Tooth resorption is an idiopathic dental disease that can be further classified as external root resorption and internal tooth resorption. The predisposing factors are diverse and have not been well explained to date. In the early stages of tooth resorption, there are no characteristic clinical manifestations. As a result, tooth resorption is often detected only after it has caused pulpal symptoms, which makes early diagnosis and intervention difficult. A variety of treatment strategies exist depending on the extent of lesion involvement, and clinicians have been attempting with innovative treatment approaches in recent years, but there is a lack of systematic categorization. This review will focus on the predisposing factors, clinical diagnosis and treatment strategy of tooth resorption.

Objective A sustained release system of titanium dioxide nanotubearray loaded with Ebselen(EB) was constructed on a titanium surface to investigate the kinetics of drug release and its effect on osteoblast behaviors. Methods Titanium dioxide nanotubes(TiO₂ nanotubes, TNT) with length of 2 μm and diameter of 120 nm was prepared on titanium substrate by anodic oxidation, and then EB of different mass was loaded by freeze-drying method. The micromorphology, surface element composition and drug release characteristics of the nanotube orifice were observed and analyzed. MC3T3-E1 osteoblasts were inoculated in different concentrations of EB release solutions, and the optimal loading amount of TNT loaded EB was explored on the basis of micro-nano morphology, osteogenic properties and release kinetic characteristics. Results The selenium element could be detected after loading EB on TNT prepared on pure titanium substrate. When the EB loaded on TNT was less than 5 μg/cm², the TNT array could be completely retained and different amounts of EB could be completely released after 24 h. When the EB concentration was less than 10 μmol/L, the proliferation and osteogenic differentiation activities of MC3T3-E1 were promoted, among which, 5 μmol/L group showed the best effect. Conclusion When the EB loaded on TNT is below 5 μg/cm², the nanotube topological structure remains intact, and the best in vitro osteogenic activity is achieved at the EB concentration of 5 μmol/L.

Objective To compare the effects of different levels of poly(acrylic acid)grafted with N-hydrosuccinimide ester(PAAc-NHS ester)on the mechanical properties and in vitro adhesion properties of PAAc-NHS ester/gelatin composite hydrogels. Methods The PAAc-NHS ester/gelatin composite hydrogels were constructed via ultraviolet cross-linking method and divided into three groups by mass fraction of PAAc-NHS ester:A(10%), B(20%)and C(30%). Scanning electron microscopy(SEM) was used to observe the surface morphology of the composite hydrogels, and Fourier infrared spectroscopy(FT-IR)was used to detect the surface characteristic functional groups of PAAc-NHS ester/gelatin composite hydrogels; mechanical properties of hydrogel were tested by tensile test; the swelling ratio and water retention ratio of the composite hydrogels were calculated and the adhesive properties and cytotoxicity of hydrogels were evaluated. Results SEM results showed that PAAc-NHS ester/gelatin composite hydrogel had porous microstructure, and the pore size decreased with the increase of PAAc-NHS ester content; the FT-IR results showed that PAAc-NHS ester was cross-linked with gelatin in all groups; the tensile results revealed that Group C had the strongest mechanical properties (tensile stress was (140.15±45.24) kPa; elongation at break was (310.19±11.43)%); the swelling and water retention test results showed that group A had the highest water absorption and water retention rates; in vitro adhesion experiments showed that all three groups of PAAc-NHS ester/gelatin composite hydrogels had good adhesion properties in vitro and showed no cytotoxicity. Conclusion All the groups of PAAc-NHS ester/gelatin composite hydrogels have good mechanical properties and adhesion in vitro, and have no cytotoxicity. Therefore, they have the potential to be applied as oral patches.

Objective Finite element analysis was used to study the effect of different implant materials on the stress of ultra-short implants and surrounding bone, in order to lay a theoretical foundation for the application of ultra-short implants in the restoration of mandibular first molars. Methods The mandible model was established by SoildWorks software and the one-step ultra-short implant model was made of three different materials, namely ZrO, Ti-Zr and CFR-PEEK. ABAQUS finite element software was used to simulate the bite force and apply axial load to each model to calculate and analyze the stress distribution of implants and surrounding bone. Results Von-Mises stress values of implants and cortical bone in the CFR-PEEK group were lower than the Ti-Zr and ZrO groups. Conclusion Compared with Ti-Zr and ZrO, CFR-PEEK has more advantages in repairing mandibular first molar area with bone deficiency from the perspective of biomechanics.

