J Korean Assoc Maxillofac Plast Reconstr Surg.  2006 May;28(3):213-221.

The effect of location and angle of drilling on the changes of the distance between two block specimens during screwing on miniplate fixation

• Oh HC
• An JS
• Gu H
• Kook MS
• Park HJ
• Oh HK

Abstract

PURPOSE: This study was aimed to evaluate the effect of the location and angle of drilling on the changes of the distance between the two block specimens.
MATERIALS AND METHODS
In experimental group 1, the screw holes were prepared by drilling in the distal portion of compression part of the plate at 90 degrees. In experimental group 2, the drilling was performed at an angle of 30 degrees proximal to the miniplate, and in experimental group 3, at 30 degrees distal respectively. In control group, the drilling was performed to the center of hole at 90 degrees. The fixation screw length was 5 mm, 7 mm, and 9 mm in all groups. The results were as follows.
RESULTS
1. In control group, the mean changes between two specimens were 0.01 mm, 0.02 mm, and 0.00 mm in 5 mm, 7 mm, and 9 mm screws respectively. 2. In experimental group 1, the compression part was moved toward the retention part. The range of mean changes were from -0.39 mm to -0.43 mm. 3. In experimental group 2, the compression part was moved toward the retention part. The range of mean changes were from -0.51 mm to -0.56 mm. 4. In experimental group 3, the compression part was moved apart from the retention part and the range of mean changes were from 0.55 mm to 0.56 mm. 5. The changes were significantly different between all groups(p<0.01).
CONCLUSION
These results suggest that 0.4~0.5 mm of compressive effect can be achieved by drilling on the distal area of the screw hole at an angle of 90.and by the proximal angulation to the miniplate, and the gap between specimens can be increased by distal angulation to the miniplate during drilling.

Keyword

Fixation; Miniplate; Screw