Purpose:This study sought to develop an understanding of the magnitude and types
of loads generated on craniofacial implants supporting an auricular prosthesis.
Materials and Methods:Strain gauges were used to measure the in vitro and in vivo
misfit loads generated when connecting auricular-style superstructures to implants
and the in vivo functional load generated during the removal and insertion of the
auricular prostheses. In addition, the vertical misfit of the 11 custom-built two-implant
superstructures used in the in vitro study was measured. Results:Superstructures
used in the in vitro study that were considered clinically passive still had considerable
preloads. In addition, the calibrated loads, which would result from the vertical misfit
alone, did not account for the magnitude of the generated preloads. Conclusion:The
clinical definition of misfit based on vertical distortion of the superstructure did not
quantify the resulting misfit load. Measured in vivo functional loads were smaller than
the misfit loads. Int J Prosthodont 2004;17:267–273.