Objective To investigate the difference between the efficacy of Nimotuzumab combined with TPF chemotherapy and TPF chemotherapy alone in patients with squamous cell carcinoma of the head and neck, and to briefly discuss the molecular mechanism of interaction between Nimotuzumaband TPF chemotherapy. Methods This study retrospectively collected 62 patients with stage Ⅲ-ⅣA head and neck squamous cell carcinoma in the Stomatological Hospital of Jiangsu Province from 2016 to 2021. Everyone engaged accepted TPF chemotherapy. Thirty patients were given 300 mg dose of Nimotuzumab before the TPF therapy, classified as group A. The rest 32 patients were classified as group B. Tissue wax blocks before and after surgery of patients receiving induction chemotherapy in group B were collected for immunohistochemical staining to observe the expression of EGFR. Results After chemotherapy, the response rate of tumor in group A was 78%, and that in group B was 43%. There was statistically significant difference between the two groups(P<0.05). The five-year overall survival rate of group A and group B was 72.2% and 36.6%, respectively, with statistically significant difference(P<0.05). The progression-free survival rates of group A and group B were 63.8% and 36.2%, respectively. The difference was statistically significant (P<0.05). Immunohistochemical staining showed that the expression of EGFR in group A decreased more significantly than that in group B or Nimotuzumab alone. Conclusion In patients with Ⅲ-ⅣA squamous cell carcinoma of the head and neck, Nimutuzumab combined with TPF chemotherapy provides patients with better efficacy compared with TPF chemotherapy alone. There is probably a synergistic effect between Nimutuzumab and TPF chemotherapy.

Objective To compare the impact between a surgery-first strategy and an orthodontics-first approach on the result and course of therapy in patients with skeletal Class Ⅲ malocclusion. Methods The sample consisted of 24 patients with severe skeletal Class Ⅲ malocclusion, who needed orthognathic surgery. Eleven patients were treated with the surgery-first approach, and 13 patients were treated with the traditional orthodontic-surgical approach. Dolphin Imaging software was used to perform cephalometric analysis on the cone beam computed tomography(CBCT)data that were collected before and after treatment. Results In skeletal Class Ⅲ patients, the overjet and soft-tissue profile were successfully normalized in both of the two groups at high rates. Before and after the treatment, there was no statistically significant difference in indexes between the two groups(P>0.05). In terms of soft and hard tissue changes before and after treatment, there was a statistically significant difference between the orthodontic-first group and the surgery-first group(P<0.05). In addition, the overall treatment duration was much shorter in the surgery-first group((18.86±3.61) months) than in the orthodontic-first group((27.15±5.16)months), with a statistical difference(P<0.001). Conclusion There is no statistically significant difference in soft and hard tissue changes between the surgery-first group and the orthodontic-first group, but there is a significant difference in treatment duration between two groups.

Objective To conduct prospective evaluation of bone volume changes and stability differences between regeneration of peri-implant bone defects guided by soft block-shaped deproteinized inorganic bovine bone containing 10% collagen(DBBM-C) and granular deproteinized inorganic bovine bone(DBBM). Methods Implant surgery was performed on the proposed implant sites(18), which were classified asⅠ-0 by the relationship between the alveolar bone defect and the expected implant placement site. “V” shaped bone dehiscence 5-8 mm occurred on the buccal side after implant placement, and guided bone regeneration(GBR) was done simultaneously, with 10 DBBM-C + collagen membrane(CM) and 8 DBBM+CM. Immediately after surgery, six months after surgery and twelve months after surgery, CBCT was performed and analyzed to measure the horizontal bone thickness(d), 45° bone thickness(d₄₅)and bone height(h) of the labial and buccal side of the implant at cervical level. Results Values of d, d₄₅ and h immediately after surgery were different between the two groups, and the differences were not statistically significant; values of d and d₄₅ in the DBBM-C group were higher than those in the DBBM group at 6 and 12 months postoperatively (P<0.05), and the differences were statistically significant. Differences between groups in h values were not statistically significant. Values of d and d₄₅ changes from the immediate postoperative period to 6 months after surgery were lower in the DBBM-C group, and the differences were statistically significant. The difference in changes of h values between the two groups was not statistically significant; the difference between the two groups was not statistically significant in d, d₄₅ and h change values from 6 months to 12 months after surgery. Conclusion In this study, DBBM-C+CM showed less bone volume change than DBBM+CM in guiding the regeneration of peri-implant bone defects and had better stability.

