## 4 Discussion
The question of implantability in the scapular flap stems from the limited bone reserve available compared to the fibula and DCIA flaps [39]. Given this premise, many studies have focused their attention on studying the possibility of the safe and adequate placement of dental implants on scapula flaps. In particular, [PERSON] et al. highlighted a possible difference in terms of implantability between men and women, especially in those with a lighter body mass [19]. However, in the studies analyzed, no substantial sex difference emerged in terms of 'implantability'. These data appear to be in line with more recent papers on the subject, which have refuted previous works [27; 37; 38]. However, despite the various studies conducted on this topic, this systematic review shows that there are still few works specifically focusing on the outcome of dental implants in the scapular flap. Pre-operative planning certainly contributes positively to this outcome, allowing the surgeon to make the best use of the available amount of bone [25; 40; 41]. Interestingly, about 38.1% of the reconstructions were secondary reconstructions compared to 61.9% of the reconstructions simultaneous with resective surgery. These data are probably explained by the possibility of using the healing time for careful and personalized planning of the reconstruction, which in more recent times has also started to make use of new customized technologies [25]. These technologies, in addition to the greater precision of reconstruction and implant placement, also allow a reduction in surgical time and can be merged with new computer-vision technologies in order to identify and preserve noble structures if feasible [41; 42; 43]. As can be clearly seen in Table 1, implants were almost never placed at the same time of jaw reconstruction, with a percentage of 4.8%, while in the remaining 95.2%, the implants were positioned at least 5 months after the surgery. This common choice is probably due to the will of waiting for the healing time of flap tissues and for the volumetric settlement of the soft tissues. This concept is not only related to locoregional healing and scarring, but also to actinic effects induced by radiotherapy. Adjuvant treatment must always be considered as a likely eventuality in the treatment of cancer patients with bone-infiltrating malignancies. Indeed, it is no coincidence that 62.8% of the patients in the cohort analyzed in the systematic review received adjuvant radiotherapy. Moreover, since the indication for reconstructive surgery is almost always related to an oncological cause, there is also the advantage of the direct post-operative monitoring of any early recurrence. The disadvantage of this choice, however, is that of the late functionalization of the reconstruction, which is an increasingly crucial problem in reconstructive surgery today [44]. Regarding the implant failure rate, this complication was seen to occur in less than 5% of the cases. Compared to the cases reported for fibula flaps and DCIA, this percentage is similar and there does not seem to be a substantial difference in this field between the major microsurgical bone flaps [39; 45]. However, it should be noted that smoking habits and the ability to maintain adequate oral hygiene were hardly ever investigated in the selected articles. Since the primary indication for resection is usually oncological in nature, patients are often smokers, a major risk factor for oral cancer. At the same time, poor oral hygiene also promotes its occurrence, especially due to chronic infections [46]. But smoking habit and poor oral hygiene are also two key factors in preventing implant failure, as they strongly predispose to infections and peri-implantitis. As shown, for example, by [PERSON] et al., peri-implantitis was the cause of failure in almost 80% of the cases and was diagnosed in almost 20% of the remaining implants [23]. Although the percentage of smokers in head and neck cancer patients decreases after surgery, the problem of oral hygiene often persists after surgery [47; 48].