Effect of surgery-first approach on quality of life and mental health of orthognathic patients: A systematic review and meta-analysis.

Objectives: This study intends to explore the effects of the surgery-first approach (SFA) on quality of life and mental health of patients who undergo orthognathic surgery compared to the conventional three-stage approach (CTA). Data: The analysis included eight studies with a total of 307 patients, of which one was randomized controlled trial (RCT), one was clinical controlled trial (CCT), and six were non-randomized studies of interventions (NRSIs). Sources: Electronic databases such as Medline, Embase, Scopus, and Web of Science were searched for eligible trials up to April 2023. Study selection: RCTs, CCTs, and NRSIs, which compared the quality of life or mental health of orthognathic patients treated with SFA and CTA, were included in this study. The meta-analysis showed that the standardized mean differences (SMD) of Oral Health Impact Profiles-14 (OHIP-14) scores and the Orthognathic Quality of Life Questionnaire (OQLQ) between SFA and CTA were -1.58 (P = 0.05) and -2.99 (P < 0.00001) at the termination of the first-stage treatment, which altered to -0.94 (P = 0.54) and 0.09 (P = 0.65) after total treatment. Two studies applied the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) and the Beck Depression Inventory (BDI-II) to examine mental health, resulting in a trend similar to the former scales. Conclusion: In contrast to the conventional procedure, orthognathic treatment with SFA can instantly enhance the quality of life at the end of the first-stage treatment but has similar effects after the overall treatment. Moreover, SFA has a positive impact on psychological conditions. Clinical significance: This study first systematically reviewed the effect of SFA on patients' mental well-being. According to our findings, it is better to select SFA if possible. Otherwise, the patient's psychological condition should be monitored appropriately throughout decompensation for better well-being both physically and mentally.

Two-phase orthodontic treatment of a patient with a low-angle skeletal class II malocclusion: a 7-year follow-up.

Low-angle skeletal class II malocclusions are often observed with sagittal and vertical developmental abnormalities of the mandible. Two-phase orthodontic treatment of functional orthopedic therapy combined with fixed correction is one of the most common methods to treat of skeletal class II malocclusions. This case report describes the two-phase orthodontic treatment of a patient with severe low-angle skeletal class II malocclusion. A Twin Block orthodontic appliance was used to improve mandibular growth, and the adjustment of the occlusal relationship using a fixed appliance after functional therapy. After treatment, a significant improvement was observed in the patient's facial appearance and occlusal relationship. Additionally, a 7-year follow-up confirmed the stability of the treatment results. Although a vertical facial growth direction is difficult to control, the Twin Block orthodontic appliance in adolescents might effectively improve the difference in the sagittal growth of the mandible. Whilst the growth pattern could not be fully controlled, the treatment significantly improved the patient's facial profile and occlusion.

Automated Sagittal Skeletal Classification of Children Based on Deep Learning.

Malocclusions are a type of cranio-maxillofacial growth and developmental deformity that occur with high incidence in children. Therefore, a simple and rapid diagnosis of malocclusions would be of great benefit to our future generation. However, the application of deep learning algorithms to the automatic detection of malocclusions in children has not been reported. Therefore, the aim of this study was to develop a deep learning-based method for automatic classification of the sagittal skeletal pattern in children and to validate its performance. This would be the first step in establishing a decision support system for early orthodontic treatment. In this study, four different state-of-the-art (SOTA) models were trained and compared by using 1613 lateral cephalograms, and the best performance model, Densenet-121, was selected was further subsequent validation. Lateral cephalograms and profile photographs were used as the input for the Densenet-121 model, respectively. The models were optimized using transfer learning and data augmentation techniques, and label distribution learning was introduced during model training to address the inevitable label ambiguity between adjacent classes. Five-fold cross-validation was conducted for a comprehensive evaluation of our method. The sensitivity, specificity, and accuracy of the CNN model based on lateral cephalometric radiographs were 83.99, 92.44, and 90.33%, respectively. The accuracy of the model with profile photographs was 83.39%. The accuracy of both CNN models was improved to 91.28 and 83.98%, respectively, while the overfitting decreased after addition of label distribution learning. Previous studies have been based on adult lateral cephalograms. Therefore, our study is novel in using deep learning network architecture with lateral cephalograms and profile photographs obtained from children in order to obtain a high-precision automatic classification of the sagittal skeletal pattern in children.

