HÌNH THÁI THÂN RĂNG HÀM SỮA THỨ HAI HÀM DƯỚI TRÊN PHIM CT CONEBEAM

Abstract

Objective: To describe the crown morphology of primary mandibular second molars on cone-beam computed tomography (CBCT) in pediatric patients presenting to the Dentistry Center, School of Dentistry, Hanoi Medical University. Materials and Methods: A cross-sectional descriptive study was performed on CBCT images of 41 primary mandibular second molars acquired from June 2024 to August 2025 at the School of Dentistry, Hanoi Medical University. Results: From the occlusal view, the crown outline was predominantly oval (56.1%). All teeth exhibited five cusps (100%). Mean crown height measured along the mesiodistal and buccolingual aspects was 5,45 ± 0,41 mm and 6,39 ± 0,57 mm, respectively. The distance from the most prominent point of the crown to the cemento-enamel junction (CEJ) was greatest on the mesial aspect (3,51 ± 0,45 mm) and smallest on the buccal aspect (2,70 ± 0.63 mm). Mesiodistal crown dimension was largest at the middle third (10,40 ± 0,59 mm) and smallest at the CEJ (7,60 ± 0,55 mm); the buccolingual dimension was largest at the middle third (9,24 ± 0,54 mm) and smallest at the occlusal level (5,94 ± 0,67 mm). Cusp heights relative to the CEJ ranged 5,56–6,18 mm (greatest at the distobuccal cusp), while cusp heights relative to the deepest occlusal fossa ranged 0,79–2,63 mm (greatest at the distobuccal cusp). Distances from the occlusal fossa to the buccal, lingual, mesial, and distal walls were 5,01 ± 0,47, 4,20 ± 0,52, 5,51 ± 0,60, and 4,84 ± 0,70 mm, respectively—indicating a slight distolingual offset of the fossa. No significant sex differences were observed (p > 0,05). Conclusion: The crown morphology of primary mandibular second molars on CBCT images demonstrates well-defined anatomical characteristics, providing a valuable reference for the selection, design and fabrication of prefabricated crowns suitable for Vietnamese children.