Three-dimensional Interlocking versus conventional miniplates for mandibular fractures fixation near the mental foramen: a split-mouth randomized clinical trial

To evaluate the 3D-Interlocking miniplate (3D-IMP) in the management of mandibular parasymphyseal fractures near the mental foramen (MF), and compare it clinically and radiographically with conventional miniplates (2MPs) in a split-mouth design. A total of 12 patients with recent bilateral mandibular fractures in the MF zone were treated with 3D-IMP on one side and with conventional 2MPs on the other side. Clinical evaluations were carried out for 6 postoperative weeks for the assessment of pain, Intra-fragmentary mobility, occlusion, wound healing complications, and an objective mental nerve neurosensory function. Radiographic assessment for the mean bone density was performed immediately after surgery and at 12 postoperative weeks. By the end of the follow-up period, all cases reported a lack of intra-fragmentary mobility, proper occlusion, a significant reduction in pain intensity scores, and proper wound healing. Objective nerve testing reported a statistically significant improvement across the clinical follow-up period in both sides; however, one patient reported Level C sensation in the 2MPs side (4.17%) at the 6th postoperative week. Both sides showed a significant increase in mean bone density at 12 weeks (P < 0.001*), with the 3D-IMP side demonstrating a significantly higher bone density (1107.4 ± 142.2 HU) than the 2MPs side (960.9 ± 97.58 HU). 3D Interlocking miniplates proved to be an effective alternative to conventional miniplates for mandibular parasymphyseal fractures near the MF, offering enhanced bone healing and better neurosensory outcomes. Trial was retrospectively registered at clinicaltrials.gov [NCT06939010/2025-4-22].