Transverse differences between cleft lip and palate and non-cleft palate with skeletal Class III malocclusion using buccolingual inclination: a cone-beam computed tomography retrospective study.

BACKGROUND: The purpose of this study was to evaluate the differences between buccolingual inclination (BI) of maxillary posterior teeth in patients with cleft lip and palate (CLP) and non-cleft palate with skeletal Class III malocclusion. We propose a method of maxillary expansion which is more suitable for patients with CLP. METHODS: For this retrospective study, 40 patients with CLP and 21 patients with skeletal Class III malocclusion were selected. The CLP group was divided into the unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP) groups. The BI of the maxillary first premolar (BI4), maxillary second premolar (BI5) and first molar (BI6) were measured using cone-beam computed tomography, and the differences between them were compared and analyzed by Student's t-test. RESULTS: There were significant differences between cleft side BI4 and non-cleft side BI4 in the UCLP group, BI5 in the BCLP group, BI4 and BI5 in all CLP groups and the skeletal Class III malocclusion group. BI6 was similar across all three groups. CONCLUSIONS: The premolars of patients with CLP do not exhibit the same regularity as those with Class III malocclusion; this may be related to surgical scarring of the cleft palate. Greater attention should be paid to the correction of BI in the maxillary expansion of patients with CLP.

External apical root resorption in orthodontic tooth movement: the risk factors and clinical suggestions from experts' consensus.

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.

Effect of chitosan/inorganic nanomaterial scaffolds on bone regeneration and related influencing factors in animal models: A systematic review.

Bone tissue engineering (BTE) provides a promising alternative for transplanting. Due to biocompatibility and biodegradability, chitosan-based scaffolds have been extensively studied. In recent years, many inorganic nanomaterials have been utilized to modify the performance of chitosan-based materials. In order to ascertain the impact of chitosan/inorganic nanomaterial scaffolds on bone regeneration and related key factors, this study presents a systematic comparison of various scaffolds in the calvarial critical-sized defect (CSD) model. A total of four electronic databases were searched without publication date or language restrictions up to April 2022. The Animal Research Reporting of In Vivo Experiments 2.0 guidelines (ARRIVE 2.0) were used to assess the quality of the included studies. Moreover, the risk of bias (RoB) was evaluated via the Systematic Review Center for Laboratory Animal Experimentation (SYRCLE) tool. After the screening, 22 studies were selected. None of these studies achieved high quality or had a low RoB. In the available studies, scaffolds reconstructed bone defects in radically different extensions. Several significant factors were identified, including baseline characteristics, physicochemical properties of scaffolds, surgery details, and scanning or reconstruction parameters of micro-computed tomography (micro-CT). Further studies should focus on not only improving the osteogenic performance of the scaffolds but also increasing the credibility of studies through rigorous experimental design and normative reports.

iCVM: An Interpretable Deep Learning Model for CVM Assessment Under Label Uncertainty.

The Cervical Vertebral Maturation (CVM) method aims to determine the craniofacial skeletal maturational stage, which is crucial for orthodontic and orthopedic treatment. In this paper, we explore the potential of deep learning for automatic CVM assessment. In particular, we propose a convolutional neural network named iCVM. Based on the residual network, it is specialized for the challenges unique to the task of CVM assessment. 1) To combat overfitting due to limited data size, multiple dropout layers are utilized. 2) To address the inevitable label ambiguity between adjacent maturational stages, we introduce the concept of label distribution learning in the loss function. Besides, we attempt to analyze the regions important for the prediction of the model by using the Grad-CAM technique. The learned strategy shows surprisingly high consistency with the clinical criteria. This indicates that the decisions made by our model are well interpretable, which is critical in evaluation of growth and development in orthodontics. Moreover, to drive future research in the field, we release a new dataset named CVM-900 along with the paper. It contains the cervical part of 900 lateral cephalograms collected from orthodontic patients of different ages and genders. Experimental results show that the proposed approach achieves superior performance on CVM-900 in terms of various evaluation metrics.