Objective To compare the esthetics and clinical outcomes in different gingival biotypes between immediate implant placement(IIP) using the conventional flap-less approach and the socket-shield technique(SST). Methods Thirty patients with maxillary anterior tooth and corresponding indications that needed immediate implant and restoration were enrolled. Selected patients(n=30) were randomly allocated to two equal groups for modified immediate implant with SST(n=15) and conventional flap-less immediate implant(n=15). Then according to the visibility of the periodontal probe, the patients were divided into thin gingival and thick gingival biotype. The patients received provisional crown immediately after surgery and definitive restoration 4 months later. Twelve months after the restoration, the patients were revisited for clinical examination. The esthetic outcomes were evaluated by pink esthetic scores(PES) assessment and model analysis including the position of gingival margin and labial contour alternation. Clinical parameters, including the modified sulcus bleeding index(mSBI) was assessed. Postoperative complications and patient satisfaction were also analyzed. Results Twelve months after surgery, all the implants survived. Labial contour alteration were (-0.49±0.18)mm in IIP group and (-0.21±0.18)mm in SST group(P<0.05).For patients with thin gingival biotype, it was (-0.58±0.17)mm in IIP group, and (-0.20±0.19)mm in SST group(P<0.05). The recession of gingival margin reached (-0.76±0.22)mm in IIP group, and (-0.41±0.12)mm in SST group. For patients with thin gingiva, it was (-0.82±0.23)mm in IIP group, and (-0.20±0.19)mm in SST group(P<0.05). PES of IIP group was 10.47±1.15 and SST group was 11.87±0.81. For thin gingival biotype, PES of IIP was 9.78±0.92 and SST was 12.01±0.85 (P<0.05). However. there was no statistical significance for patients with thick gingival biotype. The results of peri-implant exploration showed decreased mSBI values in SST group. Patients in all groups were satisfied with the final esthetic effects. Conclusion SST could significantly improve the esthetic outcome of immediate implant crown by maintaining the contour of alveolar ridge, the gingival margin and the quality of peri-implant tissue, especially for patients with thin gingival biotype.

Objctive To compare the effectiveness of intra-articular injection of hyaluronic acid(HA) combined with splint treatment and mandibular manipulation technique combined with splint treatment for acute temporomandibular joint anterior disc displacement without reduction(ADDWOR). Methods One hundred and eight patients with acute ADDWOR were included. There were 54 cases each in the intra-articular injection of HA combined with splint treatment group and the mandibular manipulation technique combined with splint treatment group. Visual analogue pain score(VAS), maximum mouth opening, maximum anterior and lateral range of motion were recorded before, immediately, 1 week,1 month and 3 months after treatment. Analysis of variance with repeated measurements was used to compare differences within and between the two groups. Results Both groups showed significant improvements in all indicators immediately,1 week, 1 month and 3 months after treatment (P<0.05). The injection combined with splint treatment group showed greater maximum mouth opening, maximum anterior and lateral range of motion than the manipulation combined with splint treatment group immediately, 1 week, 1 month and 3 months after treatment (P<0.05); there was no statistically significant difference in VAS scores between the two groups 1 week, 1 month or 3 months after treatment (P>0.05). Conclusion Both treatment methods improve mandibular function and relieve pain in patients with acute ADDWOR, but intra-articular injection of HA combined with splint treatment is more effective in improving mandibular range of motion.

Objective To describe the CT findings of IgG4-related diseases in head and neck and analyze their imaging characteristics, in order to improve diagnosis of these diseases. Methods A retrospective cohort study was conducted, including 20 patients with IgG4-related diseases who were diagnosed by histopathology in the Department of Oral and Maxillofacial Surgery of the First Hospital of Shanxi Medical University from September 2019 to December 2021. Demographic information and CT data were collected;sites involved, and lesion characteristics were observed. Results A total of 20 patients were included according to the inclusion and exclusion criteria. There were 14 cases of bilateral submandibular gland involvement, 6 cases of unilateral submandibular gland involvement, 8 cases of bilateral parotid gland involvement, 1 case of unilateral parotid gland involvement, 11 cases of lacrimal gland involvement, and only 3 cases of thyroid involvement. Enlarged lymph nodes around the involved glands or neck were observed in 95%(19 cases) of the patients. Under CT, all patients showed different degrees of diffuse enlargement or substantial mass in the affected salivary glands. No cystic lesions and calcifications were found in all the affected glands under CT scan in cases collected. Lacrimal gland involvement is usually manifested as bilateral symmetrical enlargement with uniform density, and enlargement of extraocular muscles and infraorbital nerve can be seen in some patients. Lymphatic involvement manifested as single or multiple enlarged lymph nodes with clear boundaries, without obvious calcification, necrosis and liquefaction. Thyroid involvement manifested as local hypodensity, irregular shape, and poor boundary with the normal gland. In addition, paranasal glands, nasal mucosa and blood vessels were involved in some patients under CT. Conclusion IgG4-related diseases in head and neck have some physical manifestations under CT scan. Accurate identification and judgment of these manifestations can help clinicians improve the diagnosis of IgG4-related diseases in head and neck and reduce the misdiagnosis rate.

