{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T09:59:26Z","timestamp":1790589566356,"version":"4.1.0"},"reference-count":41,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T00:00:00Z","timestamp":1790553600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T00:00:00Z","timestamp":1790553600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Int Endodontic J"],"abstract":"ABSTRACT<\/jats:title>\n \n Aim<\/jats:title>\n To develop and validate a machine learning\u2010based automated computational framework using periapical radiographs for the detection, segmentation and classification of root canal curvature in mandibular premolars with single canals, and to evaluate the contribution of geometric and deep learning features towards diagnostic performance.<\/jats:p>\n <\/jats:sec>\n \n Methodology<\/jats:title>\n A retrospective cross\u2010sectional study was performed using 1644 periapical images of mandibular premolars. A four\u2010stage multi\u2010model framework was proposed using a single fixed 10\u2010fold cross\u2010validation partition applied consistently across all four stages to prevent data leakage between training and evaluation. The object detection models were YOLOv8, YOLOv11 and RF\u2010DETR. For segmentation of the root canal, YOLOv8\u2010seg, YOLOv11\u2010seg and Attention U\u2010Net were used. The multiparametric feature extraction included five geometric morphometric features automatically derived from a binary mask and 2048 deep convolutional neural network features from ResNet\u201050. Classification of curvature was defined using an eXtreme Gradient Boosting (XGBoost) classifier with stratified 10\u2010fold cross\u2010validation, with Synthetic Minority Over\u2010sampling Technique (SMOTE) and algorithmic class weighting applied within the training folds of each cross\u2010validation iteration.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n The dataset included 633 straight, 885 moderately curved and 126 severely curved canals. RF\u2010DETR achieved a recall of 97.5%, precision of 93.3% and F1\u2010score of 95.4% for premolar detection. The YOLOv11\u2010seg model was successful in segmenting the root canal with a Dice score of 85.8% and an IoU of 77.5%. All five geometric parameters were statistically significant for different severity groups (\n p<\/jats:italic>\n \u2010value <\u20090.001). For the end\u2010to\u2010end curvature classification, the hybrid feature fusion model produced the highest overall metrics, achieving an accuracy of 89.60%, a recall of 83.80% and an F1\u2010score of 86.77%, compared to the models using either geometric features (88.38% accuracy) or deep learning features alone (82.42% accuracy).\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n The hybrid feature\u2010fusion model reached the highest overall classification accuracy at 89.60%. Although the geometric\u2010only model had higher sensitivity for severe curvature with 80.6% compared to 69.1%, L\u00fciten's angle was the most prominent predictor of curvature severity. Due to the limitations of two\u2010dimensional radiographs in displaying buccolingual curvatures, this framework works best as a screening aid as it helps identify canals that need adjunctive three\u2010dimensional evaluation.<\/jats:p>\n <\/jats:sec>","DOI":"10.1111\/iej.70281","type":"journal-article","created":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T09:43:27Z","timestamp":1790588607000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Automated Root Canal Curvature Assessment From Periapical Radiographs Using Geometric and Deep Learning Features"],"prefix":"10.1111","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-8831-3981","authenticated-orcid":false,"given":"Balaganesh","family":"Pachaiappan","sequence":"first","affiliation":[{"name":"Department of Conservative Dentistry and Endodontics Sri Venkateswara Dental College and Hospital Chennai India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8811-2960","authenticated-orcid":false,"given":"Saravanan","family":"Poorni","sequence":"additional","affiliation":[{"name":"Department of Conservative Dentistry and Endodontics Sri Venkateswara Dental College and Hospital Chennai India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6929-4594","authenticated-orcid":false,"given":"Srividhya","family":"Srinivasan","sequence":"additional","affiliation":[{"name":"Department of Conservative Dentistry and Endodontics Sri Venkateswara Dental College and Hospital Chennai India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9709-8395","authenticated-orcid":false,"given":"Cruz","family":"Nishanthine","sequence":"additional","affiliation":[{"name":"Department of Conservative Dentistry and Endodontics Sri Venkateswara Dental College and Hospital Chennai India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3651-181X","authenticated-orcid":false,"given":"Manali Ramakrishnan","family":"Srinivasan","sequence":"additional","affiliation":[{"name":"Department of Conservative Dentistry and Endodontics Sri Venkateswara Dental College and Hospital Chennai India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9798-3872","authenticated-orcid":false,"given":"Thilla Sekar","family":"Vinothkumar","sequence":"additional","affiliation":[{"name":"Department of Restorative Dental Sciences, College of Dentistry Jazan University Jazan Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3783-3156","authenticated-orcid":false,"given":"Venkateshbabu","family":"Nagendrababu","sequence":"additional","affiliation":[{"name":"Department of Restorative Dentistry, College of Dental Medicine University of Sharjah Sharjah UAE"},{"name":"Department of Conservative Dentistry and Endodontics Dr. D. Y. Patil Dental College & Hospital, Dr. D. Y. Patil Vidyapeeth (Deemed To Be University) Pimpri India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0726-7467","authenticated-orcid":false,"given":"Paul M. 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