恒牙初期前牙反治疗前后下颌咀嚼运动轨迹的比较研究

Investigation of Chewing Patterns in Anterior Crossbite Malocclusion Before and After Orthodontic Treatment

目的 :评价恒牙初期前牙反及其正畸治疗对下颌咀嚼运动的影响 .方法 :在磁电转换式下颌运动轨迹描记仪 MKG 的基础上 ,结合计算机图像处理技术开发了相应的计算机软硬件系统 .对 15名恒牙初期前牙反病人正畸治疗前后的下颌咀嚼运动轨迹进行了研究 ,并与 30名正常青少年进行对照 .结果 :前牙反的咀嚼运动轨迹向前下者居多 ,闭口末集中性不佳 ,轨迹不规则 ,不稳定 ,缺乏接触的侧向滑动 ,循环为垂直上下 ,缺乏闭口时的侧移 ,与正常青少年相比存在较大差异 .经正畸治疗后的咀嚼运动轨迹全部变为向后下 ,闭口末集中性改善 ,轨迹规则 ,稳定 ,有一定的侧向滑动 ,与正常青少年的表现相似 .结论 :前牙反经正畸治疗后咀嚼运动有明显改善 .

Objective:To describe the effects of early permanent anterior crossbite malocclusion on chewing movement and the changes following orthodontic treatment.Methods:The sample was consisted of 15 subjects with anterior crossbite were treated,30 normal were selected as control group The Recordings of habitual chewing movement during gum chewing were made with a K 5AR mandibular kinsiograph.Result:At the pretreatment stage,The direction of chewing movement is forward and downward.The end of closing movement doesn't have refinement of intercuspal position.There is a significant disturbance of the smoothness and regularity of chewing movement and no tooth-gliding contact.Following orthodontic treatment,The direction of chewing movement changes to backward and downward.It's observed an increased refinement of intercuspal position.The tracings of chewing movement show smoothness and regularity.The toothg-liding contact is increased.Conclution:Following orthodontic treatment,the chewing pattern of the patient show remarkable improvement comparing with pretreatment stage.