单侧不完全截骨牵张时颞下颌关节位移的有限元研究

Displacemental analysis with a finite element method on distractional side of canine TMJ when distraction osteogenesis with unilateral incomplete osteotomy

目的:利用犬单侧下颌不完全截骨牵张成骨有限元模型,观察牵张侧颞下颌关节(髁突)位移状况。方法:利用有限元法模拟不完全截骨模型(截骨处剩1 mm舌侧皮质骨),观察一侧下颌骨滑动骨块未被牵开和被牵开时,牵张侧颞下颌关节2个标志点位移状况。结果:当滑动骨块未被牵开时牵张侧髁状突前斜面前缘中点、髁状突后斜面后缘中点均无位移;当滑动骨块被牵开l mm时,上述两点位移均有不同程度变化。结论:犬下颌单侧不全截骨牵张时,在内外(左右或X轴)方向上髁状突前斜面前缘中点具有向外运动的趋势,髁状突后斜面后缘中点具有向内运动的趋势,此变化不足以对颞下颌关节造成损伤。

Objective： To analyze the displacemental condition of condyle process of canine temporal-mandibular joint（ TMJ） on distractional side when distraction osteogenesis with unilateral incomplete osteotomy. Methods： The method of finite element analysis was used to simulate partial-cortical-cutting distraction osteogenesis（ ＂cuting＂situation when 1 mm wide of slice was retained）. The displacemental trend of two marked points of the TMJ were observed on distractional side when the transport disc was distracted with a distance and without a distance. Results： On the side of distraction when the transport disc was distracted without a distance,the displacement of anterior edge midpoint of condyle process anterior slope and posterior edge midpoint of condyle process posterior slope in 3 dimensions（ X、Y、Z axis） was zero. Displacement of 2marked points changed respectively when the transport disc was distracted 1 mm width. Conclusion： When canine partial-cortical-cutting the distraction osteogenesis,the trend of anterior edge midpoint of condyle process anterior slope is outward on the inner and outer（ left and right or X-axis）,but the trend of posterior edge midpoint of condyle process posterior slope is inward. None sports trend enough to cause damage to the TMJ.