末端磨牙区拥挤与下颌智齿牙根形态的关系

Relationship between root morphology of the mandibular third molars and crowding in the posterior segment

目的探讨磨牙区拥挤与下颌智齿牙根发育形态之间的关系。方法选择下颌第三磨牙牙根发育完成的22-35岁成年正畸患者的曲面断层片1056张，观察下颌第一、第二及第三磨牙牙根分叉和聚拢的分布情况，探讨下颌第三磨牙阻生与完全萌出与其牙根聚拢程度的关系。结果从下颌第一磨牙至第三磨牙，牙根聚拢程度有增加的趋势。下颌第三磨牙阻生与否对于牙根的分开与聚拢没有显著影响。结论下颌第三磨牙牙根形态变异较大，牙根的分开与聚拢与末端磨牙区拥挤与否无明显关联。

Objective To investigate the root morphology of the mandibular molars and the relationship between root morphology and crowding in the posterior segment. Methods One thousand and fifty-six dental panoramic radiographs were evaluated. The age range of the patients when the X-rays were taken was from 22 to 35 years. The roots of the mandibular first, second and third molars were evaluated. The relationship between root morphology of the mandibular molars and crowding in the posterior segment was assessed. Results The root tended to become convergent from mandibular first to third molar. No significant differences were found in third molar root morphology between impacted molars and normally positioned ones. C^nelusions The root morphology of the mandibular third molars was variable. No significant correlation was found between root morphology and crowding in the posterior segment.