Objective To investigate associations between three-dimensional(3D) morphology of cervical vertebrae and skeletal maturation by cone-beam computed tomography(CBCT) and establish corresponding regression models for quantitatively evaluating cervical vertebral maturation(CVM). Methods The analyzed sample consisted of 358 CBCT images (175 male, 183 female), of which 277 images were randomly selected as the model development group and 81 as the performance test group. Twenty-one 3D morphological parameters were defined and measured, incorporating all parts of the cervical vertebrae, including the cervical vertebral bodies, transverse processes, spinous processes, pedicles, lamina, and articular processes. The cervical vertebral maturation index (CVMI) was determined by experienced orthodontists as reference standard. Spearman’s rank correlation coefficient and multivariable stepwise regression analysis were used to identify the associations and build regression models. The performance test group was employed to examine each model’s reliability. Paired-samples Wilcoxon signed-rank test compared the CVMI of the model prediction with the reference standard. Results Three-dimensional morphological changes in various parts of the cervical vertebrae correlated with CVMI (P<0.05). Six 3D morphometric parameters were each recognized for male and female models, three of which were identical. The adjusted R² was 0.899 for males and 0.902 for females, with corresponding accuracies of 85.0% and 85.4%, respectively. These models showed no difference as compared with the reference standard (P>0.05). Conclusion New associations were found between 3D morphology of cervical vertebrae and skeletal maturation. The 3D-driven morphometric CVM assessment method and corresponding regression models exhibited good credibility and high consistency with experts.

Objective To explore an overcorrection quantization method and related influencing factors through analyzing relationships between the achieved and preset intrusion values of mandibular anterior teeth with clear aligners. Methods Twenty patients receiving Invisalign were recruited. The relative intrusion values in the ClinCheck software were recorded as the preset intrusion. The achieved intrusion values were measured through the digital model superimposition. Statistical analysis was conducted to assess the differences and linear relationships between the preset and achieved intrusion values, and investigate the effect of related factors such as intrusion amounts on the intrusion efficiency. Results For the mandibular anterior teeth, the mean intrusion efficiency was 62.2%, with the highest in the central incisors and the lowest in the canines. The intrusion amounts, incisors labial inclinations, and canine attachment types affected the intrusion efficiency. The differences between the preset and achieved values were significant, and the linear relationship existed. The formula of the intrusion overcorrection for the mandibular anterior teeth is “Z=(W-0.110)/0.533-W”. Z represents the overcorrection and W represents the ideal intrusion. Conclusion The preset intrusion values in the treatment protocol could not be fully achieved. Moreover, correction should be designed in cases of mandibular canine intrusion, large amountsof intrusion, orlingually inclined incisors. Compared to the optimized attachments, the vertical rectangular attachments on the mandibular canines could improve the efficiency.

Objective To investigate the effect of different premolar extraction patterns on Bolton index and occlusal relationship of skeletal Class Ⅱ malocclusion. Methods The plaster models of 62 patients with skeletal Class Ⅱ malocclusion were selected and converted into digital models by iTeroElement scanner. Each model was simulated by the four premolar extraction pattrens, and tooth arrangement test was performed after tooth extraction. The Bolton index before and after tooth extraction was calculated, and the occlusal relationship after tooth arrangement was evaluated to explore its law. Results All the four premolar extraction patterns resulted in a significant decrease in the Bolton index over-all ratio in skeletal Class Ⅱ patients, and compared with the extraction patterns of 4/4 and 4/5, the patterns of 5/4 and 5/5 resulted in a greater decrease in the Bolton index over-all ratio(P<0.001). For skeletal class Ⅱ malocclusion, the tooth arrangement test was conducted on the basis of establishing the neutral relationship of first molar. The average value of anterior teeth over-jet obtained by patterns of 4/4 and 4/5 was within the normal range(<3 mm). The average value obtained by patterns of 5/4 and 5/5 was greater than the normal range(>3 mm), and the difference was statistically significant(P<0.001). Conclusion The premolar extraction patterns of 4/4 and 4/5 are more conducive to normalizing the Bolton index over-all ratio and establishing the better occlusal relationship for skeletal Class Ⅱ malocclusion.

