A comparison of 3 methods of Face-bow transfer recording: Implications for orthognathic surgery

Purpose: The purpose of this study was to compare the occlusal plane inclination of models mounted using 3 different systems for face-bow transfer with the actual occlusal plane inclination as measured on a cephalometric radiograph. Patients and Methods: Twenty-two subjects were enrolled in this study. Three alginate impressions of the maxillary dentition were taken, and 3 stone dental models were produced for each subject. Face-bow recordings were obtained on each subject using the SAM Anatomical Face-bow (Great Lakes Orthodontics Products, Ltd, Tonawanda, NY), the Erickson Surgical Face-bow (Great Lakes Orthodontics Products, Ltd) and a new technique developed by one of the authors (J.G.). For each subject, the dental models were mounted on a SAM articulator using each of the 3 face-bow recordings. Finally, a lateral cephalometric radiograph was obtained for each subject. The occlusal plane inclination was measured on the models and on the cephalometric radiographs. Differences among groups were tested using a 1-way analysis of variance. Bonferroni test was used for post hoc comparison between different pairs of groups. Results: The average occlusal plane inclination using the SAM Anatomical Face-bow was 7.8° ± 4.2° greater than the actual - a difference that was statistically significant. The mean occlusal plane inclination of the models obtained using the Erickson Surgical Face-bow was 4.4° ± 2.2° greater than the actual - a difference that was also statistically significant. The mean occlusal plane inclination of the models obtained by the new technique was only 0.9° ± 1.2° greater than the actual; this difference was not statistically significant. Conclusions: The new mounting technique is more accurate than the conventional SAM Face-bow or the Erickson Face-bow for reproducing the actual occlusal plane inclination.