Surgical management of persistent maxillary sinusitis with subtle residual symptoms following lateral sinus floor elevation: a report of three cases.

Postoperative graft infection and subsequent acute maxillary sinusitis are infrequent complications following sinus floor elevation (SFE). However, inadequate management may result in persistent infection with only subtle residual symptoms. This case study presents three patients who developed persistent subclinical graft-related infection following SFE. Patient 1 underwent staged implant placement (two implants) after lateral SFE, whereas the other two underwent simultaneous implant placement and SFE (four implants in Patient 2, two implants in Patient 3). Between 2 and 3 weeks postoperatively, all patients developed signs and symptoms suggestive of acute infection. Initial symptoms were partially relieved by pharmacologic treatment and superficial debridement, but subtle sinonasal symptoms persisted. Six months later, CBCT revealed sinus opacification and ostial blockage in all patients, indicating unresolved infection. Surgical management consisted of partial graft removal, preservation of consolidated grafted areas, and intentional sinus membrane puncture and drainage. Implant placement was successfully performed in Patient 1, and one implant was removed in Patient 3 due to infection-related poor-quality tissue around the implant. Histologic examination demonstrated necrotic bone and chronic inflammatory changes. The retained implants remained functional without further complications during follow-up (Patients 1 and 3, 1 year; Patient 2, 2 years). It is important to recognize that persistent subclinical infection may remain after resolution of acute graft infection. If residual sinonasal symptoms linger, they should not be neglected, and appropriate reassessment should be considered. In carefully selected cases, the present surgical approach may represent a treatment option, although further evidence with longer-term data is needed.