A comparative study of two arbitrary face-bow transfer systems for orthognathic surgery planning

Area of Science:

• Dental Occlusion and Articulation
• Orthognathic Surgery Planning
• Biomedical Engineering

Background:

• Accurate face-bow transfer is crucial for precise orthognathic surgery planning.
• Existing arbitrary face-bow systems (Denar Slidematic, Dentatus type AEB) have variable reproducibility.
• Assessing the three-dimensional spatial accuracy of maxillary cast orientation is essential.

Purpose of the Study:

• To compare the relative reproducibility of the Denar Slidematic and Dentatus type AEB face-bow systems.
• To develop a novel method for assessing three-dimensional variation in maxillary cast position and orientation.
• To evaluate face-bow transfer accuracy for orthognathic surgery planning across different skeletal types and operators.

Main Methods:

• Developed a novel method to quantify three-dimensional spatial variation of the maxillary cast.
• Assessed the reproducibility of Denar Slidematic and Dentatus type AEB arbitrary face-bow transfer systems.
• Compared system performance across different operators and skeletal types using a defined 'envelope of movement'.

Main Results:

• The overall face-bow/articulator procedure exhibited poor reproducibility.
• The Denar Slidematic system showed significantly better reproducibility (P < 0.001) than the Dentatus type AEB.
• Errors were more pronounced in the anteroposterior and lateral planes compared to the vertical plane; operator differences were not significant.

Conclusions:

• Arbitrary face-bow transfer systems demonstrate limited reproducibility for orthognathic surgery planning.
• The Denar Slidematic system offers superior accuracy over the Dentatus type AEB.
• Further improvements in face-bow technology are needed to enhance the reliability of virtual surgical planning.