The temporomandibular joint (TMJ) is the critical functional unit in the human stomatognathic system. Damage of the TMJ causes orofacial dysfunction and secondary jaw deformities, leading to seriously decreased quality of life in patients. The TMJ prosthetic replacement is an important treatment method for severe joint destruction because of its remarkable advantages compared with other methods. In recent years, this technique has gradually attracted wide attention in China, but it has not been popularized on a large scale in our country because of several limitations. Thus, in this study, the clinical experience of patients with TMJ prosthetic replacement in clinical units was summarized, and the treatment principles, treatment processes, and technical advantages were systematically discussed, aiming to promote the popularization and application of TMJ prosthetic replacement in China.

Centric relation (CR) was used in the complete dentures for edentulous jaws firstly. Then, CR was gradually applied in the clinical diagnosis and treatment of dentate jaws. Regarding the application of CR in dentate jaws, there are many doubts about its rationality. For instance, should CR be the core of diagnosis and treatment of temporomandibular disorders? Should CR be used as the jaw position of establishing occlusion in occlusal reconstruction? Should CR serve as the target jaw position in orthodontic treatment? Meanwhile, varieties of CR clinical applications are objective. According to the existing evidence, this paper summarizes the applicable conditions of several main clinical situations with little controversy. We preliminarily put forward the decision tree for the clinical application of CR, which can be used as a reference in clinical practice.

Oral cancer represents a serious public health problem affecting oral and system health with a high global incidence. Treatment strategies for oral cancer vary in different disciplines and are likely to be limited to certain doctor’s personal experience. While clinical practice guidelines are considered to enable doctors to determine the most appropriate and consistent treatment strategy according to the patient’s situation. National Comprehensive Cancer Network (NCCN) clinical practice guidelines have become the most prevalent in global clinical oncology practice. This article mainly focuses on cases to discuss the normalized treatment strategy for oral cancer in different stages based on the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines): Head and Neck Cancers, Version 3, 2024.

Objective This study aimed to explore the effects of bone morphogenetic protein 2 (BMP-2) encapsula-ted in poly(lactic-co-glycolic acid) (PLGA) microcapsules with different molecular weights on the osteogenic ability of osteoblasts. Methods PLGA microcapsules with different molecular weights (12 000, 30 000) encapsulating BMP-2, were prepared using a dual-channel microinjection pump. The morphology and structure of the microcapsules were characterized by optical microscopy and scanning electron microscopy. The sustained-release performance of the microcapsules was characterized by phosphate buffered saline immersion method. The cell compatibility of the microcapsules was detected by the Calcein-AM/PI staining and CCK-8 method. The chemotactic effect of BMP-2-encapsulated microcapsules on MC3T3-E1 cells after 48 h of treatment was detected by the Transwell assay. The alkaline phosphatase activity assay and Alizarin Red S staining were used to characterize the effect of microcapsules on the osteogenic ability of MC3T3-E1 cells. Results Both types of microcapsules with different molecular weights exhibited smooth surfaces, as well as uniform and good cell compatibility. The chemotactic effect of the 12 000 microcapsules was outstanding. The 30 000 microcapsules had a longer sustained-release time, and the initial burst release was reduced by approximately 25% compared with the 12 000 microcapsules. In addition, 30 000 microcapsules performed better in long-term osteogenesis induction than 12 000 microcapsules. Conclusion In this study, the release of BMP-2 is regulated by adjusting the molecular weight of PLGA, and the results indicate that 30 000 microcapsules can better induce the long-term osteogenic ability of MC3T3-E1 cells.

