Is it enough to just increase the height of sub-antral bone during maxillary sinus augmentation or dose its depth matter?

Purpose: Many techniques for maxillary sinus floor elevation have been used prior to implant placement in case of sever sinus pneumatization. Two-stage lateral-window sinus lifting using titanium micromesh without bone grafting was carried out in the present study. The purpose of the study was a trail to solve a question, if it is enough to just increase the height of sub-antral bone or it is also important to elevate the Schneiderian membrane medio-laterally as much as possible to accommodate for dental implants later.
Materials and Methods: Seven patients (11 sinuses) were included. A titanium micromesh was shaped in a tick shape and placed into the sinus through a lateral window to maintain the elevated membrane in place. Immediate, 6-months and 9-months postoperative cone beam computed tomography (CBCT) were performed to evaluate the relation between the medio-lateral extension of the mesh and the amount of the gained bone.
Results: When the height of the formed bone was related to the depth of the titanium mesh, no significant difference could be observed at either 6 or 9 months. However, when the depth of newly formed bone was compared against the depth of the titanium mesh, a high significant difference was noted at both 6 and 9 months.
Conclusion: At least two thirds of the sinus depth must be elevated to obtain adequate bone width for future implantation.