The periodontal ligament (PDL) is a critical player in the maintenance of tooth health, acting as the primary stabilizer of tooth position. Recent studies have identified two unique regions within the PDL, the ‘dense collar’ region and the ‘furcation’ region, which exhibit distinct structural and compositional differences. However, specific functional differences between these regions have yet to be investigated. We adapted an AFM-based nanoscale rheology method to regionally assess mechanical properties and poroelasticity in the mouse PDL while minimizing the disruption of the 3-dimensional native boundary conditions, and then explored tissue mechanical function in four different regions within the dense collar as well as in the furcation region. We found significant differences between the collar and furcation regions, with the collar acting as a stabilizing ligamentous structure and the furcation acting as both a compressive cushion for vertical forces and a conduit for nutrient transport. While this finding supports our hypothesis, based on previous studies investigating structural and compositional differences, we also found surprising inhomogeneity within the collar region itself. This inhomogeneity supports previous findings of a tilting movement in the buccal direction of mandibular molar teeth and the structural adaptation to prevent lingual movement. Future work will aim to understand how different regions of the PDL change functionally during biological or mechanical perturbations, such as orthodontic tooth movement, development, or aging, with the ultimate goal of better understanding the mechanobiology of the PDL function in health and disease.

牙周韧带 (PDL) 是维持牙齿健康的关键因素，是牙齿位置的主要稳定器。最近的研究确定了 PDL 中的两个独特区域，即“密集领”区域和“分叉”区域，它们表现出明显的结构和成分差异。然而，这些区域之间的具体功能差异还有待研究。我们采用基于 AFM 的纳米级流变学方法对小鼠 PDL 的机械性能和多孔弹性进行区域评估，同时最大限度地减少对 3 维天然边界条件的破坏，然后探索致密项圈内四个不同区域的组织力学功能以及在分叉区域。我们发现衣领和分叉区域之间存在显着差异，衣领充当稳定的韧带结构，分叉充当垂直力的压缩垫和营养运输的管道。虽然这一发现支持了我们的假设，但基于先前调查结构和成分差异的研究，我们还发现了衣领区域本身的惊人不均匀性。这种不均匀性支持先前关于下颌磨牙沿颊侧方向倾斜运动和防止舌侧运动的结构适应的发现。未来的工作将旨在了解 PDL 的不同区域如何在生物或机械扰动（例如正畸牙齿移动、发育或老化）期间发生功能性变化，最终目标是更好地了解 PDL 功能在健康和疾病中的力学生物学。