牙科三维CT研究下颌乳磨牙髓腔

Study on pulp cavities of primary mandibular molars by three-dimensional dental CT

目的测量下颌乳磨牙髓腔形态参数,为牙体解剖学提供基础资料并供临床参考。方法选择7例儿童干燥下颌骨标本,利用牙科三维CT对完全萌出的24颗乳磨牙进行三维重建以观察其髓腔解剖形态并测量相关参数。结果下颌第一乳磨牙的髓室颊舌向最大距离与近远中向最大距离、髓室底最高点水平面上近中根管口颊舌向最大距离、远中根管口颊舌向最大距离与近远中向最大距离均小于下颌第二乳磨牙(P值均＜0．05),而髓室高度大于下颌第二乳磨牙(P＜0．05),其余指标的差异均无显著性(P值均＞0．05)。左右分组比较的差异无显著性(P＞0．05)。下颌乳磨牙的近中与远中根管相比,其根管口的颊舌向最大距离及近远中向最大距离的差异均无显著性(P值均＞0．05)。结论牙科三维CT测量方法具有先进性。掌握下颌乳磨牙的髓腔特点对于牙髓治疗具有重要参考价值。

Objective To measure the morphological parameters of pulp cavities of primary mandibular molars and to provide the basic data for dental anatomy and reference for clinical practice. Methods 7 children＇s mandibular bones were chosen for rebuilt of the CT three-dimensional models of the 24 primary molars for morphological parameters of pulp cavities. Results The biggest distance between buccal and lingual side of pulp cavity, the biggest distance between mesial and distal side of pulp cavity, that between buccal and lingual side of pulp orifices at mesial root, that between buccal and lingual side of pulp orifices and that between mesial and distal side of pulp orifices at distal root in the first primary mandibular molars were smaller than those in the second primary mandibular molars（P 〈 0.05）, but the height of pulp cavity was larger than that of the second primary mandibular molar （P 〈 0.05）. All the items possessed no significant difference between the left and the right primary mandibular molars. The biggest distance between buccal and lingual side of pulp orifices and that between mesial and distal of pulp orifices at mesial and distal roots in primary mandibular molars were not significantly different（P〉 0.05）. Conclusion The measurement with three-dimensional dental CT is an advanced method. Handling the characteristics of pulp cavities in the primary mandibular molars is of great importance to endodontic therapy.