Radiographic Assessment Of The Accuracy Of Vertical Ridge Augmentation For Posterior Mandible Using Computer Guided Onlay Versus Free Hand Onlay Grafting Procedure: A Randomized Clinical Split Mouth Trial

Purpose: The aim of this study is the radiographic evaluation of the guided onlay bone grafting approach versus the freehand onlay grafting approach in the vertical augmentation of posterior mandibular ridges using bone blocks harvested from the chin by patient specific cutting guide.Methods: In this split mouth, controlled clinical trial, 10 patients with bilateral vertically deficient posterior mandibular ridges were enrolled into the study. For each patient, one side was augmented using guided onlay grafting procedure, and the other side using freehand onlay bone grafting technique. The bone blocks in both groups were both harvested from the chin using patient specific surgical cutting guide. This was followed by the radiographic superimposition of the preoperative CBCT scan with the immediate postoperative CBCT scan for each patient to the test for the accuracy of each technique.Results: The accuracy was estimated by calculating the mean value of planned vertical bone gain of the guided group (4.24 ±1.78) mm compared to the mean value of the actual immediate postoperative bone gain (4.5±1.5) mm, and the difference was not statistically significant (p=0.75). while in the control group the planned vertical bone gain of the guided group (3.17 ±1.26) mm compared to the mean value of the actual immediate postoperative bone gain (4.5±1.5) mm, and the difference was statistically significant (p=0.014)Conclusion: The use of patient specific surgical guide for the harvesting and fixation of onlay bone block in the vertically deficient posterior mandible yields more accurate results than the freehand onlay technique.