The Horizon Sign and Frontal Bar: Two Topographic Landmarks to Confirm Endoscopic Frontal Sinusotomy
Bibliographic record
Abstract
Confirming a thorough dissection of the frontal sinus during endoscopic sinus surgery can be challenging, and some surgeons would benefit from reliable topographic landmark identification to ensure completion of this sinus dissection. We defined (1) the "horizon sign" as the curvilinear shadow of the posterior table cast superiorly upon the anterior table of the frontal sinus at the acute angle of their meeting point and (2) the "frontal bar" as a sagittal septation at the union of the anterior/posterior tables. A cadaveric study, followed by an intraoperative consecutive case series, was performed to evaluate these 2 landmarks as indicators of complete dissection. The horizon sign was extremely reliable, identified in 100% of cadaveric frontal sinuses and intraoperative frontal sinuses. The frontal bar was present in only 67% of frontal sinuses by computed tomography. In live patients, the sensitivity and specificity of the frontal bar were 62% and 95%, respectively.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.002 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".