上磨牙近中颊根第二根管mb2的发现和治疗

<div class="wx_rich_media_content" id="jsWxContainer"><section style="line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class="">临床上，一些上颌磨牙根管治疗后，近中颊根根尖病变依然存在或者形成新的病变，常常是由于遗漏MB2所致。</span><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class="">以往报道MB2的发生率在离体牙为51.5%~95.2%，临床为18.6%~77.2%应用显微镜可使mb2的临床治疗率达90%以上。</span></section><p contenteditable="false" class=""><br></p><section style="text-align: center;line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span class="wxart_image" wx-style="display:inline-block;"> </span></section><p contenteditable="false" class=""><br></p><section style="line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span style="color: rgb(0, 122, 170);" contenteditable="false" class=""><strong><span style="letter-spacing: 1px;font-size: 16px;" contenteditable="false" class="">上颌磨牙近中颊根根管可分4型</span></strong></span></section><p contenteditable="false" class=""><br></p><section style="line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span style="color: rgb(255, 255, 255);background-color: rgb(89, 89, 89);" contenteditable="false" class=""><strong><span style="letter-spacing: 1px; font-size: 16px;" contenteditable="false" class="">1型</span></strong></span><strong><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class=""> </span></strong><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class="">从一个根管口至一个根尖孔；</span></section><p contenteditable="false" class=""><br></p><section style="line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span style="color: rgb(255, 255, 255);background-color: rgb(89, 89, 89);" contenteditable="false" class=""><strong><span style="letter-spacing: 1px; font-size: 16px;" contenteditable="false" class="">2型</span></strong></span><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class="">从两个根管口进入，但在根尖孔以上融合成单根管形成一个根尖孔；</span></section><p contenteditable="false" class=""><br></p><section style="line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span style="color: rgb(255, 255, 255);background-color: rgb(89, 89, 89);" contenteditable="false" class=""><strong><span style="letter-spacing: 1px; font-size: 16px;" contenteditable="false" class="">3型</span></strong></span><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class=""> 两个根管口和2个根尖孔形成独立的2个根管；</span></section><p contenteditable="false" class=""><br></p><section style="line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span style="color: rgb(255, 255, 255);background-color: rgb(89, 89, 89);" contenteditable="false" class=""><strong><span style="letter-spacing: 1px; font-size: 16px;" contenteditable="false" class="">4型</span></strong></span><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class=""> 从一个根管口进入根中分开形成2个根尖孔。</span></section><p contenteditable="false" class=""><br></p><section style="line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class="">MB2根管口位于近中颊根根管口舌侧，MB2和MB距离为(0.93~2.01)mm。</span><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class="">MB2根管口位于近中颊根和腭根(MB-P)连线的近中，与MB-P连线的垂直距离为(0.25~0.81)mm；</span><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class="">MB-MB2与MB-P连线的夹角为9.99~36.15度。</span></section><p contenteditable="false" class=""><br></p><section style="text-align: center;line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span class="wxart_image" wx-style="display:inline-block;width: 574px;height: 309px;"> </span></section><p contenteditable="false" class=""><br></p><section style="line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span style="color: rgb(0, 122, 170);" contenteditable="false" class=""><strong><span style="letter-spacing: 1px;font-size: 16px;" contenteditable="false" class="">MB2的临床检查</span></strong></span></section><p contenteditable="false" class=""><br></p><section style="line-height: 2em;margin-left: 32px;margin-right: 32px;" contenteditable="false" class=""><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class="">X线片平行或者偏移投照发现根管影像或者诊断丝不在根管中央时，应高度怀疑MB2的存在，应遵循MB2和其他根管口的关系，应用超声方法或者长圆钻沿MB-P连线的近中侧，适当去除牙本质1～2mm，就可用DG16探针或者根管口探针找到根管口，最好采用08#或10#k锉结合根管润滑剂扩通根管。</span><span style="letter-spacing: 1px;font-size: 16px;color: rgb(63, 63, 63);" contenteditable="false" class="">应注意避免过度寻找造成底穿或者侧穿。</span></section><hr style="border-style: solid; 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