Periodontal tissue, especially the alveolar bone, are closely associated with the progress and efficacy of orthodontic treatment. Prior to and during orthodontic treatment, dentists should fully evaluate the status of periodontal hard tissues to prevent clinical problems. This article aims to discuss bone issues associated with orthodontic treatment, including gingival papilla absence, alveolar bone insufficiency, excessive cortical resistance, and altered passive eruption, etc. The mechanism and prevention methods of these problems are also described.

Objective To investigate the effect of platelet-derived growth factor (PDGF) on nerve regeneration in peri-implant tissues. Methods SD rats with implants in their femurs were injected with PDGF solution. The effects of PDGF on nerve regeneration in peri-implant tissues were analyzed by immunohistochemical staining. Results PDGF increased the number of nerve fibers in peri-implant tissues at early stage. PDGF had no significant effect on the number of nerve fibers in peri-implant tissues at late stage. Moreover, these nerves had a typical structure of peripheral nerve fibers. Conclusion PDGF can promote nerve regeneration in peri-implant tissues at early stage. This study provided a certain experimental basis for the clinical application of PDGF to promote nerve regeneration and further improve the sensory function of the implant.

Objective This study aims to study the expression patterns of ectodysplasin (EDA) and ectodysplasin receptor (EDAR) during the early development of zebrafish and provide a foundation for further research of the Eda signaling pathway in tooth development. Methods Total RNA was extracted from zebrafish embryos at 48 hours postfertilization (hpf) and then reverse transcribed for cDNA library generation. The corresponding RNA polymerase was selected for the synthesis of the digoxin-labeled antisense mRNA probe of zebrafish pharyngeal tooth specific marker dlx2b and Eda signaling-associated genes eda and edar in vitro. The three sequences were ligated into a pGEMT vector with a TA cloning kit, and polymerase chain reaction (PCR) was applied to linearize the plasmid. The resultant PCR sequences were used as templates for synthesizing Dig-labeled mRNA probe dlx2b, eda, and edar. Zebrafish embryos were collected at 36, 48, 56, 60, 72, and 84 hpf, then whole mount in situ hybridization was performed for the detection of eda and edar expression patterns. Then, their expression patterns at 72 hpf were compared with the expression pattern of dlx2b. Results The mRNA antisense probes of dlx2b, eda, and edar were successfully obtained. The positive signals of eda and edar were observed in zebrafish pharyngeal tooth region at 48-72 hpf and thus conform to the signals of dlx2b in the positive regions. Conclusion The ligand eda and edar, which are associated with the Eda signaling pathway, are strongly expressed only at the pharyngeal tooth region in zebrafish from tooth initiation to the morphogenesis stage. Thus, the Eda signaling pathway may be involved in the regulation of the early development of zebrafish pharyngeal teeth.

Objective To observe the effect of Bruton’s tyrosine kinase (BTK) on the proliferation and differentiation of osteoclasts and to explore the mechanism of BTK on bone destruction in periapical periodontitis. Methods After RAW264.7 cells induced with 100 ng·L ^-1 receptor activator for nuclear factor-κB ligand (RANKL) for 5 days, osteoclast induction was confirmed by light microscopy, tartrate-resistant acid phosphatase (TRAP) staining, and quantitative real-time PCR (RT-qPCR). Then, BTK-small interfering RNA (BTK-siRNA) was transfected into cells induced for 5 days. After 24 h, the expression of TRAP mRNA was measured using RT-qPCR, and the proliferation and differentiation of osteoclasts were detected using CCK-8 and TRAP activity assay. Statistical analysis was performed. Results After RAW264.7 was induced with RANKL for 5 days, a large number of round, ellipse, irregularly protuberant, and TRAP-positive macrophages were observed under light microscopy. The expression of TRAP mRNA significantly reduced after 24 h of BTK-siRNA transfection (P<0.05). The detection of CCK-8 and TRAP activities showed that the proliferation and differentiation of osteoclasts significantly decreased (P<0.05). Conclusion Silencing of BTK can inhibit the proliferation and differentiation of osteoclasts. BTK can be used as a new target for the inhibition of osteoclasts.

