Screening and Identification of Early Biomarkers for Orthodontic External Apical Root Resorption via Gingival Crevicular Fluid Proteomics

doi:10.13701/j.cnki.kqyxyj.2026.09.006

Abstract

Abstract: Objective: To explore early diagnostic biomarkers for orthodontic external apical root resorption (EARR) and provide a molecular basis for early clinical warning. Methods: The study included 15 patients clinically and radiographically confirmed with orthodontic EARR, and their gingival crevicular fluid samples were collected. Data-independent acquisition (DIA) proteomics technology was employed for protein analysis. Key proteins were screened by combining LASSO regression machine learning algorithms. The identified key proteins were experimentally validated in clinical samples and in a mechanical stress model using osteocementum-like cells OCCM-30 via enzyme-linked immunosorbent assay (ELISA) and Western blot. Results: A total of 759 proteins were identified, among which 51 were differentially expressed proteins. Based on the machine learning algorithms, S100 calcium binding protein A2 (S100A2), S100 calcium binding protein A9 (S100A9), and Calpain 2 (CAPN2) were identified as key hub proteins. Receiver operating characteristic (ROC) curve analysis demonstrated that all three proteins possessed good diagnostic discriminatory capability [area under the curve (AUC)>0.7]. ELISA and Western blot results further confirmed that the expression levels of S100A2, S100A9, and CAPN2 were significantly upregulated at the T1 stage and under in vitro compressive conditions (P<0.05). Conclusion: S100A2, S100A9, and CAPN2 are potential early diagnostic biomarkers for EARR. Their expression is regulated by mechanical stress and they may be involved in processes such as inflammatory activation and cellular structure disruption. This study provides a molecular basis for the non-invasive monitoring and clinical prevention management of EARR.

Key words: orthodontically induced external apical root resorption, gingival crevicular fluid, proteomics, biomarkers, machine learning

HE Jiayue, CHEN Shiman, LIU Yuxin, LI Luoxin, SHEN Yufeng, ZHOU Zheng. Screening and Identification of Early Biomarkers for Orthodontic External Apical Root Resorption via Gingival Crevicular Fluid Proteomics[J]. Journal of Oral Science Research, 2026, 42(9): 764-770.

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