SỰ CẦN THIẾT CAN THIỆP CHỈNH NHA SỚM TRÊN TRẺ CÓ TƯƠNG QUAN RĂNG 6 DẠNG ĐỐI ĐỈNH Ở BỘ RĂNG HỖN HỢP

Abstract

Introduction: An end-to-end relationship of the first permanent molar (Angle Class II 50%) is a common occlusal presentation and is generally considered normal during the mixed-dentition stage. However, if not monitored and managed early, it may progress to an abnormal molar relationship in the permanent dentition. To date, no longitudinal study in Vietnam has assessed changes in this occlusion from mixed to permanent dentition. Objectives: To evaluate the developmental progression of occlusal morphology in subjects presenting with an end-to-end R6 relationship from the mixed- to the permanent-dentition stage. Materials and Methods: In this retrospective longitudinal study, 112 hemi-arches exhibiting an edge-to-edge R6 relationship in the early mixed dentition (T2) were followed until the permanent dentition stage (T3). At T2, only hemi-arches with an end-to-end first-molar relationship were included. At T3, the R6 relationship was reclassified into Angle Class I, II, or III. Results: Of the 112 hemi-arches with an initial edge-to-edge R6 relationship at T2, 84 (75%) converted to a Class I first-molar relationship by T3, while 28 (25%) progressed to Class II. Conclusion: An edge-to-edge first-molar relationship in the mixed dentition shows a high potential for spontaneous correction to Class I in most cases; however, approximately one-quarter of cases advance to Class II. Early identification and monitoring of high-risk individuals are therefore essential to facilitate timely intervention and achieve ideal molar relationships in the permanent dentition.