## 3 Discussion  
The authors thought that the autogenous bone graft could resist infection and wound debiscence with non-submerged implant placement and heal rapidly with osseous integration around the implant, even after early loading. To prevent graft infection and achieve soft tissue healing, an impression was made at 2 weeks, and the implants were loaded with provisional prostheses at 4 weeks. This resulted in a successful outcome without graft loss or implant failure. Quantitative evaluation of implant stability using resonance frequency analysis is reliable for the assessment of implant success using ISQ values. Less susceptibility to implant failure has been reported with ISQ values higher than 65 after immediate or early prosthetic loading [9]. However, due to the remodeling process, the ISQ value is known to decrease 3-4 weeks after placement, during which the transition period from primary to secondary stability occurs. Furthermore, maxillary implants show lower stability and ISQ values than mandibular implants [9]. Since ISQ values are directly related to the extent of osseointegration, the timing of the loading at four weeks was undesired in this case. Despite several unfavorable conditions, such as severe bone loss, chronic periodontitis, a smoking habit, the timing of prosthetic loading, and poor bone quality of the maxilla, all implants functioned well without failure and were supported by a well-developed corticocancellous  
Figure 3: Postoperative radiographs. (**A**) Post-operative radiographs at 14 months after the surgery. All implants were functioning well with no complications, such as graft or implant failure or marginal bone loss. (**B**) Pre-operative radiograph. (**C,D**) At 16 months after the surgery, the implants and grafted bone were well-maintained, with masticatoric and esthetic functions. bone with no marginal bone loss. We can speculate that high initial stability (\(\geq\)65 ISQ value) and autogenous bone grafting could achieve effective reconstruction of severe bone defects with early implant rehabilitation [7, 9]. In addition, we easily verified the vertical dimension using the remaining three teeth (#21, #24, and #25) during the healing period, and the left premolars were extracted before the final prosthetics. Since provisional partial dentures can be avoided through early loading, the patient could easily adapt to the implant prosthesis and showed significantly improved satisfaction and quality of life. With considering the early loading of this patient, a mechanobiological effect might also contribute positively to the grafted autogenous bone. In 2018, [PERSON] et al. highlighted that mechanical stimulation was able to augment implant osseointegration and the peri-implant bone mass in both healthy and diseased bone [10]. The mechanical loading seems to be effective, especially in the vicinity of the implant and the response of the implanted bones in the first 2 weeks after implantation. Some in vivo studies showed that mechanical stimuli have positive effects, such as enhanced bone formation and inhibited bone resorption [11, 12, 13]. [PERSON] et al. reported that an enhanced osteoblastic differentiation was observed in the early loaded group in the peri-implant tissue [14]. Implantation surgery, as well as the presence of prosthetic loading, might alter the mechanobiology of the peri-implant bone, causing a different reaction to the loading than the bone without an implant [10, 15]. Wound dehiscence, which could be contributed to by using provisional dentures, is the most frequent complication after extensive bone augmentation [7]. In 2021, [PERSON] et al. suggested an effective conservative technique for wound dehiscence by using attachable dressing material [16]. Although the conservative technique could achieve secondary healing with osteoinductive autogenous bone substitutes, some bone volume loss was inevitable in the wound dehiscence area.