Comparison of Two Types of Patient Specific Implants (PSI) and Quad Zygoma Implant (QZI) for Rehabilitation of Post-COVID Maxillary Mucormycosis Defect (PCMMD): Finite Element Analysis.

Introduction: The residual post-COVID maxillary mucormycosis defect (PCMMD) were extensive, due to unilateral or bilateral maxillectomies. The Goal of rehabilitation of PCMMD is to deliver a prosthetically driven reconstruction. FEA was to evaluate the biomechanical response of PSI struts (PSI 1), PSI Screw retained (PSI 2) and QZI to masticatory load on virtual simulation to improve accuracy and enhance the design. Aim: To validate and compare the Biomechanical benefit of the PSI struts, PSI Screw retained, QZI in a case of rehabilitation of post-COVID maxillary mucormycosis defect (PCMMD) by FEA study. Methodology: The result of stress to masticatory load on virtual simulation for (1) Maximum and minimum stress (Von Mises stress); (2) the Displacement (in three positions) and (3) the Deformation (Plastic strain) was compared on virtual simulation for PSI 1 and PSI 2 and QZI. Conclusion: The FEA and comparative evaluation of PSI 1, PSI 2 and QZI showed a good resistance to displacement. The stress and strain values are low and acceptable. In comparison QZI shows more stress in the anterior region.

Outcome of Open Surgery in Disease Progression of Post-COVID Rhinomaxillary Mucormycosis Treated by Functional Endoscopic Sinus Surgery and Proposed Evaluation Scale for Maxillary Sinus Disease and Osteomyelitis.

Introduction: Rhinomaxillary Mucormycosis (RMM) is a condition peculiarly seen as post-COVID-19 opportunistic infections with Maxillary Sinus Disease and Osteomyelitis (MSDO). The open method of debridement and closed method are two types of surgical modalities available. There is no scoring method for this infection in maxilla. This paper aims to study the clinical and CT-based outcome of open versus closed surgery of MSDO in post-COVID-19 RMM and propose a new scoring method to evaluate the disease severity, progression as well as recovery. Material and Methods: Symptomatic cases of RMM (n = 17) with a history of closed surgical treatment were enrolled for this prospective clinical study. These cases were then treated by medicinal and open surgical method. The clinical and CT scan outcomes were compared by proposed new scoring method.The CT-based score for Maxillary Sinus Disease (MSD) and Maxillary Osteomyelitis (MO) from pre-FESS (CT1), Post-FESS (Preoperative, CT2), and Post-operative (CT3) were compared for both right and left sides. One-way ANOVA test and post HOC tests were used for statistical evaluation. Conclusion: The open method of maxillary sinus surgery has given significant improvement in the treatment of RMM already treated by a closed endoscopic approach. Supplementary Information: The online version contains supplementary material available at 10.1007/s12663-022-01803-5.