Using Fiducial Markers for Live Surgical Tracking
Thermoplastic fiducial markers play a crucial role in guided implant surgery by enabling accurate anatomical tracking. When properly placed and scanned, these markers provide a reliable reference for live navigation during implant placement.
In partially edentulous patients, an impression of the teeth is taken by a fiducial marker (Figure 1A). To take that impression, the fiducial clip (X-clip) is placed in a hot water bath at a temperature of 140° to 160 °F for 3 to 5 minutes until the thermoplastic material is clear and then an impression is taken on the opposite side of the same arch that the implant is to be placed, as to not interfere with the drilling of the implants (Figure 1B).
Once an impression is taken, the fiducial is removed and placed in cold water; it is then tried on again in the patient’s mouth to confirm stability and accuracy. The clinician must ensure that whenever the fiducial is taken out, it is placed back into the same location in the patient’s mouth to ensure registration is accurate (Figure 1C). Once the fiducial is confirmed to be stable in the patient’s mouth, the clinician then takes a CBCT of that jaw with the fiducial marker in place (Figure 1D). The fiducial marker has an area to which the tracker arms and the patient tracker attach. This allows for live tracking during the surgery of the patient’s anatomy as displayed in the CBCT (Figure 2).
By carefully heating, molding, and stabilizing the fiducial clip, then verifying its consistent placement during imaging, clinicians can ensure accurate registration for CBCT-guided implant surgery. This method supports improved precision, safety, and outcomes in implant procedures.
This originally appeared in AlQallaf H, Lin SW, Polido W, Yang CC. Exploring dynamic computer-assisted implant surgery. Decisions in Dentistry. 2024;10(6):32-35.
