Doty Jonathan M, Pienkowski David, Goltz Michele, Haug Richard H, Valentino Joseph, Arosarena Oneida A
Division of Otolaryngology-Head and Neck Surgery, University of Kentucky Medical Center, Lexington, USA.
Arch Otolaryngol Head Neck Surg. 2004 Dec;130(12):1388-92. doi: 10.1001/archotol.130.12.1388.
To compare biomechanical properties of currently available plating systems used to reconstruct segmental mandibular defects.
Controlled in vitro investigation.
Academic medical center laboratory.
Thirty-two polyurethane mandibles were equally divided among 4 groups: mandibles with a 4-cm lateral segmental defect that was bridged with a (1) 3.0-mm locking-screw reconstruction plate, (2) 2.4-mm low-profile reconstruction plate, or (3) 2.4-mm reconstruction plate and (4) uncut (control) mandibles. All plates were contoured and secured to the synthetic mandibles with 4 bicortical screws on either side of the defect. Three constructs from each group were subjected to contralateral-molar single-load-to-failure testing. Mean yield displacement, yield load, and bending stiffness were quantified and compared among the 4 groups. The single-load-to-failure data were used to establish conditions for fatigue testing; such testing was then performed on the remaining 5 samples in each group. Mean cycles to failure were measured and compared among the 4 groups.
Mean yield displacement, yield load, and bending stiffness were comparable among the plated groups. Both the 3.0-mm locking-screw and 2.4-mm low-profile reconstruction plate designs withstood 1580 and 1124 times more cycles to failure, respectively (P = .005), than did the control group. The other reconstruction plate was also superior to the unplated controls, offering an 865-fold improvement.
All 3 mandibular fixation device systems tested produce comparable levels of single load to failure biomechanical integrity; however, the higher-profile plating system design offered slightly superior fatigue performance. No differences in performance were observed between the locking and nonlocking designs; neither failed at the screw-substrate interface.
比较目前用于重建节段性下颌骨缺损的接骨板系统的生物力学性能。
体外对照研究。
学术医学中心实验室。
32个聚氨酯下颌骨平均分为4组：有4厘米侧方节段性缺损的下颌骨，分别用(1)3.0毫米锁定螺钉重建接骨板、(2)2.4毫米薄型重建接骨板、(3)2.4毫米重建接骨板进行桥接，以及(4)未切开的（对照）下颌骨。所有接骨板均塑形，并在缺损两侧用4枚双皮质螺钉固定于合成下颌骨。每组3个构建体接受对侧磨牙单负荷至破坏测试。对4组之间的平均屈服位移、屈服负荷和弯曲刚度进行量化和比较。单负荷至破坏数据用于确定疲劳测试条件；然后对每组剩余的5个样本进行此类测试。测量4组之间的平均破坏循环次数并进行比较。
接骨板组之间的平均屈服位移、屈服负荷和弯曲刚度相当。3.0毫米锁定螺钉和2.4毫米薄型重建接骨板设计分别比对照组耐受多1580倍和1124倍的破坏循环次数（P = .005）。另一种重建接骨板也优于未使用接骨板的对照组，提高了865倍。
测试的所有3种下颌骨固定装置系统在单负荷至破坏生物力学完整性方面产生相当的水平；然而，较高外形的接骨板系统设计具有略优的疲劳性能。锁定和非锁定设计之间未观察到性能差异；两者均未在螺钉与骨界面处失效。
