Computer-guided Versus Conventional Modified Cortical Shell Technique for the Rehabilitation of Posterior Mandibular Deficiency: Randomized Controlled Trial

PURPOSE: The cortical shell technique lacks anatomical guidance for harvesting and grafting. This study compares the horizontal bone gain and neurosensory function of a modified free- hand and a computer-guided cortical shell graft, which was also assessed for accuracy. MATERIALS AND METHODS: This study included eighteen patients with atrophic mandibles. Nine patients received free-hand cortical shell harvest, lateral convey, and fixation (the control group), and nine patients received guided workflow (the test group) that utilized cutting and positional guides. The interpositional gap was packed with autogenous particulates from the retromolar bone. The radiographic horizontal bone gain and neurosensory function were compared between the two groups, and the accuracy of the digital workflow was assessed by superimposing and calibrating the planned and immediate postoperative horizontal bone dimensions. RESULTS: The mean horizontal bone gain of the study group recorded (4.93±0.64) mm versus (4.46 ± 0.67) mm for the control group after four months, with a difference of (0.47) mm, which was statistically significant (p=0.038*). The neurosensory function was indifferent in both groups, as all the patients recovered and were graded as (S4) after two months. Finally, the superimposed scans demonstrated close adherence to the virtual plan, with an insignificant difference between the planned and gained horizontal dimensions (p = 0.9). CONCLUSION: The digital workflow of the modified cortical shell harvest, positioning and fixation enabled precise graft harvest and orientation, with a statistically significant horizontal bone gain exceeding that of the free-hand technique, while neurosensory affection was similar between both groups.