Unilateral condylar hyperplasia (UCH) is a condyle disorder that arises due to osteoblastic hyperactivity, resulting in facial asymmetry, malocclusion and dysfunction. Authors, in this retrospective study, compared "gold standard" manual-segmentation with a "semi-manual one" using 2 kinds of open-source software (Horos and ITK-SNAP; Penn Image Computing and Science Laboratory) to calculate volume of 80 UCH condyles (40 patients). Moreover, volumetric differences between affected condyle and unaffected 1, between males and females, ages, and classification type were also analyzed. Fifteen patients (37.5%) were male and 25 (62.5%) were female. The gender ratio was 5:2, not far from the ratio 2:1 shown in literature. The mean age was 24 (SD 8.6) years; 22.9 (SD 6.6) for males and 24.6 (SD 9.6) for females according with the mean age derived from the Raijmakers et al meta-analysis and the Nitzan et al study. Right side (60%, 24 patients) was more often affected than the left side (40%, 16 patients). The 67.5% (27 patients) were classified as trasversal type, 25% (10 patients) as vertical types and 7.5% (3 patients) as combined. Despite Horos and ITK-SNAP values presenting some differences, the data follows the same tendency. The relationship is stronger for healthy condyles than affected condyles.