Objective To evaluate the process characterization of graphene oxide loaded on pure titanium surface and effect on the biological properties of Staphylococcus aureus and osteoblasts. Methods Graphene oxide at four concentrations (20, 50, 80, and 100 μg·mL ^-1) was loaded on the pure titanium surface via electroplating, and the morphology, properties, and hydrophilic properties were measured with a field emission scanning electron microscope, micro Raman spectrometer, and contact angle tester, respectively. In addition, Staphylococcus aureus and osteoblasts were used as models and cultured with pure titanium-graphene oxide. Then, field-emission scanning electron microscopy and laser confocal microscopy were utilized to observe the changes in the amount of bacteria and osteoblast morphology and structure, respectively. Results Graphene oxide at the four concentrations was successfully loaded on pure titanium surface via electroplating. It improved the hydrophilic properties of pure titanium surface, which benefitted the adhesion and growth of Staphylococcus aureus and changed the morphology and structure of the osteoblasts. Conclusion The pure titanium-graphene oxide composite has no antibacterial properties and has good biocompatibility.

Objective This work aims to uncover the promoting effect of 17% ethylenediaminetetraacetic acid (EDTA) irrigation on the dentin adhesion of Enterococcus faecalis (E. faecalis). Methods Forty-eight half split samples and twelve dentin slices were randomly divided into three experimental groups and one control group. The experimental groups and the control group were soaked with EDTA in different time lengths and with normal saline, respectively. E. faecalis was inoculated, and its dentin adhesion was measured via scanning electron microscopy, confocal laser scanning microscopy (CLSM), colony forming unit counts, and histological Gram staining. Results According to histological Gram staining, the depth showed no statistically significant differences between 1 min group and the control group, 1 min group and 3 min groups (P>0.05). E. faecalis intruded in the dentine tubules (measured by CLSM), and the thickness of the biofilm on the dentin surface and the colony numbers of experimental groups were greater than those of the control group (P<0.05). The differences between the three experimental groups were statistically significant (P<0.05). Conclusion EDTA (17%) irrigation can promote E. faecalis adhesion to dentin. This adhesion would in turn prolong EDTA treatment time.

Objective To investigate the effect of the long chain non-coding RNA H19 (lncRNA H19) on the invasion and migration of oral cancer cells and its related molecular mechanism. Methods The expression levels of lncRNA H19, miR-107, and cyclin-dependent kinase 6 (CDK6) in the immortalized oral epithelial cell line HIOEC and the oral cancer cell line CAL27 were detected by real-time quantitative polymerase chain reaction. CAL27 cells were transfected with siRNA H19, miR-107 mimics, pcDNA H19, or anti-miR-107, and the effects of H19 and miR-107 on the invasion and migration of cells were examined via Transwell assay. The TargetScan database predicted the targeting of H19, miR-107, and CDK6. Double luciferase reporter gene assay was performed to detect interactions among H19, miR-107, and CDK6. Western blot analysis was conducted to examine the effects of H19 and miR-107 on the protein level of the target gene CDK6. Results Compared with that in HIOEC cells, the expression of H19 was significantly increased in CAL27 cells (P<0.05). After transfection with siRNA H19, the expression of H19 decreased, and the invasion and migration ability of CAL27 cells were inhibited (P<0.05). H19 could bind specifically to the 3’-UTR of miR-107 to modulate the expression of miR-107. Compared with that in HIOEC cells, the expression of miR-107 significantly decreased in CAL27 cells (P<0.05). The expression of miR-107 increased after transfection with siRNA H19, and anti-mir-107 co-transfection could promote the invasion and migration ability of siRNA H19 in CAL27 cells (P<0.05). Compared with that in HIOEC cells, CDK6 expression significantly increased in CAL27 cells (P<0.05), and the expression level of the gene was co-regulated by H19 and miR-107 (P<0.05). Conclusion lncRNA H19 plays an important role in the development of oral cancer. It can regulate the invasion and migration of oral cancer cells by targeting the miR-107/CDK6 signaling axis.

