Root dentine thickness of danger zone in mesial roots of mandibular first molars

Abstract

Abstract Background Better understanding of the danger zone anatomy in mesial roots (MRs) of mandibular first molars (MFMs) may serve to decrease the risk of mishaps. This study aimed to measure the minimal distal dentine thicknesses of danger zone in MRs of MFMs in a native Chinese population using cone-beam computed tomography (CBCT). Methods CBCT images of 1792 MFMs from 898 Chinese patients were analyzed. The minimal distal dentine thicknesses of the mesiobuccal (MB) and mesiolingual (ML) canals below the furcation 1, 2, 3, 4, 5 mm were measured. The association between the minimal distal dentine thicknesses and the root lengths, patient’s age and gender, side were assessed. Results The minimal distal dentine thicknesses of MB and ML canals are located 3 ∼ 4 mm below the furcation for both men and women. There are no differences between MB and ML canals, while the minimal distal dentine thicknesses of MB and ML canals were higher in men than women (P 0.05). The minimal distal dentine thicknesses of MB and ML canals increased with age in both men and women at each location (P 0.05). Conclusions The minimal distal dentine thicknesses of MRs in MSMs have close correlation with root length, patient’s age and gender.

Keywords

• Cone-beam computed tomography
• Danger zone
• Mandibular first molars
• Mesial roots