Objective To investigate and analysis the situation of malocclusion of 49 skulls of ancient resident in Xinjiang, and discuss the history evolution and the pathologic mechanism of malocclusion. Methods The investigation was carried out based on the standard of individual normal occlusion. Results Among the group of 49 skulls, the morbility rate of malocclusion was 30. 61% ; in Angle's classification of malocclution, class I was the most (73. 33%); in Mao's classification of malocclution, class I was also the most (33. 33%). Conclusion The morbility rate of malocclusion of resident in bronze age is lower than that of modern resident and nearer ages resident. There is a close releationship between the human food construction and the pathogenesis of malocclution.

Objective:To compare and analyze the clinical efficacy of hand-assisted laparoscopic surgery (HALS) and laparoscopic assisted surgery (LAS) in the treatment of advanced gastric cancer.Methods:Articles of the efficacy comparison of HALS and LAS in D2 radical gastrectomy for gastric cancer from 2000 to 2019 published in PubMed, Cochrane library, EM-BASE, China National Knowledge Infrastructure (CNKI), Wanfang, Weipu, Chinese full-text database of Chinese Sci-Tech journals, Chinese biomedical literature database were retrieved, and the literatures were screened according to the pre-established inclusion and exclusion criteria. The quality of the two groups was evaluated, and the short-term indexes and complications for meta-analysis of the two groups were analyzed by using Revman 5.3 software.Results:A total of 1277 patients were included in 10 articles, including 629 in the HALS group and 648 in the LAS group. The results of the meta-analysis showed that compared with the LAS group, the operation time was shorter in the HALS group (WMD=24.02, 95% CI: -40.41--7.62, P=0.004), but the auxiliary incision was slightly longer (WMD=0.27, 95% CI: 0.06-0.47, P=0.01), and there were no statistically significant difference in the remaining number of lymph node dissections (WMD=0.58, 95% CI: -1.22-2.39, P=0.53), intraoperative blood loss (WMD=-7.94, 95% CI: -16.21-0.33, P=0.06), gastrointestinal tract recovery time (WMD=0.00, 95% CI: -0.03- 0.04, P=0.85), total length of hospital stay (WMD=-0.14, 95% CI0: -0.36-0.09, P=0.23) and postoperative complications ( OR=0.89, 95% CI: 0.58-1.37, P=0.61). Conclusions:Compared with the LAS for D2 radical surgery of advanced gastric cancer, HALS has significantly shorter operation time and is easier to perform than LAS, but the incision length is slightly increased. Physicians can choose the appropriate operation method according to the specific conditions of the operation and themselves.