Fig. 2

Quantification of the additional skeletal effect produced by the Herbst appliance. The morphological changes for each case in the Herbst group are shown in the first column; T2 image (yellow) is superimposed on T1 image (green). The adjacent color map shows the morphological changes that occurred in this interval, with red indicating regions of outward changes, white zero changes and blue inward changes. For example, outward changes occur at the condylar head and inward changes at the condylar neck in case one. The molars move mesially and the lower incisors procline anteriorly. Estimated morphological changes of the corresponding age- and sex-matched mandible during the same period is shown in column 2. Column 3 subtracts the morphological changes in the first and second column, indicating the additional skeletal effects for each case and these are used to calculate the mean morphological changes for the Herbst group