Does the Protrusion of Corticobasal Implants in the Maxillary Sinuses Affect Sinus Health? A Retrospective Study.

AIM: The aim of this retrospective study is to investigate the effect of corticobasal implant penetration in the nasal and maxillary sinuses on sinus health and implant survival rate in cases of severely atrophid ridges.

MATERIALS AND METHODS: This retrospective study was conducted on thirty patients with 172 implants who underwent corticobasal implant treatment between 2014 and 2018. Implants were divided into two groups according to the penetration depths (Group A, <4 mm; Group B, 4 mm). Inclusion criteria for the study included: (A) patients with severe maxillary ridge resorption with an immediately loaded corticobasal implant-supported prosthesis that showed implant protrusion inside the maxillary sinus on cone-beam computed tomography (CBCT); and (B) patients with a preoperative and postoperative follow-up CBCT scan using the same standard technique and machine. (C) Patients without any history of sinusitis before implant insertion patients who fulfilled the inclusion criteria were recalled for follow-up. The presence of sinus complications was clinically assessed according to the clinical practice guidelines for adult sinusitis of the American Academy of Otolaryngology-Head and Neck Surgery and Radiologically using CBCT. Moreover, patient satisfaction was evaluated using yes-or-no questions. The result was statistically analyzed using Fisher's Exact test.

RESULTS: Despite the differences in implant penetration depths, no clinical signs of sinusitis were evident in any patient. One patient presented with transient epistaxis after the surgery, and 2 patients with nine implants revealed nonsignificant thickening of the sinus membrane radiologically ( p = 0.055). All implants showed optimum bone-implant contact with a 100% survival rate. A significant relationship was reported between the thickness of the membrane and the patient's gender, hypertension, and smoking habits. ( p = 0.001*, p = 0.002*, and p = 0.034*, respectively).

CONCLUSION: Penetration of corticobasal implants in the maxillary sinus did not compromise the health of the maxillary sinus or implant survival rate.

CLINICAL SIGNIFICANCE: Limited posterior maxillary bony support and maxillary sinus pneumatization present challenges in implant dentistry and increase the possibility of implant protrusion inside the maxillary and nasal cavities. Hence, studying the effect of this protrusion on the maxillary sinuses' health and implant survival is highly significant.