An external modelling method, including applying to a nose of initial external shape F0, at least two modelling instruments I, to guide the growth of the nose cartilage and thus obtain a target final external nose shape Ff when the individual has stopped growing, which differs from a natural external shape Fn which would be obtained naturally in the absence of intervention. A set of modelling instruments is provided, the successive shapes of which are determined to represent an evolving succession of one or more target intermediate shapes F, from the initial external nose shape F0 through to the target final external shape Ff. A method of producing the modelling instruments is provided, during which method, starting from the initial external nose shape F0, a target final shape Ff and at least one target intermediate shape F are determined. The instruments corresponding to each target shape are manufactured.