Savoldi Fabio, Tsoi James K H, Paganelli Corrado, Matinlinna Jukka P
Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong SAR, PR China; Department of Orthodontics, Dental School, University of Brescia, P.le Spedali Civili, 25123 Brescia, Italy.
Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong SAR, PR China.
Dent Mater. 2017 Jul;33(7):e290-e300. doi: 10.1016/j.dental.2017.04.025. Epub 2017 Jun 2.
Sutures are fibrous joints connecting the bones of the head. Despite the fundamental role played by sutures in dentofacial orthopaedics, their biomechanical properties are not completely understood. This study evaluated anatomy, biomechanics, and acoustic emission (AE) during distraction of the sutural ligament (SL).
Seventy-two suture samples were removed from a twelve-months-old swine (Sus scrofa) head. Each volume was acquired using micro-computed tomography (μCT), and the linear interdigitation index was calculated on both planes (LII and LII). Mechanical testing till failure was carried at 1mm/min, and four piezoelectric sensors were used for recording of amplitude (A), duration (D), and energy (E) of AE. The relationships between interdigitation, fracture types, tensile stress (σ), and AE were statistically analysed with non-parametric tests (α=0.05).
σ of the SL had median values of 4.0MPa, and AE were characterised by A of 49.3dB (IQR=2.2), D of 826.3μs (IQR=533.4), and E of 57,715.8 eu (IQR=439,613.5). Most of the fractures happened in the SL (46%), some within the bone (34%), and fewer were combined (19%). LII had correlation with A (0.383, p=0.028), D (0.348, p=0.048), and E (0.437, p=0.011) of the AE, and σ had similar relationship with A (0.500, p=0.003), D (0.495, p=0.003), and E (0.579, p<0.001). Maximum energy values were different between fractures within the bone and within the SL (p=0.021).
Biomechanical properties under tension of most of the sutures of the craniofacial skeleton were reported. AE provided information about the sequence of events during SL distraction, and had significant relationship with its mechanical properties. Further studies are necessary to confirm these preliminary findings, and to identify their relationship with biological processes and dentofacial treatments.
缝（骨）线是连接头部骨骼的纤维性关节。尽管缝（骨）线在牙颌面正畸学中发挥着重要作用，但其生物力学特性尚未完全明确。本研究评估了缝（骨）线韧带（SL）牵张过程中的解剖结构、生物力学及声发射（AE）情况。
从12月龄猪（野猪）头部获取72个缝（骨）线样本。每个样本通过微型计算机断层扫描（μCT）获取容积数据，并计算两个平面上的线性交错指数（LII和LII）。以1mm/min的速度进行直至破坏的力学测试，使用四个压电传感器记录AE的振幅（A）、持续时间（D）和能量（E）。采用非参数检验（α = 0.05）对交错指数、骨折类型、拉伸应力（σ）与AE之间的关系进行统计学分析。
SL的σ中位数为4.0MPa，AE的特征为A为49.3dB（四分位间距 = 2.2），D为826.3μs（四分位间距 = 533.4），E为57,715.8 eu（四分位间距 = 439,613.5）。大多数骨折发生在SL（46%），部分发生在骨内（34%），较少为复合型（19%）。LII与AE的A（0.383，p = 0.028）、D（0.348，p = 0.048）和E（0.437，p = 0.011）相关，σ与A（0.500，p = 0.003）、D（0.495，p = 0.003）和E（0.579，p < 0.001）有类似关系。骨内骨折与SL内骨折的最大能量值不同（p = 0.021）。
报道了颅面骨骼大多数缝（骨）线在张力下的生物力学特性。AE提供了SL牵张过程中事件顺序的信息，且与其力学特性有显著关系。有必要进行进一步研究以证实这些初步发现，并确定它们与生物学过程及牙颌面治疗的关系。
