In the near future, oral and maxillofacial surgeon will have to deal with an increasing number of squamous cell carcinomas of the peri-implant tissues, due to the ever increasing rate of dental implant therapy in edentulous or future edentulous patients. When physicians are diagnosing the patients in early stages, the differential diagnosis is sometimes difficult to set as the onset of oral carcinoma can mimic the clinics of perimplantitis. Most of the times, if they have some sort of distress of their implant mucosa, the patients will address their dentists, who have a lesser experience regarding oral cancer. The authors want to highlight this aggressive pathology, which is not new, but when it affects the peri-implant tissues, it can cause false diagnosis. This paper presents the case of a 68-year-old patient who underwent partial mandible resection for a perimplant mucosa squamous cell carcinoma.
oral implant, peri-implantitis, squamous
Odată cu creşterea accceptării de către populaţie a tratamentelor implanto-protetice, se va remarca o amplificare a incidenţei carcinoamelor scuamoase mucozale periimplantare. În fazele incipiente, diagnosticul creează probleme de raţionament medical, din cauza cameleonismului patologiei, care îmbracă aceleaşi caracteristici ca cele ale unei banale periimplantite. De asemenea, aceşti pacienţi sunt monitorizaţi de medicii stomatologi implantologi, care sunt mai slab pregătiţi în managementul cancerului oral la pacienţii care prezintă lucrări dentare cu suport implantar. Dorim să prezentăm această patologie deosebit de agresivă, grefată pe un ţesut de neoformaţie, mucoasa periimplantară, prin expunerea unui caz de carcinom spinocelular la un pacient de 68 de ani, cu punct de plecare din ţesuturile mucozale implantar.
Implant therapy has many advantages for the edentulous patients, one of the most important being the preservation of dental tissues. Thus, there is an increasing demand for implant prosthesis in the dental offices. In the US and Europe, there is an estimate that more than 2.6 million dental implants are performed each year(1).
Oral cancer affects any area of the oral mucosa. It can be divided in primary tumours, or metastasis (seldom), with the primary site found in the lungs, the kidneys or in the breast, and from the surrounding facial regions (nasal fossa, maxillary sinuses, facial skin). Over 90% of the total of oral cancer is represented by the squamous cell subtype, which has an aggressive pattern and can metastasise rapidly.
The risk factors are, besides the well-known smoking and drinking habits, the genetic anomalies and a compromised immune system(2). Regarding local factors, one of the most important is the chronic inflammation. Chronic inflammation can be found in patients with aggressive parodontosis, as well as those with peri-implantitis.
A decrease or even lack of keratinized tissue surrounding the dental implants can be a trigger for peri-implantitis. The keratinized tissue acts as a protective barrier of the implant-alveolus junction. Peri-implantitis can lead to bony craters, sometimes extending up to anatomical landmarks such as maxillary sinuses, causing sinusitis, or inferior alveolar nerve, causing neuralgia.
Initially, there were scarce reports regarding the onset of oral carcinomas in peri-implants tissues, less than 0.01 per million patients per year(3). In the last years, there has been a higher percentage of papers addressing this issue. A hypothesis could be that bone and tissue destruction caused by peri-implantitis, as well as the chronic inflammation can be a trigger for the activation of cancer cells(4).
Most of the times, during the current management of peri-implantitis, the dentist performs a curettage of the necrotic and granular tissue found in bone geode, in the peri-implant alveolus. The tissues are not currently sent to a pathological exam, thus sometimes early forms of oral cancer can be missed by the physicians.
A 68-year-old patient was admitted to our department, complaining of recurrent pain in the mandible right area during eating. The patient was on hypertensive treatment and stated that he had been admitted to a maxillofacial department, approximately two years before, for the same condition. He had been diagnosed with gingival hyperplasia due to implant prosthesis. After some conservative treatment that included local debridement and antibiotics, a biopsy was performed which confirmed the inflammatory response.
At admittance, there was a large verrucous and vegetant mass at the level of 46 and 47 (implant pillars for a bar supported overdenture). The tumour was covering the bucal and also the lingual walls of the alveolus. On palpation, it was tender and it bled. Another biopsy under local anaesthesia was conducted which set the diagnosis of invasive carcinoma.
On CT examination along with panoramic digital RX, the bone involvement was minimal and it only seemed to involve the medial implant. That type of defect could have been a consequence of an older peri-implantitis. There weren’t any other discrepancies in the floor of the mouth; there was no cervical node involvement.
Under general anaesthesia, a surgical resection was performed en bloc with marginal mandible ostectomy. The soft tissue defect was reconstructed with a cheek advancing flap. The pathological examination along with immunochemistry tests revealed the total resection of a keratinized invasive squamous cell carcinoma, well differentiated, T2N0MxG1.
The recovery was good, and the patient was scheduled for regular check-ups.
Implant prosthetic treatment is a modern therapy for the reconstruction of edentulous ridges. With the use of implant driven prosthesis, oncologic patients who underwent bone resection can have a better quality of life.
In patients with a history of neoplasia versus cancer-free groups, there is a higher incidence of oral cancer, as they are screened frequently at local check-ups. Oral cancer can be detected in early stages and mucosal dysplasia can be treated adequately.
A rather more difficult diagnosis is seen in previously cancer-free individuals, which exhibit signs of peri-implantitis. In these patients, early signs of cancer can mimic chronic inflammation. As to further impeach physicians, oral cancer seems to present more often as a primary tumour (70%) rather than metastatic(5).
Regarding age groups, it seems that older adults (above 65-70 years old) are more likely to develop squamous carcinoma in peri-implant tissues. The mandible is more prone to oncologic cell proliferation than the upper jaw(5).
The clinical signs are very similar to peri-implantitis: gingival hyperplasia, bony craters around implants, local pain and bleeding on probing. It is usually found in older implants, but that is also where peri-implantitis is more likely to appear.
The treatment of peri-implant carcinoma is the same as for any other type of oral cancers. The surgical resection with adequate oncologic safety margins is very important to ensure a good prognosis. The bone resection is dependent on tumour extent to the alveolar bone, as it can be marginal or segmental ostectomy. Depending on tumour histological type, depth and extent, and also on clinical and CT signs of node involvement, a radical, selective or modified type of neck dissection is associated.
In the last years, there have been numerous reports highlighting the relationship between oral cancer and oral biofilm. Porphyromonas and Fusobacterium(6) have been found to be involved in cancer genesis through special receptors. Unlike dental surfaces, implants cannot be thoroughly decontaminated due to their special surface treatment and acid engraving (that favours osteointegration), but once exposed the oral cavity, it allows to be colonized by an aggressive biofilm which in turn can cause dysplastic mucosal tissue transformation.
The chronic persistent inflammation is considered to be a trigger in malignancy development, as there is a high secretion of cytokines, interleukins and growth factors in the inflammation process. The growth factors play a major part in the reduction of cell apoptosis and can lead to the onset of DNA mutations(7).
The bone invasion in oral cancer is more likely to be found along the implant-alveolus junction(8). In this micrometric space, there is usually a process of bioacceptation of the implant rather than bone integration, and this creates a path of least resistance.
The best method to diagnose an early-stage peri-implant squamous cancer remains incision biopsy, followed by pathological and immunochemistry examinations. There is no biomarker available on the market that has a high specificity and sensitivity for oral cancer. The treatment should include surgical resection en bloc with the underlying bony bed and dental implants. When the patient is disease-free, he can benefit from another oral dental prosthesis.
Conflicts of interests: The authors declare no conflict of interests.
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