Oral Squamous-Cell-Carcinoma around Dental-Implants in Patients with High-Risk for Oral-Malignancy

Objective: To report two cases of oral squamous cell carcinoma (OSCC) adjacent to dental implants in patients with multiple risk factors for oral cancer and discuss the safety of implants in such patients. Methods: Two patients presented with OSCC associated with dental implants. Both of them were at high risk for oral malignancy: one with untreated erosive lichen planus (ELP) and heavy smoking, the other with a history of OSCC 15 years prior to his presentation and metastatic colon cancer with metastases in the liver. Results: The patient with ELP had local disease with no bone involvement (stage II ) which was locally resected with modified neck dissection . She is disease free 18 months postoperatively. The patient with previous OSCC and colon cancer had advanced stage IV disease. He refused oncologic resection so he underwent palliative surgery with chemotherapy and died few months later. Discussion: Rare cases of implant associated malignancy have been reported, in all of which more than one risk factor was present prior to implant placement. Possible mechanisms for peri implant malignant transformation include: inflammatory mediators such as MIF which suppress transcriptional activity of p-53 , local trauma followed by a proliferate burst on a background of molecular changes (allelic loss (LOH) aneuploidity changes) , which are frequently found in patients with pre- malignant conditions such as ELP. These are also common in patients with previous oral malignancies. Other risk factors such as smoking may also induce molecular changes predisposing for malignancy Conclusions: There may be an increased risk for malignant transformation associated with dental implants in patients with multiple risk factors. Further investigation is necessary to evaluate this risk.