Design and validation of mirror skills instruction.

Students contorted to achieve direct vision indicate that training of mirror skills is absent or ineffective. Training referenced in the literature is not described or amounts to practice using a mirror to perform a psychomotor task often marginally related to dental procedures. No complete task analysis of mirror use is reported. In this study, the authors applied instructional engineering principles to 1) analyze the task and design instruction, 2) validate instruction, and 3) foster mirror use. First-year students (experimentals) completed the new mirror instruction as well as the regular course instruction. A randomly selected group of second-year students who had not completed the mirror instruction but had completed a similar course comprised the control group for the validation. Sets of randomly grouped experimental subjects evaluated a maxillary preparation using mirror vision at three times during the semester and one time a year later. The controls evaluated the same preparation the first time only. Accuracy in describing the critical features of the preparation was used as an indicator of mirror skill. All subjects were observed for mirror use during a practical examination involving maxillary preparations. All groups were equivalent on entering GPA, DAT-A, and DAT-P. Experimental groups made significant improvement in measures of mirror vision skill over time. Experimental groups 2, 3, and 4 significantly outperformed controls on the same measures and demonstrated significantly higher rate of mirror use during the practical exam. The mirror skills instruction appears valid.