TABLE II.
Quantification of New Grading Scale Criteria Into Evaluative Metrics for the Temporal Bone Dissection Simulator.
|
Criteria to Be Included in the New Cross-Institutional Scale |
Importance Rating (%) |
Mode of Assessment for Quantification of the Metric* |
|---|---|---|
| 1. Maintains visibility (of tool) while removing bone | 100 | Technique, contextual |
| 2. Selects appropriate burr type and size | 98.9 | Contextual |
| 3. Antrum entered | 97.9 | Violation |
| 4. No violation of facial nerve sheath | 97.7 | Violation |
| 5. Sigmoid sinus is not entered | 96.5 | Violation |
| 6. Identifies tympanic segment of the facial nerve | 96.5 | Identification |
| 7. Does not drill on ossicle | 93.1 | Violation |
| 8. Does not use excessive drill force near critical structures | 93.0 | Technique Proximity |
| 9. Firm, low, good hand position and grip on drill | 91.9 | Technique |
| 10. Identifies the chorda tympani or stump | 90.7 | Identification |
| 11. Drills with broad strokes | 88.5 | Technique, contextual |
| 12. Drills in best direction (clear understanding of cutting edge) | 88.4 | Technique, contextual |
| 13. Identifies the facial nerve at the cochleariform process | 88.3 | Identification |
| 14. Appropriate depth of cavity (cortex) | 86.0 | Identification |
| 15. Canal wall up (EAC) | 85.6 | Violation |
| 16. No holes in EAC | 84.9 | Violation |
| 17. Complete saucerization (cortex) | 83.0 | Identification |
| 18. Posterior canal wall thinned | 82.4 | Identification |
| 19. Low frequency of drill ‘‘jumps’’ (jumps defined as drilling further than 1 cm from previous spot) | 81.6 | Technique |
| 20. Identifies the facial nerve at the external genu | 80.9 | Identification |
| 21. Facial recess completely exposed (overlying bone sufficiently thinned so nerve can be seen, located, and safely avoided) | 75.9 | Identification |
| 22. No holes in tegmen | 75.6 | Violation |
| 23. Use of diamond burr within 2 mm of facial nerve | 74.5 | Proximity, technique |
| 24. No cells remain on sinodural angle | 71.8 | Identification |
*
Definitions for metric quantification modes of assessment: Contextual = contingent on sequence (steps); Technique = speed, force, angle, etc.; Proximity = distance of tool to structure(s); Violation = % of structure (volume) removed; Identification = % correlated with (composite) expert removal.
EAC = external auditory canal.