正畸治疗中磨牙的拔除和保留(四十九)——不拔牙或减数前磨牙矫治后第三磨牙萌出间隙调查

The investigation of third molar eruption space after treatment of non-extraction or premolar extraction

目的:通过对不拔牙矫治或减数前磨牙矫治后第三磨牙萌出间隙的调查,探讨在正畸患者中保留28颗牙齿的可行性。方法:297个样本均来自深圳市儿童医院口腔正畸科,男132例,女165例,其中18岁以下组(少年组)201例,18岁以上组(成人组)96例。均采用了不拔牙矫治或减数前磨牙矫治。测量矫治结束后口腔全景片上第二磨牙远中磨牙后间隙量及第三磨牙牙冠近远中宽度。结果:不拔牙矫治组较减数前磨牙矫治组第三磨牙萌出尚欠间隙量大,上颌的萌出尚欠间隙量较下颌小,少年组的萌出尚欠间隙量较成人组大,差异均具有显著性;在成人组中,有70%的患者可通过不拔牙或减数一组磨牙矫治获得保留28个牙齿的目的。结论:减数前磨牙在统计学上并不能完全解决第三磨牙萌出间隙的问题,通过减数一组磨牙实现保留28个牙齿的目的对大多数正畸患者是可行的,它是大概率事件,科学合理。

Objective： To discuss the feasibility of reservation 28 teeth through investigation of third molar eruption spaces after treatment of non-extraction or premolar extraction. Method： Samples were from orthodontic department of Shenzhen Children＇s Hospital, 132 males and 165 females,of which 201 youth group,96 adult group. All samples were treated with non-extraction or premolar extraction. The post-treatment panoramic radiographs were analyzed. The eruption spaces and crown width of third molars were measured. Result： The absent eruption spaces of third molars showed that non- extraction group was larger than premolar extraction group, maxillary jaw was larger than lower jaw, youth group was larger than adult group. The difference was significant： In the adult group, 70 % of patients could be treated by non-extraction or molar extraction to obtain the purpose of reservation 28 teeth. Conclusion： Premolar extraction can not statistically solve third molar eruption spaces. Design of molar extraction was feasible for most orthodontic patients to obtain the purpose of reservation 28 teeth. It is a great probability event, scientific and rational.