**5. Staging of MRONJ**

The clinical manifestations and staging of MRONJ are summarized in **Table 1**. Paresthesia of the chin, including the lower lip (Vincent's symptom), in patients treated with BP is an early sign of MRONJ, before alveolar bone exposure is detected [5, 12].

**1.** At risk

There is no apparent necrotic bone in asymptomatic patients who have been treated with intravenous or oral antiresorptive or antiangiogenic therapy.


**Table 1.** Staging and treatment strategies.

**2.** Stage 0 (unexposed bone variant)

These patients have no clinical evidence of necrotic bone, but nonspecific clinical findings, radiographic changes, and symptoms.

**3.** Stage 1

Stage 1 is defined as asymptomatic exposed and necrotic bone or a fistula that probes to bone. These patients have no evidence of infection and may present with radiographic findings localized to the alveolar bone region.

**4.** Stage 2 (**Figures 1**–**4**)

Stage 2 is defined as exposed and necrotic bone or a fistula that probes to bone with evidence of infection. These patients are typically symptomatic. These patients also may present with radiographic findings which are localized to the alveolar bone region.

#### **5.** Stage 3 (**Figures 5**–**11**)

Stage 3 is defined as exposed and necrotic bone or fistula that probes to bone with evidence of infection and at least one of the following:


#### Medication-Related Osteonecrosis of the Jaw http://dx.doi.org/10.5772/67980 93

(iii) Extra-oral fistula.

**2.** Stage 0 (unexposed bone variant)

**Table 1.** Staging and treatment strategies.

**3.** Stage 1

92 Osteonecrosis

**4.** Stage 2 (**Figures 1**–**4**)

**5.** Stage 3 (**Figures 5**–**11**)

(ii) Pathologic fracture.

ings, radiographic changes, and symptoms.

At risk No apparent necrotic bone in patients who have been treated with oral or intravenous bisphosphonates

Stage 0 No clinical evidence of necrotic bone but nonspecific clinical findings, radiographic changes, and symptoms

Stage 1 Exposed and necrotic bone or fistula that probes to bone in

Stage 2 Exposed and necrotic bone or fistula that probes to bone

Stage 3 Exposed and necrotic bone or a fistula that probes to bone in

patients who are asymptomatic and have no evidence of infection

associated with infection as evidenced by pain and erythema in the region of exposed bone with or without purulent drainage

patients with pain, infection, and >1 of the following: exposed and necrotic bone extending beyond the region of alveolar bone (i.e., inferior border and ramus in mandible, maxillary sinus, and zygoma in maxilla) resulting in pathologic fracture, extra-oral fistula, oral antral or oral nasal communication, or osteolysis extending to inferior border of the mandible or sinus floor

findings localized to the alveolar bone region.

dence of infection and at least one of the following:

These patients have no clinical evidence of necrotic bone, but nonspecific clinical find-

**Staging of MRONJ Treatment strategies**

No treatment indicated and patient

Systemic management, including use of pain medication and antibiotics

Antibiotic mouth rinse, clinical follow-up on a quarterly basis, patient education, and review of indications for continued bisphosphonate therapy

Symptomatic treatment with oral antibiotics, oral bacterial mouth rinse, pain control, debridement to relieve soft tissue irritation, and

infection control

Antibacterial mouth rinse, antibiotic therapy and pain control, surgical debridement or resection for longer-term palliation of infection and pain

education

Stage 1 is defined as asymptomatic exposed and necrotic bone or a fistula that probes to bone. These patients have no evidence of infection and may present with radiographic

Stage 2 is defined as exposed and necrotic bone or a fistula that probes to bone with evidence of infection. These patients are typically symptomatic. These patients also may present with radiographic findings which are localized to the alveolar bone region.

Stage 3 is defined as exposed and necrotic bone or fistula that probes to bone with evi-

(i) Exposed necrotic bone extending beyond the region of alveolar bone to the inferior border and ramus in the mandible, maxillary sinus, and zygoma in the maxilla.


**Figure 1.** MRONJ (Stage 2). Intraoral examination. The necrotic bone with evidence of infection is exposed. The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 2.** Panoramic X-ray. The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 3.** The segmental resection of the mandible is performed under general anesthesia. There is partial bone defect. The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 4.** The resected specimen of the mandible. The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 5.** MRONJ (Stage 3). Intraoral examination. The necrotic bone with evidence of infection is exposed. The molar teeth are lost naturally. The permission to use the pictures of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 6.** Necrotic bone extending beyond the region of alveolar bone is exposed, and extra-oral fistula is appeared. The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 7.** The panoramic X-ray. Regions of osteosclerosis involving the alveolar bone of lost molar teeth are depicted. The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 4.** The resected specimen of the mandible. The permission to use the picture of this figure from the Ishiyaku

**Figure 3.** The segmental resection of the mandible is performed under general anesthesia. There is partial bone defect.

The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

Publisher, Inc. in Japan.

94 Osteonecrosis

**Figure 8.** MRONJ (Stage 3). Sequester is extended to maxillary sinus. Oral antral communication is made. The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 9.** The sequester and six teethes are removed under local anesthesia. The oral antral communication is made at the anterior part of defect. The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 10.** The necrotic bone and infiltrating inflammatory cells. The stimulating micrograms are observed (HE staining: 100×). The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

**Figure 8.** MRONJ (Stage 3). Sequester is extended to maxillary sinus. Oral antral communication is made. The permission

**Figure 9.** The sequester and six teethes are removed under local anesthesia. The oral antral communication is made at the anterior part of defect. The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.

96 Osteonecrosis

**Figure 11.** Actinomycetes stained with Grocott in the granulation tissue (Grocott staining). The permission to use the picture of this figure from the Ishiyaku Publisher, Inc. in Japan.