Objective To evaluate the effect of sandblasting or acid etching on the three-point bending strength to the modified polyetheretherketone (PEEK). Methods Forty-eight bars (15 mm×2 mm×1 mm) of specimens were fabricated from the modified PEEK (BioHPP). They were randomly divided into the following groups: A, B, C and D groups, which were blasted with alumina particles; E, F, and G groups, which were etched with 98% concentrated sulfuric acid; and control group H. The sand blast pressure of groups A, B and C was 0.2 MPa, and the grain sizes of the sand blasted were 120, 50, and 250 μm, respectively. Group D was blasted with 120 μm particle size at 0.7 MPa pressure. Groups E, F and G were acid etched for 60, 120, and 300 s, respectively. No surface treatment was conducted in group H. After all the specimens were processed, one sample was randomly selected from each group to observe its surface morphology under a scanning electron microscope (SEM), and the other specimens were tested for their three-point bending strength. SPSS 22.0 software was used to analyze the experimental data and to test whether the difference was statistically significant. Results SEM observation showed that the surface morphology of the specimen changed after the treatment and revealed different degrees of cracks, pits, or voids. The three-point bending test indicated that the strength of the specimens treated with sandblasting or concentrated sulfuric acid decreased compared with that of the control group (P<0.05). At the same pressure, no significant difference in flexural strength was observed among groups A, B, and C (P>0.05). The strength of group D was lower than that of group A at the same particle size (P<0.05), and no significant difference was found in the bending strength of the specimens etched with concentrated sulfuric acid (P>0.05). Conclusion The bending strength of BioHPP could be significantly decreased by surface sand blasting or concentrated sulfate etching as the sandblasting pressure increased, but the bending strength did not decrease as sand particle size and acid etching time changed.

Objective To study the effects of mouth-breathing on maxillary arch development by comparing the palatal morphology of mouth- and nose-breathing children in mixed dentition. Methods Children in mixed dentition were enrolled and categorized into mouth-breathing (test group) and nose-breathing groups (control group) according to their breathing patterns. Children’s plaster models were scanned with 3D laser scanner, and the 3D data were reconstructed and measured using Minics 15.0 and Geomagic 12.0 software. Measurement data (inter-molar width, palatal height, palatal volume, and palatal surface area) of the two groups were compared, and the correlation among the four measurement items was analyzed. Results The participants were 73 children (37 in test group and 36 in control group) with a mean age of (8.63±0.78) years old. The test group had significantly smaller inter-molar width, palatal volume, and palatal surface area but significantly higher palatal height than the control group (P<0.05). Inter-molar width and palatal volume were positively correlated with the palatal surface area in the test group (P<0.05). Inter-molar width and palatal height were positively correlated with the palatal surface area in the control group (P<0.01). Conclusion Mouth-breathing children have significantly reduced inter-molar width, palatal volume, and surface, and substantially increased palatal height, leading to different developmental patterns of the palatal morphology.

Objective This study aimed to provide foundation for interproximal bone preservation to improve esthetic effects of inter-implant papillar by alveolar ridge preservation following tooth extraction of maxillary single anterior teeth. Methods A total of 30 patients requiring maxillary single anterior teeth extraction were randomly divided into test and control groups (15 cases in each group). The test group underwent alveolar ridge preservation after tooth extraction (Bio-Oss bone powder was implanted in alveolar fossa and fixed with surface free gingival graft suture). No other treatment was performed on the control group after tooth extraction. All patients were scanned using cone beam computed tomography with personalized digital radiographic template at 7 days and 6 months after tooth extraction. Then, measurement of height changes at the interproximal and middle buccal was performed. Results At the mesial and distal interproximal site, ridge height reduction in the test group measured (0.358±0.151) mm, (0.322±0.180) mm, whereas that of control group reached (0.653±0.260) mm, (0.667±0.274) mm, indicating statistical significance (P<0.05). At the middle buccal site, the ridge height reduction of test group amounted to (0.826±0.307) mm, whereas that of control group totaled (1.510±0.625) mm, also presenting statistical significance (P<0.05). Conclusion Alveolar ridge preservation can reduce absorption of alveolar crest height after tooth extraction, which could improve esthetic effects of inter-implant papillae gingiva.

