Περίληψη
Σκοπός της παρούσας μελέτης ήταν να απαντηθούν ερωτήματα σχετικά με τυχόν μεταβολές των μικροπλακών οστεοσύνθεσης και των παρακειμένων ιστών και να ευρεθεί, αν υπάρχει, συσχέτιση rted mainly in cases of fracture fixation and orthognathic surgery, while few of them were used for bone autografts fixation in cases of bone defects. Plates had remained in situ for 1-36 months (mean: 7.2 months, SD: 6.5). The tissue specimens were excised from the tissues adjacent to titanium plates or around loose screws. Plate removal was made in most cases (84.6%) routinely after bone healing, whilst in few cases (13.4%) plates were removed due to local i ...
The purpose of the present study was to investigate and evaluate findings on titanium osteosynthesis plates and adjacent tissues retrieved from the maxillofacial area. 65 patients with an age of 2-55 years (mean 18.2 years, SD: 12.4), who had undergone maxillofacial surgery participated in the study. From these patients 123 commercially pure titanium plates (mini and micro) of the same manufacturer (Martin Medizin-Technik) and 61 tissue specimens (48 soft and 13 hard tissue) were removed and investigated. The plates had been inserted mainly in cases of fracture fixation and orthognathic surgery, while few of them were used for bone autografts fixation in cases of bone defects. Plates had remained in situ for 1-36 months (mean: 7.2 months, SD: 6.5). The tissue specimens were excised from the tissues adjacent to titanium plates or around loose screws. Plate removal was made in most cases (84.6%) routinely after bone healing, whilst in few cases (13.4%) plates were removed due to local infection. The retrieved plates were analyzed by reflection light microscopy, X-ray fluorescence spectrometry, scanning electron microscopy and energy dispersive X-ray microanalysis and micro multiple internal reflectance FTIR spectroscopy. Tissues were studied using transmission light microscopy, scanning electron microscopy and energy dispersive X-ray microanalysis and FTIR-microscopy. Findings on plates consisted mainly of morphologic alterations of their surfaces. No chemical changes (e.g. corrosion of the metal) were detected. Regarding topographical changes, these were categorized in two major groups as they were either scratches, scraping and cracking (few or many) or permanent plastic deformation at the contour of the screw holes of the plates. All retrieved plates had scratches and 64.2% of them had plastic changes in one or more holes. These findings were compatible and were attributed to mechanical surgical manipulations during insertion and removal of the plates. Statistical analysis revealed that few scratches on every plate was a significant expected finding. Additionally, deposits found on the plates, were also measured and elementally analyzed, being either organic remnants or integrated bone. The soft tissue in all cases was fibrous connective tissue, which in 86.5% of the cases presented various degrees of inflammation (mild, moderate or pronounced regarding the type and chronic or acute regarding the grade). There was no foreign body reaction found in the tissues. Inflammation was chronic and mild in most cases. Statistical analysis revealed that this finding was statistically significant. Pigmented deposits (fine or larger in size) were detected in 68.7% of the specimens. These deposits as in most similar studies, were initially attributed to the presence of titanium particles. However, further elemental analysis of the “particles” in all cases with EDS/SEM did not confirm the presence of titanium in any significant amount, but only in traces. The hard tissue specimens were mature bone in 53.8% of the retrieved cases and partially or totally necrotic bone in the rest of them. Regarding the various correlations between the laboratory findings, statistical analysis did not reveal any significant correlation between morphologic alterations of the plates and inflammatory response of the adjacent soft tissues. No significant correlation between morphological changes of the plates and the existence of pigmented tissue was found. Titanium release from miniplates into the tissues, due to mechanical wear, was also asymptomatic and statistically insignificant related to inflammation.Additionally, none of the laboratory findings had any statistically significant correlation with the two clinical findings examined: Macroscopic soft tissue pigmentation and presence of loose screws with soft tissue around them. The fact that there were no clinical symptoms detected at the osteosynthesis area, should not lead us to the conclusion that the adjacent tissues were completely healthy. Laboratory findings (e.g inflammation of the tissue specimen) and clinical findings (e.g loose screws floating in infectious soft tissue during plate removal), were certainly present.According to the findings of the present study, the presence of inflammation in the tissues adjacent to titanium osteosynthesis plates appears that it is not related and should not be attributed to morphologic changes found on the plates. The extent of the previous tissue trauma and subsequent healing should be considered as well.
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