Kumar Prasanna, Datana Sanjeev, Londhe S M, Kadu Abhijeet
Professor (Orthodontics), Department of Dental Surgery, Armed Forces Medical College, Pune 411 040, India.
Associate Professor (Orthodontics), Army Dental Centre (R&R), Delhi Cantt, New Delhi 110 010, India.
Med J Armed Forces India. 2017 Jan;73(1):65-73. doi: 10.1016/j.mjafi.2015.10.006. Epub 2015 Dec 31.
Nonsurgical correction of deep bite involves either extrusion of posterior teeth, intrusion of incisors, or combination of both. The introduction of skeletal anchorage device with microimplant provides near absolute anchorage without producing any untoward effects on anchor unit. Connecticut Intrusion Arch (CIA) provided an efficient system of intruding anterior segment without producing much adverse affects on anchor teeth.
The study comprised of 30 patients of Class II Div 1 malocclusion with overbite of >6 mm and required therapeutic extractions of all first premolars, randomly distributed into two groups. Group 1 was treated using orthodontic microimplants, while Group 2 treated with CIA. Lateral cephalograms were taken pre-intrusion (T1) and post-intrusion at the end of six months (T2).
The rate of intrusion was 0.51 and 0.34 mm/month for Group 1 and Group 2 respectively. The average amount of change in centroid point to PP distance and U1-SN angle was significantly higher in Group 1 compared to Group 2 ( < 0.001). The average amount of change in U6 to PP distance did not differ significantly between two study groups ( > 0.05).
The amount of intrusion is significantly higher in SAD group. Although vertical molar positional change was higher in CIA group than the SAD group, it was not changed significantly in both treatment modalities. SAD group overall had better results and was easier in handling during intrusion.
深覆合的非手术矫治包括后牙伸长、前牙压低或两者结合。微种植体骨锚固装置的引入提供了近乎绝对的支抗,且对支抗单位不产生任何不良影响。康涅狄格压低弓(CIA)提供了一种有效的压低前牙段的系统,对支抗牙的不良影响较小。
本研究纳入30例安氏II类1分类错牙合患者,覆合超过6mm,均需拔除所有第一前磨牙进行治疗,随机分为两组。第1组采用正畸微种植体治疗,第2组采用CIA治疗。在压低前(T1)和6个月末压低后(T2)拍摄头颅侧位片。
第1组和第2组的压低速率分别为0.51mm/月和0.34mm/月。与第2组相比,第1组质心点至PP距离和U1-SN角的平均变化量显著更高(<0.001)。两个研究组之间U6至PP距离的平均变化量无显著差异(>0.05)。
微种植体骨锚固装置组的压低量显著更高。虽然CIA组磨牙垂直位置变化高于微种植体骨锚固装置组,但两种治疗方式下的变化均不显著。微种植体骨锚固装置组总体效果更好,且在压低过程中操作更简便。