Treating dentofacial deformities secondary to condylar resorption is a remarkable clinical challenge. Combined orthodontic treatment and orthognathic surgery is currently the main treatment scheme and is often integrated with temporomandibular joint surgery or conservative treatment according to the severity of condylar resorption. This paper discussed the etiology, clinical features, imaging features, treatment options, and prophylaxis of condylar resorption.

Objective To construct a PA28γ overexpression cell line and determine its effects after infecting an oral squamous cell carcinoma (OSCC) cell line. Methods The PA28γ gene was cloned into the pLOV.CMV.cherry.2A.EF1a.PuroR lentiviral vector by polymerase chain reaction (PCR), and PCR and DNA sequencing alignment analysis were used for identification. Then, 293T cells were used to package viral diseases. Infected OSCC cells were used to construct a cell line with stable PA28γ overexpression. Finally, the level of PA28γ expression in the OSCC cell line was detected through Western blot. Results The successful construction of PA28γ recombinant lentiviral vectors was confirmed by DNA sequencing. The results of immunofluorescence showed that the PA28γ overexpression lentivirus successfully infected the OSCC cells and showed cherry red fluorescence. The results of Western blot demonstrated that the constructed cells with stable PA28γ overexpression significantly increased the expression of PA28γ. Conclusion The PA28γ overexpression lentiviral vector can significantly increase its protein expression in OSCC cells. We provide a stable OSCC cell line for further study on the effect of PA28γ in OSCC.

Objective The expression of microRNA-125b in tongue squamous cell carcinoma (TSCC) was detected and analyzed for its relationship with the clinicopathological features of TSCC. Methods Real time fluorescence-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of microRNA-125b in 35 TSCC tissues and adjacent normal tissues from 35 TSCC cases. The relationship between the expression of microRNA-125b in TSCC tissues and the clinicopathological features of patients with TSCC was analyzed. In situ hybridization (ISH) was used to detect the expression level of microRNA-125b gene in the TSCC tissues and adjacent normal tissues. Results RT-qPCR results showed that the relative expression levels of microRNA-125b in the TSCC issues was 2.32±0.69, and that of normal tissues was 0.87±0.32. The statistical results showed that the expression level of microRNA-125b was significantly higher in the TSCC tissues than in the normal tissues (P<0.001). The expression level of microRNA-125b in the TSCC tissues was not significantly correlated with age, gender, pathological grade, and lymph node metastasis but was positively correlated with TNM stage. Patients with high TNM stage had high microRNA-125b expression levels (P<0.05). The ISH results showed that the expression levels of microRNA-125b in the TSCC tissues were 0.010±0.003, and that of normal tissues was 0.004±0.001. The expression levels of microRNA-125b in the 35 TSCC tissues were significantly higher than those in the normal tissues (P<0.05). Conclusion MicroRNA-125b is highly expressed in TSCC and associated with TNM stage, suggesting that high microRNA-125b expression may be involved in the development of TSCC.

Objective To study the effect of the focal adhesion kinase inhibitor TAE226 on epithelial-mesenchymal transition (EMT) in human oral squamous cell carcinoma (OSCC) cell line. Methods HSC-3 and HSC-4 cells were cultured with TAE226 under different concentrations (0, 1, 5, and 10 μmol·L^-1) for 24, 48, and 72 h. Real-time quantitative polymerase chain reaction was performed to detect the mRNA expressions of E-cadherin and Vimentin. The protein expressions of E-cadherin and Vimentin were determined by Western blot assay after 48 h of TAE226 treatment. Results Real-time quantitative polymerase chain reaction showed that increasing the TAE226 dose and reaction time resulted in increased and decreased E-cadherin and Vimentin mRNA expressions, respectively (P<0.05). Western blot assays showed that increasing the TAE226 dose resulted in increased and decreased E-cadherin and Vimentin protein expressions, respectively (P<0.05). Conclusion TAE226, which is expected to be an effective drug for OSCC treatment, can effectively inhibit the EMT of the OSCC cell line.

