## 4 To Remove Titanium-Based Osteosynthesis Materials or not: A Present Debate
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Reference**} & \multicolumn{1}{c}{
\begin{tabular}{c} **Titanium-Based** \\ **Alloys** \\ \end{tabular} } & \multirow{2}{*}{**Type of Study**} & \multirow{2}{*}{**Samples**} & \multirow{2}{*}{**Implications and Conclusions**} \\ \hline \multirow{7}{*}{[PERSON] et al. [79]} & \multirow{7}{*}{Titanium} & & & - a good healing of the surrounding bone (direct attachment of vital bone to the titanium \\  & & & Removed titanium & & - aft**staining** of the examined soft tissue \\  & & & & Hand and soft soft tissue & - histological signs of **fibrosis** in the examined \\  & & & tissue sample covering the & & **- defects and irregularities** of the plates when \\  & & & & & examined using scanning electron microscope (SEM) analysis, probably due to the \\  & & & & substance loss & \\  & & & & - macroscopically **dark pigmentation** was visible \\  & & & & & in all cases \\  & & & & - the histological examination revealed the \\  & & & & & presence of **fibrous connective tissue** with \\  & & & sample & macrophages-like cells that contained metal \\  & & & & & particles \\  & & & & -presence of CD68-positive cells, CD11c-positive cells, CD11a-positive cells, CD11b-positive cells, CD4b, CD62P and CD54 \\  & & & & - the first report that outlined the **existence of an immune-inflammatory reaction** \\  & & & Tissue sample & & - all the examined sample contained metal debris \\  & & & & bone–titanium & & and T lymphocytes (OKT11) and macrophages \\  & & & & plate & - when exposed to titanium and \\  & & & & & titanium-aluminium, fibroblasts showed no \\  & & & & increase of ion concentrations \\ [PERSON] et al. [89] & Titanium-aluminium & & In vitro & Fibroblasts & - when exposed to only titanium metallic \\  & & & & particles, the fibroblasts showed a ruffled \\  & & & & membrane and filopodia \\  & & & & - when exposed to titanium–aluminium metallic \\  & & & & debris, fibroblasts showed no modifications \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._that there is no need to routinely remove the titanium materials and the indications for removal are strictly in relation with the existence of complications. The most common encountered complications identified were infection, exposure, loosening of the screws or discomfort. Although, the clinical performance of titanium is widely recognized, there are still questions regarding the long-term relations with the tissue and the possible consequences. The removal of titanium-based materials is indicated when complications are associated, and the asymptomatic removal is still a discussed alternative [104]. Most reports express a clear concern towards the persistence of the titanium plates and the occurrence of corrosion [74]. Several studied report the dark pigmentation of the surrounding tissue, the mechanical wear, and the mechanical disruption during the insertion manoeuvres as being accompanied by local metal release that could potentially disseminate in other organs [74, 105, 106]. The finite element analysis (FEA) is useful to predict the stress distribution, the possible fracture localizations based on the design, and the material of the plate [107]. The masticatory muscles generate tension and compression of the jawbone during the physiological movements. In order to perform osteosynthesis, the main concern is to assure a correct load of force and distribution of stress in the interface between bone and implant. [PERSON] et al. [108] conducted an in vitro study on polyurethane mandibles that aimed to mechanically test all designs of osteosynthesis plates used for high neck condylar mandibular fractures Their results showed that the specific designed plates for this type of fractures were weaker in comparison to the use of two straight plates, and loosening of the screws occurred in the distal fragment. In conclusion, the shape of the plate is also a factor that must be considered, taking into account the muscle insertions and the generated tension. The study that belongs to [PERSON] et al.