阻生上颌尖牙曲断片影像学指标与治疗预后的相关性

Correlation between panoramic radiographic findings and prognosis of impacted maxillary canines

目的:对影响上颌阻生尖牙治疗时间长短的影像学指标进行了相关性评估.方法:选取了25位存在阻生上颌尖牙患者矫治前后的全颌曲面断层片,记录了31颗阻生尖牙与平面的距离、倾斜角度,牙尖与邻牙的关系和牙根弯曲的发生率.用统计学分析方法得出积极治疗时间长短与上述影像学因素之间的相关性.最后,将治疗前后的曲面断层片进行对比,判断牙根吸收和边缘骨缺损的发病率,并与治疗时间做相关性研究.结果:治疗时间和阻生牙的倾斜度呈负相关(r=-0.76,P<0.001)、和阻生牙到平面的距离呈正相关(r=0.59,P<0.01),疗程长短与治疗后的牙根吸收率有较弱的关联性(r=0.34,0.01<P<0.05),而与牙尖位置(r=-0.05)、牙根弯曲(r=0.11)及骨缺损的发生率(r=0.18)之间都没有相关性.结论:由曲面断层片所提供的影像学信息中对上颌阻生尖牙治疗最具有指导性意义的指标为:倾斜角度以及与平面的距离.

AIM： To evaluate the radiographic factors that influence the duration of orthodontic treatment of impacted maxillary canines. METHODS： The following factors of 31 impacted permanent canines were worked out based on their panoramic radiographs： the inclination, the distance to the occlusal plane, the position of the crown tip, and the frequency of mesiodistal root deviations. The duration of active treatment was recorded and analyzed statistically in relation to the degree of displacement and the incidence of root deviation. Finally, pre-and post-therapeutic panoramic radiographs were compared to determine the incidences of root resorptions and marginal bone defects. RESULTS： There was a strong direct correlation of the treatment duration with the angle of inclination （r = - 0.76, P 〈 0.001 ）, the distance from the occlusal plane （ r = 0.59, P 〈 0.01 ）, and a weaker inverse correlation with the incidence of root resorptions （r = 0.34, 0.01 〈 P 〈 0.05 ）. No significant correlation was found between treatment duration and other variables, including position of the crown tip （ r = - 0.05 ）, the root deviation （ r = 0.11 ）, or the marginal bone defects （r = 0. 18 ）. CONCLUSION： The duration of orthodontic treatment for impacted maxillary cannies, based on panoramic radiographs, seems to be primarily influenced by two factors： inclination and distance to the occlusal plane.