Three-dimensional Analysis Of Maxillary Sinus Floor Elevation Based On CBCT

Objective:To evaluate the changes of bone graft volume in the short term after maxillary sinus floor elevation and to analyze the preoperative status and intraoperative complications by observing CBCT data,METHODS:From April 2016 to August 2018,7 patients with delayed maxillary lateral sinus floor elevation were selected from Hospital.The CBCT images of the patients before,immediately after and 6 months after operation were retrospectively studied.The changes of bone graft volume,vertical bone mass and mucosal thickness in the short term were counted,and the maxilla was observed.Anatomical variation of sinus structure,complications,etc.Result:1.The average age of the patients was 48.14 ± 11.85 years old,and those below 40 years old were all females.Among them,3 cases found the maxillary sinus septum located in the area of edentulous space;1 case showed sinking of the maxillary sinus floor;2 cases had uneven maxillary sinus floor;5 cases had obvious thickening mucosa in edentulous area(more than 2 mm),even 1 case had more than 10 mm;the angle between the inner and outer walls of the maxillary sinus was between 30 degrees and 60 degrees;no membrane perforation and obvious bleeding occurred during and after operation.2.The average residual alveolar ridge height before maxillary sinus floor elevation was 2.28±1.12 mm,and the average immediate bone height after operation was 14.69±1.68 mm.The bone increment of 12.41 ± 1.68 mm was obtained with statistical significance.The average bone height of 6 months after maxillary sinus floor elevation was 13.62±2.26 mm,and the average bone height decreased by 1.29±0.61 mm,with statistical significance.The implanted bone volume of maxillary sinus floor elevation was 1448.79±459.32mm3 and 1363.39±389.42mm3,6 months later.The average reduction of bone volume was 171.12±147.6mm3,which was about 11.33±5.93.There was statistical significance.3.The maturity of new bone/implant in maxillary sinus was evaluated by using the reconstruction index of maxillary sinus graft.All 7 cases had 3.No sinus membrane collapse was observed and sinus floor was formed in a new position.CONCLUSION:CBCT can provide sufficient three-dimensional data for maxillary sinus floor elevation before operation.It can visualize and objectively reflect the difference and variation of maxillary sinus anatomy and pathological changes.It can provide a reference for evaluating surgical risk and operation,and reduce the occurrence of complications.At the same time,it can provide sufficient imaging data for the changes of bone graft materials and implants after operation.