Mandibular prognathism is a facial disharmony characterized by an anterior relationship of the mandible to the upper jaw. Some authors associate the increased volume of the tongue with the development of this anomaly. Currently in scientific literature it is debated whether the tongue actively shapes the surrounding tissues or adapts to existing conditions. The aim of this study is to evaluate the volume of the tongue at the patients with class III malocclusion compared to class I patients using three-dimensional volumetric analysis based on computed tomography