Objective To investigate the prevalence and related risk factors of temporomandibular disorders(TMD)in vocal students with questionnaire survey. Methods A total of 407 vocal students were randomly selected, and their years of professional training and weekly practice hours were asked about. Fonseca anamnestic index(FAI)was used to diagnose vocal students to evaluate the prevalence and severity of TMD. The PHQ-4(patient health questionaire-4, PHQ-4) was filled out to evaluate their psychological condition. SPSS 26.0 chi-square test and Logistic binary regression analysis were used to analyze the correlation between TMD and gender, age, professional years, weekly practice time and mental health status. Results The prevalence of TMD in vocal students was 56.8%. There was no statistically significant correlation between the years of professional training and the prevalence of TMD. Female, younger age, longer practice time, and poor mental health were closely related to the incidence of TMD. Conclusion Temporomandibular joint disorder has a high prevalence and causes great harm in vocal students, which seriously affects their career,so it needs to be paid more attention to. As a TMD screening tool, FAI is of great significance for the early diagnosis of TMD. It is necessary to conduct a longitudinal study on vocal students to track the prevalence of TMD and health care needs of TMD patients.

The good alveolar bone shape and sufficient bone mass are of great significance to the success of implantation. Some patients have moderate to severe alveolar bone defect before tooth extraction; thus the alveolar bone could not reach the ideal height and width after socket healing, which increases the difficulty of implantation. Socket preservation, as a common clinical method, can reduce alveolar bone absorption and maintain soft tissue contour. This article will review the research progress of socket preservation in oral implantation.

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease. The existing literature shows that psychological factors are one of the important pathogenic factors. At the same time, OLP is an autoimmune disease caused by immune dysregulation. We suspect that psychological factors may cause immune dysregulation through the chemical reaction of some factors and local immunity in the pathogenesis of OLP. 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter, which can be used as a mediator of bilateral contact between the nervous system and the immune system. 5-HT may activate different signaling pathways through binding with multiple receptors, and it plays an important role in regulating emotion regulation and the proliferation, migration and apoptosis of immune cells. Recent studies have shown that 5-HT may be involved in the occurrence and development of OLP. This paper will review the function of 5-HT and its receptors, their specific expression in autoimmune diseases and their possible roles in OLP.

Poor retention is a common problem after wearing complete dentures. In recent years, denture adhesives have been widely used in oral clinics because they improve denture retention, stability, chewing efficiency and reduce food residues. In this article, the clinical application and research status of denture adhesives are reviewed. The challenges and development of denture adhesives in the future are discussed and prospected.

The naturally occurring curve of Spee in human dentition is crucial for masticatory movement and occlusal balance. Changes in the position and alignment of the patient's teeth during orthodontic treatment involve adjustment of the curve of Spee, and a long-term stable curve of Spee is closely related to the stability of orthodontic treatment. This paper reviews the research progress of the curve of Spee in orthodontics, including the development process, influencing factors, measurement methods, means of leveling, maintenance and recurrence, to provide guidance for future orthodontic clinical diagnosis and treatment of patients with an abnormal curve of Spee.

Caries is a common oral disease that jeopardizes human health. With the improvement of living standards in recent years, people pay more and more attention to oral health care and put forward new requirements for the prevention and treatment of oral diseases. Searching for safer and more effective means of caries prevention and treatment has become a hot spot in research on oral diseases. As a traditional Chinese medicine ingredient, propolis has many functions such as antibacterial, anti-inflammatory, and antioxidant. This article reviews research on propolis' biological activity, biosecurity, dental caries prevention and treatment.

Vertical root fractures(VRFs)are complete or incomplete longitudinal fractures that occur in the root. In recent years, cone beam CT(CBCT)has been widely used in the diagnosis of VRFs because of its extremely high spatial resolution. However, various artifacts may exist on CBCT images, which will affect the performance of CBCT in diagnosing VRFs. In this paper, CBCT artifacts in the diagnosis of VRFs were reviewed, and how to reduce artifacts as much as possible in scanning, and differential diagnosis of artifacts and fracture lines were discussed.

Because of the large number of bone fragments, the obvious displacement of broken ends and the complex anatomical structure, open reduction and internal fixation of complex mandibular fractures are difficult. The traditional operation method relies heavily on operator's experience and is time-consuming and laborious. In recent years, with the development of medical imaging technology and computer technology, digital surgery technology has been gradually applied to all kinds of maxillofacial surgery. Domestic and foreign scholars have also tried to apply it to the restoration of various types of multiple jaw fractures. In this paper, clinical application of 3D simulation technology in the field of complex mandibular fracture, combined rapid prototyping technology, surgical navigation, mixed reality and artificial intelligence are reviewed, and its application is summarized and prospect is analyzed.