Dynamic 3D images (a tongue model) are crucial for tongue movement analysis in patients with speech disorders. Therefore, a tongue model construction tool was developed at the Showa University School of Dentistry and Tokyo City University to examine tongue movements during phonation. First, the ultrasound images of the tongue were obtained at a resting position and during speech using the 3D/4D probes of an ultrasound diagnostic device, both for a healthy subject (Normal subject) and a patient with lateral articulation (LA patient). Then, a tongue model construction tool was developed, which created a tongue model based on 2D ultrasound images. Subsequently, the 3D movies of the tongue movements of a both subjects were developed and analyzed. By observing the 3D tongue movements of the LA patient, the tongue model construction tool revealed asymmetrical heights at the lingual edges, upper protrusion of the tongue, and groove formation for airflow. Therefore, this study generated 3D movies using the tongue model construction tool, which were considered useful for conducting detailed observations of tongue movements. Furthermore, visualizing tongue models may be effective in patients with speech disorders, thereby helping them regain normal speech.