Referencing for intraoperative navigation: Evaluation of human bias

Marker‐free registration for intraoperative navigation using the transverse palatal rugae

“…The discrepancies between the model based reference point position and manually planned preoperative reference points were quantified using Elements (Brainlab AG) as FLE. The average FLE describes the discrepancy between the actual and digitally planned registration points on the transverse palatal rugae) was 0.48 mm (Figure 6) which is in accordance with the current literature 18 and possibly caused by misidentification of in situ landmark placement due to human error 18 . TRE was as follows: 0.5 mm to the posterior nasal spine (Point #01, Figure 7), 0.8 mm to the anterior nasal spine (Point #02; Figure 8) 0.3 mm point on the infraorbital rim (Point #03), 0.6 mm to the tip of the right canine (point #02 Figure 9) 0.9 mm at the entrance of the foramen magnum (point #06, Figure 10) and 0.8 mm at the post‐glenoid process (point #07, Figure 11) which corresponds to a mean deviation of 0.65 mm.…”

“…The discrepancies between the model based reference point position and manually planned preoperative reference points were quantified using Elements (Brainlab AG) as FLE. The average FLE describes the discrepancy between the actual and digitally planned registration points on the transverse palatal rugae) was 0.48 mm (Figure 6) which is in accordance with the current literature 18 and possibly caused by misidentification of in situ landmark placement due to human error. 18 TRE was as follows: 0.5 mm to the posterior nasal spine (Point #01, of 8 mutual transformation matrix by calculating the relationship between the coordinates of the actual patient space and the coordinates of the medical image and is therefore the most important step when performing surgical navigation.…”

“…The average FLE describes the discrepancy between the actual and digitally planned registration points on the transverse palatal rugae) was 0.48 mm (Figure 6) which is in accordance with the current literature 18 and possibly caused by misidentification of in situ landmark placement due to human error. 18 TRE was as follows: 0.5 mm to the posterior nasal spine (Point #01, of 8 mutual transformation matrix by calculating the relationship between the coordinates of the actual patient space and the coordinates of the medical image and is therefore the most important step when performing surgical navigation. While skin surface based registration methods in CMFS like the laser surface scanning are subject to wide variations due to regular intraoperative swelling, anatomical landmarks are often hard to reproduce and bonesupported markers require invasive insertion as well as additional 3D imaging for their detection.…”

Metallic Artifact Reduction in Midfacial CT Scans Using Patient-Specific Polymer Implants Enhances Image Quality

“…Contemporary osteosynthesis materials for the mandible and midface are made of titanium which provides excellent biocompatibility and mechanical stability to withstand bite forces. It is generally agreed upon that navigation-assisted surgery and patient-specific osteosynthesis are the gold standard for complex reconstructive procedures to provide superior fitting accuracy compared to manually bending plates [ 4 , 5 ]. However, titanium is well known for causing substantial metallic artifacts in computer tomography (CT) imaging [ 6 , 7 , 8 , 9 ].…”