Applications of hydrogels in tissue-engineered repairing of temporomandibular joint diseases.

Epidemiological studies reveal that symptoms of temporomandibular joint disorders (TMDs) occur in 60-70% of adults. The inflammatory damage caused by TMDs can easily lead to defects in the articular disc, condylar cartilage, subchondral bone and muscle of the temporomandibular joint (TMJ) and cause pain. Despite the availability of various methods for treating TMDs, few existing treatment schemes can achieve permanent recovery.

YAP/TAZ: Molecular pathway and disease therapy.

The Yes-associated protein and its transcriptional coactivator with PDZ-binding motif (YAP/TAZ) are two homologous transcriptional coactivators that lie at the center of a key regulatory network of Hippo, Wnt, GPCR, estrogen, mechanical, and metabolism signaling. YAP/TAZ influences the expressions of downstream genes and proteins as well as enzyme activity in metabolic cycles, cell proliferation, inflammatory factor expression, and the transdifferentiation of fibroblasts into myofibroblasts. YAP/TAZ can also be regulated through epigenetic regulation and posttranslational modifications.

Customized planning of the visible maxillary arch width in harmony with interparopia width and smile width for female facial aesthetics.

Background: The visible maxillary arch width (VAW) is an important aesthetic-determining feature. To date, there is no well-established methodology to determine the aesthetically optimal VAW in customized treatment planning.

Methods: In this study, the common traits of the dentofacial configuration were investigated in most attractive Asian and Caucasian female smiles.

The Host Response to Autogenous, Allogeneic, and Xenogeneic Treated Dentin Matrix/Demineralized Dentin Matrix-Oriented Tissue Regeneration.

Dentin is a bone-like matrix that forms the bulk of the tooth. By fabricating dentin with protocols involving demineralization, sterilization, and preservation, treated dentin matrix (TDM)/demineralized dentin matrix (DDM) could be obtained, which is considered as a useful tool for bone and tooth-tissue regeneration. Non-negligible inflammatory and immune responses are reviewed in this article of autogenous, allogeneic, and xenogeneic TDM/DDM for the first time.

YAP/TEAD1 and β-catenin/LEF1 synergistically induce estrogen receptor α to promote osteogenic differentiation of bone marrow stromal cells.

Bone remodeling is vital to the maintenance of bone homeostasis and may lead to destructive skeletal diseases once the balance is disrupted. Crosstalk between Wnt and estrogen receptor (ER) signaling has been proposed in bone remodeling, but the underlying mechanism remains unclear. This study was designed to explore the effect of Wnt-ER signaling during the osteogenic differentiation of bone marrow stromal cells (BMSCs).

XGBoost-aided prediction of lip prominence based on hard-tissue measurements and demographic characteristics in an Asian population.

Introduction: Prediction of lip prominence based on hard-tissue measurements could be helpful in orthodontic treatment planning and has been challenging and formidable thus far.

Methods: A machine learning-based cross-sectional study was conducted on 1549 patients. Hard-tissue measurements and demographic information were used as the input features.

Orthodontic retreatment need and related self-perceived factors among contemporary college freshmen in China.

Given that an increasing number of patients who received orthodontic treatment during their childhood or adolescence are seeking retreatment in contemporary China, it is of great necessity to comprehensively understand their motivations. A valid and reliable self-designed questionnaire, based on the Index of complexity, outcome and need (ICON), was distributed online to college freshmen who received orthodontic treatment during their childhood or adolescence. After collecting their basic information and orthodontic retreatment needs data from the survey, the participants' general self-perception of front facial appearance, lateral facial appearance and tooth alignment, as well as their self-perceived dental alignment, occlusal status, oral function and psychological status, were assessed.

Orthodontic correction of a skeletal Class II malocclusion with severe gummy smile by total intrusion of the maxillary dentition.

A 22-year-old woman visited the hospital complaining of lip protrusion, crowded teeth, and a gummy smile. The clinical examination showed a convex profile with a hyperdivergent mandible and a severe gummy smile in both anterior and posterior regions. The unstable mandible position was considered during treatment planning, and a targeted mechanic system was carefully designed.

A survey regarding orthodontic treatment among contemporary college freshmen in China.

Background: A growing number of Chinese residents are seeking orthodontic treatment. The aim of the study was to investigate rates of orthodontic publicity, orthodontic treatment history and related factors among college freshmen in China, to preliminarily understand the current situation of orthodontic publicity and treatment in China, especially after the 2020s.

Methods: Referred to previous studies, a self-designed online questionnaire of Chinese college freshmen was conducted.

Nonsurgical treatment of a hyperdivergent skeletal Class III patient with mini-screw-assisted mandibular dentition distalization and flattening of the occlusal plane.

Treatment of hyperdivergent skeletal Class III malocclusion is challenging for orthodontists, and orthognathic-orthodontic treatment is usually required. This report presents the successful nonsurgical treatment of a 20-year-old man who had a skeletal Class III malocclusion with anterior open bite, anterior and posterior crossbite, hyperdivergent growth pattern, steep occlusal plane, early loss of three first molars, and an uncommon convex profile with a retruded chin. An orthodontic camouflage treatment plan was chosen based on the etiology and the patient's complaints.

Rodent incisor and molar dental follicles show distinct characteristics in tooth eruption.

