Three-dimensional (3D) alveolar ridge deficiencies necessitate horizontal and vertical bone reconstruction for optimal implant positioning. Despite several available techniques, achieving desired augmentation outcomes remains challenging. This case study aims to present a modified ridge split technique for bone reconstruction in horizontal and vertical dimensions. The proposed technique was used to reconstruct the horizontal and vertical ridge defect from removing a previously failed implant. This technique includes placing a cortical allograft plate as an internal tent in the split ridge. A portion of the plate was inserted into the ridge, while the other part was placed in the coronal of the vertical defect. Additional guided bone regeneration was performed around the tented plate on both the buccal and lingual sides. After 5 months, cone beam computerized tomography revealed sufficient bone formation in horizontal and vertical dimensions. Within the limitations of the present case study, internal cortical tenting would be a reliable method for 3D bone reconstruction in cases where the ridge split is feasible.