Squamous cell carcinoma around a subperiosteal implant in the maxilla and the association of chronic mechanical irritation and peri-implantitis: a case report

Abstract

Background As carcinogenic risk factors, environmental factors can be classified into physical, biological, and chemical factors. Subperiosteal implants (SIs) are associated with complications, such as framework exposure, infection, and fistula formation. A current hypothesis suggests that chronic mechanical irritation could be a co-factor in carcinogenesis, while peri-implantitis might be an initiating or promoting agent in the development of oral mucosal cancer. Herein, we report a case of squamous cell carcinoma (SCC) around a maxillary SI associated with chronic mechanical irritation and peri-implantitis as physical and biological factors, respectively. Case presentation A 74-year-old male patient presented with severe mobility of the SI and an undermined ulcer with induration, accompanied by a palatal fistula and the exposure of the metal framework. The SI had been placed on the maxilla for the occlusal reconstruction of the molar area 20 years ago. An incisional biopsy of the ulcer revealed SCC (cT4aN2cM0). Neoadjuvant chemotherapy was initiated, followed by bilateral neck dissection and partial resection of the maxilla with SI removal. Energy-dispersive X-ray analysis suggested that the SI was fabricated using pure titanium, and titanium was absent in the specimen. Scanning electron microscopy of the SI in contact with the SCC showed a few microcracks, suggesting pitting corrosion. Discussion Chronic mechanical irritation due to the mobility of an improperly designed SI can be a physical factor, and prolonged peri-implantitis without regular maintenance can be a biological factor in carcinogenesis. Improperly designed main struts and a large masticatory force in the molar area resulted in deterioration of the retention and mobility of the SI. The screw and framework frequently moved on mastication and came in direct contact with the ulcer as chronic mechanical irritation. Bacterial invasion into the subperiosteal space expanded by the mobility of the metal framework led to peri-implantitis. The influence of chemical factors was considered relatively small in this case since the patient had no history of smoking or drinking, and titanium was absent in the specimen. Therefore, it is conceivable that SCC can arise owing to persistent inflammation caused by chronic mechanical irritation and peri-implantitis as physical and biological factors, respectively.

Clinical retrospective analysis of peri-implant oral malignancies

“…From the several articles regarding case reports and related review articles, the possible contributing factors of relevant PIOM could be summarized as: (1) dental implant corrosion and possible association between corrosion products and SCC; (2) the possible association between particulate titanium and SCC; (3) migration of malignant cells through the implant surrounding sulcus; and (4) the hypothesized carcinogenic effect of sustained metallic ion release after implant placement [ 7 , 11 , 12 ].…”

“…Although dental implants have seen tremendous clinical success over the last few decades, there are some worrying reports in literature describing SCC in close association with dental implants. This article also provides a critical assessment of the published literature relating to the presence of carcinomas in association with dental implants, analyzed previously published and hypothesized carcinogenic responses to an implant, and attempted to come to a conclusion regarding the plausibility and clinical risks for cancer formation in association with dental implants [ 2 , 4 , 7 , 9 , 20 , 21 ].…”

“…Even less on primary carcinomas in patients without a previous history of malignancy at the local or regional levels, OSCC cases with implants have increased as the number of implants placed have increased. To date, several articles on osseointegrated dental implants surrounding SCC cases have been published under the name of "mimicking or imitating peri-implantitis", "vicinity of dental implant" [ 4 – 6 ], "association or adjacent to dental implant" [ 7 , 8 ], or "oral malignancy surrounding or after dental implants" [ 9 , 10 ]. Therefore, we designated all kinds of malignancies surrounding dental implants with the term of peri-implant oral malignancy (PIOM).…”