ABSTRACT
Objective: To measure and analyze the shoulder circumferences of adults' permanent teeth crown preparations based on data collected through the intraoral scanning, so as to provide dental anatomy data for clinical diagnosis and analysis. Methods: Intraoral scanning data of 840 complete crown preparations were collected, and were entrusted to the World Dental Laboratory Co., Ltd. in Fuzhou between March 2021 and June 2022. Except the data of the third molar, the rest data were categorized in terms of 14 tooth positions in the upper and lower jaw (each category involved 30 samples from male group and 30 samples from female group). Image measurement software was used to measure the shoulder circumferences of permanent teeth crown preparations. And analysis was conducted to reveal the difference of shoulder circumference diameters between male and female groups. And then they were grouped according to the mean value at each tooth position, on the premise that the difference between the maximum and minimum values and the mean value of the entire group was≤±1.00 mm. Analysis were further conducted to determine the differences of shoulder circumference diameters between each dental position and the differences between male and female in the same groups. Results: Bivariate analysis of variance showed that gender had no effect on the shoulder circumference of full crown preparations (F=0.55, P=1.457), while tooth position had a significant impact on the shoulder circumference of full crown preparations (F=273.15, P<0.001). The samples were classified into 5 groups according to the mean values of shoulder circumference diameters relating to each tooth position. Statistical analysis showed that Group 1, covering maxillary lateral incisor, mandibular central incisor and mandibular lateral incisor, had shoulder circumference with diameters of (16.62±2.21) mm; Group 2, consisting of maxillary central incisor, maxillary cusp, mandibular cusp, mandibular first premolar and mandibular second premolar, had diameters of (20.78±2.48) mm; Group 3, consisting of maxillary first premolar and maxillary second premolar, had diamerters of (22.09±2.72) mm; Group 4, covering maxillary first molar, maxillary second molar and mandibular first molar, had diamerters of (30.21±2.67) mm; while group 5, with mandibular second molar alone its member, had diamerters of (31.34±3.18) mm. The difference among the 5 groups was statistically significant (P<0.05). Conclusions: Significant differences of shoulder circumference diameters could be found between different tooth positions, while at the same tooth position, the differences between male and female are not significant. The 14 tooth positions could be grouped into 5 groups according to their shoulder circumference diameters. Future research could take the grouping as reference.
ABSTRACT
OBJECTIVE: To establish and optimize in vitro lipolysis model, and then to study griseofuvin(GRI) distribution during in vitro lipolysis of self-nanoemulsifying drug delivery systems(SNEDDSs). METHODS: The lipolysis rate and extent of triglyceride (TG)were two index for in vitro lipolysis model optimization. The partitioning of GRI into lipolysis phases (aqueous phase, pellet phase, lipid phase) was exploited to investigate the impact of structure and lipid loaded of TG on GRI distribution of SNEDDSs in vitro lipolysis. RESULTS: The optimal lipolysis model at the start of the experiment was as follows: 800 U · mL-1 Pancreatin extract, 5/1.25 mmol · L-1 NaTDC/PC micelle and 50 mmol · L-1 Trizma maleate. The addition way of Ca2+ for medium chain triglyceride (MCT) and long chain triglyceride (LCT) were fixed addition 5 mmol · L-1 and continuous addition 0.008 mmol · min-1, respectively. With the same amount of TG in SNEDDSs, percent content of GRI in aqueous phase of LCT-SNEDDS was higher than MCT-SNEDDS. When TG loaded doubled, GRI in aqueous phase of LCT-SNEDDS significantly increased by 32.4%, and which of MCT-SNEDDS raised only 5.7%, respectively. CONCLUSION: The lipolysis rate and extent of TG were correlated with its structure and composition of TG and in vitro lipolysis model. Compared to GRI-SNEDDS without lipolysis, during in vitro lipolysis GRI had transferred to aqueous phase, pellet phase and lipid phase from which was only dispersed in emulsion droplet. And the distribution of GRI during in, vitro lipolysis depended on the composition and loading rate of TG in SNEDDS. These results may provide useful references to study the absorption mechanism of SNEDDS.