Table
2:
Implant evaluation according to the classification
proposed by Wiesner and Schizas.
|
Grade |
Description |
|
|
Cortical
encroachment |
Questionable perforation. |
|
|
Frank
penetration: |
Distance
that the edge of the screw thread extended outside the pedicle cortex. |
|
|
|
Minor |
≤
2.0 mm. |
|
|
Moderate: |
2.1-4
mm or < 1 screw thread diameter. |
|
|
Severe: |
>
4 mm or > 1 screw diameter. |