## 4 Discussion
In our study, bony bridge formation was only statistically related to age, with no significant effect of R-plate fracture, medication type, or duration of medication intake. There are several treatment options for the reconstruction of segmental mandiublectomy. The placement of a vascularized bone graft, which is the gold standard for mandibular reconstruction, remains controversial due to requirements of advanced skill and technology and several side-effects as mentioned above. Furthermore, it requires a donor siteand is associated with a risk of donor site morbidity. Other reconstruction techniques, such as distraction osteogenesis and the induced membrane technique, are other technical options [19; 20], but these treatment options require several visits or secondary surgery. The R-plate reconstruction could therefore be a promising and suitable treatment option for patients with MRONJ. Recent studies have reported that some novel approaches and adjuvant therapies concomitant with the standard approach may offer advantages in terms of surgical techniques and bone healing [31]. Leukocyte and platelet-rich fibrin (LPRF) and leukocyte and platelet-rich plasma (LPRP) are used to promote bone healing and showed a significant improvement in quality of life [32]. A novel surgical technique called fluorescence-guided surgery was introduced for its enhancing effect of the transition from necrotic to vital bone during surgical debridement [33]. In addition, necrotic bone can be vaporized by laser ablation such as an Er:YAG laser, leading to a faster bone healing without risk of thermal damage [34]. Additionally, antimicrobial agents such as chlorhexidine gluconate mouthwash are prescribed in some cases to prevent oral infection on the surgery site with regard to intraoral microbial approaches. Some recently introduced compounds have been demonstrated as having a significant influence on the oral environment [35]. The use of lysates [36] and postbiotics [37] can modify clinical and microbiological parameters, so these products can also be considered an oral microbial approach in maxillofacial surgery. When these adjuvant techniques are combined with R-plate reconstruction, the healing outcome might be more favorable. However, there are several limitations in this study. Along with the involvement with a single limited population, the retrospective nature of this study leads to a limited sample size of rare cases without sample size calculation. Furthermore, limitations within operator-related factors such as experience level or the learning curve exist as all of the cases were performed by a single operator. Additionally, comparisons on the healing outcome with other reconstruction are required, as this study investigated the healing outcome of only one surgical procedure. A systematic review about the prognostic factors of MRONJ revealed that as prognostic factors of treatment outcomes, the type of medication, the stage of MRONJ, and the type of surgical intervention were significant independent factors in the multivariate analysis [38]. Thus, further studies might be needed to investigate the effects of medication type and MRONJ stage on the spontaneous osteogenesis in R-plate reconstruction after segmental mathiblectomy with larger case numbers of MRONJ patients. Furthermore, as only the presence of new bone formation and bony bridge formation was assessed in the present study, further research on the quantitative measurement of bony bridge formation using CBCT images and three-dimensional views is necessary.