Patients with skeletal Class Ⅱ often show symptoms such as protrusion of maxillary anterior teeth, mandibular retraction, open lips and teeth, deep overbite, and deep overjet, which seriously affect the facial appearance. This article reports a case of an adolescent male patient with skeletal Class Ⅱ combined with impacted teeth treated by one-stage early correction and two-stage fixation. After treatment, the patient’s skeletal Class Ⅱ symptoms improved significantly, including the improvement of mandibular retraction. The problem of open lips and teeth was solved; the facial appearance tended to be straight, and there was no obvious abnormality of the temporomandibular joint. This case shows that early correction can achieve good therapeutic effects on this kind of patients and can avoid or reduce the possibility of orthognathic surgery for these patients in adulthood.

Objective To evaluate the inhibitory activity of fluoxetine alone and in combination with fluconazole on Candida albicans. Methods This study used standard strains of Candida albicans, clinical isolates of Candida albicans, and drug-resistant strains of Candida albicans for experiments to prepare the planktonic and biofilm states of Candida albicans, respectively. The effect of fluoxetine on Candida albicans was detected by XTT reduction method. Pharmacodynamic properties of fluoxetine against Candida albicans biofilm were determined by improved time-kill test. The morphological changes of fluoxetine on Candida albicans biofilm were observed by scanning electron microscopy, and the synergistic effect of fluoxetine combined with fluconazole on Candida albicans biofilms was detected by the checkerboard dilution method. Results Fluoxetine had inhibitory effects on three types of Candida albicans biofilms. The minimum drug concentration that inhibited 50% activity (SMIC₅₀) of biofilms of standard strains of Candida albicans and drug-resistant strains was 32 μg/mL; the SMIC₅₀ of clinical strains of Candida albicans biofilm was 64 μg/mL. Time-kill test displayed that the biofilm activity of three types of Candida albicans significantly decreased compared to the control group at the fluoxetine concentration of 1×SMIC₅₀ and 2×SMIC₅₀. Scanning electron microscopy observation showed that compared with the control group, the number of fungal hyphae in the biofilm of Candida albicans treated with fluoxetine decreased and their morphology wrinkled. The checkerboard microdilution method showed that the combination of fluoxetine and fluconazole exhibited a synergistic effect on the standard strain of Candida albicans bioflim, while showing no or antagonistic effects on the other two strains. Conclusion Fluoxetine alone has inhibitory effects on biofilms of different types of Candida albicans and has a synergistic inhibitory effect on biofilms of standard strains of Candida albicans combined with fluconazole.

Objective To investigate the effect of Versican V0/V1 on biological behaviors of mouse dental papilla cells (mDPCs). Methods mDPCs were isolated from C57BL/6J mice at embryonic day 16.5 (E16.5). A small interfering RNA (siRNA) constructed specifically for Versican V0/V1 was transfected into mDPCs.The silencing efficiency was verified by quantitative real-time fluorescence polymerase chain reaction (qRT-PCR) and immunofluorescence staining. The proliferation rate of mDPCs was determined using EdU assay; the migration ability of mDPCs was evaluated by scratch test and transwell assay. Alkaline phosphatase (ALP) staining and alizarin red staining were used to assess the mineralization capability of mDPCs. The molecules related to odontogenic differentiation and mineralization at mRNA levels were measured by qRT-PCR. Results After siRNA transfection,the mDPCs of si-Versican V0/V1 group showed weaker proliferation and migration abilities compared with si-NC group (P<0.01). An enhanced ALP staining intensity,mineralized nodule formation and up-regulations of the molecules related to odontogenic differentiation and mineralization at mRNA levels (P<0.05) were observed in the mDPCs of si-Versican V0/V1 group. Conclusion Versican V0/V1 silencing inhibits the proliferation and migration of mDPCs,but enhances the abilities of odontogenic differentiation and mineralization.

