MRONJ was located in the mandible, affecting the mandibular bone more frequently when compared to the maxillary bone, corroborating previous studies (4, 6, 11–14). In our results we also observed that in some cases, MRONJ can cause simultaneous impact on the maxilla and mandible, as observed in previous studies (15). When we observe patients affected in the maxilla, the posterior region is the most affected, another finding supported by previous studies (12). Studies showed that even in asymptomatic patients who use medication, mucosal healing may be deficient if the teeth and the formation of sequestrations are involved. Furthermore, teeth are often affected by endodontic and/or periodontal diseases, which are risk factors for its development (16). When assessing the triggers of MRONJ, our findings corroborated with previous studies (2, 6, 16, 17), showing that dental extractions are the main factors. As additional support, Jeong et al. (18) performed a randomized study reporting that MRONJ frequency was higher after lower tooth extractions than upper tooth extractions, with statistically significant differences. Professionals must be aware of prosthesis presence and how their trauma may trigger the disease. Also, Mauriceri et al. (17) and our study verified a dental implant case as a triggering factor.
Instruction and awareness of patients treated with bisphosphonate and the higher level of health education are relevant for preventing osteonecrosis (19), and the lack of dental treatment before bisphosphonate therapy may lead to MRONJ diagnosis. The Italian Consensus in 2020 (20) and the American Association of Oral and Maxillofacial Surgeons (AAOMS) in 2022 (8) indicated that primary MRONJ prevention mainly aims to eliminate and reduce oral and dental risk factors and restore and maintain good oral health, reducing the risk of the emergence of pathological conditions or other adverse events. Dentists must also evaluate the risk factors of MRONJ development and suggest strategies to remove these factors or minimize risks.
Criteria were established for the radiographic analysis of risk patients without apparent necrotic bone and asymptomatic patients treated with intravenous or oral antiresorptive therapy to help dentists treat and prevent MRONJ. These patients were classified as stage 0, without clinical evidence of necrotic bone but with unspecified symptoms or clinical findings, such as toothache not explained by odontogenic causes, dull and painful mandibular bone pain that may irradiate to the temporomandibular joint region, sinus pain potentially associated with inflammation and thickening of the maxillary sinus wall, changes in neurosensory functions, tooth loosening not explained by chronic periodontal disease, and intra- and extraoral edema. These patients radiographically presented alveolar bone loss or resorption not attributed to chronic periodontal disease, changes in the trabecular pattern of the sclerotic bone, no new bone in extraction sockets, osteosclerosis regions involving the alveolar and/or surrounding basilar bone, and periodontal ligament thickening/darkening (hard layer thickening, sclerosis, and size reduction of the periodontal ligament space) (9, 21).
Focusing on prevention, Yanaguizawa et al. (6) evaluated computed tomography exams of the mandible and axial cervical vertebra of oncological patients under antiresorptive drugs, concluding that tomographic examination may detect early changes associated with bisphosphonate therapy and predict likely necrosis cases after a more invasive dental intervention. Our findings also showed that computed tomography may be effective as an assessment method for mandibular bone density because the comparative analysis between bone densities found higher mean values in the group receiving antiresorptive drugs than the control group, obtaining statistically significant differences for the bone density analysis of the mandibular medullary bone and showing bone density variations compared to the control group (Table 3).
In conclusion, computed tomography can be used as a supplementary diagnostic examination for mandibular bone density. This imaging modality was able to identify initial alterations linked to bisphosphonate therapy in cancer patients. Furthermore, it is useful for the dual purpose of predicting and facilitating the monitoring of potential cases of necrosis after more invasive dental interventions. In alignment with prevailing preventive methodologies in the domains of medicine and dentistry, healthcare professionals must acknowledge the relevance of dental pretreatment and preventive measures in order to mitigate the risk of medication-related osteonecrosis of the jaw (MRONJ).