Calreticulin silencing inhibits extracellular matrix synthesis of human gingival fibroblasts cultured on three-dimensional poly(lactic-co-glycolic acid) scaffolds by inhibiting the calcineurin/nuclear factor of activated T cells 3 signalling pathway.

BACKGROUND: The retraction and compression of gingival tissue have a significant impact on the efficiency and stability of orthodontic treatment, but the underlying molecular mechanism has not been fully elucidated. The aim of the current study was to investigate the effects of mechanical forces on the expression level of calreticulin (CRT), the activity of the calcineurin (CaN)/nuclear factor of activated T cells (NFAT) 3 signalling pathway, and extracellular matrix (ECM) synthesis in human gingival fibroblasts (HGFs) cultured on three-dimensional (3D) poly(lactic-co-glycolic acid) (PLGA) scaffolds and to further explore the mechanical transduction pathways that may be involved. MATERIALS AND METHODS: A mechanical force of 25 g/cm2 was applied to HGFs for 0, 6, 24, 48, or 72 h. The expression of CRT, CaN, NFAT3, phosphorylated NFAT3 (p-NFAT3) and type I collagen (COL-I) were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting. Subsequently, small interfering RNA (siRNA) was used to knock down the expression of CRT in HGFs, and the impacts of the applied force on the expression levels of CaN, NFAT3, p-NFAT3, and COL-I were also evaluated by RT-qPCR and western blotting. RESULTS: The application of mechanical force on HGFs cultured on 3D PLGA scaffolds led to a significant increases in CRT, CaN, and COL-I expression as well as a decrease in p-NFAT3 expression. However, the effects of mechanical force on CaN, p-NFAT3, and COL-I expression were reversed following downregulation of CRT and displayed a significant decrease in CaN/NFAT3 activity and COL-I synthesis. CONCLUSION: This study showed that the CaN/NFAT3 signalling pathway and CRT appear to be involved in the mechanotransduction of HGFs, and downregulation of CRT inhibits COL-I synthesis potentially via the CaN/NFAT3 signalling pathway. Taken together, these findings ultimately provide novel insight into the mechanisms underlying mechanical force-induced ECM synthesis, which may be conducive to the development of targeted therapeutics to treat fibrotic diseases, including gingival fibrosis caused by orthodontic treatment.

Factors associated with alveolar bone depth mesial to the mandibular third molars after orthodontic protraction.

INTRODUCTION: The objective of this research was to study the factors associated with the alveolar bone depth mesial to the mandibular third molars (M8) after the mandibular second (M7) and third molars were protracted into the space of the mandibular first molars (M6), which were newly extracted for orthodontic treatment or extracted more than 1 year before treatment. METHODS: This retrospective study included 57 adult patients (mean age 23.40 ± 4.40 years) in whom M6 were newly extracted for orthodontic treatment or extracted more than 1 year before treatment. The alveolar bone depth mesial to M8 was measured on posttreatment panoramic radiographs. The vertical, horizontal, and angular changes of M8 were measured on both pre- and posttreatment panoramic radiographs. Linear correlation and regression analyses were conducted to explore the factors associated with the alveolar bone depth mesial to M8. RESULTS: The alveolar bone conditions of M6 (R= -0.391, P <0.001) and the vertical movement directions of M8 (R= -0.433, P <0.001) were significant factors associated with the alveolar bone depth mesial to M8 after orthodontic protraction. CONCLUSIONS: Without considering the pretreatment periodontal status of M8, patients with M6 extracted exceeding 1 year before treatment and with M8 extruded after orthodontic protraction may exhibit deeper alveolar bone depth mesial to M8.

Effects of Smad4 on the expression of caspase­3 and Bcl­2 in human gingival fibroblasts cultured on 3D PLGA scaffolds induced by compressive force.