Objective To prepare zinc-loaded polydopamine coating on the surface of pure titaniumand investigate its biocompatibility and corrosion resistance. Methods Pure titanium specimens were successively immersed in a dopamine alkaline solution and a zinc sulfate solution to form a zinc-loaded polydopamine coating on the surface of the specimens. The smooth titanium surface and the polydopamine-coatedtitanium surface were used as the control group, and the zinc-containing polydopamine-coated titanium surface was used as the experimental group. Scanning electron microscopy(SEM) was used to observe the micro-morphology of the specimen surface, and energy dispersive spectrometer(EDS) was used to determine the binding of zinc elements on the polydopamine coating. The hydrophilicity of the specimen surface was detected by a contact angle meter. L-929 fibroblasts were cultured in vitro and the biocompatibility of the modified titanium surface was evaluated by CCK-8 assay. An electrochemical potentiostat was used to obtain the open-circuit potential and potentiodynamic polarization curves of specimens of each group in artificial saliva to analyze the effect of zinc-doped polydopamine coating on the corrosion resistance of titanium surface. Results SEM and EDS analyses showed that there were differences in the surface micro-morphology among three groups, and the presence of zinccould be detected on the surface of the specimens in the zinc-doped polydopamine coating group. The hydrophilicity of the specimen surface was enhanced after coating modification.The results of in vitro experiment revealed that the zinc-doped polydopamine coating had good biocompatibility.The open-circuit potential and potentiodynamic polarization curves obtained from electrochemical tests and their fitting data showed that the zinc-doped polydopamine coating group had the strongest corrosion resistance, followed by the polydopamine coating group, and the smooth titanium group had the smallest. Conclusion Zinc-doped polydopamine coatingscanbe successfully prepared on titanium surfaces usingchemical immersion method, and the modified titanium surfacespossess good biocompatibility and corrosion resistance.

Objective To investigate the effect of medical ozone injection therapy on temporomandibular joint (TMJ) osteoarthritis and its pain in SD rats. Methods Fifity-four rats were randomly assigned according to a random number table into three groups: control group, model group, and medical ozone group, with 18 rats in each group. In the control group, only physiological saline was injected during modeling; in the model group, only sodium iodoacetate was injected for modeling; in the medical ozone group, after injecting sodium iodoacetate into the joint cavity for modeling for one week, medical ozone was then injected into the joint cavity for intervention at a frequency of once a week, totaling 5 times. One week (week 2 after modeling), 3 weeks (week 4 after modeling), and 5 weeks (week 6 after modeling) after medical ozone injections, 6 rats from each group were euthanized. Mechanical withdrawal threshold of rats in each group was assessed before euthanasia, and the expression levels of interleukin-1β (IL-1β) in joint fluid of rats in each group were measured after euthanasia. Gross observation and modified Mankin’s scoring were performed on TMJ cartilage of rats in each group after stained with Pelletier score and Safranin O-Fast Green. Results During the same time period, compared to the control group, the model group showed a significant decrease in the mechanical pain threshold of the TMJ in rats at 1 week, 3 weeks, and 5 weeks (P<0.01). The expression levels of IL-1β in the TMJ fluid increased (P<0.01), and the Pelletier score and modified Mankin’s score of TMJ cartilage increased (P<0.01). In comparison to the model group, the medical ozone group exhibited a significant increase in the mechanical pain threshold of the TMJ in rats after 3 weeks and 5 weeks of medical ozone injections (P<0.01). The expression levels of IL-1β in the TMJ fluid decreased (P<0.01), and the Pelletier score and modified Mankin’s score of TMJ cartilage decreased (P<0.01). However, there were no statistically significant difference in the measured parameters in the TMJ cavity after 1 week of medical ozone injection (P>0.05).Within the medical ozone group, compared to the 1-week treatment, the mechanical pain threshold of the TMJ increased (P<0.01) and the expression levels of IL-1β in the TMJ fluid decreased at 3 weeks and 5 weeks (P<0.01). However, there was no statistically significant difference in the Pelletier score and modified Mankin’s score of TMJ cartilage (P>0.05) between different treatment duration.Additionally, there were no statistically significant differences in the mechanical pain threshold of the TMJ, expression levels of IL-1β in the TMJ fluid, Pelletier score, and modified Mankin’s score of TMJ cartilage between the medical ozone group at 3 weeks and 5 weeks (P>0.05). Conclusion Medical ozone treatment for more than 3 weeks can improve temporomandibular joint osteoarthritis and its associated pain in rats.

