Objective To investigate the correlation between articulation, velopharyngeal function, and surgical age by comparing the changes in articulation after velopharyngeal closure is performed. This study is also conducted to investigate the influencing factors of omission change between pre-and post-operation. Methods A total of 48 patients, including 18 males and 30 females, mean age (13.3±5.8) years, with non-syndromic cleft lips and palates were selected from January 2011 to December 2011. Their speech data and articulation between pre-and post-operation were retrospectively analyzed using non-parametric tests. Correlation study was performed to analyze the influencing factors of the changes in articulation. P<0.05 was considered statistically significant. Results The difference in articulation after velopharyngeal closure occurred was significant (Z=–3.796, P=0.000). A negative correlation between the ratio of post-operative normal articulation and surgical age (R=–0.487, P=0.000) was observed. The change in omission was positively correlated with surgical age (R=0.589, P=0.000) and gender (R=0.404, P=0.047). By comparison, the change in omission was negatively correlated with follow-up time (R=–0.235, P=0.040). Conclusion Articulation and intelligibility are significantly improved after velopharyngeal closure is performed. These parameters are negatively correlated with surgical age to some extent. In addition, the change in omission is positively correlated with surgical age and gender, whereas the change in omission is negatively correlated with follow-up time.

Objective To evaluate the role of the combined periodontic-orthodontic treatment in the esthetic reconstruction of the anterior teeth area following periodontitis. Methods Thirteen adult patients with anterior teeth displacements were treated. The probing pocket depth (PD; 102 teeth, 612 sites), bleeding on probing (102 teeth, 204 sites), papilla index (PI; 128 papillae), and papillary height (PH; 128 papillae) of each patient were assessed at baseline, 3 months after the initial therapy, and the end of the orthodontic treatment. Non-parametric and paired-sample t tests were carried out for the statistical analysis of the data. Results Three months after initial therapy, the sites with PD≤3 mm accounted for 79.58% (487/612) of the observed teeth, and 88.73% (181/204) of the buccal and lingual sites of the teeth showed negative bleeding on probing. These findings were better than those at baseline [26.31% (161/612) and 22.06% (45/204), respectively] (P<0.05), but no significant difference was observed compared with pro-orthodontic treatment (P>0.05). Prior to orthodontic treatment, the levels of the PI of 8 and 21 papillae were Ⅲ and Ⅱ, respectively, among the 128 observed papillae. After the orthodontic treatment, 51 papillae were at level Ⅲ and 68 papillae were at level Ⅱ. The PH of the 102 papillae was 2.84 mm±0.62 mm after orthodontic treatment. This result indicated significant difference compared with that of pre-orthodontic treatment (1.69 mm±0.57 mm) (P<0.05). Conclusion After initial therapy, moderate orthodontic teeth movements may reconstruct the interproximal soft tissue, with esthetic improvement of the papillary level and resolution of the periodontal defects.

Objective This study aims to investigate the expression levels of serum and urinary vascular endothelial growth factor-A (VEGF-A) and epidermal growth factor-like domain 7 (EGFL7) in proliferating infantile hemangioma patients under propranolol treatment. Methods Propranolol (0.5–2 mg•kg−1) was orally administered to 30 infants every day for 4–8 months. The Achauer method was used to measure the tumor radius and thus evaluate the clinical curative effects of the treatment. Enzyme-linked immunosorbent assay was used to measure the serum and urinary concentrations of VEGF-A and EGFL7 at 0, 4, and 12 weeks after the treatment. Results The treatment response was excellent in 2 patients, good in 11, moderate in 14, and poor in 3. Serum VEGF-A (335.692 pg•mL−1±136.146 pg•mL−1) was high before the treatment and then significantly decreased after 4 weeks (264.853 pg•mL−1±122.120 pg•mL−1) and 12 weeks (211.345 pg•mL−1±104.035 pg•mL−1) of treatment (P<0.05). Urinary VEGF-A (76.234 pg•mL−1±24.169 pg•mL−1) was high before the treatment and then significantly decreased after four weeks (56.454 pg•mL−1±16.111 pg•mL−1) and twelve weeks (34.728 pg•mL−1±12.656 pg•mL−1) of treatment (P<0.05). Serum and urinary EGFL7 also decreased after the treatment, showing a positive relationship with VEGF-A. Conclusion Propranolol can be safely and effectively used to treat proliferating infantile hemangiomas. This treatment can reduce the peripheral serum and urinary concentrations of VEGF-A and EGFL7 in affected children.