Objective This study aimed to identifyPAX9variants in non-syndromic tooth agenesis families of China, as well as to analyze the genotype⁃phenotype of non-syndromic tooth agenesis caused by PAX9variants, which can provide a basis for the genetic diagnosis of tooth agenesis. Methods We collected the data of 44 patients with non-syndromic oligodontia who underwent treatment at Stomatological Hospital of Hebei Medical University between 2018 and 2023. Whole-exome sequencing was performed on the peripheral blood of the proband and its core family members, and the variants were verified by Sanger sequencing. Pathogenicity analysis and function prediction of the variants were performed using bioinformatics tools. The correlation between the genotype of PAX9 variant and its corresponding phenotype was examined by reviewing 55 publications retrieved from PubMed. The studies involved 232 tooth agenesis patients with PAX9 variants. Results A novel PAX9 c.447delG (p.Pro150Argfs*62) and a reported PAX9 c.406C>T (p.Gln136*) were identified in two Chinese families. Through bioinformatics analysis and three-dimensional structural modeling, we postulated that the frameshift variant was pathogenic. The outcome was the premature cessation of PAX9 protein, which caused severe structural and functional deficiencies. Summarizing the PAX9 genotype-phenotype relationship revealed that patients carrying the PAX9 variant commonly led to loss of the second molars. Conclusion We identified the novel PAX9 c.447delG (p.Pro150Argfs*62) in a Chinese family of non-syndromic oligodontia, expanding the known variant spectrum of PAX9. The most susceptible tooth position for PAX9 variants of tooth agenesis was the second molars and the deciduous molars during the deciduous dentition.

Objective This study aimed to investigate the protective effect and mechanism of carvacrol hydrogel on the alveolar bone in rats with periodontitis. Methods A thermosensitive hydrogel supported by carvacrol was prepared using poloxamer and hydroxypropyl methyl cellulose as matrix. SD rats were randomly divided into blank group, periodontitis group, blank hydrogel group, and low-, medium-, and high-dose hydrogel groups. The periodontitis symptoms and the CT structure of the alveolar bone were observed. The changes in liver, spleen, kidney, and periodontal tissues were observed. The related indexes of bone metabolism in serum were detected. The expression of osteoprotegerin (OPG) and nuclear transcription factor-κB (NF-κB) pathway proteins was determined by Western blot. The levels of inflammatory factors were assessed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Results Carvacrol hydrogel had good slow release, biocompatibility, and cell adhesion. The periodontitis of rats in the carvacrol hydrogel group was significantly alleviated, the expression of OPG protein in gingival tissue was significantly increased (P<0.01), and the levels of receptor activator of NF-κB ligand (RANKL), receptor activator of NF-κB (RANK), NF-κB protein, and inflammatory factors were significantly decreased (P<0.01). Conclusion Carvacrol hydrogel can regulate the OPG and NF-κB pathways, reduce alveolar bone absorption, and improve periodontal inflammation.

Objective This study aims to provide craniofacial features and incisor position prediction models among esthetics population after orthodontic treatment. Methods A total of 338 patients with esthetic profiles were selected from 1 055 post-orthodontic adults based on inclusion and exclusion criteria and scored by five dental students. Mean values of cephalometric measurement were demonstrated with gender and sagittal skeletal pattern (ANB) differences assessed by generalized estimating equation. Correlations among age, skeletal, and soft tissue variables in different genders were determined. Multivariate analysis was used to assess the influence of skeletal and soft tissue variables on orthodontic incisor position. Results Within the esthetic cohort after orthodontic treatment, gender differences existed in cranial and mandibular length, mandibular rotation, protrusion of pogonion, inclination of maxillary incisors, upper lip thickness, lower 1/3 face height, and nose protrusion. However, in class Ⅰ malocclusion, the development of the chin showed no significance, whereas the protrusion of the lower lip significantly differed between genders, with less protrusion in males. In males, the protrusion of lip and chin varied among groups, with thinner basic upper lip thickness of class Ⅱ than class Ⅰ and greater lower lip height of class Ⅲ than class Ⅰ. In females, the protrusion and height of the upper lip and chin varied in groups, with thicker basic upper lip thickness of class Ⅲ than class Ⅰ. Upper lip thickness, female basic upper lip thickness, and female lower lip height were correlated with age. The protrusion of the upper lip was mainly correlated with posterior cranial base, mandibular body length, ANB in male and SNA, ANB, sagittal maxillary length, mandibular rotation, and protrusion of pogonion in female. The protrusion of the lower lip in males was mainly correlated with ramus height, mandibular rotation, protrusion of pogonion in male and ANB, mandibular rotation, and protrusion of pogonion in females. After employing skeletal variables to fit dental parameters, optimal results were achieved in male IMPA (adjusted R²=0.712) and female G Vert-U1 (adjusted R²=0.795). After employing skeletal and soft tissue variables simultaneously, optimal results were achieved in male and female G Vert-U1, which was mainly influenced by the protrusion of the chin and nasal base in males (adjusted R²=0.836) and the protrusion of the nasal base as well as ANB in females (adjusted R²=0.842). Conclusion This study demonstrated the craniofacial features of esthetics population after orthodontic treatment and revealed the correlation of gender, age, skeleton, and soft tissues to provide reliable prediction models for aesthetic orthodontic incisor position.