Objective By investigating the retention and fatigue performance of polyetheretherketone(PEEK) clasps with increased proportions of clasp arm engaging the undercut, an innovative method to improve PEEK clasps’ performance was proposed and verified. Methods Three groups of PEEK clasps(n=10/group) with the terminal 1/3, 2/3 and whole of their retentive arms engaging the 0.75 mm undercut were designed and fabricated respectively along with a group of cobalt-chrome clasps(n=10) with their terminal 1/3 of retentive arms engaging the 0.25 mm undercut. Retentive forces were recorded initially and every 1 500 cycles for a total of 15 000 insertion and removal fatigue cycles. Optical scanning and software analysis were applied to evaluate the deformation of the clasps by root mean square (RMS) after fatigue test. The inner surface morphology of clasps’ arms was observed by scanning electron microscopy. Results PEEK clasps with the whole of their retentive arms engaging the undercut exhibited highest mean retentive force (9.24±1.78) Namong other PEKK clasps, which was slightly lower than that of cobalt-chrome clasps (11.88±2.05) N. The retentive force of each group turned out to be reduced after fatigue cycles and cobalt-chrome clasps showed the greatest reduction (38.38%). The RMS of the PEEK clasps groups were of no statistical difference (P=0.111) and were lower than that of cobalt-chrome clasps (105.47±10.82) μm. Evidence of surface abrasion was observed on all groups of clasps especially on the section that engaged the undercut. Conclusion Increasing the proportion of PEEK clasp arm engaging the undercut effectively improved the retentive force and satisfied clinical requirements after fatigue cycles. PEEK clasps exhibited greater retention stability than cobalt-chrome clasps. It is feasible to improve the performance of PEEK clasps by increasing the proportion of clasp arm engaging the undercut.

Objective To evaluate the efficacy of selective curettage when apical lesions are adjacent or involved to important structures in endodontic microsurgery (EMS). Methods A total of 264 patients who underwent EMS in the Department of Endodontics, The Affiliated Stomatological Hospital of Nanjing Medical University from January 2021 to January 2023 were selected as the research subjects. The cases of EMS were divided into selective curettage group (SC-EMS) and conventional curettage group (C-EMS). In SC-EMS group, patients with apical lesions involving or adjacent to important structures (mental foramen, mandibular neural tube, nasopalatine neural canal, maxillary sinus, nasal base and adjacent vital pulp teeth) were included, and the adjacent areas around important structures were selectively cureted. In C-EMS group, patients with apical lesions adjacent to important structures were treated with conventional apical curettage. The postoperative follow-up was 12 months, and the postoperative symptoms and imaging examinations of the patients were observed, and the efficacy was evaluated. The failure cases were examined after tooth extraction and preoperative pathological review to analyze the causes of failure. Results The success rate of SC-EMS group is 90.2%, and the success rate of C-EMS group is 95.4%. The rate of success in C-EMS group was higher, but there was no statistical difference between the two groups(P>0.05). Root fracture is the important causes for the failure of the two groups. There were 6 cases of short-term discomfort and 2 cases of long-term discomfort after SC-EMS. The C-EMS group didn’t meet any short-term or long-term discomfort case. Conclusion Selective curettage has no significant effect on the success rate of EMS surgery, and is an effective method to protect important structures during surgery. Short-term discomfort may occur after surgery, and irreversible pulp damage of adjacent teeth occurs in a few cases.

