The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
Angle Orthod. 2012 Sep;82(5):839-45. doi: 10.2319/101011-633.1. Epub 2012 Feb 23.
To develop a model of gradually induced backward movement of the mandible under normal masticatory action and to examine morphological changes in the mandible and condylar cartilage in rats.
The newly developed Twin Inclined Plane Device (TIPD) was composed of upper and lower posterior metal crowns with a long inclined plane on both sides separately and was applied in experimental groups of 6-week-old male Wister rats. After 3, 14, 30, and 60 days, the rats were euthanatized and samples were collected. Various measurements and hematoxylin-and-eosin stains were performed.
From day 30 on, the length of the condylar process was shorter in the TIPD groups than in the control groups (P < .05). The angulation of the condylar process axis to the mandibular plane was greater in the TIPD groups (P < .01). The thickness of the condylar cartilage in the posterior part of the posterior region was thinner in the TIPD groups (P < .05) on day 30 and even thinner (P < .01) on day 60; from day 30 on, the thickness in the anterior part of the posterior region was thicker in the TIPD groups (P < .01).
TIPD can successfully induce backward movement of the mandible under normal masticatory action. TIPD can cause region-specific changes in condylar cartilage and leads to a continuous remodeling.
在正常咀嚼动作下开发下颌逐渐向后移动的模型，并研究大鼠下颌骨和髁突软骨的形态变化。
新开发的 Twin Inclined Plane Device（TIPD）由上下后金属冠组成，两侧分别有长斜面，应用于 6 周龄雄性 Wistar 大鼠实验组。在 3、14、30 和 60 天后，处死大鼠并采集样本。进行了各种测量和苏木精-伊红染色。
从第 30 天开始，TIPD 组髁突过程的长度比对照组短（P <.05）。TIPD 组髁突过程轴与下颌平面的夹角较大（P <.01）。在第 30 天，TIPD 组后区后部的髁突软骨厚度较薄（P <.05），甚至在第 60 天更薄（P <.01）；从第 30 天开始，TIPD 组后区前部的厚度较厚（P <.01）。
TIPD 可以成功诱导正常咀嚼动作下的下颌向后移动。TIPD 可引起髁突软骨的特定区域变化，并导致连续重塑。
