正畸治疗前后切牙区龈乳头变化的研究

目的调查正畸治疗前后上下切牙区牙龈乳头的变化,分析牙龈乳头发生退缩的相关因素。方法本研究选择68名接受正畸治疗的患者,根据其治疗前后的头颅侧位片、中切牙 X 光片、(牙合)像以及模型等临床资料,对正畸治疗的初始年龄、中切牙的形态、牙周状况、切牙区的拥挤度、是否拔牙矫治、切牙的移动方式以及中切牙牙槽骨高度进行统计学分析,探讨上下前牙区黑三角(Black triangle,BT)易发因素。结果 1)上颌切牙区 BT 发生率为19%,下切牙区高达48%;2)早期矫治患者的切牙区 BT 发生率较低;3)临床冠较长、牙冠切端近远中宽度与牙颈部宽度相差较大的患者 BT 发生率明显增高;4)治疗后牙槽骨吸收明显的患者,BT 发生率高;5)前牙过度代偿的患者 BT 发生率较高;6)BT 的形成与性别以及是否拔牙矫治均无显著性相关。结论 BT 的形成与治疗初始年龄、牙冠形态、牙槽骨的吸收程度以及牙齿移动方式存在密切关系。

Changes of anterior papilla after orthodontic treatment

Objective To investigate the gingival conditions regarding the presence of the black triangle(BT) between the central incisors during orthodontic treatment.Methods Sixty-eight patients who received orthodontic treatment were examined and the relationship between the incidence of BT and the following items (the initial age of the treatment,the shape of the crown,the severity of crowding,the extraction of the teeth,the periodontal state,the type of the tooth movement and the resorption of alveolar bone crest) were evaluated.Results 1) The rate of BT was 19% and 48% in the upper and lower arches, respectively.2) Earlier treatment reduced the occurrence of BT.3) The teeth which had longer crown or larger difference of the crown width between the maximum and the cervical width showed higher rate of BT. 4) A significant relation was found between the existence of BT and the resorption of the alveolar bone crest.5) The rate of BT was higher in patients with over-compensation of the anterior teeth.6) No significant differences were found between the existence of BT and sex,and extraction of the teeth. Conclusion These results demonstrated that the occurrence of BT might he related to the age at treatment,the crown shape and the conditions of the alveolar,especially in the lower arch.