Comparing the Outcomes of Self-drilling and Self-tapping Mini-Screws in Midfacial Fractures: A Randomized Split-Face Study

A variety of screw types have been used in Midfacial fracture bone fixation such as lag screws, pre-tapped screw, self-drilling screws (SDS) and self-tapping screws (STS) with varying degrees of success.

A split face technique was adopted in which both SDS and STS of 8 mm in length were inserted in the same patient but the site of placement (right or left side) was done using random allocation by computer generated sequence method. We designed this study to evaluate all screws with respect to torque measurement, pain and infection and to determine the relative advantages of each type.

In all the 30 patients included in the study, the average time for fixation of SDS was 17.7 ± 8.2 s while it was 36.7 ± 3.0 s for STS. The insertional torque for SDS was determined to be 20.5 ± 1.9 cNm while it was 13.1 ± 1.2 cNm for STS. All patients, experienced pain on 5th post-operative day bilaterally. After 1 month of surgery, out of 30 patients only 8 (26.7%) patients reported presence of pain at the SDS side whereas 15 (50%) patients were experiencing pain at the STS side. All patients in either of the two groups did not show any sign or symptom of infection till 1 month follow-up. In 3rd month follow-up, out of 30 patients, 2 patients developed infection at the SDS site and 4 patients developed infection at the STS site.

SDS were found superior in comparison with STS in terms of intra-operative fixation time and insertional torque in midface while in terms of pain and plate infection, SDS were not significantly different when compared with STS.