Keskin Cangül, Lee Jong-Ki, Ceylan Alper, Yılmaz Özlem Sivas, Keleş Ali, Perinpanayagam Hiran
Faculty of Dentistry, Department of Endodontics, Ondokuz Mayıs University, Samsun, Türkiye.
Private Practice, Changwon, Korea.
Odontology. 2025 Sep 9. doi: 10.1007/s10266-025-01196-0.
This study aimed to investigate the age-related alterations in mesial roots of mandibular first molar in terms of root canal curvature values, dentin thickness, interorifice distance, deviation from apical foramen, and location of apical foramen using a three-dimensional curvature measurement method and micro-computed tomography (micro-CT). Forty-five mesial roots of mandibular first molars from three age groups (Group 1: ≤ 30 years, Group 2: 31-59 years, Group 3: ≥ 60 years) were scanned using micro-CT. The central axis of each mesiobuccal and mesiolingual canal was analyzed using cubic B-spline curves to calculate canal curvature. Dentin thickness, deviation of apical foramen from the anatomical apex, and the location of apical foramen in mesiobuccal and mesiolingual canals were measured and recorded. Statistical analyses, including one-way ANOVA, Mann-Whitney U, Kruskal-Wallis and Pearson's correlation tests, were performed to assess age-related differences in curvature, interorifice distance, and dentin thickness with a 5% significance threshold. No statistically significant differences in root canal curvature were observed across the three age groups (p > .05), although a slight increase in curvature was noted in Group 3. Interorifice distance was significantly lower in Group 2 (p < .05), but no significant relationship was found between mesiobuccal curvature and interorifice distance. Dentin thickness, however, showed significant variations: Groups 1 and 2 exhibited thinner mesial dentin (2-6 mm levels), while Group 3 demonstrated greater distal dentin thickness (5-8 mm levels) (p < .05). Apical foramen location and deviation remained consistent across age groups (p > .05), predominantly situated centrally on the root surface. While root canal curvature did not vary significantly with age (p > .05), dentin thickness showed notable age-related differences (p < .05). A significant correlation was observed between the mesiolingual canal curvature and interorifice distance, but no such correlation was found for the mesiobuccal canal. A significant age-related increase in dentin thickness in both the mesiobuccal and mesiolingual canals underscores the impact of secondary dentin deposition, which is probably uniform as the root canal curvature seems to remain relatively stable across the lifespan in mandibular first molars.
本研究旨在采用三维曲率测量方法和显微计算机断层扫描（显微CT），从根管曲率值、牙本质厚度、根管口间距离、根尖孔偏移以及根尖孔位置等方面，研究下颌第一磨牙近中根的年龄相关变化。对来自三个年龄组（第1组：≤30岁，第2组：31 - 59岁，第3组：≥60岁）的45个下颌第一磨牙近中根进行显微CT扫描。使用三次B样条曲线分析每个近中颊根管和近中舌根管的中心轴，以计算根管曲率。测量并记录牙本质厚度、根尖孔相对于解剖根尖的偏移以及近中颊根管和近中舌根管中根尖孔的位置。进行了包括单因素方差分析、曼-惠特尼U检验、克鲁斯卡尔-沃利斯检验和皮尔逊相关检验在内的统计分析，以评估曲率、根管口间距离和牙本质厚度的年龄相关差异，显著性阈值为5%。尽管第3组的曲率略有增加，但在三个年龄组之间未观察到根管曲率的统计学显著差异（p＞0.05）。第2组的根管口间距离显著更低（p＜0.05），但未发现近中颊根管曲率与根管口间距离之间存在显著关系。然而，牙本质厚度显示出显著差异：第1组和第2组的近中牙本质较薄（2 - 6毫米水平），而第3组的远中牙本质厚度更大（5 - 8毫米水平）（p＜0.05）。根尖孔位置和偏移在各年龄组之间保持一致（p＞0.05），主要位于牙根表面中央。虽然根管曲率并未随年龄显著变化（p＞0.05），但牙本质厚度显示出明显的年龄相关差异（p＜0.05）。观察到近中舌根管曲率与根管口间距离之间存在显著相关性，但近中颊根管未发现此类相关性。近中颊根管和近中舌根管中牙本质厚度随年龄显著增加，这突出了继发性牙本质沉积的影响，由于下颌第一磨牙的根管曲率在整个生命周期中似乎保持相对稳定，继发性牙本质沉积可能是均匀的。
