【摘要】 目的:通过对离体上颌第一磨牙测量根长,观察牙根不同部位根管数目和形状,为临床治疗提供参考资料。方法:收集20岁以上人上颌第一恒磨牙,测量根长度后将牙根横切分为3部分:根上1/3、根中1/3和根尖1/3,在体视镜下观察不同部位的根管数目、形状。结果:上颌第一磨牙腭根、近颊根和远颊根长度分别是(13.82±1.51)mm、(13.06±1.12)mm和(11.64±0.85)mm。近颊根管上1/3双根管检出率为51.00%,根中1/3和根尖1/3分别为53.88%、54.09%;远颊根中1/3和根尖1/3偶见双根管。腭侧根管横截面以圆形为主,未见有双根或多根管存在;近颊根和远颊根管形状变异大,形状多样。结论:上颌第一磨牙腭根和远颊根长度相近,腭根比近颊根长约2~3mm;近颊根和远颊根管形状变异大,近颊根双根管约50%以上,偶见多根管。根管上1/3线条形时,根中1/3和根尖1/3多为双根管。更多还原

【Abstract】 Objective:To investigate the root length,number and the transverse shape of first maxillary molars using root sectioning technique. Methods:100 isolated first permanent maxillary molars from above 20 years old patients were collected. The roots were cross-sectioned in three parts(superior 1/3,middle 1/3 and apex 1/3) after measuring the length of roots. The transverse shape of root canals were observed under the stereomicroscope.The number and shape of root in three parts of roots were recorded. Results:The length of lingual root,MB and DB of the first maxillary molar is (13.82±1.51) mm;(13.06±1.12) mm and (11.64±0.85) mm respectively; complex degree of MB and DB of the first marxillar molar is very high. 51% double roots in superior 1/3 of MB were found. Above 50% dual roots in the middle 1/3and apex 1/3 in the mesiobuccal root of first maxillar molar were recorded. Conclusion:Root number and transverse configuration in MB and DB of first maxillary molar varied in different parts of roots; There may be double root canals in medium 1/3 and apex 1/3 in MB of first maxillary molar when one line type canal in superior 1/3 was found.更多还原