Human gingival fibroblasts (HGFs) are the main cells that comprise gingival tissue, where they transfer mechanical signals under physiological and pathological conditions. The exact mechanism underlying gingival tissue reconstruction under compressive forces remains unclear. The present study aimed to explore the effects of Smad4, caspase­3 and Bcl­2 on the proliferation of HGFs induced by compressive force. HGFs were cultured on poly(lactide­co­glycolide) (PLGA) scaffolds under an optimal compressive force of 25 g/cm2. Cell viability was determined via Cell Counting Kit­8 assays at 0, 12, 24, 48 and 72 h. The expression levels of Smad4, caspase­3 and Bcl­2 were measured via reverse transcription­quantitative PCR and western blotting. The application of compressive force on HGFs for 24 h resulted in a significant increase in cell proliferation and Bcl­2 expression, but a significant decrease in the expression of Smad4 and caspase­3; however, inverse trends were observed by 72 h. Subsequently, a lentivirus was used to overexpress Smad4 in HGFs, which attenuated the effects of compressive force on HGF proliferation and Bcl­2 expression, but enhanced caspase­3 expression, suggesting that Smad4 may regulate compressive force­induced apoptosis in HGFs. In conclusion, these findings increased understanding regarding the mechanisms of compressive force­induced HGF proliferation and apoptosis, which may provide further insight for improving the efficacy and stability of orthodontic treatment.

A Meta-analysis and Systematic Review Comparing the Effectiveness of Traditional and Virtual Surgical Planning for Orthognathic Surgery: Based on Randomized Clinical Trials.

PURPOSE: To explore the advantages of virtual surgical planning (VSP) and traditional surgical planning (TSP) to determine whether the current VSP technique is superior to the TSP technique for orthognathic surgery. METHODS: An electronic search was carried out in the CENTRAL, PubMed, and Embase databases to identify randomized clinical trials (RCTs) that compared the VSP and TSP techniques regarding their surgical accuracy for hard tissue, prediction precision for soft tissue, required time for planning and surgery, cost and patient-reported outcomes. RESULTS: Eight articles from 5 RCTs, involving 199 patients, were identified. The findings showed that the VSP and TSP techniques were similar in surgical accuracy for hard tissue in the sagittal plane, although the VSP technique was significantly more accurate in certain reference areas, especially in the anterior area of the maxilla. Both the VSP and TSP techniques had significantly better surgical accuracy for the maxilla than for the mandible. The VSP technique showed clinically significantly greater precision for soft tissue prediction in the sagittal plane. Patients who were treated via the VSP technique presented a more symmetrical frontal view, regardless of whether hard or soft tissue was involved. The VSP technique required more time for software planning, but it showed an advantage in time savings when considering the entire preoperative process. Accompanied by the use of an accurate computer-aided splint, the VSP technique could effectively reduce the operative time. Apart from the initial financial investment of software and hardware, the total cost of the VSP technique was similar to that of the TSP technique. Patients who were treated via the VSP or TSP technique showed similar improvements in quality-of-life. CONCLUSIONS: Currently, the VSP technique has become a good alternative to the TSP technique for orthognathic surgery, especially regarding frontal-esthetic considerations. Studies reporting indicators with good representativeness and sensitivity using an identical comparative method are recommended.

Stepwise versus single-step mandibular advancement with functional appliance in treating class II patients : A meta-analysis.