Objective Mandibular condyle injury usually results in malocclusion and disharmony of facial growth in growing children. This study aimed to evaluate the long-term effects of autogenous coronoid grafts on the facial growth of children with unilateral temporomandibular joint (TMJ) ankylosis who underwent mandibular condyle reconstruction. Methods Ten growing patients with unilateral bony TMJ ankylosis admitted in West China Hospital of Stomatology, Sichuan University between January 1st, 2008 and December 31st, 2016 were followed up and evaluated. These patients include three males and seven females with ages ranging from 5 years to 12 years at the time of surgery. Each patient underwent gap arthroplasty, condyle reconstruction with ipsilateral coronoid, and interposition of the pedicled temporalis fascial flap in a single operation. The postoperative follow-up ranged from 3 years to 8 years with an average of 4.9 years. Postoperative panoramic radiographs determined the growth of the mandibular height and length on the affected side and compared it with those of the healthy side. Results All patients recovered uneventfully after surgery. At the end of follow-up period, the maximal mouth opening ranged from 32 mm to 41 mm with an average of 35.6 mm. Mandibular height and length continued to grow after the successful treatment of ankylosis using autogenous coronoid grafts for condyle reconstruction. However, growth deficit still existed. The final ramus height and mandibular length of the affected side at the end of follow-up increased by 25.3% (P<0.05) and 26.1% (P<0.05), respectively, compared with the initial values measured immediately after surgery. Growth rates of ramus height and mandibular length of the affected side were 47.1% and 27.2% lower (P<0.05) than those of the healthy side, respectively. Conclusion Mandibular height and length continued to grow after the successful treatment of ankylosis by using autogenous coronoid grafts for condyle reconstruction. However, growth deficit still existed. The growth rate of the affected mandible was reduced compared with that of the undisturbed side even after treatment of ankylosis.

Objective This study aims to investigate the occlusal and myoelectric characteristics of implant-supported fixed denture in the mandibular region and provide reference for the design of fixed restoration. Methods Sixty edentulous patients with implant-supported fixed denture were selected and divided into three groups: group A, 20 cases with implant-supported fixed restoration in the maxillary region; group B, 20 cases with natural dentition, and group C, 20 cases with removable partial denture. The T-scan 8.0 digital occlusion analysis system was used to evaluate the occlusal characteristics of patients in the three groups at intercuspal, protrusion, and left and right lateral positions. Electromyography was used to analyze the myoelectric amplitude and bilateral asymmetry index of the anterior temporalis and masseter of the three groups in different states such as resting and clenching. The relationship between occlusion and myoelectricity was also investigated. Results In the occlusion analysis by T-scan, the occlusion time, the balance of left and right bite force, the left and right asymmetry of the occlusion center, the trajectory of central occlusion force, and the disclusion time were higher in group C than in groups A and B (P<0.05). No significant differences were observed in the anterior and posterior asymmetry of the occlusion center and percentage of bite force at anterior region among the three groups. In the analysis of myoelectricity, the myoelectric amplitude at resting state and the asymmetry index of masticatory muscles in group C were higher than those in groups A and B (P<0.05). The myoelectric amplitude during clenching in groups A and B groups was higher than that in group C (P<0.05). Conclusion In implant-supported fixed restoration at edentulous mandibular, when maxillary includes the removable partial denture, degree of occlusal instability and left and right asymmetry of occlusion center are greater than those with the natural dentition and implant-supported fixed denture at maxillary. The myoelectricity is closely related to occlusion. The removable partial denture can increase the myoelectric activity and reduce the potential of the masticatory muscle. The asymmetry of bilateral myoelectricity is related to the occlusion imbalance.

Objective To propose and evaluate the clinical effect of midpiece facial nerve dissection through transparotid approach in regional parotidectomy. Methods A total of 136 patients with benign parotid tumors were categorized into three groups according to the way of facial nerve dissection: anterograde dissection from main trunk (anterograde, n=70), retrograde dissection from distal branches (retrograde, n=34), and midpiece dissection through transparotid approach (middle dissection, n=32). Surgery duration, facial nerve injury, salivary fistula, earlobe sensation, Frey’s syndrome, and aesthetic evaluation were compared. Results The surgery duration in the middle dissection group was significantly shorter than that in the other two groups. The proportion of salivary fistula was higher in the anterograde group (9 cases, 12.9%; P<0.05) compared with that in the other groups. Postoperative facial nerve injury was similar between the middle dissection (1 case, 3.1%) and anterograde groups (3 cases, 4.3%) with lower injury rate compared with the retrograde group (7 cases, 20.6%). The anterograde group had more cases of hypoesthesia of the earlobe (12 cases, 17.1%; P<0.05) than the other two groups. Aesthetic score was higher in the anterograde and middle dissection groups compared with that in the retrograde group (P<0.05). Conclusion Midpiece facial nerve dissection is technically feasible and clinically viable in regional parotidectomy.

Objective To investigate the status of oral health knowledge, attitude, behavior of 12-15 years old children and provide a theoretical basis of prevention. Methods Multi-stage stratified sampling method was used to extract four middle school students from Chongqing districts and counties (2 in the main urban area and 2 suburbs), and their oral health knowledge, attitudes and behaviors were investigated through questionnaires. All data were entered using Epidata and statistical analysis was performed using SPSS 21.0 software. Results A total of 3 902 valid questionnaires were collected. The proportion of people who had good brushing habits was 39.7% (1 548), the average oral health knowledge accuracy rate was 58.9%, and the average oral health positive attitude was 88.6%. The number of middle school students who attended the dental experience was 54.5% (2 127), and that of the school who received oral health education was 17.5% (681). There were gender and regional differences in brushing habits. Conclusion The knowledge and behavior of oral health among 12-15-year-old middle school students in Chongqing need to be improved. Oral health education for middle school students should be strengthened, especially in rural and suburban areas.

