RESUMO
BACKGROUND: To quantify the accuracy of Dolphin Imaging software in predicting soft tissue changes of Class II Division 1 incisor relationship treated by all first premolar extraction compared with actual changes. METHODS: Pretreatment and post-treatment lateral cephalograms of 30 young adult subjects (25 females and 5 males; age range of 16 to 21 years) were imported and traced in Dolphin Imaging software (version 11.95). Tracings of actual treatment results and the Dolphin predicted treatment outcome were superimposed to calculate the prediction errors. The mean difference for the Holdaway soft tissue analysis and at each landmark was measured in both the X and Y axes. Paired t test was used to compare the statistical differences in Holdaway soft tissue analysis parameters. RESULTS: There were significant differences between the predicted and actual values in three parameters of the Holdaway soft tissue analysis (P < 0.05). The overall accuracy of estimation was better in vertical direction than horizontal. Prediction of upper and lower lip landmarks was overestimated horizontally and underestimated vertically, whereas that belonging to chin was underestimated horizontally and overestimated vertically. Soft tissue nasion and soft tissue A-point were most accurately predicted, whereas the least accuracy was found in soft tissue chin region. CONCLUSIONS: Dolphin Imaging Software (version 11.95) can be accurate enough for use in patient communication and education but should be used with caution. It is most accurate in predicting soft tissue changes in the nasion and A-point regions, but least accurate in chin region.