Impaction risk increases significantly with each year of late third molar development in Western Canadian youths
Bibliographic record
Abstract
OBJECTIVE: Third molar (M3) impaction affects millions of patients annually worldwide yet its etiology is unclear. Here we study an underexplored risk factor for impaction, later versus earlier M3 development, towards calculating impaction risk as a resource for clinicians. DESIGN: A total of 324 M3 areas (157 maxillary, 167 mandibular) were studied using retrospective CBCT scans and orthopantomograms of 99 Western Canadians (57 females, 42 males) aged 6-24 years. M3 crypt, crown and root development stage data were collected at an earlier timepoint T1 and then tested for association with M3 eruption status data documented at a later timepoint T2. This testing used Generalized Linear Mixed and Estimation modeling to explore relationships between M3 development stage and eruption status, and measure likelihood of versus functional emergence versus impaction risk (alpha level=0.05). RESULTS: Statistically, each year of late M3 development at T1 nearly doubled an M3's risk of impaction at T2. Early-developing M3s had minimal impaction risk, as low as 5 %. This outcome was equivalent in upper and lower jaws and both sexes. Impacted M3s' development was delayed due to later developmental onset, not to slower developmental rate. CONCLUSIONS: Late-developing M3s are statistically more likely to become impacted. Clinical monitoring of M3 development from preadolescence is suggested. As early-developing M3s present minimal impaction risk, they are less likely to require prophylactic removal. This work provides foundational new insights into molar odontogenesis alongside practical information to help develop guidelines for managing patients with developing M3s.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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 teacher head, 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".