The prevalence of Class III malocclusion varies among different countries and regions. The populations from Southeast Asian countries (Chinese and Malaysian) showed the highest prevalence rate of 15.8%, which can seriously affect oral function, facial appearance, and mental health. As anterior crossbite tends to worsen with growth, early orthodontic treatment can harness growth potential to normalize maxillofacial development or reduce skeletal malformation severity, thereby reducing the difficulty and shortening the treatment cycle of later-stage treatment. This is beneficial for the physical and mental growth of children. Therefore, early orthodontic treatment for Class III malocclusion is particularly important. Determining the optimal timing for early orthodontic treatment requires a comprehensive assessment of clinical manifestations, dental age, and skeletal age, and can lead to better results with less effort. Currently, standardized treatment guidelines for early orthodontic treatment of Class III malocclusion are lacking. This review provides a comprehensive summary of the etiology, clinical manifestations, classification, and early orthodontic techniques for Class III malocclusion, along with systematic discussions on selecting early treatment plans. The purpose of this expert consensus is to standardize clinical practices and improve the treatment outcomes of Class III malocclusion through early orthodontic treatment.
Humans ; Malocclusion, Angle Class III/classification* ; Orthodontics, Corrective/methods* ; Consensus ; Child

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

The migration of two potential contaminants, formaldehyde and acetaldehyde, from two paper materials into food simulant Tenax was studied. A rapid and simple one-step extraction-derivatization method combined with ultra high performance liquid chromatography was established for the determination of formaldehyde and acetaldehyde in paper packaging materials and food stimulants. The linear correlation coefficients (R2) were greater than 0. 9999 in the range of 0. 14-35. 7 mg/m2 for both formaldehyde and 0. 20-49. 1 mg/m2 for acetaldehyde, with detection limits of 0. 03 mg/m2 for formaldehyde and 0. 04 mg/m2 for acetaldehyde. The recoveries were 90. 1%-108. 6% for paper sample and Tenax. The migration behaviors of formaldehyde and acetaldehyde at different temperatures and migration times were investigated. Both for formaldehyde and acetaldehyde, the amount of migration gradually increased with time first, then decreased, finally reached a steady value. The migration rates of formaldehyde and acetaldehyde were differently influenced by temperature. After reaching a steady value, the maximum migration rate for formaldehyde was at 30℃, and for acetaldehyde was at 70℃ and 50℃. The migration rates of formaldehyde and acetaldehyde greatly varied, and the migration rate of acetaldehyde was far more than the migration rate of formaldehyde when reaching a steady value.

Objective To investigate the effects of unilateral and bilateral electrical stimulation of the upper and lower limbs on motor function following cerebral infarction and the expressions of microtubule-associated protein-2 (MAP-2) and survivin in the infarction border zone of rats. Methods Adult male Sprague-Dawley (SD) rats were randomly divided into sham operation, control, impaired limb and bilateral limbs electrical stimulation groups (each group included 32 rats). Acute cerebral infarction was mimicked using a middle cerebral artery occlusion tech-nique. After cerebral infarction for 24 h, the rats were treated daily with or without electrical stimulation. A beam walking test (BWT) was used to measure limbs motor function and immunohistochemistry and HE staining were used to detect the expressions of MAP-2 and survivin in the border zone of infarcted area after electrical stimulation treat-ment for 3, 7, 14 and 21 d. Results Comparet with the control group treatment with electric stimulation led to BWT scores increasing significantly, and bilateral stimulation was more potent in ameliorating motor function thanstimulating the impaired limb only. The expression of MAP-2 was significantly higher in eleetrieal stimulation groups than in control group from the 7th of treatment, and it was higher in bilateral stimulation group than that in unilateral stimulation group from tbe 14th day of treatment. There was no significant difference in MAP-2 expression between bi-lateral stimulation group and sham operation group at the 21st day of treatment. In electrical stimulation groups, at every time point the expressions of survivin were obviously higher than that in sham operation group, and it was higher than that in control group and peaked at the 7tb and 14th day of treatment and in bilateral stimulation group it was no-tably higher than that in unilateral stimulation group. At the 21st d of treatment the level of survivin expression drop-per; however, there was no significant difference between unilateral and bilateral electrical stimulation groups. Con-clusions Treatment with electrical stimulation, particularly in bilateral limbs stimulation, could induce MAP-2 and survivin expressions in the infarction border zone of rats. It also could promote the recovery of motor function in para-lyzed limbs after cerebral infarction of rats. The improvement might involve the up-regulation of MAP-2 and survivin expressions.

Objective To investigate the effects of electric stimulation on motor function and expression of microtubule-associated protein-2(MAP-2) and survivin of brain tissue in the cerebral infarction rats.Methods Cerebral infarction rat models were made using middle cerebral artery occlusion.After cerebral infarction for 24 h,the rats were respectively treated with electric stimulation on paralyzed(unilateral)or bilateral limbs for 3 d,7 d,14 d,21 d.By using beam walking test(BWT) and immunehistochemistry,the motor function and the expression of MAP-2 and survivin of brain tissue in the border of cerebral infarction area were examined at various time following treatment.Results Compared to control group,the electric stimulation groups showed significant increase in BWT scores after treatment 7 d(all P0.05).In the electric stimulation groups,the expression of survivin of brain tissue were obviously higher than those in the sham operation group at various time points(all P0.05).Conclusions Treatment with electric stimulation,in particular bilateral electric stimulation,can promote the recovery of motor function of paralyzed limbs and induce up-regulation of expression of MAP-2 and survivin in the brain tissue of cerebral infarction rats.