Objective To evaluate the preliminary application effects of digital guide plate in immediate autogenous tooth transplantation. Methods A total of 54 patients who attended the Department of Dental Surgery Clinic, the First Affiliated Hospital of Xinjiang Medical University for autotransplantation from October 2022 to October 2023 were collected, and randomly divided into the experimental group and the control group, with 27 cases in each group. In the control group, conventional autogenous tooth transplantation was carried out. In the experimental group, digital guide technology was added, and the operation time (including the time of extraction of the affected tooth and the donor tooth, the time of alveolar socket preparation, and the time of donor tooth in vitro), the healing of transplanted roots, and the clinical efficacy of transplanted teeth were recorded in the two groups, respectively. Results The average total surgical time, alveolar socket preparation time and the time of donor tooth in vitro of the test group were (23.77±4.32), (6.54±1.77) and (2.80±0.57) min, respectively, which were significantly less than those of the control group (P<0.05); the cervical distance deviation, apical distance deviation, depth deviation and angular deviation of the test group were smaller than those of the control group, and the difference was statistically significant (P<0.05); there was no statistical difference in root healing and clinical efficacy between the two groups (P>0.05); the number of trial implantation of 3D model teeth in the test group was significantly less than that in the control group (P<0.05). Conclusion The digital guide plate can effectively reduce the time for immediate autogenous tooth transplantation, accurately prepare the socket in the recipient area and successfully implant the donor tooth in a single pass, reducing the distance between the actual position and the preoperative design.

Hematological tumor is a kind of tumor caused by abnormal proliferation of hematopoietic stem cells or lymphocytes and granulocytes which are differentiated from hematopoietic stem cells. In addition to abnormal manifestations of the hematopoietic system, hematological tumors can also involve multiple organs such as the skin, oral cavity, viscera and eyes. Among them, oral cavity is one of the most common sites for hematological tumors, and because the oral cavity is located in the anterior part of the digestive tract, it is easier to be found when lesions occur. Therefore, some patients with hematological tumors often complain of oral discomfort and are first diagnosed in the dentistry department. This article reviews the oral manifestations of hematological tumors in order to facilitate the early diagnosis and treatment of hematological tumors and improve the prognosis of patients.

Recent studies have demonstrated that bitter taste receptors are distributed not only in oral cavity but also in non-gustatory systems, such as the respiratory, digestive, reproductive and cardiovascular systems. The physiological role of bitter taste receptors is to recognize bitter substances or bacterial secretions, to trigger the immune response and to maintain the internal environmental homeostasis. In addition, oral bitter taste receptors are expressed not only in taste buds, perceiving bitter taste, but also in many other parts of periodontal tissues, which is the potential treatment target for oral infectious diseases. This review summarized the expression and distribution of oral bitter taste receptors which was off the taste buds and their roles in regulating oral inflammation and oral bacteria, discussed the effects of genetic polymorphism of bitter taste receptor 38 subtype(TAS2R38)on innate immunity and its relationship with the susceptibility of dental caries and periodontal, aimed to provide novel ideas for the better prevention and treatment of dental caries and periodontal diseases.

The accessory parotid gland is a normal salivary gland tissue completely separated from the main parotid gland, which is mostly located in the middle of the face. Any tumor originating from the parotid gland can occur in the accessory parotid gland. Due to the special location of the disease, the diagnosis and treatment of accessory parotid gland tumor is more difficult and more dangerous than that of the parotid gland tumor. This article reviews the anatomy and physiology, clinical diagnosis and treatment of accessory parotid gland tumors, in order to provide guidance for clinical diagnosis and treatment.