不同速率牵张山羊下颌后下齿槽血管变化与血管生成的实验研究

目的:研究不同速率牵张延长山羊下颌骨后下齿槽动静脉的变化和新骨组织内血管生成情况。方法:8只成年山羊随机分为3组,A组(3只)以110 mm/d牵张,B组(3只)以210 mm/d牵张,C组(2只)为对照。A、B两组均牵张延长下颌10 mm,于牵张结束固定后第2周时处死动物,取牵张区下齿槽动静脉及新骨组织行组织学和定量组织学研究,观察下齿槽血管的管壁厚度和管径大小变化,以及新骨中微血管数量变化。结果:两种速率牵张后均未见下齿槽血管壁有病理性改变,但210 mm/d组的血管管径变小,管壁变薄,与对照组相比有显著差异(P<0105)。110 mm/d牵张后微血管密度较210 mm/d牵张后微血管密度高,且新生骨小梁更为成熟,其差异具有统计学意义(P< 0105)。结论:下颌骨牵张后下齿槽血管无明显变化,但快速牵张可能对牵张间隙内血管生成有不良影响。

Changes in the Inferior Alveolar Vessels and Angiogenesis Following Mandibular Lengthening with Different Rates of Distraction

Objective:The purpose of this study was to study the changes in the inferior alveolar vessels and angiogenesis following mandibular lengthening with different rates of distraction. Methods:Bilateral mandibular corticotomies were performed in 6 goats. The mandibles in 6 goats were legnthened 10.0 mm using a custom_made distractor with different rates of distraction (1.0 mm/d and 2.0 mm/d ); the other 2 nondistracted mandibles served as control. The goats with distracted mandibles were killed at 2 weeks after completion of distraction. The inferior alveolar vessels with distracted calluses were harvested and processed for histologic and morphometric evaluation.Results:No pathological changes in the inferior alveolar vessels were found following mandibular osteodistraction. However, the number of microvessels within distraction gap in the animals distracted at a rate of 1.0 mm/day was greater than that in the goats distracted using a rate of 2.0 mm/day, and more mature newly formed bone trabeculae was observed.Conclusion:There were no significant changes in the inferior alveolar vessels after mandibular lengthening with distraction osteogenesis, but rapid distraction may have adverse effects on the aniogenesis in the distraction gap.