Dr. Zeev Abraham (DMD, MS, MSc)

This example case demonstrates the value of new digital technologies, when using the cephX (Orca) automated teeth segmentation service for CBCT data.

Patient History:

Patient Profile: Patient is 13-years old male.

Classification: Skeletal Class l Medium crowding in Maxilla Mild crowding in the mandible Bilateral Crossbite

Dental History: No restorations (only Fissure Sealant) ; A few prior visits to the dentist.

Breathing: Combined mouth and nose.

Case Evaluation:

  1. Symmetric soft tissue smile
  2. Upper midline coincides with mid-facial line
  3. Exposure of 95% of central incisors
  4. Slight gum exposure
  5. Lower teeth shown in smile
  6. Lower midline 2 mm right of uppermidline (dental shift)
  7. Crossbite – 14 to 17, and 24 to 35
  8. Tooth 13 unerupted and impacted
  9. Tooth 23 ectopic and eruptedbuccal to 22

Intraoral Evaluation vs. Study Model (Left)

Intraoral Evaluation vs. Study Model (right)

Panoramic Analysis:

  • The Condyles are symmetrical
  • 3rd molar buds developing
  • Tooth 13 is impacted
  • The root of 12 is probably resorbedPeriapicalsX-Rays:
  • Dilacerations of lower incisor roots
  • Impacted Tooth 13 partially buccal and partially palatal to 12 root.
  • Impacted 13

CBCT

Discussion:

In the panorex, generated by the DICOM of a standard CBCT, there is a suspicion that the root of 12 has been resorbed by the impacted 13 situated above and palatal to its root.

The extent of resorbtion is not clear in any of the relevant anterior/posterior cuts numbered 12 to 16.

There is no suspicion that the root of 22 has been damaged by the buccaly positioned 23, to the extent that the technician did not even identify any 2D transverse cuts in that area.

However, in the 3D STL file generated by the cephX’s automated segmentation algorithm, we could clearly see the relationship and extent of resorbtion of the 12 and 22 roots.
Video – https://youtu.be/Y_2r6Hhgo8o

A video of the segmentation, generated automatically by CephX

Of particular interest, the 22 root was unsuspectedly and uncharacteristically resorbed on its buccal side while leaving the absolute length of the root intact.

Conclusion:

As a result of the clear resorbtion of 12 and 22 roots, there is a valid reason to extract both the 12 and 22 and resolve space requirements accordingly

CephX software was a tremendous help enabling quick detection and diagnosis of the resorbed teeth. The STL files that were generated by CephX allowed us to view each tooth separately and to have a better understanding of the patients’ intra-alveolar dental layout.