Introduction of the axial vision filmoscope - Endoscopy performed till the genu inferius. Detailed location of the puncture point thanks to the parietal transillumination - Skin disinfection - Local anaesthesia of the puncture subject - Skin incision - Introduction of the torcard and of the guiding thread - Exit of the guiding thread at the patient mouth - The oral end of the guiding thread is tied at the securing ring of the probe - Traction on the abdominal end of the thread - Exit of the probe - Setting of the external devices.