Objective: Rodent incisors and molars show different eruption patterns. Dental follicles and their interaction with dental epithelia play key roles in tooth eruption. However, little is known about the differences between incisor dental follicle (IF) and molar dental follicle (MF) during tooth eruption of rodents.

Roles and mechanisms of YAP/TAZ in orthodontic tooth movement.

Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are transcriptional coactivators encoded by paratactic homologous genes, shuttle-crossing between cytoplasm and nucleus to regulate the gene expression and cell behavior and standing at the center place of the sophisticated regulatory networking of mechanotransduction. Orthodontic tooth movement (OTM) is a process in which extracellular mechanical stimuli are transformed into intracellular biochemical signals to regulate cellular responses and tissue remodeling. Literature studies have confirmed that YAP/TAZ plays an important role not only in embryonic development, homeostasis and tumorigenesis, but also in mechanical-biochemical signal transduction of periodontal tissues under the mediation of various signal molecules in its upstream and downstream.

Estrogen effects on orthodontic tooth movement and orthodontically-induced root resorption.

Estrogen is an essential regulator of the bone tissue. The remodeling of the alveolar bone and periodontal ligament is the basis of orthodontic tooth movement (OTM). There is a negative coregulation between physiological estrogen levels and the rate of OTM.

Control of SARS-CoV-2 transmission in orthodontic practice.

The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has attracted worldwide concerns because of its high person-to-person infectivity and lethality, and it was labeled as a pandemic as the rapid increase in the number of confirmed patients in most areas around the world became evident. The SARS-CoV-2 is mainly transmitted through respiratory droplets and close contact. There is also evidence of transmission through aerosols and digestive tracts.

Accurate bracket placement using a computer-aided design and computer-aided manufacturing-guided bonding device: An in vivo study.

Introduction: A protocol was introduced to achieve accurate bracket placement in vivo, which consisted of operative procedures for precise control, and a computer-aided design and computer-aided manufacturing-guided bonding device. To evaluate the accuracy of this protocol, a 3-dimensional assessment was performed.

Methods: Ten consecutive patients were enrolled.

YAP regulates periodontal ligament cell differentiation into myofibroblast interacted with RhoA/ROCK pathway.

During orthodontic tooth movement (OTM), periodontal ligament cells (PDLCs) receive the mechanical stimuli and transform it into myofibroblasts (Mfbs). Indeed, previous studies have demonstrated that mechanical stimuli can promote the expression of Mfb marker α-smooth muscle actin (α-SMA) in PDLCs. Transforming growth factor β1 (TGF-β1), as the target gene of yes-associated protein (YAP), has been proven to be involved in this process.

Are Hertwig's epithelial root sheath cells necessary for periodontal formation by dental follicle cells?

Objective: The role of Hertwig's epithelial root sheath (HERS) cells in periodontal formation has been controversial. This study aimed to further clarify whether HERS cells participate in formation of the periodontium, and the necessity of HERS cells in differentiation of dental follicle cells (DFCs) for periodontal regeneration.

Design: HERS cells and DFCs were isolated and identified from post-natal 7-day Sprauge-Dawley rats.

Comparative study on differentiation of cervical-loop cells and Hertwig's epithelial root sheath cells under the induction of dental follicle cells in rat.

Cervical loop cells (CLC) and Hertwig's epithelial root sheath (HERS) cells are believed to play critical roles in distinct developmental patterns between rodent incisors and molars, respectively. However, the differences in differentiation between CLC and HERS cells, and their response to inductions from dental follicle cells, remain largely unknown. In present study, CLC and HERS cells, as well as incisor dental follicle (IF) cells and molar dental follicle (MF) cells were isolated from post-natal 7-day rats.

Polymerization stress evolution of a bulk-fill flowable composite under different compliances.

Objective: To use a compliance-variable instrument to simultaneously measure and compare the polymerization stress (PS) evolution, degree of conversion (DC), and exotherm of a bulk-fill flowable composite to a packable composite.

Methods: A bulk-fill flowable composite (Filtek Bulk-fill, FBF) and a conventional packable composite (Filtek Z250, Z250) purchased from 3M ESPE were investigated. The composites were studied using a cantilever-beam based instrument equipped with an in situ near infrared (NIR) spectrometer and a microprobe thermocouple.

Expression analysis of α-smooth muscle actin and tenascin-C in the periodontal ligament under orthodontic loading or in vitro culture.

α-smooth muscle actin (α-SMA) and tenascin-C are stress-induced phenotypic features of myofibroblasts. The expression levels of these two proteins closely correlate with the extracellular mechanical microenvironment. We investigated how the expression of α-SMA and tenascin-C was altered in the periodontal ligament (PDL) under orthodontic loading to indirectly reveal the intrinsic mechanical microenvironment in the PDL.

Morphological characteristics influencing the orthodontic extraction strategies for Angle's class II division 1 malocclusions.

Background: Extraction has now been accepted widely in various malocclusions including Angle's class II division 1. However, the levels of scientific evidence in orthodontic treatment planning have been weak, and it is unlikely to systematically provide a rationale and consistent basis in decisions of extraction. This study was retrospectively designed to investigate the initial morphologic characteristics of class II division 1 subjects involving four different extraction strategies, to determine the relevant influential factors when choosing extraction strategies with the most commonly used mechanics and the principle of simplicity in orthodontic treatment based on cases diagnosed and treated by an experienced orthodontist.