Radiological sinus lift: a new minimally invasive CT-guided procedure for maxillary sinus floor elevation in implant dentistry.

PURPOSE: Implant therapy has become an excellent treatment modality as its inception into the modern era of dentistry. However, when patients present with advanced atrophy of the maxillary alveolar ridge, the procedure of choice to restore the anatomic bone deficiency is surgical maxillary sinus floor elevation or sinus lift. The purpose of this study was to describe the CT guided sinus lift technique and to illustrate the minimally invasive aspect of this new radiological procedure called radiological sinus lift.

MATERIAL AND METHODS: For this prospective study, 17 cadaver heads which met our inclusion criteria (edentulous posterior maxillary sector and bone height less than 5 mm) were analyzed using cone beam computed tomography (CBCT) and orthopantomography (OPT). CT and sinus endoscopy was used to guide each step in the procedure. The radiological sinus lift technique consists of the following four stages: Approach. A 14.5 G OstyCut needle was inserted mesial to the canine eminence, and manual drilling was performed parallel to the sinus floor. Osteotomy. An inner obturator with a blunt tip was introduced to compress bone, to push it in close proximity to the sinus membrane and finally to create an osseous window opening into the submucosal space. Lifting. The sinus lift was performed using hydrodissection with dilute iodinated contrast medium. Filling. The submucosal space was then filled with an injection of dilute collagen. Success of the radiological sinus lift procedure was defined by the presence of a dome shape visible within the maxillary alveolar recess. All cases were imaged postoperatively using OPT and maxillary CBCT.

RESULTS: Twelve maxillary sinuses underwent the radiological sinus floor elevation procedure. A dome shape of the Schneiderian membrane was achieved in eight maxillary sinuses (66.7%). All failures (n = 4) were caused by mucosal perforation at the time of maxillary sinus osteotomy. Mean height of membrane elevation was 12.0 mm, with a mean intervention time of 45 min.

CONCLUSION: This experimental study evaluates a new minimally radiological procedure for maxillary sinus floor elevation, which provides an interventional radiological alternative to the classical surgical lateral approach and achieves an equivalent success rate to that cited in the literature for the surgical approach, a low morbidity and a shorter operating time.