Efficacy and safety of rhBMP/ß-TCP in alveolar ridge preservation: a multicenter, randomized, open-label, comparative, investigator-blinded clinical trial.

BACKGROUND: The aim of this multicenter, randomized, open-label, comparative, investigator-blinded study was to investigate the efficacy and safety of recombinant human bone morphogenetic protein 2 (rhBMP-2) combined with ß-TCP (rhBMP-2/ß-TCP) in alveolar ridge preservation. MATERIALS AND METHODS: Eighty-four subjects from three centers were enrolled in this clinical trial. After tooth extraction, rhBMP-2/ß-TCP (n = 41, test group) or ß-TCP (n = 43, control group) were grafted to the extraction socket with an absorbable barrier membrane for alveolar ridge preservation. Using computed tomography images obtained immediately after and 12 weeks after surgery, changes in the alveolar bone height and width were analyzed for each group and compared between the two groups. RESULTS: Both the test and control groups showed a significant decrease in alveolar bone height in the 12 weeks after surgery (both groups, p < 0.0001). However, the test group exhibited a significantly lower decrease in alveolar bone height than the control group (p = 0.0004). Alveolar bone width also showed significantly less resorption in the test group than in the control group for all extraction socket levels (ESL) (p = 0.0152 for 75% ESL; p < 0.0001 for 50% ESL; p < 0.0001 for 25% ESL). There were no statistically significant differences in the incidence of adverse events between the two groups. No severe adverse events occurred in either group. CONCLUSIONS: The results of this study suggest that rhBMP-2/ß-TCP is a safe graft material that provides a high alveolar bone preservation effect in patients receiving dental extraction. TRIAL REGISTRATION: Clinicaltrials.gov , NCT02714829 , Registered 22 March 2016.

Receptor Activator of Nuclear Factor Kappa-B Ligand-Induced Local Osteoporotic Canine Mandible Model for the Evaluation of Peri-Implant Bone Regeneration.

The canine mandible is useful for studying bone regeneration after dental implant placement. However, it is limited in investigations of peri-implant osteogenesis under osteoporotic conditions due to the insignificant osteoporotic effect of ovariectomy. This study aimed at establishing a local osteoporotic model without ovariectomy by using receptor activator of nuclear factor kappa-B ligand (RANKL) in a canine mandible model. This new model was used to evaluate the effects of injectable ß-tricalcium phosphate (TCP) microsphere bone grafts on peri-implant bone regeneration under osteoporotic conditions with combinations of recombinant human bone morphogenetic protein-2 (rhBMP-2). A local osteoporotic canine mandible model was designed by creating a hole in the mandibular alveolar bone, then implanting a collagen sponge soaked with 20, 40, or 60 µg RANKL into the hole, and leaving it for 2 weeks. After the establishment of the dose for maximum osteoporotic bone loss at 40 µg of RANKL, the main surgery was performed. RANKL-soaked collagen sponges were removed, and dental implants were placed with bone grafts in five groups: implant only, TCP, and TCP + rhBMP-2 at 5, 15, and 45 µg. Peri-implant bone generation was determined by radiologic and histologic evaluations at 6 weeks after dental implant placement. On performing micro-computed tomography analysis, the group with TCP + 5 µg rhBMP-2 showed the highest bone volume than the other groups and a 22% increase (p < 0.05) compared with the implant-only group. In the histologic analysis, the TCP-only and TCP + 5 µg BMP-2 groups showed higher bone areas (14% and 16% increase, respectively) and bone-implant contact (12% and 7% increase, respectively) compared with the implant-only group, but there was no significant difference among the groups. In this study, the RANKL-induced local osteoporotic canine mandible model was useful for peri-implant bone regeneration under osteoporotic conditions such as those found in geriatric patients. The injectable ß-TCP bone grafts used in this study were effective in peri-implant bone generation under osteoporotic conditions, and their efficiency was enhanced at 5 µg BMP-2 compared with higher concentrations of BMP-2.

Evaluation of intra-articular distance narrowing during temporomandibular joint movement in patients with facial asymmetry using 3-dimensional computed tomography image and tracking camera system.

INTRODUCTION: Functional overloading can lead to disc displacement in the temporomandibular joint (TMJ), and a high incidence of disc displacement has been reported in patients with facial asymmetry. The aim of this study was to assess the dynamic condylar movement in patients (n = 26) with facial asymmetry using a simulation system with 3-dimensional computed tomographic images and tracking camera system. MATERIAL AND METHODS: The intra-articular distance (IAD) between the condyle and glenoid fossa was recorded during TMJ movement as a parameter for functional overloading and compared between Group I with severe asymmetry and Group II with mild asymmetry. RESULTS: The average IAD was shorter in Group I than Group II, especially at the lowest point (P < 0.05). The ratio of IAD narrowing in Group I was significantly larger than in Group II (P < 0.05). The mean IAD were slightly smaller on the deviated side (3.41 mm) than on the nondeviated side (3.55 mm) in Group I, even though there was no statistical significance. The maximum displacement in Group I was longer than in Group II and had no significant difference between deviated side and nondeviated side. CONCLUSION: We suggested that the reduced IAD resulting from TMJ overloading can lead to internal derangement in severe facial asymmetry.