Efficiency of three mandibular anchorage forms in Herbst treatment: a cephalometric investigation

The aim of this study was to analyze the efficiency of the mandibular banded and cast splint anchorage forms used in Herbst treatment. The records of 16 Class II:1 subjects treated with mandibular banded premolar anchorage (group A), 19 Class II:1 subjects treated with mandibular banded premolar-molar anchorage (group B), 34 Class II:1 subjects (group C), and 18 Class 11:2 subjects treated with mandibular cast splint anchorage (group D) were screened. The subjects in all four groups were treated for an average period of 0.6 years. Lateral head films were analyzed on four occasions ie, before treatment, after treatment, two years after, and four years after treatment. Mandibular anchorage loss during treatment was measured by the amount of anterior movement and proclination of the lower incisors as well as the anterior movement of the lower molars. During the treatment period a pronounced (P < .001) anchorage loss was found for all anchorage forms ie, incisor anterior movement/proclination as well as anterior movement of the lower molars. When comparing the cast splint anchorage in the Class II:1 and Class II: 2 cases, no difference was found with respect to the amount of mandibular anchorage loss of the incisors. After Herbst treatment, relapsing tooth movements were found in all three anchorage forms. It can be concluded that none of the three mandibular anchorage forms used in Herbst treatment could prevent an anchorage loss. Against all expectations, the cast splint anchorage was not better than the two banded anchorage forms.