[Study of the structural compensation of the mandible during treatment with cervical headgear].

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.