Study on the ideal sagittal position of the lower third of the face in high-angle patients with different forehead forms / 口腔疾病防治

Objective@#To explore the ideal sagittal position of the lower third of the face in high-angle patients with different forehead forms and to provide a reference for clinical treatment. @*Methods@#Informed consent and portrait authorization were obtained from all patients, and the study passed the ethical review of the unit. We categorized forehead forms into four types: straight, rounded, type I angular (angled at the middle third of the forehead) and type II angular (angled at the upper third of the forehead). Profiles of high-angle patients with different forehead forms were collected. The initial position was when the facial axis point (FA point) was positioned at the goal anterior-limit line (GALL). After being silhouetted, the lower third of the face was moved forward and backward by 1 mm, 2 mm, 3 mm, and 4 mm each, plus the initial silhouetted picture, to obtain 9 images for each patient. A survey was created with these lateral profile silhouettes, and the silhouette images were ranked by 30 orthodontists and 30 laypersons. @*Results@# There were significant differences in profile scores at different movement distances of the lower third of the face among high-angle patients with different forehead shapes (P<0.05). Overall, high-angle patients with straight or type II angular foreheads had higher scores when the lower third of the face did not move. For high-angle patients with a rounded forehead, orthodontists and laypersons gave the highest scores when the lower third of the face was moved backward by 2 mm and 4 mm, respectively. For high-angle patients with a type I angular forehead, orthodontists thought the scores of backward movement of 4 mm were the highest, and laypersons thought the scores of backward movement of 3 mm were the highest. No significant difference was found in scores between orthodontists and laypersons (P>0.05). @*Conclusion @#The forehead forms and the sagittal position of the lower third of the face will affect the face’s profile aesthetics. Patients with straight and type Ⅱ angular foreheads has the best profile when the FA point is located on the GALL line. For patients with rounded and type Ⅰ angular foreheads, a posterior location of the lower third of the face is more desirable than the initial position.

Bone remodeling at microscrew interface near extraction site in the beagle dog mandible-histologic and immunohistochemical analyses

Extraction is often used as part of orthodontic therapy, and good control of anchorage is a key step after extraction. Although microscrews can be implanted close to the extraction site in order to achieve orthodontic support, the efficiency of bone remodeling at the implant-bone interface near the extraction region is dubious. OBJECTIVE: The purpose of this study was to investigate bone remodeling of the bone-microscrew interface near the tooth extraction site, in the absence of loading. MATERIAL AND METHODS: Third and fourth premolars were extracted from the mandibles of beagle dogs, followed by placement of test microscrews near the extraction sites. Control microscrews were placed further away from the extraction site. All samples were collected after 1, 3, 8, or 12 weeks of healing following extraction. The bone remodeling process at the interface was evaluated using histologic and immunohistochemical analyses. RESULTS: Initially, a large number of inflammatory cells were aggregated at the interface. The expression levels of core binding factor (Cbfa1), osteocalcin (OC) and transforming growth factor beta (TGF-β) were inconspicuous in both groups, whereas tumor necrosis factor alpha (TNF-α) was strongly expressed, especially in the test groups (P<0.05). Subsequently, the expression levels of Cbfa1, OC and TGF-β were found to increase significantly, and active osteogenesis was observed. CONCLUSIONS: During week 1, inflammatory reaction is a major concern at the bone-microscrew interface near the extraction site. However, with healing, the influence of extraction on the remodeling of bone surrounding the microscrews decreases, thus facilitating successful treatment. .

The Protective Effect of Ascorbic Acid and Thiamine Supplementation against Damage Caused by Lead in the Testes of Mice / 华中科技大学学报（医学）（英德文版）

Lead is a ubiquitous environmental and industrial pollutant that may have toxic effects on the male.Vitamins may protect against toxic effects of lead in the liver and reproductive system,which is confirmed by our initial research.The aim of this study was to further investigate the protec-tive effects of vitamins (ascorbic acid combined with thiamine) on lead acetate (Pb)-induced repro-ductive toxicities in mice and study the possible mechanisms underlying these effects.Forty-five male mice were randomly divided into 3 groups,15 mice in each and received daily intragastric ad-ministration with control,Pb (20 mg/kg),and Pb+vitamins (ascorbic acid of 420 mg/kg+thiamine of 30 mg/kg) for 6 weeks,respectively.The Pb-treated animals showed significant decreases in the epididymal sperm count and motility compared to the control group,while the Pb+vitamins group had significant increases for these variables.Moreover,an increasing apoptosis of germinal cells in-duced by Pb was reduced by vitamin treatment.Pb induced the activation of Caspase-3,Fas/Fas-L and Bcl-2 with elevated levels,and the adaptor protein primarily regulated signaling through Fas and required for Fas-induced apoptosis.In conclusion,ascorbic acid combined with thiamine exhibited protective effect on reproductive system by inhibiting Pb-induced excessive cell apoptosis.