To evaluate the treatment effect of immediate implantation with the elevation of maxillary sinus floor through the lateral wall, accompanied with maxillary cyst or chronic maxillary sinusitis.

From March 2014 to March 2018, a total of 53 immediate implantations with the elevation of maxillary sinus floor through the lateral wall were selected from dental implant department and surgery department in stomatology hospital of Haizhu District. According to the inclusion criteria of literature reports, all the cases were divided into three groups, including 17 cases with maxillary cyst, 15 cases with chronic maxillary sinusitis and 21 cases without cyst or sinusitis for control. Mucosal thickness and residual bone height of maxillary sinus were recorded preoperatively. Mucosal ruptures of maxillary sinus were recorded during the operation. Postoperative complications were recorded 7 days after the operation. Sinus bone gain (SBG) , apical bone height (ABH) , marginal bone loss (MBL) , cyst change and mucosal thickening were also recorded 12 months after restorations. Statistical data analysis was taken by SPSS 20.0. Acute postoperative infections among the three groups were compared with Fisher exact test. Mucosal thickness of maxillary sinus, sinus bone gain and marginal bone absorption among the three groups were compared with single factor variance analysis. Preoperative and postoperative diameter of the cyst and mucosal thickness of maxillary sinus were compared with paired t test.

All patients finished treatments without mucosal rupture. Acute inflammations were found, including two cases in the maxillary cyst group, three cases in the chronic maxillary sinusitis group and one case in the control group. No significant difference was found among the three groups for acute inflammations (Fisher exact test χ² = 2.049, P = 0.352) . Postoperative hematocele and hydrops in sinus was not found in all cases. SBG at 12 months after restoration in the cyst group, the sinusitis group, and the control group was found to be (8.09 ± 1.20) , (7.17 ± 1.18) and (7.36 ± 1.41) mm, respectively. There was no significant difference in SBG among the three groups (F = 2.409, P = 0.100) . ABH in the cyst group, the sinusitis group and the control group was (1.94 ± 1.34) , (1.40 ± 1.12) and (2.10 ± 1.30) mm, respectively. There was no significant difference in ABH (F = 1.382, P = 0.261) , either. MBL in the cyst group, the sinusitis group and the control group was (0.53 ± 0.70) , (0.47 ± 0.92) and (0.48 ± 0.67) mm, respectively. There was no significant difference in bone absorptions (F = 0.118, P = 0.889) . In the cyst group, the mean postoperative diameter of cysts (2.35 ± 3.51) mm was smaller than that of the pre-operative ones (8.41 ± 3.04) mm, which was significantly different (t = 5.216, P<0.001) . In sinusitis group, the thickness of mucosa (6.27±2.15) mm was increased than that of pre-operation (5.27±1.58) mm, which was of significant difference (t = -2.562, P = 0.023) .

It may be feasible to apply immediate implantation with the elevation of maxillary sinus floor through the lateral wall, in case of maxillary cyst or chronic maxillary sinusitis.