## 4 Discussion
The pre- and post-surgical amoxicillin in the case of osteotomy was evaluated on the basis of 4 studies, for a total of 612 surgeries (see Figure S16, Supplementary material). This prophylaxis did not show a significant benefit, with zero heterogeneity. Therefore, it is possible to state that from the analysis of the literature no advantages emerged in the pre- and post-surgical prophylaxis with penicillin antibiotic in case of osteotomy. The meta-analysis of the data regarding pre- and post-surgical prophylaxis with non-penicillin antibiotics in the case of osteotomy included 3 studies for a total of 328 surgeries (see Figure S17, Supplementary material). The RR was significantly in favor of prophylaxis with both the fixed and random models, with an identical value (0.47). Furthermore, the heterogenicity of the data was mild and not significant (10%, \(p>0.10\)) and the NNT was equal to 13. Therefore, it is possible to state that the literature homogeneously indicates a favorable effect in favor of the pre- and post- surgical administration of non-penicillin antibiotics in case of osteotomy. Overall, in case of osteotomy, the pre- and post- surgical administration of antibiotics for the prophylaxis of surgical wound infections following mandibular third molar extraction has a significant efficacy. However, this result is not homogeneous in the scientific literature due to studies that consider the use of amoxicillin, which also has not proved useful in the prevention of postoperative infections of the surgical site in case of osteotomy. Instead, the data in the literature unanimously indicate a significant and clinically important efficacy for pre- and post- surgical prophylaxis with non-penicillin antibiotics in case of osteotomy. Post-surgical prophylaxis in the case of osteotomy has not shown any advantages either in the case of all antibiotics being considered (see Figure S18, Supplementary material) or in case only amoxicillin is considered (see Figure S19, Supplementary material). Furthermore, in the case of administration of non-penicillin antibiotics, it was not possible to perform a meta-analysis due to insufficient number of studies. The analysis of data classified by odontotomy and the type of antibiotic did not yield significant results. Therefore, from the literature analysis, it is not possible to deduce that antibiotic prophylaxis, in any modality, is effective in case of only mandibular third molar odontotomy. Furthermore, it is not possible to say that penicillin antibiotics are more or less effective than non-penicillin ones (see Figures S20-S24, Supplementary material). Some meta-analyses previously evaluated the effectiveness of antibiotic prophylaxis for the prevention of surgical wound infections following tooth extractions. [PERSON] and [PERSON] [1] published a meta-analysis in 2007 on mandibular third molars. They analyzed slightly fewer surgeries than we did (2396 vs. 2726 in the present study). That study, like the present one, found significant efficacy of pre- and post-surgical prophylaxis and a lack of efficacy of exclusively post-surgical prophylaxis. Unlike the present study, however, [PERSON] and [PERSON] [1] reported an almost triple NNT (25 vs. 9 in the present study) for prophylaxis in general and a lack of significant efficacy of prophylaxis with non-penicillin antibiotics and exclusively pre- surgical one, even if a pre surgical single dose was reported nearly as effective as the multiday dosing strategy. These differences can be explained both by the inclusion of more recent studies in the present review, and by different inclusion criteria that led to the exclusion of studies that were included in the previous review. The review by [PERSON] and [PERSON]. [42] concluded that there is little conclusive evidence to suggest the routine use of antibiotic prophylaxis for third molar extractive surgery in healthy young adults.