Objective To investigate the changes on the number and distribution of myoepithelial cells (MECs) during parotid gland regeneration. Methods A total of 54 Wistar rats were divided into eight experimental groups and one normal control group, with six rats in each group. The right parotid ducts of the rats in the experimental groups were ligated for 14 days and then reopened. The parotid tissue specimens were harvested at days 0, 1, 3, 5, 7, 10, 14, and 21. The histological changes of the regenerating gland were examined using hematoxylin–eosin staining. Immunohistochemical labeling was also performed to investigate the changes in the number and distribution of MECs at different time points of parotid regeneration. Both the histological and immunohistochemical changes observed in the experimental groups were compared with those in the normal control group. Results The parotid gland showed marked atrophy 14 days after ligation. Most acinar cells disappeared, but the number of duct-like structures obviously increased. MECs apparently increased in number and were mainly located at the periphery of the duct-like structures. Three days after duct reopening, the number of acinar cells significantly increased and the duct-like structures significantly reduced. Meanwhile, MECs also decreased in number and were mainly located at the periphery of the newly formed acini and duct-like structures. The number of MECs noticeably decreased 3 and 5 days after duct reopening. At 14 days after duct reopening, the glandular structures and the number and distribution of MECs returned to normal compared with those in the normal control group. Conclusion The number and distribution of MECs returned to normal condition after parotid gland atrophy. Parotid regeneration mainly occurred within 5 days after duct reopening.

Objective To photoelastically investigate the difference in load distribution of Tension More (TM) implants with different conical angle designs. Methods The following five groups of implants of different conical angles were designed: cylinder implant, upper 1/3 TM implant (taper length of 3 mm); 1/2 TM implant (taper length of 5 mm); lower 1/3 TM implant (taper length of 7 mm); and bottom TM implant (taper length of 10 mm). The implants were centrally located in individually photoelastic models consisting of a simulated trabecular bone and a 1 mm-thick layer of cortical bone. Vertical and 45° oblique static loads were applied at the center of the superstructures. The resulting stresses were monitored photoelastically and recorded photographically. Results With vertical loading, the cylinder implant showed higher stress levels in the cortical bone and trabecular bone than the upper 1/3 TM implant, 1/2 TM implant, and lower 1/3 TM implant. The four groups of TM implants showed lower stress levels in the cortical bone than the cylinder implant under oblique loads. The least favorable stress concentration in cortical bone was observed in the upper 1/3 TM implant under vertical and oblique loads. Conclusion TM implants of rational conical angle designs seem to be effective in stress distribution. For all designs and load directions, the upper 1/3 TM implant is the most favorable around the crest.

Objective To investigate the changes in the expression of phospholipase C-gammaltyr783 (PLC-γ1tyr783) in the condylar cartilage of a young rat during functional mandibular protraction. This work also explores the function of PLC-γ1tyr783 in the rat mandibular condylar cartilage bone remodeling, which could provide experimental evidence for clinical bone orthopedic work. Methods A total of 60 four-week-old male Sprague–Dawley (SD) rats were used in this study. The rats were divided equally and randomly into experimental group and control group. The functional appliances that were fitted to the upper incisors of the animals in the experimental group were worn 24 h a day after the rats were fed for 7 d with homemade pellet feed. The animals in the experimental group, along with their matched controls, were sacrificed after 1, 3, 7, 14, 21, and 28 d. The bilateral condylar was fixed, decalcified, dehyded, and then conventional paraffin embedded. Immunohistochemistry of PLC-γ1tyr783 was applied to observe its express distribution and variation. Results The expression of PLC-γ1tyr783 decreased gradually in the control group, which showed age-related changes (P>0.05). On the 14th day, PLC-γ1tyr783 expression in the experimental group was significantly higher than that in the control group. PLC-γ1tyr783 expression began to appear statistically and significantly different between the two groups (P<0.01). Conclusion PLC-γ1tyr783 is involved in the bone remodeling process of the rat condylar cartilage after functional mandibular protraction.

Objective To investigate the radiographic features of submandibular sialiths in cone beam CT (CBCT) images. Methods Eighty-four patients with submandibular radiopaque sialiths were included in this study. The clinical features of gender and age and the radiographic features on CBCT, including the number, morphology, size, and location, were recorded for further statistical analysis. Results A total of 128 sialiths were detected from the 84 subjects; 22 subjects (26.19%) had multiple sialiths. The morphology of the sialiths was classified into five types: spot, round, spheroid, elongated, and irregular shapes. Among these types, the spheroid shape was the most frequently detected. A correlation was observed between the size of the sialiths and their location, with the large sialith located at the posterior portion of the duct. About 39.06% (50/128) of sialiths was located at the anterior portion of the duct, and 60.94% (78/128) was located at the posterior portion. The horizontal position of the sialith was significantly correlated with its vertical position (P<0.000 1). Conclusion The CBCT images showed important data for the evaluation, diagnosis, and treatment plan of the submandibular sialolithiasis.