BACKGROUND: Difference in the functional orthopedic effect between stepwise mandibular advancement (SWA) and single-step mandibular advancement (SSA) in Angle class II patients remains unclarified. OBJECTIVE: To compare the treatment effects of SWA and SSA on skeletal and dentoalveolar changes in class II patients. METHODS: Randomized controlled trials (RCTs) and nonrandomized studies that compared differences in skeletal and dentoalveolar effects on class II patients between SWA and SSA were identified in PubMed, Embase, CENTRAL, and Web of Science. The grey literature was also searched. The primary outcomes were the mandibular length, L1-MP, and (ANB). Secondary outcomes included Pog sagittal, SNB, overjet, and mandibular plane angle. RESULTS: Seven studies, including three RCTs and four cohort studies, were retrieved. Meta-analyses revealed pooled mean differences (95% confidence interval) of 0.79 mm (0.45 to 1.12 mm) for Pog sagittal, 0.53° (0.19 to 0.87°) for SNB, -0.51° (-0.83 to -0.20°) for ANB, -0.17° (-0.72 to 0.39°) for the mandibular plane angle, -0.41 mm (-0.90 to 0.09 mm) for overjet, -1.87° (-3.23 to -0.52°) for L1-MP, and 1.03 mm (0.63 to 1.42 mm) for the mandibular length. Publication bias was not observed, except for Pog sagittal. The quality of evidence for each outcome was judged as low (mandibular length, SNB and overjet) and very low (Pog sagittal, ANB, L1-MP and mandibular plane angle). CONCLUSIONS: Although the magnitude of differences in clinical practice was limited, SWA might be more appropriate because it produces a greater skeletal change and less dental compensation than SSA. As the level of current evidence is low, more high-quality RCTs are needed.

Potential Role of Integrin α5ß1/Focal Adhesion Kinase (FAK) and Actin Cytoskeleton in the Mechanotransduction and Response of Human Gingival Fibroblasts Cultured on a 3-Dimension Lactide-Co-Glycolide (3D PLGA) Scaffold.

BACKGROUND The stability of orthodontic treatment is thought to be significantly affected by the compression and retraction of gingival tissues, but the underlying molecular mechanism is not fully elucidated. The objectives of our study were to explore the effects of mechanical force on the ECM-integrin-cytoskeleton linkage response in human gingival fibroblasts (HGFs) cultured on 3-dimension (3D) lactide-co-glycolide (PLGA) biological scaffold and to further study the mechanotransduction pathways that could be involved. MATERIAL AND METHODS A compressive force of 25 g/m² was applied to the HGFs-PLGA 3D co-cultured model. Rhodamine-phalloidin staining was used to evaluate the filamentous actin (F-actin) cytoskeleton. The expression level of type I collagen (COL-1) and the activation of the integrin alpha5ß1/focal adhesion kinase (FAK) signaling pathway were determined by using real-time PCR and Western blotting analysis. The impacts of the applied force on the expression levels of FAK, phosphorylated focal adhesion kinase (p-FAK), and COL-1 were also measured in cells treated with integrin alpha5ß1 inhibitor (Ac-PHSCN-NH 2, ATN-161). RESULTS Mechanical force increased the expression of integrin alpha5ß1, FAK (p-FAK), and COL-1 in HGFs, and induced the formation of stress fibers. Blocking integrin alpha5ß1 reduced the expression of FAK (p-FAK), while the expression of COL-1 was not fully inhibited. CONCLUSIONS The integrin alpha5ß1/FAK signaling pathway and actin cytoskeleton appear to be involved in the mechanotransduction of HGFs. There could be other mechanisms involved in the promotion effect of mechanical force on collagen synthesis in addition to the integrin alpha5ß1 pathway.

Study the predisposing factors of root resorption during orthodontic uprighting treatment of impacted mandibular third molars.

OBJECTIVE: To analyse the amount of root resorption of mesially or horizontally impacted mandibular third molars after orthodontic uprighting treatment. MATERIALS AND METHODS: Twenty-four patients with an age range of 20∼26years old who had mesially/horizontally impacted third molars with complete root formation. And those with decayed or missing the mandibular first molar on the same side were selected. The lower third molars were uprighted and the extraction spaces closed. Root resorption was compared with paired t-test. The related risk factors for root resorption were compared with Pearson correlation analysis. RESULT: The average uprighting time was 10.00 months (4∼16months). The study showed that all the impacted third molars were uprighted and got satisfactory outcomes after treatment. Shortening in length of mandibular third molar roots was detected at the end of the treatment, but no statistically significant differences were found (P<0.05). Root resorption was correlated with the duration of uprighting and the distance that root moved. CONCLUSION: Impacted mandibular third molars were uprighted and the amount of root resorption of third molar after treatment was not increased. The duration of uprighting and the distance that root moved influence the degree of root resorption.