Objective This study aimed to explore the differences and influencing factors of static teeth exposure in different postures of orthognathic surgery patients. Methods A total of 148 patients were collected before or after orthognathic surgery. Photographs were taken in the upright and supine positions, and the static teeth exposure values were measured to compare whether the difference among different positions was statistically significant. The patients were classified in accordance with gender, presence or absence of orthodontic brackets, measurement time (preoperative or postoperative), and maxillary movement direction (forward or backward), and the difference of static teeth exposure was compared. The correlation between the difference of static teeth exposure and age was analyzed. Results The diffe-rence of static teeth exposure between the two positions was 0.99 mm±0.95 mm, which was statistically significant (P=0.000). A statistical difference in the difference of static exposure was observed between female and male (P<0.05). No statistical difference in the difference of static exposure was observed among orthodontic brackets, preoperative or postoperative time points, and maxillary movement direction. In addition, no significant correlation was found between the difference of static teeth exposure and age (r=-0.087, P=0.291). Conclusion Compared with the upright position, the static exposure of teeth increased by approximately 0.99 mm in the supine position. The difference of static exposure under different postures was greater in males than in females. Furthermore, orthodontic bracket, maxillary surgery, maxillary movement direction, and age had no effect on the difference of static teeth exposure in different postures.

Objective This study aimed to explore the effect of surgery combined with bone perforation for treating stage Ⅱ medication-related osteonecrosis of the jaw (MRONJ). Methods A total of 21 patients with stage Ⅱ mandibular MRONJ who underwent surgical treatment from June 2020 to June 2023 were included in this study. Retrospective analysis was conducted on their clinical data, including gender, age, primary disease, drug name and administration method, pre-surgery drug cessation, and prognosis. The cohort comprised 14 males and 7 females, with an average age at onset of 68.33±10.74 years. According to the guidelines of the American Association of Oral and Maxillofacial Surgeons, the included patients had stage Ⅱ mandibular MRONJ. The treatment approach consisted of partial mandibulectomy combined with bone perforation techniques, ensuring tension-free suturing of soft tissues. Follow-up was performed regularly, and the curative effect was evaluated. The SF-12 health survey was used to assess the quality of life for all patients before and after surgery. Results A total of 21 patients were followed up for 8-38 months after surgery, and the mucosal healing of 17 patients was good (80.95%). The postoperative quality of life score (83.62±5.90) was significantly higher than that before operation (63.67±4.70, P<0.05). Conclusion Surgery combined with bone perforation technique is an effective treatment method with high success rate in refractory stage Ⅱ MRONT patients.

Objective This study aims to obtain a three-dimensional reconstruction model based on magnetic resonance imaging (MRI) data of patients with different degrees of unilateral cleft lip and analyze the anatomy and changes in multiple groups of nasolabial muscles under dynamic and static conditions. Methods One normal person and four adult patients with unilateral cleft lip were included, and MRI was performed under static (upper and lower lips closed naturally) and dynamic (pout and grin) conditions. 3D Slicer software was used to reconstruct the model and draw the anatomic morphology of nasolabial muscles. The distance between the junction (where the muscle merges into the orbicularis oris) of the levator muscle, zygomaticminor muscle, and zygomatic major muscle to the median sagittal plane, the starting point to the junction point, the dynamic and static junction points, and the angle between the connection of dynamic and static junctions and the horizontal plane were measured under three kinds of movements, and the ratio was calculated. Results In all patients, under dynamic and static conditions, the distance from the muscle junction to the median sagittal plane, their ratios of the cleft side to the non-cleft side were all greater than 1. While the ratios of the distance from the starting point of the muscle to the junction point were less than 1. At static conditions, the two ratios of the same muscle increased gradiently with the severity of the cleft, and the ratio of the zygomatic minor muscle was prominent in the same patient. The ratio of the cleft side to the non-cleft side was greater than 1, and the value for comparison was the angle of the line from the static to the dynamic junction and the horizontal plane. Conclusion The symmetry of the insertion site of the orbicularis oris and the linear distance of both sides of the muscle are related to muscle and cleft types. The angle of muscle contraction on the cleft side is greater than that on the non-cleft side.