Objective To demonstrate the regularity of velopharyngeal function recovery after primary cleft palatoplasty and its correlation with different surgical procedures, ages, cleft types, and follow-up times. Methods Patients with cleft palate under 5 years old who had more than two follow-up records were included in this study, and consecutive evaluations of postoperative velopharyngeal function were performed. Univariate and multivariate logistic regression analysis were used to reveal the regularity of postoperative velopharyngeal function and the possible influencing factors. Results A total of 165 patients were included. Inconsistent functions of the velopharyngeal closure were observed in 31 patients, of which velopharyngeal insufficiency (VPI) in the first follow-up converted to velopharyngeal competence (VPC) in the second follow-up, accounting for 18.79% of the total, and 134 patients had consistent velopharyngeal function. The patients in the group who had consistent velopharyngeal function were younger than those in the group who were inconsistent, and the differences between the two groups were statistically significant. The younger the operation age, the patient’s velopharyngeal function was more likely to stabilize at the first follow-up. At the time of the first follow-up in 15, 28, and 40 months, the probability that the patients had stable postoperative velopharyngeal function was 80%, 90%, and 95%, respectively. Conclusion The recovery of velopharyngeal function after surgery is a dynamic process. The velopharyngeal status of patients can be converted from VPI to VPC. Meanwhile, VPC cannot switch to VPI. The follow-up time is the most important factor affecting the consistency of the evaluation of velopharyngeal function. Choosing appropriate follow-up time is the key to obtain the stable evaluation of velopharyngeal function.

Objective To investigate the correlation between the clinical diagnostic criteria of sleep bruxism and the frequency of mandibular movements during sleep. Methods Video polysomnography was used to record 20 healthy adults with at least one of the following clinical symptoms and signs: 1) report of frequent tooth grinding; 2) tooth wear and dentin exposure with at least three occlusal surfaces; 3) masticatory muscle symptoms in the morning; 4) masseter muscle hypertrophy. The rhythmic masticatory muscle activity (RMMA) and isolated tonic activity were scored to compare the correlations with clinical symptoms and signs. Finally, the incidence of temporomandibular disorders (TMD) was investigated in patients with isolated tonic and RMMA subjects. Results Among the 20 subjects, RMMA events were observed (5.8±3.1) times·h-1 and isolated tonic episodes were observed (2.1±0.9) times·h-1. The frequency of RMMA events was significantly greater in the patients with acoustic molars than in those without (P<0.05). Similarly, the frequency of RMMA events was significantly greater in the patients with tooth attrition than in those without (P<0.05). However, no difference was observed between the occurrence of RMMA and the symptoms of masticatory muscles or masseter hypertrophy in the morning. The incidence of TMD was significantly higher in the patients with RMMA than in the isolated tonic patients. Conclusion The clinical symptoms and signs often used to diagnose sleep bruxism are different clinical and physiological mandibular movements during sleep. RMMA during sleep can reflect the occurrence of tooth attrition and the high risk of TMD.

Objective To systematically evaluate the repairing effect of stem cells on facial nerve defects. Methods Articles regarding the regenerating effect of stem cells on facial nerves in animals were collected from the databases of Pubmed, Cochrane Library, Web of Science, Embase, Scopus, and CBM. Two professionals independently completed the article screening, data extraction, and bias risk assessment. RevMan 5.3 and random-effects models were used for the statistical analysis, and the results were presented in the form of mean differences (MD) with a 95%CI. The results of functional evaluation (vibrissae movement, facial paralysis) and histological evaluation (density of myelinated fibers, diameter of fibers, thickness of myelin sheath, G ratio) of facial nerve were Meta-analyzed. Results A total of 4 614 articles were retrieved from the 6 databases, and 15 of these articles were included in the Meta-analysis. For vibrissae movement and facial paralysis, the stem cell group scored significantly higher than the non-stem cell group (P<0.05). The density of myelinated fibers and thickness of the myelin sheath in the stem cell group were higher than those in the non-stem cell group (P<0.05). The G ratio in the stem cell group was smaller than that in the non-stem cell group (P=0.001). There was no significant difference in fiber diameter (P=0.08). Conclusion Stem cells have potential in promoting facial nerve regeneration.

