Until now, lateral two-dimensional methods are used to assess three-dimensional changes that occur in the facial soft tissue of orthodontic patients. In this study a method for three- dimensional morphometric assessment of facial soft tissue changes following orthodontic treatment was introduced. Forty patients who underwent orthodontic treatment that resulted in lateral profile changes in the facial soft tissue were included in the study. Twenty patients underwent orthodontic treatment that resulted in facial soft tissue profile retraction and twenty patients underwent orthodontic treatment that resulted in soft tissue profile advancement. Two dimensional comparisons between pre-treatment and post- treatment lateral radiographs were carried out . Then, computerized pre-treatment and post-treatment three-dimensional head models were constructed for each patient utilizing frontal and lateral photographs. Computer graphic facial analysis was carried out to measure the three-dimensional volumetric deformation in each head model after orthodontic treatment in order to determine the changes that occur in the facial soft tissue of patients following orthodontic treatment.