Mucosal Coverage of Deeply Protruded Implant in the Maxillary Sinus: A Case Report
Protrusion of the dental implant into the maxillary sinus is known to cause thickening of the sinus mucosa and bacterial sinusitis. However, there are many cases where protruded implants do not cause long-term complications clinically or radiologically. Questions arise about whether the protruding implant was exposed or covered with sinus mucosa. In the present case, lateral sinus floor elevation was planned on the maxillary sinus adjacent to the deeply protruded (6.5 mm) implant #13. The protruding implant was scheduled for removal. During sinus floor elevation through a lateral sinus window, there was no damage or perforation of the elevated sinus mucosa around the protruded implant, and the implant surface was visibly clean. This suggests that the protruding implant was covered with sinus mucosa and not exposed. Therefore, maxillary sinus augmentation can be performed without explantation or surface treatment of the protruding implant. Within the limitations of this case report, implants that are deeply protruded into the maxillary sinus can be covered with sinus mucosa.
Panoramic radiography and CBCT were taken before surgery. (a) Panoramic radiography showed severe alveolar bone resorption around #14 and #15 teeth and thickening of the sinus membrane in the maxillary sinus. In addition, an image of implant #13 protruding deep into the maxillary sinus was also observed. (b) A panoramic image of the CBCT showed a thickening of the sinus mucosa. (c) On the coronal image, implant #13 protruded deep into the maxillary sinus was observed. (d) The cystic appearance of the dome-shape was also observed in the axial image of CBCT.
Panoramic radiography and CBCT were taken 3 months after the removal of #14 and #15 teeth. (a) Severe vertical bone discrepancy was present at the #14 and #15 extraction sites. (b) On a panoramic image of the CBCT, the sinus mucosal thickening was significantly reduced. (c) In the coronal image of the CBCT taken before surgery, implant #13 protruded very deeply into the maxillary sinus (protruding depth: 6.5mm). The maxillary sinus mucosa was slightly thickened around the implant on the sinus floor. (d) The previous cystic appearance was not seen in the axial image of CBCT.
(a) After 3 months of extraction of #14 and #15 teeth, the buccal flap was reflected under local anesthesia for lateral sinus floor elevation. (b) An oval lateral access window was prepared. The lateral access window was removed, and the sinus floor mucosa was elevated. There was no perforation or tearing in the elevated sinus mucosa. (c) The elevated sinus cavity was filled with xenograft. The removed lateral bony lid was separated into 2 pieces and repositioned. No barrier membrane was used. (d) The flap was closed using 4–0 nylon and black silk. (e) Uncovering was performed after 6 months. Bone formation at the lateral access window site was observed after the buccal flap was reflected. (f) Prosthesis was delivered after an additional 2 months.
(a) A bone graft was observed around the #13 implant apex on a panoramic radiograph taken immediately after surgery. (b) There was no leakage of bone graft particles in the panoramic image of CBCT taken immediately after surgery. (c) In the coronal image of the CBCT taken immediately after surgery, a bone graft was observed around implant #13, which had been protruded. (d) The ostium is open in the coronal image of the CBCT scan with implant #14 visualized.
Radiographic findings were taken 1 year after the prosthesis was delivered. (a) A well-consolidated bone was observed in the left maxillary sinus on panoramic radiography. (b) In the panoramic image of CBCT, there were no abnormal findings of the bone graft around the previously protruded #13 implant. (c, d) In the coronal images of CBCT, well-consolidated bone grafts were observed around #13 and #14 implants.
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