Objective This study aims to identify the crack tip stress intensity factor of the propagation process, crack propagation path, and the changes in the shape of the crack tip by the finite element method. Methods The finite element model of dentino-enamel junction was established with ANSYS software, and the length of the initial crack in the single edge was set to 0.1 mm. The lower end of the sample was fixed. The tensile load of 1 MPa with frequency of 5 Hz was applied to the upper end. The stress intensity factor, deflection angle, and changes in the shape of the crack tip in the crack propagation were calculated by ANSYS. Results The stress intensity factor suddenly and continuously decreased in dentino-enamel junction as the crack extended. A large skewed angle appeared, and the stress on crack tip was reduced. Conclusion The dentino-enamel junction on human teeth may resist crack propagation through stress reduction.

Objective To assess the quality of reporting by randomized controlled trial (RCT) related to dental implants in China during 2000 to 2012 by using the revised Jadad scale and consolidated standards of reporting trials (CONSORT 2010)statement. Methods The following electronic databases were searched: Chinese Biomedical Literature Database, Database for Chinese Technical Periodicals, China National Knowledge Infrastructure, PubMed, and EMBASE. A total of 19 journals of stomatology in China were also searched manually. The qualities of RCT with dental implant published between 2000 and 2012 were assessed using CONSORT(2010)statement and revised Jadad scale. Results Twenty-eight RCTs related to dental implants were identified. The quality of reporting in 28 articles was low. The mean revised Jadad score was 1.29±0.71 and the CONSORT(2010)score was 9.75±3.60. Conclusion The methodological qualities of the included studies on dental implants are generally low, and reporting quality remain unsatisfactory.

Objective To investigate the status of deciduous dental caries among preschool children in Chongqing city and to compare the oral health status of preschoolers from public and private kindergarten. Methods According to the criteria recommended by The Third National Oral Health Investigation, the deciduous caries of 5 030 preschool children aged 3 to 6 years old from 40 private kindergartens and 16 public kindergartens in Yuzhong district of Chongqing were examined. The prevalence of dental caries and the mean dmft and filling rate were calculated. The results were analyzed using SPSS 21.0 software package. Results Maxillary deciduous central incisors and mandibular deciduous molar were most prone to decay in 5 030 children. The prevalence of dental caries was 54.08% (2 720/5 030). The mean dmft score was 2.58 and the filling rate was 0.98% (127/12 993). The prevalence of dental caries and mean dmft increased gradually as the children were growing up (P<0.05). The rate of filling teeth of the 6 year old group was higher than other groups (P<0.05). No significant difference between males and females were noted (P>0.05). The prevalence rate of deciduous dental caries among private kindergartens was 61.04% (1 656/2 713), with a mean dmft of 3.12 and filling rate of 0.35% (30/8 465). The prevalence rate of deciduous dental caries among public kindergartens was 45.92% (1 064/2 317), with a mean dmft of 1.95 and filling rate of 2.14% (97/ 4 528). Statistical analysis revealed significant differences in the prevalence rate, mean dmft, and filling rate between two kinds of kindergarten (P<0.05). Conclusion Deciduous dental caries of preschool children is an important problem in Chongqing city and the children from private kindergarten had very low filling rate.

Objective To seek a new method for reconstructing bilateral internal jugular vein invaded by metastasis lymph node in advanced oral cancer patients. Methods A combination of microvascular anastomosis and longitudinal constriction suture venoplasty was performed to reconstruct internal jugular vein. We resected the part of the bilateral internal jugular vein of advanced oral cancer patients invaded by metastasis lymph node and used the external carotid vein to reconstruct the internal jugular vein. A part of the vessel wall of the internal jugular vein could also be resected to reconstruct the vein. Longitudinal constriction suture venoplasty could slowly narrow the lumen diameter of the internal jugular vein. Thus, difference in anastomosis diameter should be avoided because it generates eddy currents and subsequently causes blood clots. A total of five advanced cases of oral squamous cell carcinoma were involved in this study. We performed bilateral radical neck dissection on all patients to reconstruct the internal jugular vein and observed their postoperative conditions. Results Postoperative follow-up of 5 months to 19 months was performed on all patients. Doppler or CT angiography and related tests showed no internal jugular vein thrombosis. No patient with facial edema, throat swelling, cerebral edema, and high intracranial pressure or other serious complications caused by blocked venous blood was observed. The one-year survival rate of five patients was 60% (3/5). Conclusion Microvascular anastomosis combined with longitudinal constriction suture venoplasty is a new method for reconstructing internal jugular vein. This method was proved successful and clinically feasible.

