Changes in growth and morphology of the condyle following mandibular distraction in minipigs: Overloading or underloading?
Changes in growth and morphology of the condyle following mandibular distraction in minipigs: Overloading or underloading?
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DOI：
10.1016/j.archoralbio.2007.04.014
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发表时间：
2007-10-01
影响因子：
3
通讯作者：
Herring, Susan W.
中科院分区：
文献类型：
--
作者：
Rafferty, Katherine L.;Sun, Zongyang;Herring, Susan W.
目的：下颌骨牵张过程中颞下颌关节组织负荷可能引起髁突生长和软骨厚度的变化。本研究通过明确测量生长和体内负荷，在大型动物模型中检查牵引对髁突的影响。设计：将20只生长期小型猪随机分为3组，进行单侧下颌骨牵张。一组进行了牵引，但没有巩固，而其他两组被允许的巩固期为1或2周。动物接受荧光染料和5-溴-2 '-脱氧尿苷（BrdU）标记，并从髁突颈部测量咀嚼张力。髁突应变也记录在一个年龄匹配的样本8只动物，没有接受牵引手术。用免疫组化方法鉴定分裂的前成软骨细胞，用组织学方法测量矿物沉积率，计数分裂细胞，并测量髁突软骨厚度。结果：非牵张侧髁突的应变量，特别是压缩应变，远大于牵张侧髁突。与正常载荷水平相比，牵引侧髁突载荷不足，而完整侧髁突载荷过大。与对侧相比，牵引侧髁上的矿物沉积和软骨厚度更大。两侧之间的差异在无巩固组中最明显，并随着巩固时间的推移逐渐减少。结论：矿化增加。牵张侧髁上的软骨厚度与减少的而不是增加的负荷相关，这可能是因为牵张侧咬肌的破坏。(C)2007爱思唯尔有限公司保留所有权利。
Objective: Loading of temporomandibular tissues during mandibular distraction may cause changes in condylar growth and cartilage thickness. This study examines the effects of distraction on the condyle in a large animal model by explicitly measuring growth and in vivo loading. Design: Unilateral mandibular distraction was carried out on 20 growing minipigs divided into three groups. One group underwent distraction but not consolidation, whereas the other two groups were allowed a period of consolidation of either 1 or 2 weeks. Animals received fluorochrome and 5-bromo-2'-deoxyuridine (BrdU) labelling and masticatory strain was measured from the condylar neck. Condylar strain was also recorded in an age-matched sample of eight animals that received no distraction surgery. Immunohistochemical procedures were used to identify dividing prechondroblasts and histological analysis was used to measure mineral apposition rate, count dividing cells, and measure the thickness of condylar cartilage. Results: Strain magnitude, particularly compressive strain, was much larger on the non-distraction side compared to the distraction side condyle. Compared to normal loading levels, the distraction side condyle was underloaded whereas the condyle on the intact side was overloaded. Mineral apposition and cartilage thickness were greater on the distraction side condyle compared to the opposite side. Differences between the sides were most pronounced in the group with no consolidation and became progressively reduced with consolidation time. Conclusions: Increased mineralisation. and cartilage thickness on the distraction side condyle are associated with reduced, not increased loading, perhaps because of disruption of the distraction side masseter muscle. (C) 2007 Elsevier Ltd. All rights reserved.