**8. Radiological characteristics of MRONJ**

The involvement of the region by medication-related osteonecrosis can be assessed by radiographic analysis. This type of imaging is also useful in monitoring the disease and in diagnosing complications that occur in osteonecrosis such as fractures and sinusitis. By radiological analysis we can detect different stages of the disease and even the zero stage. Two-dimensional panoramic images (**Figure 3**) are recommended as an initial radiographic technique that give an excellent overview of the bones, teeth and the surrounding structure. Sclerosis found in the lamina dura of the alveolar ridge, after radiological examination, is the most common radiological change at risk patients. We can also find others radiological changes that are not so common, namely: sclerosis of the marginal parts of the jaw (most commonly in the mandible), narrowing of the mandibular canal, difficult or complete absence of healing of postextraction alveoli, radiolucent regions around the bone corresponding to osteolysis and necrotic bone sequesters that occur in the later stages of medication-related osteonecrosis [59–61]. More precisely, the lesion can be represented by one of the three-dimensional display techniques such as computed

*Application of Photodynamic Therapy in the Treatment of Osteonecrosis of the Jaw DOI: http://dx.doi.org/10.5772/intechopen.94257*

#### **Figure 3.**

*MRONJ in a patient with multiple myeloma and treated with zoledronic acid (Zometa).*

**Figure 4.** *CBCT scan (of same patient as in Figure 1) after surgical treatment.*

tomography or cone-beam computed tomography. In the CBCT scan (**Figure 4**) we can get more precise data on the localization and on the progression of the disease and useful data on the surrounding bone structures. At early diagnosis of MRONJ, magnetic resonance (MRI), single-photon emission computed tomography (SPECT) and positron emission tomography with computed tomography (PET/CT) were also proved as an excellent diagnostic tool [59, 62–67].
