[The appearance after osteotomy of the jaw]

A patient undergoing orthognathic surgery wants to know in advance what he will look like after the treatment. For this purpose a prediction tracing may be used. The value i.e. precision of such a tracing is discussed. Several factors seem to limit the reliability of the prediction, such as 1. the surgery is not always executed as planned; 2. a (partial) relapse influences the final result; 3. rotational movements cannot yet be integrated with precision in the prognosis; 4. the ratios used in the planning are not absolutely reliable. Nevertheless, the prediction tracing is useful if one is aware of its shortcomings.