Lack of adherence to periodontal sup- portive therapy in oncological patients treated with bone targeting agents. Does it play a role in ONJ development?

Background: to prevent medication-related osteonecrosis of the jaw (MRONJ) induced by infection and or surgical injury, periodontal questionable teeth are often extracted prophylactically before receiving bone targeting agents (Btas). Extensive prophylactic teeth extractions can compromise the patients’ quality of life especially when they are a removable prosthesis pillar and has an impact on patients’ emotional well-being. the decision to extract asymptomatic teeth before Btas therapy is actually based on the surgeons personal experience. in cancer patients, the adherence to periodontal supportive therapy (SPt), with regular attendance to follow-up visits and no interruption of more than 1 year, could not be always guaranteed, thus periodontally compromised teeth could represent a factor predisposing to the development of Mr-oNJ. In order to address informations to evaluate the risk of Mr-oNJ, the aim of the study was to retrospectively assess the compliance in periodontal maintenance, survival rate and stability of periodontally involved teeth in cancer patients treated with Btas and their extraction needs during the follow-up. Methods: we retrospectively reviewed the medical and dental records of all patients treated with Btas who later developed MRONJ or not, followed in the Department of Oral Surgery of the University of Messina between 2007 and 2017. Patients were included in the study if they had periodontal disease at baseline and at least one tooth with increased mobility combined with clinical attachment loss and relative bone loss which was whether maintained, splinted or extracted. SPT was assessed through the patient clinical diary in the registry of hospital access to the Unit. Patient clinical history and tooth-related factors were assessed retrospectively before (baseline) and after the beginning of Btas treatment. changes in periodontal parameters were assessed through follow-up dental rx and compared to baseline. teeth extractions were recorded as well as MRONJ occurrence and location and the relationship between the two was evaluated. Conclusions: Partially edentulous cancer patients, if affected by generalized periodontitis prior to start Btas therapy, frequently showed a worsening of oral health parameters during follow-up. Despite the periodontal stability usually observed in closely monitored patients, this effect may be related to the limited adherence of many oncologic patients to SPt, due to the priority given to primary disease treatment, leading to resistant periodontal infection as well as dental extraction needs. to our knowledge, this is the first attempt to highlight a clinically relevant point that is to maintain or not dental elements with increased periodontal probing depth, loss of clinical attachment and mobility prior to Btas beginning. Since severe periodontitis may increase the risk of MRONJ a more strict tooth extraction protocol is suggested in patients with limited oral compliance.. References: 1. Ruggiero S, Gralow J, Marx RE, et al. Practical guidelines for the Prevention, Diagnosis, and treatment of osteonecrosis of the Jaw in Patients With cancer. Journal of oncology Practice. 2006;2(1):7-14. 2. Lindhe J, Nyman S. The effect of plaque control and surgical pocket elimination on the establishment and maintenance of periodontal health. a longitudinal study of periodontal therapy in cases of advanced disease. J Clin Periodontol. 1975;2:67–79. 3. Sonnenschein SK, Betzler C, Rütters MA, Krisam J, Saure D, Kim TS. Long-term stability of splinted anterior mandibular teeth during supportive periodontal therapy. Acta Odontol Scand. 2017 oct;75(7):475-482.