Objective To assess the temperature variation of the root surface using Nd: YAG laser irradiation in the root canal with different power and to evaluate the safety of laser application on the periodontal region. Methods Thirty extracted human teeth with single-roots were collected. The teeth were cross-sectioned in the cervical portion, standardizing the roots at a 12-mm length. The roots were used as specimen. The roots were radiographed in the buccal-lingual direction to measure the thickness of the proximal walls, by means of a digital radiographic system. The specimens were divided into three groups according to the laser potency (1.5, 3.0, and 4.5 W). Each group was subdivided into two subgroups according to laser frequency (15 and 30 Hz). With the Nd: YAG laser irradiation for 20 s, the temperature variation of the root surface was monitored by thermocouples located at different parts of the root external wall and recorded by digital thermometers. Results The groups irradiated with 4.5 W presented the greatest temperature variation (above 10 ℃), followed by 3.0 and 1.5 W. The temperatures were statistically different (P<0.01). The groups irradiated in the same potency, regardless of whether 15 Hz or 30 Hz was used, presented with no statistical difference (P>0.05). The apical half of the root presented statistically higher temperature rises than the cervical half of the root (P<0.01). Conclusion The temperature variation of the root surface was associated with laser power, irradiation time, and the thickness of dentin. Application of Nd: YAG laser in the root at 1.5 W for 20 s can safely be used in endodontic treatment.

Objective This study aims to observe the effect of orbital implant lengths on stress distribution in peri-implant surfaces. Methods The three-dimensional finite element analysis models of craniofacial and orbital implants with a diameter of 3.75 mm and lengths of 3, 4, 6, and 10 mm were established. A force of 20 N was applied to the models. The stress and displacement distribution under every condition were recorded and analyzed. Results The loading direction along the implant axis and the stress concentration on the implant root were observed. The loading direction was at a 45 degree angle relative to the implant axis, and the stress concentration was located at the implant neck and the first screw thread. The maximum stress of the 3 mm implant was significantly higher than that under the other two loading directions. The maximum displacement of the four lengths exhibited no significant change. Given the same implant length, stress, and displacement, the peak of the implant axial direction was lower than that of the 45 degree direction. The loading type was an important factor influencing the stress and displacement of peri-implant bones. Conclusion The implants of more than 4 mm length can be considered for clinical use. The implant of 3 mm length should be implanted in a region with thicker cortical bone.

Objective We aimed to construct a recombinant adenovirus Ad-APN-EGFP and to evaluate the transfection efficiency and effect of the adenovirus promoting osteogenesis around implants. Methods Recombinant adenovirus Ad-APNEGFP containing adiponectin (APN) was constructed by DNA sequencing and restriction enzyme digestion. Rat bone marrow stem cells (BMSCs) were transfected in vitro. Transfection efficiency and APN mRNA expression were tested. Animal models of rat femoral epiphysis and hydroxyapatite (HA)-coated implants were established. The Ad-APN-EGFP adenovirus at 10 μL was injected into the defect around HA-coated implants in the experimental group, whereas the same volume of phosphate-buffered saline was injected into the defect in the control group. Osteogenesis around implants was observed by hematoxylin–eosin staining four weeks after implantation. Results Ad-APN-EGFP was successfully constructed by DNA sequencing and restriction enzyme digestion. The transfection efficiency of Ad-APN-EGFP to BMSCs was up to ≥90%. APN mRNA expression of BMSCs transfected with Ad-APN-EGFP was higher than that of the control group. Osteogenesis in the experimental group was more evident than that in the control group in vivo. Conclusion Ad-APN-EGFP could be transfected into BMSCs and express APN mRNA at a high level. Ad-APN-EGFP could improve osteogenesis around implants in vivo.

