The use of microimplants in orthodontic anchorage.
OBJECTIVE
Various types of temporary implants have been introduced to serve as orthodontic anchorage. The hypothesis of this study is that microimplants of 1.2 mm diameter can be used as orthodontic anchors, and that their success is related to their length. The aim of this study is to determine the incidence of anchor retention after orthodontic force application for moving teeth, and to determine the relationship of microimplant length to retention rate.


METHODS
Fifty-nine microimplants (diameter: 1.2 mm) were placed in 29 patients as orthodontic anchorages. After 2 weeks of microimplant placement, a force of 100 to 200 g was loaded with an elastometric chain or NiTi coil spring. Risk factors were characterized as to why a microimplant may fail, and Fisher's exact test was used for statistical analysis.


RESULTS
Nine microimplants were removed and the overall success rate was 84.7%. Exploring the causes for failure, we found significant differences between the length of microimplants and success rate; 6 mm was 72.2% and 8 mm was 90.2%.


CONCLUSIONS
The results suggest that microimplants are suited as an alternative orthodontic anchorage. We recommend that 8-mm microimplants are preferable to 6-mm.
Chen
Chung-Ho
CH
Department of Oral and Maxillofacial Surgery, Kaohsiung Medical University, Kaohsiung, Taiwan.
Chang
Chao-San
CS
Hsieh
Chi-Hsin
CH
Tseng
Yu-Chuan
YC
Shen
Yee-Shyong
YS
Huang
I-Yueh
IY
Yang
Chia-Fu
CF
Chen
Chun-Ming
CM
D000328:Adult; D000539:Alveolar Process / Q000601:surgery; D001863:Bone Screws; D015921:Dental Implants; D003799:Dental Stress Analysis; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008904:Miniaturization; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
D015921:Dental Implants