The invention relates to a method for computer-aided planning of a repair or adjustment of a dental partial prosthesis with the following method steps: generation of a first digital 3D model of a jaw with the partial prosthesis positioned on the jaw as a prosthesis reference model (M1), generation of a second digital 3D model of the jaw, without the partial prosthesis, as a jaw model (M2), determination of a positional relationship of the prosthesis reference model (M1) to the jaw model (M2), generation of a digital prosthesis model (P) by subtracting the jaw model (M2) from the prosthesis reference model (M2) while taking the positional relationship into account, automatic identification and/or identification carried out by a user of holding and/or support elements in the prosthesis model (P), calculation of an insertion axis of the partial prosthesis on the basis of the prosthesis model (P), calculation of undercut depths, resulting from the insertion axis, of the holding and/or support elements in the prosthesis model (P), display of the insertion axis and the undercut depths in the presentation of the jaw model (M2).
