A distribution block provided for distributing molten thermoplastic material for depositing and superimposing it in layers (6, 6', 6") on a support with a view to fabricating a three-dimensional object: - the distribution block comprising at least one extrusion die and a rotary spindle to which the extrusion die is fastened in a manner such as to rotate with the extrusion die in a plane parallel to the deposition face of the extruded thermoplastic material; - the extrusion die being provided for depositing and superimposing layers (6, 6 ', 6") of molten thermoplastic material on a support in accordance with a deposition plane with a view to fabricating a three-dimensional object, said extrusion die comprising at least one flow channel for supplying at least one extrusion orifice with thermoplastic material through which the thermoplastic material is expelled out of the extrusion die in accordance with a direction defining the extrusion axis of the extrusion die, the extrusion orifice being located laterally in the lower part of the extrusion die in a manner such that, when the extrusion die has a zero inclination with respect to a vertical plane, the thermoplastic material is expelled out of said extrusion orifice in accordance with a substantially horizontal extrusion axis; and the extrusion block is characterized in that: - the rotary spindle is a substantially cylindrical part which is rotatably housed in a cylindrical recess provided in the body of the distribution block and the rotary spindle comprises at least one annular groove which is open towards the internal face of the cylindrical recess of the body of the distribution block, this annular groove communicating both with the flow channels of the extrusion die and with at least one flow channel provided in the body of the distribution block and communicating with a device for supplying thermoplastic material. - the distribution block comprising at least one extrusion die and a rotary spindle to which the extrusion die is fastened in a manner such as to rotate with the extrusion die in a plane parallel to the deposition face of the extruded thermoplastic material; - the extrusion die being provided for depositing and superimposing layers (6, 6 ', 6") of molten thermoplastic material on a support in accordance with a deposition plane with a view to fabricating a three-dimensional object, said extrusion die comprising at least one flow channel for supplying at least one extrusion orifice with thermoplastic material through which the thermoplastic material is expelled out of the extrusion die in accordance with a direction defining the extrusion axis of the extrusion die, the extrusion orifice being located laterally in the lower part of the extrusion die in a manner such that, when the extrusion die has a zero inclination with respect to a vertical plane, the thermoplastic material is expelled out of said extrusion orifice in accordance with a substantially horizontal extrusion axis; and the extrusion block is characterized in that: - the rotary spindle is a substantially cylindrical part which is rotatably housed in a cylindrical recess provided in the body of the distribution block and the rotary spindle comprises at least one annular groove which is open towards the internal face of the cylindrical recess of the body of the distribution block, this annular groove communicating both with the flow channels of the extrusion die and with at least one flow channel provided in the body of the distribution block and communicating with a device for supplying thermoplastic material. - the rotary spindle is a substantially cylindrical part which is rotatably housed in a cylindrical recess provided in the body of the distribution block and the rotary spindle comprises at least one annular groove which is open towards the internal face of the cylindrical recess of the body of the distribution block, this annular groove communicating both with the flow channels of the extrusion die and with at least one flow channel provided in the body of the distribution block and communicating with a device for supplying thermoplastic material.