Objective To clone and construct a eukaryotic expression vector of human bone morphogenetic protein (BMP) 2 and histidine in vitro and synthesize chitosan (CS)/pIRES2-EGFP-hBMP2-His nanoparticles. Methods pMD18T-hBMP2-His was digested by EcoRⅠand BamHⅠto obtain the hBMP2-His gene, which was inserted into pIRES2-EGFP to form pIRES2-EGFP-hBMP2-His. Afterward, CS, which exhibited five different molecular weights and deacetylation degrees, was complexed with pIRES2-EGFP-hBMP2-His to form CS/pIRES2-EGFP-hBMP2-His nanoparticles; in this procedure, a desolvent method was used at different N/P ratios (amino in CS to phospho in plasmid DNA). The gene-encapsulating ability of CS was evaluated by agarose gel electrophoresis and fluorescence spectrophotometry; size, distribution, and potential were analyzed using a ZetaPALS analyzer. The shape of the nanoparticles was observed under an atomic force microscope. Results 1) pIRES2-EGFP-hBMP2-His was constructed after the cloned hBMP2-His gene was confirmed by sequencing. 2) CS/pIRES2-EGFP-hBMP2-His nanoparticles were synthesized and pIRES2-EGFP-hBMP2-His was packaged by CS. 3) CS/pIRES2-EGFP-hBMP2-His nanoparticles were globular with an average size of 111.7 nm to 3 214.2 nm and an average zeta-potential of 4.93 mV to 16.79 mV. Conclusion   CS/pIRES2-EGFP-hBMP2-His nanospheres are successfully synthesized.

Objective To investigate in situ visualization using near-infrared quantum dots (QDs) conjugated with arginineglycine-arginineglycine-aspartic acid (RGD) peptide fluorescent probes in oral squamous cell carcinoma (OSCC). Methods QDs with emission wavelength of 800 nm (QD800) were conjugated with RGD peptides to produce QD800-RGD fluorescent probes. Human OSCC cell line BcaCD885 was inoculated in nude mice cheeks to establish OSCC mouse models. Frozen BcaCD885 tumor slices were immunofluorescence double stained by using QD800-RGD and CD105 monoclonal antibody and were observed using a laser scanning confocal microscope. QD800-RGD was injected into the OSCC models through the tail veins, and the in situ visualization was analyzed at different time points. The mice were sacrificed 12 h after injection to isolate tumors for the ex vivo analysis of probe localization in the tumors. Results QD800-RGD specifically targeted the integrin αvβ3 expressed in the endothelial cells of tumor angiogenic vessels in vitro and in vivo, producing clear tumor fluorescence images after intravenous injection. The most complete tumor images with maximal signal-to-noise ratios were observed 0.5 h to 6 h after injection of the probe and significantly reduced 9 h after the injection. However, the tumor image was still clearly visible at 12 h. Conclusion Using intravenously injected QD800-RGD generates high quality OSCC images when integrin αvβ3, which is expressed in the endothelial cells of tumor angiogenic vessels, is used as the target. The technique offers great potential in the diagnosis and individual treatment of OSCC.

Objective   To investigate the expressions of serine-threonine kinase (Akt)/ mammalian target of rapamycin (mTOR)/p70 S6K in oral squamous cell carcinoma (OSCC) and provide references for early diagnosis and prognosis evalua-tion of OSCC. Methods   A total of 51 cases of OSCC, 10 cases of paracancerous mucosa, and 10 cases of normal oral mucosa were collected. The expressions of Akt/mTOR/p70 S6K in these cases were detected using the SP method of immunohisto-chemistry. The correlation between their expressions in OSCC was also analyzed. Results   The positive expressions of p-Akt, p-mTOR, and p70 S6K in OSCC were significantly higher than those in normal oral mucosa and paracancerous mucosa. The expressions of p-Akt, p-mTOR, and p70 S6K in OSCC were not correlated with age, gender, and clinical stage; by comparison, these expressions were correlated with lymph node metastasis and pathological grade. Strong positive correlations were also observed between the expressions of p-Akt, p-mTOR, and p70 S6K in OSCC. Conclusion   Akt/mTOR/p70 S6K signaling molecules exhibit active expressions in OSCC and may be implicated in the occurrence and development of OSCC.

