Outcomes of alveolar segmental 'sandwich' osteotomy with interpositional particulate allograft for severe vertical defects in the anterior maxilla and mandible

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.

Bone Tissue Engineering (BTE) of the Craniofacial Skeleton, Part I: Evolution and Optimization of 3D-Printed Scaffolds for Repair of Defects

Bone tissue regeneration is a complex process that proceeds along the well-established wound healing pathway of hemostasis, inflammation, proliferation, and remodeling. Recently, tissue engineering efforts have focused on the application of biological and technological principles for the development of soft and hard tissue substitutes. Aim is directed towards boosting pathways of the healing process to restore form and function of tissue deficits. Continued development of synthetic scaffolds, cell therapies, and signaling biomolecules seeks to minimize the need for autografting. Despite being the current gold standard treatment, it is limited by donor sites' size and shape, as well as donor site morbidity. Since the advent of computer-aided design/computer-aided manufacturing (CAD/CAM) and additive manufacturing (AM) techniques (3D printing), bioengineering has expanded markedly while continuing to present innovative approaches to oral and craniofacial skeletal reconstruction. Prime examples include customizable, high-strength, load bearing, bioactive ceramic scaffolds. Porous macro- and micro-architecture along with the surface topography of 3D printed scaffolds favors osteoconduction and vascular in-growth, as well as the incorporation of stem and/or other osteoprogenitor cells and growth factors. This includes platelet concentrates (PCs), bone morphogenetic proteins (BMPs), and some pharmacological agents, such as dipyridamole (DIPY), an adenosine A 2A receptor indirect agonist that enhances osteogenic and osteoinductive capacity, thus improving bone formation. This two-part review commences by presenting current biological and engineering principles of bone regeneration utilized to produce 3D-printed ceramic scaffolds with the goal to create a viable alternative to autografts for craniofacial skeleton reconstruction. Part II comprehensively examines recent preclinical data to elucidate the potential clinical translation of such 3D-printed ceramic scaffolds.

Maxillary vertical alveolar ridge augmentation using sandwich osteotomy technique with simultaneous versus delayed implant placement: A proof of principle randomized clinical trial

BACKGROUND

The sandwich osteotomy technique usually requires high surgical skills and prolonged intraoperative time and had some technical drawbacks with a subsequent deficient amount of vertical bone gain. The aim of this study was to evaluate the final vertical bone gain using sandwich osteotomy with simultaneous versus delayed implant placement in the anterior maxilla.

MATERIAL AND METHODS

This study included 16 patients having multiple missing maxillary anterior teeth with a vertically deficient alveolar ridge. Patients were randomly assigned into two equal groups. Both groups were treated using sandwich osteotomy with interpositional particulate bovine bone graft. In the study group (8 patients, 17 implants), the transport mobilized bone segment was fixed in position using simultaneous implant placement. Whereas in the control group (8 patients, 18 implants), micro-plates and screws were used, followed by a second-stage surgery for plates removal and delayed implant placement. Radiographic assessment included 4 months postoperative mean of vertical gain in alveolar ridge height, taken from cross-sectional cuts of cone beam CT.

RESULTS

The mean vertical bone gain in the study group was 4.04 ± 0.59 mm compared to 3.86 ± 0.52 mm in the control group with no statistically significant difference (p = 0.518). The mean value of bone gain percentage in the study group was 33.02% compared to 31.75% in the control group, with no statistically significant difference (p = 0.656).

CONCLUSION

The sandwich osteotomy technique with simultaneous implant placement is a reliable method for vertical ridge augmentation that eliminates the need for a secondary surgery.