Objective To study the biomechanical effect of jumping distance on dental implants with socket-shield technique (SST), so as to provide references for clinical standards of jump distance. Methods Based on clinical characteristics, four groups of three-dimensional (3D) SST implant system models with 0, 0. 5, 1 and 1. 5 mm jumping distance were established, and the corresponding material parameters were assigned. The peak stress and stress distributions on models were simulated under specific occlusal condition. Results When the jumpingdistance was non-zero, namely, the implant was not in contact with the retained root fragment, the stress of the implant and abutment increased with the increase of jumping distance, and the peak stress in root fragment and periodontal membrane decreased with the increase of jumping distance. When the jumping distance was zero, the peak stress of the implant, abutment, root fragment and periodontal membrane reached the maximum, far exceeding that of the other groups. Conclusions The jumping distance has a significant effect on the SST implant system. It is recommended to take a larger jumping distance in clinical practices. The edge of the root fragment should be rounded, and the size of the lower edge should not be too small.

The role of malate dehydrogenase 2 (MDH2) in tumors is double-sided,it has a cancerpromoting effect in some tumors and an inhibitory effect in other tumors.The function of MDH2 is related to energy metabolism,tumor resistance and its pseudo hypoxia.MDH2 plays an important role in the occurrence,development,invasion and metastasis of tumors.An in-depth understanding of the functional mechanism of MDH2 in tumors can provide new molecular targets for tumor intervention in the clinic.

OBJECTIVE: To assess the geometrical matching of a new anatomical adaptive titanium mesh cage (AA-TMC) with the endplate and its effect on cervical segmental alignment reconstruction in single- and two-level anterior cervical corpectomy and fusion (ACCF) and compare the compressive load at the endplate between the AA-TMC and the conventional titanium mesh cage (TMC). METHODS: Twelve cervical cadaveric specimens were used to perform single- and two-level ACCF. The interbody angle (IBA), interbody height (IBH) and the interval between the AA-TMC and the endplate were evaluated by comparison of the pre- and postoperative X-ray images. The maximum load at the endplate was compared between the AA-TMC and TMC based on American Society for Testing and Materials (ASTM) F2267 standard. RESULTS: No significant differences were found between the preoperative and postoperative IBA and IBH in either single-level ACCF (11.62°±2.67° 12.13°±0.69° and 23.90±2.18 mm 24.23±1.13 mm, respectively; > 0.05) or two-level ACCF (15.63°±5.06° 16.16°±1.05°and 42.93±3.51 mm 43.04±1.70 mm, respectively; > 0.05). The mean interval between the AA-TMC and the endplate was 0.37 ± 0.3 mm. Compared to the conventional TMC, the use of AA-TMC significantly increased the maximum load at the endplate in both single-level ACCF (719.7±5.5 N 875.8±5.2 N, < 0.05) and two-level ACCF (634.3±5.9 N 873±6.1 N, < 0.05). CONCLUSIONS The use of AA-TMC in single-level and two-level ACCF can significantly increase the maximum load at the endplate to lower the possibility of implant subsidence and allows effective reconstruction of the cervical alignment.
Biomechanical Phenomena ; Cervical Vertebrae ; Humans ; Prostheses and Implants ; Spinal Fusion ; Surgical Mesh ; Titanium ; Treatment Outcome