Factors affecting the clinical success of screw implants used as orthodontic anchorage.
BACKGROUND
The purposes of this study were to examine the success rates and find factors affecting the clinical success of screw implants used as orthodontic anchorage.


METHODS
Eighty-seven consecutive patients (35 male, 52 female; mean age, 15.5 years) with a total of 227 screw implants of 4 types were examined. Success rates during a 15-month period of force application were determined according to 18 clinical variables.


RESULTS
The overall success rate was 91.6%. The clinical variables of screw-implant factors (type, diameter, and length), local host factors (occlusogingival positioning), and management factors (angle of placement, onset and method of force application, ligature wire extension, exposure of screw head, and oral hygiene) did not show any statistical differences in success rates. General host factors (age, sex) had no statistical significance. Mobility, jaw (maxilla or mandible), and side of placement (right or left), and inflammation showed significant differences in success rates. Mobility, the right side of the jaw, and the mandible were the relative risk factors in the logistic regression analysis when excluding mobility, inflammation around the screw implants was added to the risk factors.


CONCLUSIONS
To minimize the failure of screw implants, inflammation around the implant must be controlled, especially for screws placed in the right side of the mandible.
Park
Hyo-Sang
HS
Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea. parkhs@knu.ac.kr
Jeong
Seong-Hwa
SH
Kwon
Oh-Won
OW
D000293:Adolescent; D000328:Adult; D001863:Bone Screws / Q000009:adverse effects; D015921:Dental Implants / Q000009:adverse effects; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology; D016015:Logistic Models; D008297:Male; D008904:Miniaturization; D016017:Odds Ratio; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D012307:Risk Factors; D016896:Treatment Outcome
D015921:Dental Implants