Mechanical force promotes the proliferation and extracellular matrix synthesis of human gingival fibroblasts cultured on 3D PLGA scaffolds via TGF­ß expression.

Human gingival fibroblasts (HGFs) are responsible for connective tissue repair and scarring, and are exposed to mechanical forces under physiological and pathological conditions. The exact mechanisms underlying gingival tissue reconstruction under mechanical forces remain unclear. The present study aimfed to investigate the effects of mechanical forces on the proliferation and extracellular matrix synthesis in HGFs by establishing a 3­dimensional (3D) HGF culture model using poly(lactide­co­glycolide) (PLGA) scaffolds. HGFs were cultured in 3D PLGA scaffolds and a mechanical force of 0, 5, 15, 25 or 35 g/cm2 was applied to HGFs for 24 h. A mechanical force of 25 g/cm2 induced the highest proliferation rate, and thus was selected for subsequent experiments. Cell viability was determined using the MTT assay at 0, 24, 48 and 72 h. The expression levels of type I collagen (COL­1) and matrix metallopeptidase (MMP)­1 were examined by reverse transcription­quantitative polymerase chain reaction and ELISA, and transforming growth factor (TGF)­ß expression was evaluated by ELISA. The application of mechanical force on HGFs cultured on the 3D PLGA scaffolds resulted in a significant increase in cell proliferation and COL­1 expression, as well as a decrease in MMP­1 expression. A TGF­ß1 inhibitor was also applied, which attenuated the effects of mechanical force on HGF proliferation, and COL­1 and MMP­1 expression, thus suggesting that TGF­ß signaling pathways may mediate the mechanical force­induced alterations observed in HGFs. In conclusion, these findings helped to clarify the mechanisms underlying mechanical force­induced HGF proliferation and ECM synthesis, which may promote the development of targeted therapeutics to treat various diseases, including gingival atrophy caused by orthodontic treatment.

[Sequence orthodontic treatment of impacted dilacerated maxillary central incisors].

OBJECTIVE: To explore an effective orthodontic method for treating impacted dilacerated maxillary central incisors. METHODS: 12 impacted teeth of 11 cases were chosen. The position of the impacted teeth and the relations with neighbour tissues were assessed by X-ray images, oral examination and plaster model, etc. The impacted teeth were induced to erupt with the closed-eruption technique and fixed orthodontic appliances, root canal therapy, apicoectomy and prosthetic treatment. RESULTS: 12 impacted teeth were moved into arches, and the occlusal relationship was normal. There were no root resorption or conglutination in those impacted teeth. The labial impacted teeth of nine cases had bigger labial crown torsion. The root apexes of four impacted teeth were palpable under mucosa of the labial sulcus and operated by root canal therapy and apicoectomy. One of them received prosthetic treatment. Others (five cases) hadn't accepted root canal therapy, and were observed temporarily. The effects of two palatal impacted teeth was stable. CONCLUSION: It was a good method to expand indication with sequence orthodontic treatment. The impacted dilacerated maxillary central incisors could be aligned with good esthetical and functional effect.

[Periodontal expression pattern of osteopontin mRNA induced by orthodontic tooth movement in pregnant and non-pregnant rats].

OBJECTIVE: Through orthodontic tooth movement in the pregnant and non-pregnant rats, to investigate the osteopontin (OPN) mRNA expression pattern in the periodontal tissues, and to probe its possible roles in orthodontic periodontal remodeling. METHODS: Fixed appliances were used to mesially move the rats' maxillary first molars. In situ hybridization method was used to detect the expression changes of OPN mRNA in periodontal tissues. RESULTS: Compared to the non-pregnant rats, the expression of OPN mRNA in periodontal cells of the pregnant rats was more intensive. During the gestational period, the expression intensity had significant difference at different pregnant stages. The highest expressions occurred at the mid-pregnant stage, less at the late-stage and lest at the early-stage. CONCLUSION: Under the pregnant state, the expression of OPN mRNA in periodontal tissues may be up-regulated by increased serum progesterone level.