Objective To investigate the effects of Wuling Powder on insulin resistance of C57BL/6J mice induced by high lipid diet, and discuss the mechanism. Methods C57BL/6J mice were randomly divided into six groups:normal group, model group, rosiglitazone group, Wuling Powder in low, middle, and high dose groups, 10 mice per group. Besides the normal group, other five groups were fed with high fat and sugar diet, with a purpose to establish insulin resistance model. Normal group and model group were given pure water. Rosiglitazone group received a gavage with rosiglitazone of 0.75 mg/kg. Wuling Power low, middle, and high groups received gavage with Wuling Power of 1.23, 3.69, 11.07 g/kg, respectively, the does volume was 0.2 mL/10 g, once a day. The weight and abdominal girth were detected every week. At the end of the sixth week, mice were given 12-hour fasting, and their eyeball were taken for blood. The body weight, length, and fat in abdomen and both kidneys were detected. Paraffin section was made with HE staining. FPG and FINS of each group were detected. ISI and IRI were calculated, and TC and TG were detected. Results Compared with the model group, Wuling Powder can significantly reduce the body weight and abdominal girth of mice (P<0.01, P<0.001), improve liver fatty degeneration, lower the FPG, FINS, TCH, TG, IRI, and increase the ISI in mice (P<0.05, P<0.01). Conclusions Wuling Powder has the effect of preventing insulin resistance of C57BL/6J mice induced by high lipid diet.

OBJECTIVETo investigate the development of third molar embryo and establish the normal value of posterior arch length of adolescence in Chengdu.

METHODSThe samples consisted of 40 males and 41 females with Class 1 dentitions, normal second molar occlusion, no history of orthodontic treatment, and good facial balance. Cephalometry and statistic analysis were conducted for all the subject.

RESULTSThe normal value of posterior arch length of maxilla in male was(16.52 +/- 2.35) mm and in female was(16.42 +/- 2.55) mm. The normal length of mandible was(13.00 +/- 2.44) mm in male and(12.43 +/- 2.18) mm in female. But statistic analysis showed no gender difference. Most of the third molar embryo had been formed and their tooth crowns had been calcified, the occurrence ratio was 84.0% in maxilla and 85.2% in mandible. Most of them located in the middle and inclined mesially.

CONCLUSIONThe data obtained in this study will be valuable for our clinical practice and be helpful for the study concerning dento-facial growth and development.

Adolescent ; Alveolar Process ; anatomy & histology ; diagnostic imaging ; Cephalometry ; Child ; Dental Arch ; anatomy & histology ; diagnostic imaging ; Dental Occlusion ; Dentition ; Female ; Humans ; Male ; Mandible ; anatomy & histology ; diagnostic imaging ; Maxilla ; anatomy & histology ; diagnostic imaging ; Molar, Third ; anatomy & histology ; diagnostic imaging ; Radiography ; Reference Values ; Tooth Migration

OBJECTIVETo investigate the regulatory effect of central synaptic plasticity on pain induced by experimental tooth movement and to analyzethe expression of protein kinases Mζ (PKMζ) in the anterior cingulate cortex (ACC) after applying different magnitude of orthodontic force.

METHODSOne hundred and thirty-six male Sprague-Dawley (SD) rats (200-250 g) were used in this study. Orthodontic tooth movement devices were placed on the teeth in the experimental group, and different orthodontic forces (0.39, 0.78, 1.17 N) were applied to move the maxillary first molars, respectively. The same mechanical devices were placed on the teeth in sham-treated group and no orthodontic force was applied. No orthodontic procedure was applied in blank control group. The average time spent on mouth- wiping behavior in each group was recorded after experimental tooth movement. Brain tissue of the anterior cingulate cortex was isolated on day 3 after experiment, and the expression level of PKMζ was analyzed with the method of immunohistochemistry and enzyme-linked immune sorbent assay. ζ-pseudosubstrate inhibitory peptide (ZIP), a selective inhibitor for PKMζ, was injected into ACC on day 3 after experimental tooth movement, and the effects of ZIP on mouth-wiping behavior were evaluated.

RESULTSNo statistical difference was found between the blank control group and the sham- treated group in the average time spent on mouth-wiping, value of A and expression level of PKMζ (P > 0.05). Compared with the sham-treated group and blank control group, the average time of mouth-wiping behavior [(58.6±6.9), (66.3±7.8), (78.9±8.7) s], value of A (4 569±454, 6 850±365, 8 294±558) and expression level of PKMζ [(0.32±0.02), (0.34±0.02), (0.36±0.02) mg/L] in 0.39, 0.78, 1.17 N force group were found to be up-regulated with the increase of orthodontic force (P < 0.05). LSD test in three experimental sub-group showed statistical difference (P < 0.05). After microinjection of ZIP, the average time spent on mouth-wiping behavior significantly decreased (P < 0.01), while microinjecting saline did not change rats' mouth-wiping behavior (P > 0.05).

