Bone Union Quality after Fracture Fixation of Mandibular Head with Compression Magnesium Screws

Abstract

For some years now, fixation devices created with resorbable magnesium alloys for the mandibular head have been clinically available and are beginning to be used. It is thus valuable to evaluate the quality of unions in these cases. The aim of this study was radiological comparison of magnesium versus titanium open reduction and rigid fixations in the mandible condylar head. Thirty-one patients were treated for fractures of the mandibular head with magnesium WE43 alloy headless compression screws (diameter 2.3 mm) and, as a reference group, 29 patients were included with similar construction titanium screws (diameter 1.8 mm). The 12-month results of the treatment were evaluated by the texture analysis of CT. Near similar treatment results were found with magnesium screws in traditional titanium fixation. Magnesium screws result in a higher density of the bone structure in the mandibular head. Conclusions: The quantitative evaluation of bone union after surgical treatment of mandibular head fracture with magnesium compression headless screws indicates that stable consolidation was achieved. Undoubtedly, the resorption process of the screws was found to be incomplete after 12 months, evidenced by a marked densification of the bone structure at the fracture site.

Current Frequency of Mandibular Condylar Process Fractures

“…In the last 20 years, advances in surgical techniques that are safe for cranial nerves have been documented [ 24 , 25 , 26 , 27 , 28 ] to ensure proper bone consolidation [ 29 , 30 , 31 ]. This became the basis for ORIF to become the widespread treatment for patients diagnosed as having mandibular head fractures.…”

“…Note, however, that groundbreaking articles from more than 50 years ago are cited here [ 2 , 3 , 4 , 5 , 6 , 7 , 9 , 13 , 16 , 38 , 56 , 57 ]. It is concerning that citations are rising by 5.6% per year, with them doubling every 12 years among scientific papers with a gap in the citation of brand new or very old research [ 58 ]; the strength of this paper is that there are also many citations of research that is younger than six years old [ 1 , 14 , 17 , 18 , 23 , 24 , 28 , 29 , 30 , 34 , 36 , 42 , 43 , 44 , 45 , 46 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 56 ].…”

The Osteosynthesis of the Mandibular Head, Does the Way the Screws Are Positioned Matter?

“…In general, the matter requires further investigation and it is obvious that going through-and-through the mandibular head during osteosynthesis should be avoided. The Bone Index is a known measure of whether or not the examined bone has the characteristics of a valid cancellous bone [ 22 , 23 , 33 ]. To reconstruct a cancellous bone in a union place, the BI value would be expected to be approx.…”

“…The structure of the bone union was also examined by means of digital texture analysis on coronary sections of the mandibular head [ 23 ]. ROI covered the post-fracture site and the next controlled ROI in the cancellous bone of mandibular head were described in MaZda 4.6 software developed by University of Technology in Lodz, Poland [ 24 ].…”

“…The Bone Index (BI) texture feature in ROIs was calculated for the control bone and for the post-fracture site: where Nr is the number of series of pixels with density level i and length k ; Ng —number of levels for image optical density; p is probability, log is common logarithm [ 25 ]; Nr —number of pixels in series; [ 26 , 27 ]. The equation above was used for the Bone Index construction [ 28 ], which represents the ratio of the measure of the diversity of the structure observed in the radiograph to the measure of the presence of uniform longitudinal structures ( Figure 5 ) [ 22 , 23 ].…”