Objective To explore the differentially expressed genes and related signaling pathways in MC3T3-E1 osteoblasts in response to suitable fluid shear stress values and action time with cDNA microarrays. Methods MC3T3-E1 cells cultured on a cover slip were subjected to fluid shear stress using a parallel plate flow chamber. The harvested RNA was used for microarray hybridization comprising approximately 44 170 genes, as well as for the subsequent real-time quantitative polymerase chain reaction validation of expression levels for selected genes. Microarray results were analyzed by using both GO and Pathway analysis. Results Microarray analysis indicated that 884 differentially expressed genes were found. Among these genes, 444 were upregulated, whereas 440 were downregulated. The Notch signal and RIG-Ⅰ-like receptor signaling pathways were involved in the Pathway analysis. GO analysis mainly involved different functional classifications, such as prostaglandin biosynthesis, nitric oxide-mediated signal transduction, calcium mediated signal, and cellular immune response, among others. Conclusion The mechanism underlying the protective effect of fluid shear stress on MC3T3-E1 cells might be related to promoting cell survival-and inhibiting cell apoptosis-related signaling pathways and biological processes.

Objective This study aimed to synthesize a novel nano-antibacterial inorganic filler that contains a quaternary ammonium salt with long chain alkyl and to report the antibacterial property of dental resin composites. Methods A novel nano-antibacterial inorganic filler that contains a quaternary ammonium salt with long chain alkyl was synthesized based on previous research. The antibacterial property of the filler was measured. The surface of the novel nano-antibacterial inorganic filler was modified by a coupling agent to achieve a good interfacial bonding between the filler and the resin matrix. Infrared spectrum analysis was carried out. The modified novel nano-antibacterial inorganic fillers were then incorporated into the dental resin matrix. The dispersion of the fillers was observed and compared with those incorporated into Tetric N-Ceram, a commercial resin composite, under a scanning electron microscope. Streptococcus mutans was used in testing the antibacterial property of the dental resin composites. Results A quaternary ammonium salt with a long chain alkyl was successfully grafted onto the surface of nano-silica particles. The novel nano-antibacterial inorganic filler that contains quaternary ammonium salt with a long chain alkyl showed stronger antibacterial efficacy than the antibacterial inorganic filler that contains quaternary ammonium salt with a short chain alkyl. The modified novel antibacterial inorganic fillers displayed a homogeneous dispersion in the resin composite bulk and combined closely with the resin matrix, similar to the Tetric N-Ceram. The resin com-posites that contain novel antibacterial inorganic fillers showed stronger antibacterial effect on Streptococcus mutans compared with the control group. Conclusion The novel nano-antibacterial inorganic filler that contains a quaternary ammonium salt with long chain alkyl showed a strong antibacterial property. It also exhibited good compatibility with the dental resin matrix after undergoing coupling treatment.

Objective To modify biomacromolecules, such as chitosan and collagen, to synthesize a mineralized template that will induce self-growing remineralization of tooth enamel. Methods Natural polycation polysaccharide chitosan was modified through phosphorylation to synthesize the polyanion derivative of phosphorylated chitosan. Parent hydrogels combined with chitosan and collagen Ⅰ were built through peptide binding reaction using genipin as a crosslinker. The gels selfassembled on the tooth’s inert surface, which was stimulated by ultraviolet radiation. The bionic saliva provided mineralized ion, and then the hydroxyapatite assembled and grew in situ on the tooth. Results The functional group PO43− (3 446 cm−1) was grafted on chitosan as confirmed by the Fourier transform infrared spectroscopy. The porous polyelectrolyte complex hydrogel formed by the interaction between the polycation chitosan and the polyanion phosphorylated chitosan could induce hydroxyapatite crystal nucleation and growth on the hydrogel fiber surfaces. The neonatal crystal was hydroxyapatite as confirmed by X-ray diffraction and was tightly connected to the tooth. A continuous structure of column crystals with sizes ranging from 30 nm to 60 nm was observed. The structure was in parallel direction similar to the direction of the enamel rod, and its hardness was close to dentin. Conclusion The parent hydrogels that were easily obtained and controlled could mimic the template of the enamel mineralization and induce a self-growing hydroxyapatite, which is an important step in the structural bionics of enamel.

Sialolithiasis is a common disease of the salivary gland. This disease mainly involves the major salivary gland. Sialolithiasis of the minor salivary gland is rare. A case of sialolithiasis of the upper lip was reported, and relevant literature was reviewed in this paper.

Considering the World Health Organization’s classification of Helicobacter pylori as a definite (class Ⅰ) carcinogen, the relationship between oral microbial community and tumors is gaining increased interest. This review focused on three relationships between oral microbiota and tumors, i.e., between oral Helicobacter pylori infection and gastric tumors, between oral microbiota and oral squamous cell carcinoma, and between human immunodeficiency virus and tumors. The aims were to realize the early diagnosis of tumors with oral microbiota and support studies on treatment development.