Department of Orthodontics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
Angle Orthod. 2009 Nov;79(6):1095-101. doi: 10.2319/112608-603R.1.
To test the hypothesis that mandibular advancement with the use of a fixed functional appliance combined with prohibition of labial movement of the lower incisors will have no effect on mandibular growth in growing rats.
Fifteen 4-week-old male rats were divided into fixed, unfixed, and control groups (n = 5, each). Bite-jumping appliances were used in the fixed and unfixed groups. Sites of bone perforation and the lower incisors were connected with ligature wires in the fixed group. The ramus height, mandibular length, and inclination of lower incisors were examined for 4 weeks, and those values were compared among five intervals and three groups by through one-way analysis of variance models and the Bonferroni multiple comparison test for post hoc comparison.
Increases in ramus height and mandibular length during the experimental period were 1.5 mm and 2.5 mm in the fixed group, 1 mm and 1.5 mm in the unfixed group, and 1.2 mm and 1.9 mm in the control group, respectively. Growth of ramus height and growth of mandibular length in the fixed group were greater than in the unfixed and control groups during the experimental period. The inclination of lower incisors in the unfixed group was increased 8.0 degrees throughout the experimental period, which differed from results obtained in the other groups.
Mandibular growth was accelerated effectively before and during the pubertal period in rats by mandibular advancement with a fixed functional appliance combined with prohibition of labial movement of the lower incisor.
为了验证“使用固定功能矫治器使下颌前伸并限制下颌切牙唇向运动不会影响生长发育期大鼠下颌生长”这一假说，进行了本研究。
将 15 只 4 周龄雄性大鼠随机分为固定组、非固定组和对照组（每组 5 只）。固定组和非固定组使用咬撬矫治器。固定组使用结扎丝将下颌骨穿孔部位和下颌切牙连接起来。在 4 周的实验过程中，测量下颌支高度、下颌长度和下颌切牙倾斜度，采用单因素方差分析和 Bonferroni 事后多重比较检验比较 5 个时间点和 3 组间的差异。
在实验期间，固定组的下颌支高度和下颌长度分别增加了 1.5mm 和 2.5mm，非固定组分别增加了 1mm 和 1.5mm，对照组分别增加了 1.2mm 和 1.9mm。在实验期间，固定组的下颌支高度和下颌长度增长均大于非固定组和对照组。非固定组下颌切牙倾斜度在整个实验期间增加了 8.0 度，与其他两组的结果不同。
在大鼠青春期前和青春期期间，通过使用固定功能矫治器使下颌前伸并限制下颌切牙唇向运动，可有效促进下颌生长。
