To evaluate the clinical outcome of the modified transcrestal around detached sinus floor elevation technique and simultaneous implantation in severe atrophic alveolar ridge of maxillary posterior region.

A total of 50 patients (65 implant sites) underwent transcrestal around detached sinus floor elevation technique with bone grafting were included in this study in Jianli Stomatological Hospital of Dongguan from October 2017 to October 2019. These patients were randomly divided into two groups with 25 in each. The experimental group was treated with the modified transcrestal around detached sinus floor elevation technique while lateral window technique was used in the control group. A total of 65 implants were placed simultaneously with sinus floor elevation. The second stage operation and implant restoration were performed nine months later. The patients were followed up 12 months after final restoration. Data of CBCT in the process of implantation were collected.

Both the follow-up rate of the patients and the survival rate of implants were 100%. The residual bone height in the posterior maxilla of the experimental and control groups were (2.94 ± 0.31) mm and (3.06 ± 0.32) mm, respectively, where there was no significant difference (t = -1.395, P = 0.168) . The post-op height in the posterior maxilla of the control and experimental group were (10.90 ± 1.78) and (12.01 ± 1.88) mm, respectively, where there was significant difference (t = 5.298, P<0.001) . This height was found to be (10.14 ± 1.33) and (11.40 ± 1.38) mm, respectively, after nine months, where there was significant difference (t = 3.786, P<0.001) . Further, this height changed into (10.01 ± 1.22) and (11.18 ± 1.26) mm, respectively, where there was significant difference (t = 2.474, P<0.001) . In this study, a total of 31 implants were implanted in the experimental group for 25 maxillary sinuses. No perforation of maxillary sinus mucosa was found during the operation, but one patient had bleeding in the nasal cavity on the second day after operation. After active anti-inflammatory treatment, the bleeding stopped and then the suture was removed on the 7th day. CBCT was taken at the re-examination of three months, and no abnormal fluid in the maxillary sinus was found. In the control group, a total of 34 implants were implanted at the same time, involving 25 maxillary sinuses. Among them, three cases had sinus mucosal perforation during fenestration. The perforation lesion was covered with collagen membrane, and there were no adverse reactions after operation. The mucosal perforation rate in the experimental group was 4%, which was much lower than that of the control group (12%) .

The modified maxillary sinus elevation and simultaneous implantation can achieve a better effect in the cases with severe alveolar ridge atrophy in the posterior maxillary area. The complications such as perforation of the sinus membrane are low and the short-term implant effect is satisfactory.