Assessment of bone gain and neurosensory affection with the sandwich osteotomy technique for vertically deficient posterior mandible using a full digital workflow versus conventional protocol: A randomized split mouth study

Background

Using the sandwich osteotomy technique in the posterior mandible is delicate. This study aimed to assess the safety and the amount of bone gain using a full digital workflow versus the conventional procedure.

Patients and methods

This split mouth study included 10 patients with bilateral vertically deficient posterior mandible. One side received conventional sandwich interpositional bone grafting (control group), while the other side received the same protocol using two patient-specific guides. The first guide (cutting guide) was used to place the osteotomies safely and accurately according to the predetermined dimensions and locations, and the second guide was used to fix the mobilized bony segment, leaving the desired gap to be filled with a particulate xenogenic bone graft.

Results

Full neurosensory recovery was documented at 2 months postoperative for all patients and bilaterally. After 4 months, there was a statistically significant difference in vertical bone gain between both groups (p = 0.001), measuring an average of 3.76 ± 0.72 mm in the study group and 2.69 ± 0.37 mm in the control group. No statistically significant difference was found between the planned vertical augmentation (3.85 ± 0.58 mm) and the obtained vertical bone gain (3.76 ± 0.72 mm) in the study group (p = 0.765) proving the accuracy of the guided procedure.

Conclusion

Computer-guided sandwich interpositional grafting is predictable regarding the execution of the osteotomies and the accuracy of fixation of the transport segment.