CONCLUSIONSMore pain caused by increased orthodontic force maybe due to the up-regulation of PKMζ in the anterior cingulate cortex.

Animals ; Behavior, Animal ; Gyrus Cinguli ; enzymology ; Male ; Maxilla ; Molar ; Neuronal Plasticity ; Protein Kinase C ; metabolism ; Rats ; Rats, Sprague-Dawley ; Time Factors ; Tooth Movement Techniques ; instrumentation ; Up-Regulation

Objective: To study the change of STAT1 expression in the anterior cingulate cortex on rats under orthodontic force, and to further explore the roles of STAT1 and related JAK-STAT1 signaling pathway in the mediation and regulation of pain during tooth movement. Methods: 112 male Sprague-Dawley (SD) rats (225±25 g) were used in this study. They were randomly divided into experimental groups (96 rats) and control groups (16 rats). All rats were installed bilateral maxillary device for tooth movement models. Rats in the experimental groups were applied 80g orthodontic force on both sides and were divided into six subgroup 4 h, 12 h, 24 h, 2 d, 3 d, 7 d, with 16 rabbits in each subgroup. The control groups were only installed the same orthodontic devices, without the application of orthodontic force. Brain tissue of the anterior cingulate cortex was isolated after 4 h, 12 h, 24 h, 2 d, 3 d, 7 d since experiment, and the expression level of STAT1 and p-STAT1 was analyzed with the method of immunofluorescence and PCR. Results : For the immunofluorescence result, there was significant difference in STAT1 expression between control groups and different experimental groups at different time points in total (P < 0.05). The STAT1 expression amount in the 4 h group decreased significantly when compared with the control group (P < 0.05); to the 2 d group, the difference is still statistically significant (P < 0.01). 3 d group, 7 d group and control group had no statistically significant difference. The STAT1 expression amount in 4 h group, 12 h group, 24 h group was significantly lower than that in 3 d and 7 d groups, differences were statistically significant (P < 0.05). The STAT1 expression in the 2 d group was significantly lower than that of 7 d (42.35 ± 5.77) group, the difference was statistically significant (P < 0.05). There was significant difference in p-STAT1 expression between control groups and different experimental groups at different time points in total (F = 623.518, P < 0.05). The p-STAT1 expression amount in experimental groups were higher than that in the control group (P < 0.05). The p-STAT1 expression in 4 h group was lower than that in 12 h and 24 h group and higher than that in 2 d, 3 d and 7 d groups, of which the differences were statistically significant (P < 0.05). The p-STAT1 expression in 12 h group was lower than that in 24 h group and higher than that in 2 d, 3 d and 7 d groups, of which the differences were statistically significant (P < 0.05). For the PCR result, the expression of mRNA in STAT1 of experimental groups of 4 h, 12 h, 24 h, 2 d, 3 d, 7 d and the control groups were not statistically significant (P > 0.05). Conclusions After applying orthodontic force, the expression of STAT1 decreased transiently and the expression of p-STAT1 increased transiently. The reduction of STAT1 was probably caused by the phosphorylation of STAT1 and decrease in the translation level of STAT1, rather than changes in the transcriptional levels. The orthodontic pain might be related with the activation of STAT1 into phosphorylated STAT1.

