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多年未见的一位老年朋友,见我问道:“我的上前牙越来越前突,而且出现缝隙。这是为什么?”我告他,形成上前牙前突的因素很多,但最重要的原因是他的“(牙合)型”异常！什么是“(牙合)型”呢?(牙合)型是指人的上下牙齿在静止无功能状态时的接触位置关系。正常的(牙合)型应该是上下牙齿排列整齐,上前牙切端覆盖下前牙牙冠的垂直距离(复(牙合))不超过下前牙冠长的1/3;而上前牙的切端与下前牙冠间的水平距离(覆盖)不应该超过3毫米;上颌第一恒磨牙前颊尖应咬于下颌第一恒磨牙的前颊沟上,而上颌第一恒磨牙的前舌尖应咬在下颌第一恒磨牙的中央窝内;上下中切牙间的中线对正。这样除下中切牙和上颌第三磨牙外,其余的上
As an old friend who had not seen me for many years, I asked him, “My front teeth are more and more protruding, and there are gaps. Why is this?” I told him that there are many factors that make anterior teeth anterior process. The important reason is his “occlusal” type abnormal! What is “occlusal” type? (Occlusal) type refers to the human upper and lower teeth in the static non-functional status of the contact position relationship. The normal occlusion type should be the upper and lower teeth arranged neatly, the vertical distance covered by the anterior incisor covered under the anterior crown (complex occlusion)) does not exceed 1/3 of the length of the lower anterior crown; and the anterior teeth The horizontal distance (coverage) between the incision and the anterior crown should not exceed 3 mm; the anterior cheek tip of the maxillary first permanent molar should bite into the anterior cheek groove of the first permanent molar of the maxilla, and the anterior tip of the maxillary first permanent molar Should be bitten in the mandibular first permanent molar central fossa; upper and lower midline incision between the alignment. In this way, except for the maxillary third molar and the maxillary third molar, the rest of the upper