下颌第三磨牙近中阻生的临床应用研究

Clinical study on mesioangular impacted mandibular third molars

目的探讨下颌第一或第二磨牙缺失后,近中阻生的第三磨牙代替缺失磨牙的临床效果,以及分析矫治后的牙髓、牙根及牙周状况,并比较3种矫治方法的差异,为临床中第三磨牙的矫治提供重要的临床参考。方法选取符合纳入标准的患者36例,共计阻生第三磨牙48颗,按照随机化原则分为3组,每组16颗。A组:种植体支抗辅助悬臂梁;B组:磨牙后垫区种植体;C组:鱼钩丝。对矫治后牙髓、牙根及牙槽骨的变化以及3种矫治方法进行对比分析。结果各组矫治后的第三磨牙牙根长度减少,差异有统计学意义(P<0.05);远中根平均吸收程度较近中根重,差异无统计学意义(P>0.05);矫治后第三磨牙近中牙槽骨高度增加,差异有统计学意义(P<0.05);探诊未见牙周袋,龈沟深度与对侧牙相比,差异有统计学意义(P<0.05);矫治后牙髓活力无异常。各组间对比牙根长度减少及牙槽骨高度增加,差异无统计学意义(P>0.05);B组直立时间最短(P<0.05)。结论矫治近中阻生的第三磨牙并前移替代被破坏的第一或第二磨牙是切实可行的,但在治疗过程中要注意牙根吸收的问题以及牙周健康状况,并及时检查牙合创伤。

Objective To explore clinical effect of moving the third permanent molar to replace the damaged first or second permanent molar, and to investigate the health of the pulp, root and periodontal and compare the difference among three treatment methods,in order to provide important clinical reference.Methods A total of 36 patients and 48 impacted third molars were included. All the teeth were randomly divided into three groups with sixteen in each group, group A:implant anchorage assisted cantilever, group B:implant in the retromolar area and group C:fishhook wire. Changes of the pulp, root and alveolar bone and three different orthodontic methods were compared and analyzed.Results The results showed that the root length of the third permanent molar was absorbed, and the difference was statistically significant(P<0.05). The resorption degree of the distal roots was slightly higher than that of the mesial roots, but the difference was not statistically significant(P>0.05). The height of alveolar bone increased significantly after treatment,and the difference was statistically significant(P< 0. 05). No periodontal pocket was found in the periodontal exploration after treatment, and the depth of gingival crevicular was statistically significant compared with that of the contralateral teeth(P<0.05). Vitality test was performed to all teeth after treatment and they all gave response of being vital. The results of pairwise comparison between the three groups showed that the reduction of root length and the increase of alveolar bone height had no significant difference(P>0.05). The treatment time of the implants in the retromolar area was the shortest, and the difference was statistically significant(P<0.05).Conclusion It is practicable to move the mandibular third molar to close the missing gap of the first or second molar. It is necessary to pay attention to the root absorption and periodontal health during clinical treatment. The occlusal trauma should be checked in time.