Comparison of two resorbable membrane systems in bone regeneration after removal of wisdom teeth: a randomized-controlled clinical pilot study.

OBJECTIVES: To compare the performance and safety of Inion GTR(TM) Biodegradable Membrane System and Geistlich resorbable bilayer Bio-Gide((R)) membrane in human bone regeneration. MATERIAL AND METHODS: In a multicenter, split blind, comparative, randomized, prospective, pilot study 15 patients have been randomized at surgery whether to be treated either with Inion GTR(TM) Biodegradable Membrane System on one and Geistlich resorbable bilayer Bio-Gide((R)) membrane on the other side or vice versa after surgical removal of both fully impacted wisdom teeth. During the follow-up visits at week 1, 2 and 6 and at months 3 and 6 the general state, the wound, eventual adverse events and the medication of the patients were assessed. Computed Tomography (CT) scans were performed immediately and 3 months after the surgery, before biopsy collection. Semi-quantitative histological evaluation and histomorphometric analyses were performed according to the ISO 10993-6 standard. New bone formation and membrane integration were evaluated by CT scan measurements. Tissue healing was evaluated clinically and by photographs between the time on teeth extraction and during follow ups. RESULTS: Five patients were smokers, none drank alcohol. Mild adverse events like wound infection, haematoma or late swelling of the gums occurred in three patients. The trephine bur harvest of bone biopsies under local anaesthesia was uneventful. Whereas specimens from the sites treated with the Inion membrane yielded 17.0% (SD 24%), the Bio-Gide membrane sites yielded 13.5% (SD 15%) of bone tissue density. In sites treated with the Inion membrane, 9.5% of old bone density and 7.5% of newly formed bone could be found, whereas the Bio-Gide((R)) membrane sites showed 3.8% of old bone density and 9.8% of newly formed bone. There were no statistically significant differences between the two groups with respect to the two variables. The osteoid rim was more extended with the Bio-Gide((R)) (6.6 mm) than with the Inion membrane (5.1 mm) but the difference between the two treatments did not reach statistical significance. Highly significant reductions in the area of the defect with both membranes were detected with significant increases in CT density at the immediate inferio-buccal adjacent bone and in the surgical defect area with both membranes. However, there was neither significant change in CT density in the immediate inferior-lingual adjacent bone of the two membranes, nor significant difference between the membranes on any of the four measurements (area of defect: P=0.1354; CT density immediate inferio-buccal adjacent bone: P=0.7615; CT density surgical defect area: P=0.1876; CT density immediate inferio-lingual adjacent bone: P=0.4212). CONCLUSION: The overall clinical outcome was satisfying and the majority of the patients showed an uneventful healing phase. Both membranes presented similar capacities regarding their barrier function and were associated with analogous bone regeneration. No statistically valid evidence about the superiority of one particular membrane was obtained. For the patient the only difference is that one product is animal derived and the other synthetic.

Stereomodel-assisted fibula flap harvest and mandibular reconstruction.

PURPOSE: To describe a method for stereomodel-assisted fibula flap harvest and mandibular reconstruction utilizing multiple fibula bony segments. MATERIALS AND METHODS: Stereomodels of the mandible and the fibula were obtained from computed tomography scan data. The length of fibula to be harvested was predetermined by measurement of the stimulated of existing mandibular defect on the mandibular stereomodel. A titanium reconstruction plate was shaped to fit the original mandibular contour. The stereomodel fibula was divided into multiple segments and the segments were placed on the mandibular stereomodel in the ideal edentulous position against the upper dentition and simulate the angular contour of the mandible for best comesis. The predetermined bony segments were measured and the system was then transferred to the patient in the operation theater using acrylic locating splints. RESULTS: Experience with 8 patients (2 primary and 2 secondary reconstructions) indicated that a good clinical outcome in terms of mandibular contour and positions of the reconstructed segment was possible. The outer facial appearance and symmetry were consistently excellent and no instability or malposition of the graft segments was encountered. CONCLUSION: Stereomodel-assisted fibula flap harvest and insertion is a worthwhile attempt at improving the results of mandibular reconstruction and deserves further attention.