Objective To explore the effect of concentrated growth factors (CGF) on postoperative pain and swelling in patients with complex dental implants. Methods A total of 28 patients with single maxillary anterior teeth loss and labial orbital bone defect were recruited randomly and divided into two groups. Each group included 14 patients. The experimental group was applied with CGF membrane to guide bone regeneration, whereas the control group was treated with collagen membrane to guide bone regeneration. The postoperative pain degree and swelling degree were compared, and data were analyzed with SPSS 23.0 software. Postoperative pain was measured by visual analogue scale (VAS), and the degree of swelling was divided into four grades according to swelling range. Results VAS scores of patients in experimental and control groups reached 35.1±22.5 and 47.0±20.3, respectively. The duration of postoperative pain in experimental and control groups totaled (2.1±1.5) and (2.8±1.0) days, respectively. No statistically significant difference was observed between the two groups (P>0.05). Percentages of non-swelling, mild swelling, moderate swelling, and severe swelling in experimental group reached 21.4%, 57.1%, 21.4%, and 0, respectively, and those in control group were 7.1%, 35.7%, 35.7%, and 21.4%. Swelling duration reached (2.4±1.4) and (4.2±2.2) days in the experimental and control groups, respectively. A statistically significant difference was observed in the swelling degree of experimental and control groups (P<0.05). Conclusion The use of CGF can significantly reduce the degree of postoperative swelling and shorten swelling time but cause no significant effect on pain.

Objective To study the accuracy of 3D printing implant-guided anterior tooth implantation under flap or flapless surgery. Methods Twenty-one cases (32 teeth) with missing teeth were divided into two groups: tooth implantation on the maxillary models under flap surgery (FP group) and tooth implantation on the maxillary models under flapless surgery (FPS group). A dental implant guide was designed and used in the two groups. The actual position of the dental implants in the two groups was compared with the preplanned deviation values of implant top, bottom, vertical distance, and angle deviation. SPSS 19.0 software was used for statistical analysis. Results The deviation values of implant top, bottom, vertical distance, and angle were significantly lower in the FP group than in the FPS group (P<0.05). Conclusion High accuracy of tooth implantation can be realized by using the 3D printing implant guide. The different surgical methods influence the precision of tooth implantation. Clinicians can choose the surgery reasonably depending on the actual situation.

Objective The varying width ratio patterns of posterior hard palate cleft to posterior maxillary tuberosity plane and their relationship with growth and development were studied in specific-age patients with simple cleft palate before surgery to provide a reference for evaluating operation difficulty and predetermining operative period. Methods A total of 581 patients with simple cleft palate who received surgical treatment and are aged 8 months to 38 years participated in this study. All patients were categorized into seven groups based on age at preoperative measurement. The widths of posterior maxillary tuberosity plane and hard palate cleft were selected from the preoperative direct measurements. The relative width ratio of the hard palate to posterior maxillary tuberosity plane in each patient was used to objectively reflect the relative width of cleft palate. Results For patients with simple cleft palate, the widths of posterior maxillary tuberosity plane and hard palate showed remarkably increasing trends. Conclusion The transverse proportion of cleft palate fissure in the upper mandible increases statistically with age, suggesting the need for complex operation.

