Successful Management of Apically Exposed Implants in the Maxillary Sinus and Associated Sinus Pathologies Via Maxillary Sinus Floor Augmentation
One common complication with dental implants placed in the atrophic posterior maxilla, especially with simultaneous transcrestal sinus augmentation, is the implant protruding into the sinus without apical bone support. Frequently, apically exposed implants contribute to various sinus pathologies that may lead to implant failure. Treatment options include (1) managing asymptomatic sinus pathology; (2) regrafting the apically exposed portion of the implant(s); and (3) removing the implant and placing a new implant with simultaneous grafting. The purpose of this case report is to present 4 clinical cases of apically exposed implants in the maxillary sinus. The report will cover: (1) exposed implants with asymptomatic sinus pathologies and (2) show successful management of protruding implants and pathologies using maxillary sinus floor augmentation. Various methods of implant surface detoxification, mechanical and chemical, are described for predictable bone remodeling around existing implants as well as newly installed implants. After 6 months of healing, osseointegration was well achieved for all implants and sinonasal complications were not observed. Clinical photographs and 3-dimensional imaging of surgical sites were used to validate clinical assessments.
Case 1. (a) A sagittal view of the baseline CBCT showing an implant penetration beyond the sinus floor and the nearby thickened sinus membrane. (b) Cross-sectional view of the implant and the sinus. (c) The perforated site around the protruding implant is seen with the visible mucosal lesion. (d) The pathologic lesion is removed with a pincette. Apically exposed implant without any bone support. (f) Detoxification using tetracycline HCl. (g) An island of bone detached during osteotomy preparation is used as a physical barrier. (h) CBCT taken 12 months post-surgery in a sagittal view. (i) Cross-sectional view showing successful augmentation.
Case 2. (a) Baseline CBCT in a sagittal view. (b) Baseline CBCT in a cross-sectional view. The #4 implant apex is protruding into the maxillary sinus with a thickened sinus membrane. (c) Perforated sinus membrane near the protruded implant during sinus floor elevation. (d) A Prichard elevator is used to prevent graft migration into the sinus cavity through the perforated site. (e) CBCT taken 23 months post-prosthesis insertion. The thickness of the sinus membrane has decreased significantly. (f) Previously exposed part of the #4 implant apex is well surrounded by newly formed bone.
Case 3. (a) Sagittal view of the preoperative CBCT scan showing a large, circumferentially thick membrane in the maxillary sinus. (b) Cross-sectional view of the baseline CBCT. Severe membrane thickening is observed. (c) Sagittal view of the CBCT taken 14 months after prosthesis delivery. The thickness of the sinus membrane has decreased significantly.
(d) Cross-sectional view of the 14-month follow-up CBCT. No abnormal findings are found in the exposed implant apex and the surrounding bone.
Case 4. (a) Baseline sagittal image of CBCT showing the #15 implant penetrating apically into the maxillary sinus. (b) Baseline CBCT showing the extent of the pathologic lesion inside the sinus. (c) Osteotomy preparation and the perforated sinus membrane. (d) CBCT taken 23 months after prosthesis delivery showing significant reduction in membrane thickness. The #15 implant is well surrounded by newly formed bone.
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