Sinus floor augmentation with recombinant human growth and differentiation factor-5 (rhGDF-5): a pilot study in the Goettingen miniature pig comparing autogenous bone and rhGDF-5.

AIM: The aim of this study was to test the hypothesis that recombinant human growth and differentiation factor-5 (rhGDF-5) in combination with a beta-tricalcium phosphate (beta-TCP) scaffold material results in superior bone formation in sinus floor augmentations in miniature pigs compared with a particulated autogenous bone graft combined with the scaffold material. MATERIAL AND METHODS: Six adult female Goettingen minipigs underwent a maxillary sinus floor augmentation procedure. In a split-mouth design, the sinus floors were augmented with beta-TCP mixed with autogenous cortical bone chips, in a ratio of approximately 1 : 1, on one side. The contralateral test site was augmented using beta-TCP coated with two concentrations of rhGDF-5 (400 microg rhGDF-5/g beta-TCP or 800 microg rhGDF-5/g beta-TCP; three animals in each case). Simultaneously, one dental implant was inserted into each sinus floor augmentation. After 12 weeks, a histological and histomorphometric assessment of non-decalcified histological specimens was made. RESULTS: There were significantly higher mean values of volume density of newly formed bone using beta-TCP coated with two concentrations of rhGDF-5 (400 microg: 32.9%; 800 microg: 23.9%) than with the corresponding control (autogenous bone/beta-TCP) (14.6%, 12.9%) (P=0.012, P=0.049). The bone-to-implant contact rates (BIC) were significantly enhanced in test sites (400 microg: 84.2%; 800 microg: 69.8%) compared with the corresponding control sites (24.8%, 40.8%) (P=.027, P=.045). CONCLUSION: rhGDF-5 delivered on beta-TCP significantly enhanced bone formation compared with beta-TCP combined with autogenous bone in sinus lift procedures in miniature pigs.

Results of electromyostimulation therapy in obstructive sleep apnea.

Innovative muscle stimulation techniques have become alternatives for therapy of obstructive sleep apnea syndrome breathing disorders. In group I, an individually shaped mouth floor electrode (IME) and in group II, an individually adaptable multi-point electrode (MPE) on a silicone carrier has been used for electromyostimulation (EMS) therapy in patients with obstructive sleep apnea. The enoral-cutaneous EMS was carried out with the low-frequency stimulation apparatus I-pulse over a period of 8 weeks, two times daily for 30 min during daytime hours only. In group III, the patients used EMS therapy for half a year continuously. Before and after stimulation treatment, three-dimensional volumetric sonographical measurement of the geniohyoid muscle was carried out. All patients (n = 14) totally applied the EMS therapy. Under IME and MPE application after 4 weeks of EMS therapy, a median volume increase of 19.6% (minimum 9.7%, maximum 27.9%) was registered, the median after 8 weeks IME was 27.6% and in MPE 24.0%). No significant difference (analysis of variance type: P > 0.05) between electrodes could be found. In all groups, a reduction of the muscle length of 4.7% was proved. In groups I and II after 26 weeks, the volume was near baseline before stimulation (+4.3%). In the third group, the increase of volume persisted (+29.4%) over the observation period of 12-26 weeks. Opposed to established stimulation techniques, a threefold effectiveness enhancement could be verified by using both individually adaptable electrodes. The EMS therapy should be carried out as continuous long-term therapy or as interval therapy.

Sinus floor augmentation with recombinant human growth and differentiation factor-5 (rhGDF-5): a histological and histomorphometric study in the Goettingen miniature pig.

AIM: The aim of this study was to test the hypothesis that recombinant human growth and differentiation factor-5 (rhGDF-5) enhances bone formation in sinus floor augmentations in miniature pigs. MATERIAL AND METHODS: The maxillary sinus floors in 12 adult female Goettingen minipigs were augmented with beta-tricalcium phosphate (beta-TCP) on one side. The contralateral test side was augmented using two concentrations of rhGDF-5 (400 microg rhGDF-5/g beta-TCP; 800 microg rhGDF-5/g beta-TCP) delivered on beta-TCP (six animals each). One dental implant was inserted into each sinus floor augmentation. After 4 and 12 weeks, histological and histomorphometric assessment of non-decalcified histological specimens was performed. RESULTS: The results showed significantly higher mean values of volume density (VD) of newly formed bone using the concentration of 400 microg/g beta-TCP (22.8%) compared with the respective control (8%) after 4 weeks (P=0.05). The bone-to-implant contact rates were also significantly enhanced after 4 weeks between test sites (400 microg: 41.9%; 800 microg: 40.6%) and control sites (400 microg: 7.8%; 800 microg: 16.4%) (400 microg: P=0.024; 800 microg: P=0.048). CONCLUSION: It is concluded that rhGDF-5 delivered on beta-TCP significantly enhanced early bone formation compared with beta-TCP alone in sinus lift procedures in miniature pigs.