Objective This study aimed to evaluate the thickening of sinus membrane, which is also named Schneiderian membrane (SM), in patients and its relationship with periapical lesions (PAL) in the posterior maxillary region to provide reference for the prevention and treatment of odontogenic maxillary sinusitis. Methods A retrospective analysis was conducted on 554 cone beam computed tomography (CBCT) imaging data of maxillary sinuses from 301 patients who met the inclusion criteria to determine the correlation between PAL and SM thickening in the posterior maxillary region. Cases of pathological SM were recorded and classified on the basis of the degree and type of SM thickening. The correlation between SM thickening and the diameter of PAL, the relationship between the upper edge of PAL and the maxillary sinus floor, and its relationship with whether affected teeth with PAL undergo root canal treatment were evaluated. Results The detection rate of SM thickening in patients with PAL was significantly higher than in those without PAL, so PAL was correlated with SM thickening. Analysis on the correlation between PAL detection indicators and SM thickening degree showed that SM thickening degree was positively correlated with PAL diameter (cone beam computed tomography-periapical index) and not correlated with the three spread effects between the upper edge of PAL and the maxillary sinus floor, as well as whether the teeth with PAL undergo root canal treatment. The correlation analysis between PAL detection indicators and SM thickening types showed that whether the teeth with PAL undergo root canal treatment was not correlated with SM thickening types, and the diameter of PAL, the three spread effects between the upper edge of PAL, and the maxillary sinus floor were not correlated with SM thickening types. Conclusion The PAL of posterior maxillary teeth is closely related to SM thickening, and the diameter of PAL is positively correlated with the degree of SM thickening. Patients with PAL who have undergone root canal treatment often exhibit SM polyp thickening. In addition, the relationship between the upper edge of PAL and the maxillary sinus floor does not affect the possibility of SM development.

Objective This study aimed to estimate the therapeutic effects of preformed metal crown (PMC) and prefabricated zirconia crowns (ZC) on decayed primary morals in children, as well as to analyze the possible influencing factors. Methods A retrospective cohort study was performed on the data of 192 patients (aged 3 to 8) in the Stomatological Department of Shenzhen Children’s Hospital from October 2021 to December 2021. The decayed mandibular first molars were selected and restored by vital-pulp therapy followed by PMC and ZC, including 96 cases (96 caries) in the PMC group and 96 cases (96 caries) in the ZC group. Oral clinical examination was performed at 3 months, 1 year, and 2 years after treatment, overwiewing the clinical therapeutic effects and periodontal status of PMC and ZC groups, as well as recording the crown integrity, gingival index (GI), probing bleeding index (BI), plaque index (PLI) and various prosthetic indices. Results No significance differences existed in the periodontal status of PMC and ZC groups at 3 months, 1 year, and 2 years after treatment (P>0.05). However, the GI, BI, and PLI in the PMC group were higher than those in the ZC group at 3 months, 1 year, and 2 years after treatment, and the difference was dramatically significant (P<0.05). No significances difference existed in various prosthetic indices (P>0.05), as well as in the GI, BI, and PLI, between the two groups (P>0.05). No significant differences existed in various prosthetic indices between genders after PMC restoration (P>0.05). The scores of girls in various prosthetic indices after ZC restoration were higher than those of boys (P<0.05). Pearson correlation analysis indicated an inverse correlation between age in the PMC group and the GI, BI, PLI, and FDI indices (P<0.01), rather than in the ZC group (P>0.05). Conclusion PMC and ZC can be applied to restore deciduous molar caries. The periodontal status of deciduous teeth in ZC group was superior to that in the PMC group. The periodontal status of deciduous teeth in PMC group may be stable with increased age.