Objective: Exploring the position and bone wall thickness characteristics of the maxillary central incisors in Southern Chinese adults to provide a clinical reference for the design of immediate maxillary central incisor implantation surgery. Methods: The hospital ethics committee approved the study, and the patients provided informed consent. CBCT images of 990 adult patients (aged 20-79 years) from the Stomatology Hospital (January 2018 to December 2021) were categorized based on the dental arch form and age-sex groups. Sagittal CBCT images of the maxillary central incisors were used to measure the labial and palatal bone thickness wall at 4 mm the CEJ to apical, the middle of the root, and the angle between the tooth long axis and the long axis of the alveolar process, to compare the thickness of the labial and palatal bone walls in samples of male and female patients, and to explore the relationship between the angle between the tooth long axis and the alveolar process long axis in samples of male and female patients in different age groups (20-39 years; 40-59 years; 60-79 years). Results: Significant differences were found in the labiopalatine side of the alveolar bone of the maxillary incisor root position. A total of 95.8% (948/990) of the maxillary incisors were positioned more buccally, 4.1% (41/990) were positioned more midway, and 0.1% (1/990) were positioned more palatally. The thicknesses of the bone wall at the CEJ of 4 mm below the palatal side, the middle of the root, and at the apex were greater (1.82 ± 0.56 mm, 3.20 ± 1.10 mm, and 7.70 ± 2.00 mm, respectively) than those at the labial side (1.21 ± 0.32 mm, 0.89 ± 0.35 mm, and 1.86 ± 0.82 mm, respectively), with statistical significance (P<0.05). Male bone wall thickness was generally greater than female bone wall thickness (P<0.05). The angle between the long axis of male teeth and the alveolar bone was 14.77° ± 5.66°, while that of female teeth was 12.80° ± 5.70°, with a statistically significant difference (P<0.05). The angle between the long axis of teeth and the alveolar bone in the 40-59-year-old group and the 60-79-year-old group was greater than that in the 20-39-year-old group, and the difference was statistically significant (P<0.05). Conclusion A total of 95.8% of adults in South China have maxillary central incisors with root deviation toward the labial bone cortex. The thickness of the labial bone wall is much thinner than that of the labial bone wall, which is the middle of the thickness of the root. In Southern Chinese adults, the angle between the upper central incisor and the long axis of the alveolar bone in males is greater than that in females, and the degree of the angle increases with age. It is recommended to pay attention to the thickness of the bone wall around the root and the angle between the teeth before immediate implantation surgery to choose a reasonable implantation plan.

Objective: To analyze the spatial relationship between the roots of maxillary anterior premolars and the maxillary sinus, thus providing an anatomical basis for timing, planning, surgical approaches, and implant selection at this site. Methods: Cone beam CT (CBCT) images were collected from 264 patients (aged 20-65 years) who visited the Ruihua Dental Clinic between January 2017 and March 2023. The minimum distance from the apex of the maxillary anterior premolar roots to the lower wall of the maxillary sinus was measured on the coronal plane. The classification of the vertical relationship between the tooth root and the lower wall of the maxillary sinus was performed, and comparisons were made bilaterally, between genders, and among different age groups. Results: The minimum distance (Q50) from the apex of the first maxillary premolar root to the lower wall of the maxillary sinus was 7.34 mm for the single-root type, 7.80 mm for the buccal root of the double-root type, and 7.36 mm for the palatal root. For the second maxillary premolar, the median distance was 2.56 mm for the single root type, 1.73 mm for the buccal root type, and 1.23 mm for the palatal root type. There was a significant difference in the shortest distance from the apex of the right second maxillary premolar single root to the lower wall of the maxillary sinus among the different age groups (P<0.05), with the 20-29-year-old group having the smallest median distance (1.52 mm) and the ≥ 40-year-old group having the largest (4.44 mm). There was no significant difference in the effect of sex or laterality on distance (P>0.05). The most common vertical relationship between the apex of the maxillary anterior premolar roots and the lower wall of the maxillary sinus was noncontact. There was no significant difference in the vertical relationship classification between the single-root and double-root types (P>0.05). Conclusion Most maxillary first premolar roots can provide sufficient bone height, which makes it easy to achieve immediate implantation. The maxillary second premolar root frequently involves insufficient bone, which is necessary to make full use of the bone wall of the extraction socket or the sinus floor cortical bone to achieve initial stability. The vertical relationship between the premolar root and maxillary sinus was influenced by age and dental position. Younger age groups often exhibit inadequate bone height, and the indication for immediate implantation should be carefully considered. The number of roots does not significantly affect the relationship between the sinus and root; however, double-rooted premolars offer more support for immediate implantation and socket healing due to the small root diameter and bony separation between the roots.

External apical root resorption is among the most common risks of orthodontic treatment, and it cannot be completely avoided and predicted. Risk factors causing orthodontic root resorption can generally be divided into patient- and treatment-related factors. Root resorption that occurs during orthodontic treatment is usually detected by radiographical examination. Mild or moderate root absorption usually does no obvious harm, but close attention is required. When severe root resorption occurs, it is generally recommended to suspend the treatment for 3 months for the cementum to be restored. To unify the risk factors of orthodontic root resorption and its clinical suggestions, we summarized the theoretical knowledge and clinical experience of more than 20 authoritative experts in orthodontics and related fields in China. After discussion and summarization, this consensus was made to provide reference for orthodontic clinical practice.
Humans ; Tooth Movement Techniques/adverse effects* ; Root Resorption/etiology* ; Consensus ; Dental Cementum ; Risk Factors