the correction of Angle Class II relationship were achieved. In the twin-block group, the mandibular plane angle and gonial angle increased, although a decrease in the degree of overbite occurred. In the monoblock group, upper incisors demonstrated a greater degree of retrusion. However, within the twin-block group, the lower incisors showed a greater degree of proclination.

[Study of the structural compensation of the mandible during treatment with cervical headgear]. / Servikal headgear ile tedaviye karsi alt çenede görülen yapisal kompanzasyonun arastirilmasi.

This study was performed on two cephalometric films of each fourteen subjects with skeletal class 1 facial structure and Angle Class II molar relation treated with cervical headgear for a period 0.777 +/- 0.06 years; and of each thirteen control subjects with skeletal class 1 facial structures and normal occlusion observed for a period of 0.807 +/- 0.03 years. The correlation coefficients for the longitudinal changes of angular and linear measurements during control and treatment periods in both groups were evaluated. The correlation coefficients belonging to each group were compared; and the compensational regions during cervical traction were investigated. It was concluded that; the structural compensations occurred in the mandible according to the inhibition of the mesial migration of lower permanent first molars because of the interdigitation with the upper ones were the increase in the ramus inclination, change in the growth pattern of the mandibular condyle, increases in the gonial angle, lower anterior facial height and the mandibular plane angle.

[The changes in orthodontic area after retention period in skeletal Class 2 cases treated with activator]. / Aktivatör ile tedavi edilmis iskeletsel 2 sinif vakalarda kontansiyon sonu ortodontik bölgedeki degisiklikler.

The aim of this study is to investigate the stability of the results obtained through functional orthodontic treatments after the retention period in skeletal class 2 cases. 14 subjects having skeletal class 2 structures with a skeletal age of approximately 11 years were examined. 7 out of 14 were separated as treatment group, where the other 7 were separated as the control group. Contantion treatment was performed to the treatment group, for a period of 2 years in average, which have been treated with activators for approximately 1 year. The cephalometric radiographs of all subjects were taken at the beginning and the end of treatment and retention. The measurements relating to cephalometric tracing were statistically evaluated.