Objective To assess the efficacy of bone anchorage and maxillary facemask protraction devices in treating skeletal class Ⅲ malocclusion in adolescents. Methods Articles relating to the use of bone anchorage and maxillary facemask protraction devices for treating skeletal class Ⅲ malocclusion in adolescents were searched from the databases of Cochrane Library, PubMed, EmBase, CNKI, and Wanfang database. Several inclusion and exclusion criteria were developed for the article screening. The clinical data were extracted, and the quality of the selected articles was evaluated. A Meta-analysis of SNA, SNB, ANB, ANS-Me, Wits, and U1-PP change was performed by using RevMan 5.3. Results Seven studies (264 patients) were included in the Meta-analysis. Among these studies, three were randomized controlled trials, and four were non-randomized controlled trials. Compared with the maxillary facemask protraction device group, the bone anchorage device group had higher SNA changes and lower ANS-Me, Wits, and U1-PP changes (P<0.05). No significant differences were observed in the SNB and ANB changes between these two groups. Conclusion Compared with the maxillary facemask protraction device, the bone anchorage device can increase the extent of protraction of the maxilla and has better controls for the labial inclination of the maxillary anterior teeth in treating skeletal class Ⅲ malocclusion among adolescents. However, additional high-quality randomized controlled trials must be performed to verify the results.

Self-healing materials have rapidly developed in recent years to overcome the micro-cracks occurring in the polymer matrix. Self-healing ability offers autonomous crack repairs to prolong the service lives of polymers or polymer composites. As a main approach, extrinsic self-healing materials based on microcapsules have been applied in dentistry recently. This paper comprehensively presented and reviewed the definition and classification of self-healing materials, the synthesis of microcapsules, the calculation of self-healing efficiency, and the application of self-healing materials in dentistry. The future directions of self-healing polymers are also discussed.

The relationship between areca nut as a primary carcinogen and oral cancer has been widely concerned. Areca can change the levels of reactive oxygen species (ROS) and autophagy in cells, and the levels of ROS and autophagy are closely related to the occurrence and development of tumors. This paper reviewed the relationships among areca nut, intracellular ROS, and autophagy.

Vertical bone insufficiency in the maxillary posterior teeth is a common clinical situation. At present, the bone insufficiency in the maxillary posterior teeth is mainly overcome by bone grafting through maxillary sinus floor elevation. Compared with traditional axial implantation, tilted implantation can better avoid bone grafting, reduce complications, shorten the treatment cycle, reduce the treatment cost for patients, and gradually be promoted in clinical settings. This article reviews the concept, biomechanics, clinical evaluation, and digital trend of tilted implants of maxillary posterior teeth.

With the development of industrial robot technology, robotics has entered the medical field, and the research and development of new robots for many medical applications have become a significant research direction in global robotics. Robots are widely used in various aspects of dentistry, such as prosthodontics, orthodontics, implants, endodontics, and oral surgery. This article mainly introduces the application of robots in stomatology from the above five aspects.

Dental implants have become the main choice for patients to fill in their missing teeth. A precise placement is the basis for a functional and aesthetic restoration. A digital surgical guide is a carrier that transfers the preoperative plan of dental implants to the actual surgery. This paper provides some references that can help clinicians improve the accuracy of implant surgery by stating the development, classification, advantages and disadvantages, and factors that affect the accuracy of digital guides.

This article reports a case of an orthodontic adolescent patient without a right inferior incisor. The right lower canine was used as the abutment. The single-retainer all-ceramic resin-bonded fixed partial denture was used to restore the complete dentition. Thus, the missing space was filled, and the function and aesthetics were restored.

Hereditary gingival fibromatosis (HGF) is a familial hereditary disease; while it is rare and usually benign, it is also characterized by the slow and progressive development of gingival tissue. This paper reports on the clinical examination and history of HGF in a family of patients.

Identifying the ideal implantation site is important for the long-term stability and effectiveness of follow-up restorations. Implant surgical guide and navigation are used to determine the implantation site in clinic and improve the precision of implantation. However, due to difficulties in digital methods, such as multiple procedures, high cost, and actual accuracy of more than 1 mm, many physicians still prefer to operate with free hand. In preoperative, intraoperative, and postoperative procedures, time-saving and practical methods for implant site evaluation are lacking. In many cases, oral physicians found that the position deviates only by cone beam CT, which was costly to modify the position. In this article, we presented a precise implantation insertion technology that is guided by a measurable technique throughout the implantation application for all implant systems. This method was guided by a dynamic control measuring ruler, which functions together with the measuring and intraoperative locating rulers. The 3D space of the operative area was measured by a measuring ruler prior to operation, and the implant plan and quantitative guidance design were conducted according to the measured and cone beam CT data. The whole implantation process was guided by the dynamic control measuring ruler, and measuring verification results were also considered. This method can realize the quantification of the entire preoperative space analysis, intraoperative precise implantation guidance, and postoperative site measurement and evaluation. This practical technique also helps to adjust the position, improve the implantation accuracy and is suitable in generalizing dental implantation.