Objective We aim to determine the thickness of the labial plate, the distance between the cement-enamel junction (CEJ) and alveolar crest, and the inclination angle of the long axis of healthy maxillary anterior teeth by using cone- beam computed tomography (CBCT). Methods A total of 345 CBCT volumes obtained by Newtom VGI ^? CBCT were analyzed by using the NNT software. The digital measurements of the labial bone plate thickness at level 4 mm below the CEJ, the midpoint of tooth root and the radiological tooth apex, the distance between the CEJ and alveolar crest, and the angle between the long axis of the teeth and the long axis of alveolar process were obtained from the mid-sagittal planes of maxillary incisors and canines. Plate thickness 4 mm below the CEJ was measured, and values below ≥1 mm were recorded. Results In the central incisor, 1) the angle between the long axis of the teeth and alveolar bone was 15.2°±6.2°, the distance between the CEJ and alveolar crest was (1.5±1.0) mm, labial bone plate thickness at 4 mm below the CEJ was (0.8±0.4) mm, the midpoint of tooth root was (0.6±0.4) mm, and the radiological tooth apex was (1.3±0.7) mm; in the lateral incisor, 16.2°±8.8°, (1.6±1.0) mm, (0.7±0.5) mm, (0.4±0.6) mm, and (1.1±0.7) mm, respectively; and in the canine, 19.0°±6.2°, (1.8±1.0) mm, (0.9±0.6) mm, (0.4±0.6) mm, and (1.2±0.7) mm, respectively. 2) The frequencies of plate thickness ≥1 mm were 28.3%, 25.8%, and 42.7% in the central incisor, lateral incisor, and canine, respectively. 3) The distance between the CEJ and alveolar crest was positively correlated with age. The correlation coefficients was 0.42 (P<0.01) in the central incisor, 0.50 (P<0.01) in the lateral incisor, and 0.62 (P<0.01) in the canine. Conclusion The thickness of labial bone plate is thin, the distance from CEJ to alveolar crest increases with age, and the long axis of the teeth is more inclined than the long axis of alveolar process. Knowledge of these special morphological characteristics can improve the safety and result for many dental procedures.

Objective To investigate the effect of pre-surgical orthodontic treatment on temporomandibular joint (TMJ) in patients with skeletal class Ⅲ malocclusion treated with orthodontic-orthognathic surgical treatment. Methods Twenty-four patients with skeletal class Ⅲ malocclusion who underwent orthodontic-orthognathic surgical treatment were included in the study. Before and after the completion of orthodontic treatment, the symptoms of TMJ were examined and recorded, and the short- and the long-axis diameter of the condylar (d), condylar height (h), joint space (L) at different angles, bilateral condylar spacing (R), and the condylar angles were measured, with scanning performed by using cone-beam computed tomography (CBCT). Then, the changes of TMJ symptoms and bone structure at different periods were analyzed. Results No significant changes were observed in the joint symptoms before and after the pre-surgical orthodontic treatment. No significant changes were found in the measurements of the bone structure of TMJ in the dimensional direction (P>0.05). Conclusion In the orthodontic-orthognathic surgical treatment procedure, the pre-surgical orthodontic process does not have a significant effect on TMJ.

Periodontitis is a chronic inflammatory disease of periodontal tissues initiated by oral biofilm. Cellular autophagy is an effective weapon against bacterial infection. Recent studies have shown that autophagy not only promotes the removal of bacteria and toxins from infected cells, but also helps to suppress the inflammatory response to maintain the homeostasis of intracellular environment, which is closely related to the development of periodontitis. Here, we reviewed the relationship between autophagy and periodontitis from three aspects: the interactions between autophagy and periodontal pathogen infection, the regulation of autophagy and immune inflammatory responses, and the relationship between autophagy and alveolar bone metabolism. We aim to provide ideas for further study on the mechanisms of autophagy and periodontitis, and ultimately contribute to a better prevention and treatment of periodontitis.

