Search PubMed⌕ Search

Biomedical subjects

Marc Christian Metzger

Publications and source records attributed to Marc Christian Metzger.

5 recordsLinked to original sources

Bone formation after sinus augmentation with engineered bone.

OBJECTIVES: The aim of the following investigation was to quantify the resorption rate of tissue-engineered bone grafts in the maxillary sinus using volume measurements. MATERIAL AND METHODS: Sinus floor augmentation using autologous bone grafts from the iliac crest (n=17, group 1) was compared with commercially produced transplants of human cells seeded on polyglycolid-polylactid (PLGA) scaffolds (Oral Bone) (n=14, group 2). RESULTS: The total resorption rate for autologous transplants 3 months post operation was 29%, while the tissue-engineered bone showed a resorption rate of 90%. The autologous bone had a bone density of up to 266-551 Hounsfield units (HU), while sufficient mineralization of tissue-engineered bone was found in only one case (152 HU). CONCLUSION: In this clinical study, the use of autologous cancellous bone grafts in sinus augmentation was more reliable than scaffolds containing cultured osteoblasts. Further tissue-engineered bone transplants should be examined to draw general conclusions about the use of tissue-engineered grafts compared with autologous bone grafts for maxillary sinus augmentation.

Alveolar Ridge Augmentation↗

Individual preformed titanium meshes for orbital fractures.

OBJECTIVES: The aim of this investigation was to develop and test the accuracy of a procedure for fabricating individual preformed titanium meshes for orbital fractures. STUDY DESIGN: Preoperative CT datasets from five patients with orbital fractures were used for 3D reconstruction by mirroring the unaffected side onto the defective one, resulting in a new sub-volume. A template for adaptation of the titanium mesh was produced by applying these sub-volumes. Navigation-aided procedures guaranteed the exact placement of the preformed mesh during the operation. RESULTS: The accuracy of the reconstructed orbital floor was determined to be approximately 1 mm, which lies within the technical limit of detection. CONCLUSION: These results indicate a further application or navigation-aided reconstruction, which will serve as a pilot project for further investigations. Clustered databases of patients will be used to produce various template sets, reflecting ideal skeletons, according to age, sex, and other patient variables. These could be used for manufacturing preformed osteosynthesis templates.

Databases, Factual↗

Computer-assisted extracorporeal orbital reconstruction after optic nerve decompression by removal of sphenoid bone.

The removal of sphenoid bone parts was performed by the admitting neurosurgeons on a patient who presented an optic nerve compression syndrome. Beside the orbital trauma, an extensive midfacial trauma was sustained with dislocated multifractures of the zygomatic complex. In a secondary procedure, the orbital cavity was reconstructed successfully using 3 different methods of computer-assisted surgery. First, the reconstruction of the zygomatic complex was controlled intraoperatively by a virtual model obtained by mirroring the unaffected side to the affected side. Second, extracorporeal bone parts were virtually preoperatively relocated and orientated. The reconstruction of the orbital cavity by the insertion of these bony fragments was performed intraoperatively as planned after the zygomatic complex reconstruction. Third, the virtual reconstruction of the orbital floor was performed using preoperatively individually bent and preformed orbital titanium mesh. Combinations of these methods demonstrate the practical and high value of computer-assisted surgery in complex reconstructive craniofacial surgery.

Adult↗

Computer-assisted reconstruction of orbital floor based on cone beam tomography.

We used a navigation system for computer-assisted preoperative planning based on cone beam tomography with virtual reconstruction to obtain symmetry of the orbit and intraoperative control of virtual contours. In operations for reconstruction of the orbital floor this technique offers a reliable intraoperative control in an area of limited exposure and visibility. There was no significant difference in visualisation of anatomical structures between the cone beam tomographic digital imaging and communication (DICOM) data and computed tomographic data. Cone beam tomography seems to be suitable for computer-assisted planning in the management of orbital trauma with reduced costs and less radiation.

Aged↗