Schneiderian Membrane Elevation up to 8 mm by Transcrestal Technique Using Hollowed Osteotomes: A Human Cadaver Study

The objective of this study was to compare the detachment surfaces of Schneiderian membrane elevation of 4-8 mm by transcrestal technique using hollowed osteotomes on human cadavers with 4 mm residual bone height.

The study followed the CACTUS (ChAracteristics of Cadaver Training and sUrgical Studies) guidelines. Thirty-four heads with maxillary bilateral edentulous posterior zones and type IV bone (a residual bone height of 4 mm) were selected using cone beam computed tomography (CBCT) scans. Heads were randomly allocated to a group and both sinuses received the same treatment. A sinus floor elevation was performed on the 68 sites using new hollowed osteotome (C.M.C Tech, IBS Implant, Daejeon, South Korea). Samples were divided into two groups: Group 1: sinus elevation of 4 mm; and Group 2: sinus elevation of 8 mm. A postoperative CBCT was performed to analyze membrane integrity and to assess the membrane detachment in mesiodistal and buccopalatal plane.

Of the 68 membrane elevations, only 4 were associated with perforations; 2 occurred in each group. The detachment surface variations between group 1 and group 2 were linear in all directions (Pearson correlation coefficient ρ = 0.99). The Student's t-test unveiled significant differences in detachment surfaces between group 1 and group 2 in all directions (p < 0.001). The ratio of detachment surface group 2/group 1 was homogeneous in all directions (1.5 ≤ r ≤ 1.54). The quality of Schneiderian membrane elevations of 4-8 mm by transcrestal technique was similar using the hollowed osteotomes on human cadavers with 4 mm residual bone height.

In a transcrestal approach using this new-generation osteotome, sinus membrane elevations of 8 mm were performed with a low perforation rate in cadavers. The use of the new hollowed osteotome allowed a Schneiderian membrane elevation of up to 8 mm in a safe and reproducible manner. This transcrestal elevation protocol could increase the indications of the technique, especially concerning single implant restorations and for frail patients with significant medical history for whom a lateral approach would be too invasive.