The aging society of the global population has led to an increase in the number of patients with edentulous jaw, a common multiple disease. Given the developments in implant techniques, the method of implant denture has received a positive and good response in terms of the quality of life and psychological well-being of patients. Implant-supported overdenture in mandible has two main advantages. 1) It has better retention and chewing efficiency than those of mandibular conventional denture. The required implant site of implant-supported overdenture is less than that of fixed implant-supported denture and can repair more defect tissues to help restore beauty and pronunciation. The price of the former is more acceptable than that of the latter. Therefore, this article aimed to systemically analyze and further discuss the clinical effect of implant-supported overdenture in elderly patients; combine existing related studies on the selection of number, site, and upper restoration of implants; and illustrate the advantages of removable implant-supported protheses in the repair of toothless mandible.

Acquired immunodeficiency syndrome (AIDS) is an infectious disease caused by human immunodeficiency virus (HIV). The disease is highly infectious, quickly spreads, and has a high fatality rate. Hence, it is a major concern in public health, and an important subject in the prevention and treatment of infectious diseases. The medical staff of stomatological departments, which handle the diagnosis and treatment of oral diseases, are at particularly high risk of occupational exposure to HIV/AIDS. This study summarizes the HIV/AIDS epidemic status, disease transmission routes, oral lesions in HIV/AIDS patients, occupational exposure, and occupational protection in stomatological departments.

With the rapid development of 3D printing, it is widely used in the field of cranio-maxillofacial surgery. Through the individualized production of 3D printing, the backward mode of traditional production relying on manual shaping has been changed to meet the needs of different patients. However, as no clear specification exists for the performance requirements of 3D printing metal powder for cranio-maxillofacial surgery, its long-term development is not feasible. In this paper, the preparation technologies of 3D printing metal powder for cranio-maxillofacial prostheses (i.e., gas atomization, rotating electrode atomization, and radio frequency plasma spheroidization) and 3D printing forming technologies (i.e., selective laser melting, electron beam selective melting, and laser-engineered net shaping) are introduced. The performance requirements of 3D printing metal powder for cranio-maxillofacial prostheses are then summarized according to the characteristics of the preparation and forming technologies described.

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract with a high incidence but a poor therapeutic outcome. However, IBD is generally caused by complicated interactions between environmental factors and gut microflora in genetically susceptible individuals. In view of a series of oral manifestations in patients with IBD and a high detection rate of oral bacteria among this population, oral microbiota may play an important role in the development of IBD. This article reviews the relationship between oral microbiota and IBD.

Negative pressure pulmonary edema is a rare complication of general anesthesia. This paper presents a case of acute negative pressure pulmonary edema that occurred during general anesthesia resuscitation. The patient is a young male that underwent bimaxillary surgery under general anesthesia. Laryngospasm spasm ensued after extubation. The treatment for laryngeal spasm retained the smoothness of the nasopharyngal airway, and the pulse oxygen saturation rapidly decreased after anesthesia resuscitation. Pink foam sputum was sucked out from the cavity due to respiratory shortness from mouth and nose. Highly concentrated oxygen was immediately given to assist ventilation and as a symptomatic support (diuretics, hormones), and the condition evidently improved. The diagnosis and treatment of this case suggest that when acute pulmonary edema occurs during general anesthesia resuscitation, negative pressure pulmonary edema should be highly suspected. The first line of treatment is to relieve respiratory tract obstruction. Supplying highly concentrated oxygen to assist positive pressure ventilation is an effective treatment to alleviate pulmonary edema.

We report a clinical case of type Ⅲ dens invaginatus with endodontic-periodontal lesion in a maxillary lateral incisor. The palatal radicular anomaly predisposed the tooth to periodontal lesions. The caries along the palatal groove caused tooth pulp necrosis and periapical lesions. By means of microscopic root canal therapy, apical surgery, and guided periodontal tissue regeneration, the apical and periodontal infection were controlled, and the affected tooth was retained.