Table 1: Classification of frontal osteomas according to extension and implantation.
|
Computed Tomography |
GRADEI |
Posterior inferior implantation in frontal recess Tumor medial to the lamina papyracea Anteroposterior diameter of the tumor is 75% of the anteroposterior diameter of the frontal recess |
GRADEII |
Anteroposterior diameter of the tumor is greater than 75% of the anteroposterior diameter of the frontal recess |
GRADEIII |
Implantation is anterior or superior in the frontal sinus Tumor extends lateral to the lamina papyracea |
GRADEIV |
The tumor occupies the entire frontal sinus |