TMJ Concepts Scanning Protocol
This protocol is to ensure that accurate 3-D bone models can
be created and used for the design and manufacture of patient-fitted
temporomandibular joint prostheses. This protocol is not intended for
use with cone beam scanners. TMJ Concepts does not accept cone beam
scans for models that are intended to be used for the fabrication of
TMJ prostheses. Please review the following information before
proceeding with the scanning process.
If you have any questions, please contact our modeling vendor,
ProtoMED, at 303-466-5610 or TMJ Concepts at 805-650-3391 (Toll free
800-504-9527) prior to scanning the patient. TMJ Concepts can be
visited on the web at www.tmjconcepts.com.
|
Helical Scanning
Parameters
|
|
Scan Area
|
TMJ/Mandible/Maxilla
(per diagram) |
| Algorithm |
Standard
(Do not use Detail or Bone) |
Preferred
Algorithms
GE..............Standard
Phillips........B
Siemens.....H30s
Toshiba......FC30 or FC03* |
| FOV |
20
cm (may be adjusted to best fit patient anatomy) |
| Pitch |
1:1 |
| Slice Interval |
0.5mm to 1mm
Do Not Reformat |
| Slice
Thickness |
Same
as slice interval |
| mAs |
120-180
(maximize without overheating tube) |
| Archival |
Uncompressed
DICOM image data on CD |

* Toshiba scanners: Use whichever is identified as a STANDARD
algorithm on your machine.
PRE-SCAN CHECKLIST
- Remove any jewelry that is in the scan area.
- Stabilize the patient with sponges, tape, and any other
accessories that will not cause injury to the patient or affect the
quality of the scan. It is extremely important that the
patient does not move or swallow during the scanning process.
- Position the patient so that he/she lay supine.
- Patient should be scanned in good occlusion when possible.
Patients that cannot achieve a good occlusal position should be scanned
with a bite jig or other apparatus to stabilize and separate the teeth.
If there is any question regarding what is appropriate, please contact
the ordering surgeon.
PROCEDURE
- Inform the patient when the actual scanning process
starts. Instruct them to not move or swallow until the scan is
complete. If there is movement, the patient must be re-scanned.
- Take a scout view and locate the first slice position. Make
sure the head is positioned symmetrically so that the first slice is
positioned correctly for both the left and right TMJ.
- Start the scan a minimum of 5mm above the roof of the
fossae. Be sure that both inferior orbital borders and EAC’s are
included. Scan through the tip of the chin.
- Scans must not
be provided with greater than 1mm slice intervals. If your standard
scanning parameters are .5mm, .625mm, or .75mm slice intervals, please
provide the greatest level of detail scanned. Do not
reformat axial slice data into a different slice interval.
- Only axial image data is required. If possible, retain the
raw CT data until the scan has been reviewed by TMJ Concepts.
- Data should be archived onto a CD or optical disk in an
uncompressed DICOM format using a standard-type algorithm. Do not
use a Detail or Bone algorithm. Preferred algorithms for common
scanners are shown in the table above.
- Label the disk with surgeon name, patient name, date of
scan, technician name, scanner type, scan site name and phone number.
- Send data to TMJ Concepts via overnight shipping or via
ftp. For instructions on uploading CT data via ftp, contact TMJ Concepts.