Successful Management of Late Sinus Graft Infection via Functional Endoscopic Sinus Surgery and Press-Fit Block Bone Graft: A Case Report
The purpose of this case report is to feature an interesting case where a staged approach was used to manage a failed implant site that led to a late sinus graft infection and sinusitis with an oroantral fistula (OAF), by using functional endoscopic sinus surgery (FESS) and an intraoral press-fit block bone graft technique. Sixteen years ago, a 60-year-old female patient underwent maxillary sinus augmentation (MSA) with 3 implants placed simultaneously in the right atrophic ridge. However, No. 3 and 4 implants were removed due to advanced peri-implantitis. The patient later developed purulent discharge from the site, headache, and complained of air leakage due to an OAF. The patient was referred to an otolaryngologist for FESS to treat the sinusitis. Two months after FESS, the sinus was re-entered. Residual inflammatory tissues and necrotic graft particles in the OAF site were removed. A block bone harvested from the maxillary tuberosity was press-fitted to the OAF site and grafted. After 4 months of grafting, the grafted bone was well incorporated with the surrounding native bone. Two implants were successfully placed in the grafted site with good initial stability. The prosthesis was delivered 6 months after implant placement. After the 2 years of follow-up, patient was functioning well without sinus complications. Within limitation of this case report, the staged approach via FESS and intraoral press-fit block bone graft is an effective method that can be used to successfully manage OAF and vertical defects at the implant site.
(a) Panoramic radiography 16 years after lateral sinus floor augmentation using xenograft. Due to severe peri-implantitis, the No. 3 and 4 implants developed bone loss and mobility. (b) Two implants with mobility were explanted. The vertical bone defects were severe. (c) In the sagittal image of cone beam computed tomography (CBCT), the sinus floor was lost due to a severe bone defect in the sinus augmented site. The right maxillary sinus had complete opacification. (d) In the coronal image of CBCT, the sinus augmented site was severely damaged and led to chronic maxillary sinusitis. The sinus ostium was also closed. A cross-sectional coronal slice at tooth No. 2. There was sufficient height of alveolar bone around the No. 2 tooth, which was suitable as a donor for an autogenous bone graft. (The white dotted line represents the boundary for obtaining autogenous block bones; also in 1b.)
Functional endoscopic sinus surgery procedure. (a) Drainage of inflammatory products in the maxillary sinus through the enlarged maxillary ostium. (b) Some of the necrotic bone graft particles were removed through the middle meatus.
(a) Clinical findings 2 months after functional endoscopic sinus surgery (FESS): oroantral fistula (OAF) was not closed. Severe vertical bone defects were observed at the compromised extraction socket of the implant. (b) An OAF was identified using an implant depth gauge. (c) After reflecting the flap, extensive bony defects (Ø 15 mm) were observed. Granulation tissues were thoroughly removed. (d) After the No. 2 tooth was extracted, a 3- to 4-mm thick bone block of 20 mm × 20 mm was harvested from the maxillary tuberosity and the extraction socket using surgical round bur and bone chisel. The harvested bone block was then trimmed to be slightly larger than the size of the recipient site. (e) The block bone was inserted into the defect and then secured using a mallet and an osteotome. Fixation screws were not used. (f) The top of the bone graft was covered with a resorbable collagen membrane. (g) The flap was sutured without tension. (h) Clinical findings after 4 months of bone graft: OAF site was closed. Some vertical augmentation was achieved. (i) After the flap was reflected, the autologous block bone at the OAF site was integrated by the surrounding recipient bone. New implants were placed without issues. Core biopsy was performed using a 2.0-mm trephine drill before drilling for histologic analysis. (j) The primary stability of the implants was excellent. The flap was closed after healing abutments were placed. (k) After 6 months, the final prosthesis was delivered. (l) In the clinical photograph after 2 years, a gingival recession at the No. 4 implant was observed.
The histologic finding of the core biopsy taken from transplanted autogenous block bone (H-E stain). (a) Bottom square: ridge crest portion of autogenous bone block. Several vessel ingrowths have been found. Top square: sinus floor portion of autogenous bone block. (b) In the sinus floor portion of the autogenous block bone, the capillarity of the blood vessel was abundant and new bone formation was observed. (c) A large number of osteocytes (yellow arrow) and osteoblasts (red arrow) were found. (d) The crestal ridge portion of the transplanted autogenous bone. Blood vessels were observed, and new bone formation and osteocytes were observed. However, most of the other areas had no newly developed vascular network; no osteocytes and osteoblasts were observed. (e) Newly formed osteoid tissue observed around lacuna containing blood vessels in the crestal ridge portion. Osteocytes (yellow arrow) observed around the osteoid tissue.
Radiographic findings after the bone graft, implant placement, and prosthesis delivery at oroantral fistula (OAF) site. (a) Image of panoramic radiograph after bone graft. (b) Image of panoramic radiograph after implant placement and healing abutment insertion. (c) Image of panoramic radiograph after prosthesis delivery. The crestal bone level around the implant was stable. (d) Image of panoramic radiograph 2 years after prosthesis delivery. Bone level changes around the implant were not observed. (e) Coronal image of cone beam computed tomography (CBCT) scan after bone graft at the OAF site. (f) Coronal image of CBCT scan after implant placement and healing abutment insertion. (g) Coronal image of CBCT scan after prosthesis delivery. The mucosal thickening was reduced, and the ostium was open. (h) Coronal image of CBCT 2 years after prosthesis delivery. Sinus membrane thickening was further reduced, and the level of grafted bone around the implant did not change.
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