Abstract: A peg has a one-piece clip essentially consisting of two branches, each branch having an anterior part forming a jaw and a posterior part forming a lever arm. The peg also has a hinge around a rotational axis that connects the branches at an intermediate point. A spring extending along a direction substantially perpendicular to the rotational axis is mounted and compressed between the two lever-forming parts of the two branches. The spring urges, under its biasing resilience, the two branches to a closed position. The spring has a biasing force in the direction of increasing its axial longitudinal dimension that is more controllable over time than a spring having a biasing torque. Thus, over time the pressure exerted by the arms of the peg in the closed position remains more constant.