Dentofacial changes in children with negative overjet treated by a combined orthodontic and orthopaedic approach

The intention of this study was to investiga$$$e whether any morphologic characteristics found at an early age are helpful in prediction of a good or poor response to early treatment of Angle Class III malocciusions, and to study the dento-alveolar and basal effects of combined retractor and chin-cap therapy. The data were obtained from lateral cephalometric radiographs of 51 children taken before treatment at an age of 4 to 9 years, after a treatment period of 5–18 months and about one and a half years after treatment. A group of children with a normal maxillo-mandibular relationship and a positive overjet was used as a control group. The pretreatment comparison revealed a more anterior position of the jaw angle, a more open angle, and a more acute chin prominence in the group that responded poorly to treatment. The differences between each of the two treatment groups and the control group were very similar. The treatment changes were approximately the same in the two treatment groups, but changes in the group with the good treatment response were more like the changes in the control group than in the group with poor results. Also during the observation period the changes were very similar in the two groups, and without exception indicated a relapse towards Class III morphology. The positive overjet and overbite were maintained in the group with good treatment results. The study does not indicate whether it is possible to maintain the good result throughout the rest of the growth period, but obviously a correct anterior occlusion is favourable for dento-alveolar compensation of unfavourable skeletal change.