Foreign bodies in the anterior cranial fossa are unusual. This is a case of a 50-year-old man who presented with a dental implant displaced into the anterior cranial fossae, which was removed endoscopically with dural reconstruction.
Prosthetic implant rehabilitation is one of the most common dental procedures. Such techniques are commonly successful but rarely cause serious complications . There are reports of dental implant displacement into the maxillary sinus , the ethmoid and sphenoid sinuses, nose and cranial fossa . Endoscopy appears to be the most suitable treatment for complex localization and CSF leak repair. This article describes a dental implant displaced into the anterior cranial fossa and its removal followed by dural repair.
A 50-year-old man presented with persistent rhinorrhoea, which began 3 days previously, after a left maxillary dental implant was inserted at another hospital. The patient also complained of a median left canthus haematoma. Radiographic examination showed the implant displacement and a CT scan confirmed that the implant was in the anterior cranial fossae between the medial orbital wall and the greater wing of the sphenoid, fracturing the upper medial orbital corner ( Fig. 1 ). As the dental implant was in direct contact with the cerebral parenchyma, it was decided to remove the foreign body endoscopically.
Through an anterior rhinoscopy, access was gained to the left nasal cavity and the medial turbinate partially removed to reach the nasal cavity roof. The bottom of the implant was located and it was removed successfully. The dural perforation was repaired, eliminating the residual cerebrospinal fluid leak using Tutopatch ® cover and a muco-periostal graft from the left middle turbinate. The postoperative CT scan showed the complete removal of the foreign body ( Fig. 2 ).
The patient’s recovery was free of any complications with follow-up at 1 week, 2 weeks,1 month, 3 months and 1 year including CT scan evaluation.
Displacement of dental implants has been reported in the international literature. The presence of a foreign body leads to serious complications such as sinusitis, rhinorrhoea and oroantral fistulas. Low bone density may be a predisposing cause of implant failure, but poor osteointegration or changes in nasal air pressure may also affect implant success.
Several authors describe dental implant displacement in the maxillary sinus, ethmoid and sphenoid . In the last decade, minimally invasive endoscopic surgery has been developed for various indications in the craniomaxillofacial area . Repair of CSF leaks , is a valuable surgical option to obtain a wide and precise visual field and to access rhinobasal structures through an endonasal approach without skin incision and osteotomies or bone segment dislocations. Endoscopic CFS leak repair is a safe and definitive procedure, when practicable .
In the present case, the foreign body was directly in contact with the cerebral parenchyma. In the authors’ opinion, open access could represent an additional risk because of possible movements of the dental implant or consequences of the surgical approach. The localization and removal of the implant was relatively simple. The real challenge was repairing the CSF leak. Various materials, such as nasal and extra-nasal autologous or heterologous materials, have been suggested for this repair . The authors prefer autologous grafts, specifically nasal septum or concha. In this case, as for the fistula dimension, they applied Tutopatch ® to avoid adhesions with the cerebral parenchyma and the muco-periostal flap grafted from the medial nasal concha.
In the immediate postoperative period, the patient is kept supine for 3 days to prevent CSF drainage. Postoperative clinical and radiographic follow up showed good resolution of the initial symptoms.