# MRONJ Treatment Strategies: A Systematic Review and Two Case Reports
## 4 Discussion
### Surgical Resection
The most widely used definition of healing, for example, is based on clinical criteria, such as maintenance of the seal of the oral mucosa without any symptoms. This definition is largely incomplete, as it completely misses the assessment of the bone, which is where the disease develops and may recur over time, regardless of the persistence of the overlying mucosal seal [21,34,53]. The term'resective surgery' refers to the en bloc removal of pathological bone down to healthy tissue [54]. Unlike oncological surgery, bone resection margins in drug-related ONJ, as in all forms of osteonecrosis and osteomyelitis of the jaws, are not codified [50]. Preoperative TC and RM evaluation of the resection margins allows for identifying the adjacent normal bone tissue with good accuracy, which, if nonpathological on histological examination, ensures complete and stable healing over time [40]. There are two forms of resective surgery: marginal and segmental. Marginal resective surgery consists of the en bloc removal of pathological tissue without interruption of the anatomical continuity of the skeletal segment concerned. This surgery can be performed under locoregional anesthesia or general anesthesia, depending on the extent of the process, the clinical conditions, and the patient's compliance [47]. Segmental resective surgery refers to the en bloc (full-thickness) removal of a skeletal segment with interruption of its anatomical continuity [54]. This surgery is performed under general anesthesia. It must always include an additional osteoplasty of the resection margins to eliminate possible residual asperities and mucosal closure by the first intention of the defect, by mobilizing a mucoperiosteal flap if no other form of reconstruction is indicated [26]. In the treatment of advanced stages of ONJ, the high full-thickness mucoperiosteal flap was prepared after a horizontal incision to the periosteum. It was fixed with resorbable suture material within the periosteum for the closure of the bone defect. However, in cases of oral soft-tissue breakdown, the phylohyoid muscle flap (MMF) in the lower jaw, and the buccal fat flap (BFF) in the upper jaw, were reliable methods to have better coverage of the bone defects and healing of tissues [38,71]. [PERSON] et al. evaluated the use of MMF and BFF as additional tissue closure in stage III cases of AAOMS classification, compared to mucoperiosteal flap closure alone. Mylohyoid muscle was carefully detached from the mouth base mucosa to have complete mobilization, and MMF was performed for tissue closure after the resection of osteonecrosis of the lower jaw. BFF was separated from the lateral pterygoid muscle and was used in the lateral upper jaw to cover the defect in cases of oroantral communication. The flap was fixed at the periosteum with absorbable suture material for holding it in position. These flaps ensured better results than the mucoperiosteal flap alone and were a good alternative to the usual procedure of soft tissue closure in stage III cases of MRONJ [46]. Similar outcomes were found in the study of [PERSON] et al., which observed the advantages of MMF and BFF in stage I, stage II, and stage III cases of AAOMS classification. Double-layer closure techniques after surgery in MRONJ increased the chances of tissue healing due to increased mechanical stability and better vascularization of the flaps covering the bone defect. MMF and BFF were only used if the anatomical sites were suitable and, with a low rate of complications, turned out to be very convenient for tension-free wound closure through MMF, BFF, and mucoperiosteal flap to guarantee wound closure [35]. The standard resective surgery for the mandible is mandibular. It always causes the loss of symmetry of the lower third of the face and occlusion. Reconstruction after surgery can be achieved with titanium reconstruction plates to replace the removed bone with anatomical mandibular replicas or, alternatively, with vascularized bone flaps.