MRONJ RELATED TO RETRACTOR THREAD USE IN CONSERVATIVE TREATMENT: A CASE REPORT

Aim: to report a MRONJ related to Black Class V in a 56-yearold woman. MRONJ is defined as a “drug-related adverse reaction, characterized by the progressive destruction and necrosis of the mandibular and/or maxillary bone of subjects exposed to treatment with drugs for which an increased risk of disease has been ascertained in the absence of previous radiation treatment”. In conservative procedure Black Class V, the use of retractor thread could induce vasoconstriction in gingival tissues and then necrosis. Methods: a 56-year-old woman comes to our attention with oral pain in the left hemimandibular region. Intraoral examination revealed an ulcerated lesion and bone exposure (about 1 cm) in attached gingiva, in correspondence with element 3.6; the surrounding mucosa appeared erythematous and edematous. She reported a postmenopausal osteopenia treated with Alendronate orally and a conservative treatment, on the element 3.6, close to the gum (Black Class V). The use of retractor thread and slight trauma linked to the insertion of this one was hypothesized as etiopathological factor. Results: the diagnosis, compatible with the clinical and pharmacological history, was MRONJ. The patient underwent polyantibiotic therapy, irrigation of hydrogen peroxide, application of chlorhexidine gel and monitored for 4 weeks. After 3 weeks MRONJ was resolved. Conclusions: this case is extremely significant; clinicians should pay particular attention to conservative dental procedures in patient taking anti-bone resorption drugs and the occurrence of MRONJ in these treatments.