ẢNH HƯỞNG CỦA SAI KHỚP CẮN ĐẾN THỜI GIAN ĐÓNG VÀ MỞ KHỚP LIÊN HÀM Ở NGƯỜI TRƯỞNG THÀNH

Abstract

Objectives: To determine the influence of malocclusion according to Angle’s classification on intermaxillary occlusion time (OT) and disclusion time (DT) in adults aged 18 - 25. Methods: A comparative, cross-sectional descriptive study was conducted on 124 adults at University of Social Sciences and Humanities, Vietnam National University Hanoi with Angle class I, II (divisions 1 and 2), and Angle III malocclusion whose OT and DT were measured using the T-scan system from August to November 2025. Results: OT and DT (DT-L, DT-R, DT-P) increased progressively with the severity of malocclusion, following a distinct order: Angle class III > Angle class II/2 > Angle class I > Angle class II/1 (p < 0,05). Angle class III and Angle class II/2 exhibited the longest DTs, reflecting less stable mandibular pathways, more occlusal interferences, and longer functional glide distances. Angle class I remained within normal functional limits, whereas Angle class II/1 consistently showed the shortest times due to the increased overjet, which facilitates faster disclusion and earlier posterior tooth contact during the occlusal cycle. Conclusion: OT and DT significantly affect the functional stability of the masticatory system. These parameters should, therefore, be used as criteria for predicting and evaluating the functional outcome of orthodontic or prosthodontic treatment.