Objective This study aimed to evaluate the clinical outcomes of immediate implantation of single maxillary central incisor and explore factors affecting post-implant bone volume. Methods Clinical data and imaging records from pre-surgery, the day of surgery, and 6 months post-surgery of 100 patients (100 implants) with non-salvageable maxillary central incisors who underwent immediate implantation were collected. Bone thickness at the cervical, middle, and apical regions of the implant’s labial and palatal sides were measured immediately post-surgery and at 6 months, and bone volume changes were observed. A regression analysis model was used to assess predictive factors for labial and palatal bone plate thickness. Results At 6 months post-surgery, the labial bone thicknesses at the cervical, middle, and apical regions were 2.35, 2.29, and 3.28 mm, respectively, and those of the palatal side were 0.00, 2.40, and 6.05 mm, respectively. The cervical region had the highest alveolar crest collapse rates, with 32.87% on the labial side and 62.20% on the palatal side. The regression model indicated that factors influencing the thickness of bone at the cervical labial side of the implant included initial bone thickness, the implant center to adjacent tooth center angle, implant diameter, and the type of implant closure (P<0.05). The initial bone thickness on the palatal side was the sole predictor for bone thickness on the palatal side (P<0.05). Conclusion Immediate implantation of single maxillary central incisors yields effective clinical results. The thickness of new bone around the implant is influenced by multiple factors. A comprehensive consideration of these factors in the planning of immediate implantation is necessary to achieve optimal therapeutic outcomes.

Localized juvenile spongiotic gingival hyperplasia (LJSGH) is a kind of gingival hyperplasia with unique pathological manifestations. Its clinical manifestations are atypical, and the etiology and pathogenesis are unclear. No case report was reported in China. The diagnosis of this disease mainly relies on pathological testing, and recurrence may occur after treatment. The best treatment method still lacks medical evidence. This paper reports a case of LJSGH in a teenager and summarizes its clinical, pathological, and treatment through literature review. This work provides a reference for the diagnosis and treatment of this disease.

Rosai-Dorfman disease (RDD) is a rare non-Langerhans cell histiocytosis. The etiology and pathogenesis of RDD have not been fully explained, and its occurrence is even rarer in the maxillofacial region. This paper reported a patient who was first misdiagnosed as facial inflammation caused by oral disease and finally diagnosed as RDD. Clinical features, diagnosis, treatment, and prognosis were discussed based on the literature. This work provides reference for future diagnosis and differentiation of RDD in cheek.

Burkitt lymphoma is a highly aggressive B-cell lymphoma and the fastest proliferating human malignant tumor. If the disease is found in the early stage, the patient could have a high possibility to be cured successfully, whereas the prognosis is poor in the late stage. Burkitt lymphoma can occur in children and adults, and it is categorized as local (Africa), sporadic, and immunodeficiency associated type. Sporadic Burkitt lymphoma mainly affects children and adolescents, and the most common initial sites are abdominal organs and lymph nodes. Sporadic Burkitt lymphoma manifested by initial oral and maxillofacial lesions is relatively rare. Here, a case of pediatric sporadic Burkitt lymphoma, with oral and maxillofacial lesions as the first symptoms, was reported. The patient was treated in the Department of Periodontology, Shandong University School and Hospital of Stomatology. After timely checkup was provided, the patient was transferred to another hospital and had good results. In this article, an incidence of Burkitt lymphoma, with oral and maxillofacial lesions as the first symptom, was reviewed to provide reference for oral clinicians to achieve early diagnosis and treatment of patients with Burkitt lymphoma with oral diseases and improve the success rate of treatment.

Transcrestal maxillary sinus floor elevation is an effective method to solve the problem of insufficient bone height in the posterior maxillary region. However, current methods, such as osteotome sinus floor elevation, cushioned grind-out technique, Smart Drill technique, etc., require specialized surgical tool boxes. In this article, we introduce a new method of transcrestal maxillary sinus elevation that uses built-in reamers of various implant systems to scrap residual bone at the sinus floor and uses the implant to push the sinus membrane during implant placement. This technique is easy to operate and time saving and has a low rate of sinus membrane perforation. After a one-year follow-up observation of 146 people and 175 implants, the endo-sinus bone gains were 5.00 (4.70, 5.30) mm and 2.10 (1.40, 2.70) mm in the group of 3 mm≤residual bone height (RBH)<5 mm and the group of 5 mm≤RBH<8 mm, respectively, which can meet the clinical requirements of implant stability. This technique is suitable in generalizing dental implantation.