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Three-dimensional finite element models, reconstructed from cone beam computed tomography (CBCT) data, were used to simulate elevator-assisted extraction processes. Stress distributions and root fracture thresholds were analyzed under three loading modes (wedge, lever, and rotational force) at different abduction angles.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results<\/jats:title>\n            <jats:p>Horizontal impactions demonstrated the lowest fracture resistance under lever forces (38.7\u201350.3\u00a0N), while vertical impactions exhibited the highest thresholds (110.3\u2013342.2\u00a0N). Wedge forces showed angular dependence inversely correlated with fracture thresholds for horizontal impactions (76\u2013174\u00a0N). Rotational moments maintained relatively stable thresholds across all impaction types (X-axis: 21\u201332\u00a0N\u00b7m, Y-axis: 20\u201340.8\u00a0N\u00b7m, Z-axis: 16.3\u201333.5\u00a0N\u00b7m). Surrounding tissue stress decreased with increasing abduction angles under lever and wedge forces (<jats:italic>p<\/jats:italic>\u2009&lt;\u20090.05) but no significant directional correlation was observed under rotational moments.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusions<\/jats:title>\n            <jats:p>Dentin anisotropy and elevator angulation significantly influence fracture mechanics. Clinical protocols should prioritize lever forces for vertical impactions (safety margin\u2009&gt;\u2009100\u00a0N), with wedge and rotational force more effective for horizontal impaction. The findings provide an important theoretical basis for oral surgeons in extracting impacted third molars and for the subsequent development of surgical path planning and intelligent reasoning systems by the research group.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1186\/s12903-025-06744-2","type":"journal-article","created":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T11:52:30Z","timestamp":1759924350000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Fracture threshold of tooth roots and stress analysis of surrounding tissue during the extraction of impacted mandibular third molars using dental elevators"],"prefix":"10.1186","volume":"25","author":[{"given":"Zhengfen","family":"Li","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yijun","family":"Liu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiangling","family":"Sun","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Meiyan","family":"Rong","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cheng","family":"Niu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xubo","family":"Duan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"Yang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mingkun","family":"Liu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2025,10,8]]},"reference":[{"issue":"3","key":"6744_CR1","doi-asserted-by":"publisher","first-page":"267","DOI":"10.1177\/0022034515615857","volume":"95","author":"K Carter","year":"2015","unstructured":"Carter K, Worthington S. 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