Abstract:Objective To study the variety patterns of the midpalatal suture density ratio in children of different ages(6 to 15 years old)and genders to provide reference for clinical diagnosis and the timing of palatal expansion treatment.Methods The clinical and imaging data of 164 children aged 6 to 15 years old who visited the West China Hospital of Stomatology from January to December 2023 were collected and analyzed retrospectively.The three-dimensional model of the maxillary complex was reconstructed using Dolphin Imaging software based on cone beam CT data of children.Soft tissue was filtered out to obtain palatal images.ImageJ software was used to measure the grey density of the middle pala-tal suture and the average grey density of both sides of the palate.The ratio was recorded as the midpalatal suture density ratio,and the differences in the midpalatal suture density ratio in children of different ages and genders were compared.Results The best regression curve between the midpala-tal suture density ratio and age was a fourth power regres-sion curve in male children(R2=0.606,P＜0.001),and a fifth power regression curve in female children(R2=0.591,P＜0.001).The change trend of the midpalatal suture density ratio could be divided into flat,declining and rising periods,the corresponding age groups of male children were 6-10 years old,＞10-13,and＞13-15 years old,and the midpalatal suture density ratio was 0.629±0.065,0.510±0.078,and 0.535±0.042.Except for the comparison between the declining and rising periods,the comparisons of mid-palatal suture density ratio between each two of other periods showed statistically significant differences(P＜0.05 for all);the corresponding age groups of female children were 6-9,＞9-12,and＞12-15 years old,and the midpalatal su-ture density ratio were 0.593±0.062,0.491±0.075,and 0.554±0.061.There were statistical differences in the midpal-atal suture density ratio between each two periods(P＜0.05 for all).Children aged 6-15 were divided into 5 age groups on average.Among them,there were statistically significant differences in the midpalatal suture density ratio in children aged＞7-9,＞9-11,and＞13-15 between different genders(P＜0.05 for all);there were no statistically significant dif-ferences in the midpalatal suture density ratio in children aged 6-7 and＞11-13 between different genders(P＞0.05 for all).Conclusion There are differences in the development process of the midpalatal suture in children between differ-ent genders.The time point of the change in regression curve between the midpalatal suture density ratio and age in the female is about 1 year earlier than that in the male.Based on the research results and clinical experience,the periods of 7-10 years old in the male and 7-9 years old in the female may be a better opportunity for maxillary expansion,which provides some reference for the formulation of clinical personalized correction plans.

Abstract:Peri-implantitis,a prevalent inflammatory complication following dental implant rehabilitation,is patho-logically defined by progressive inflammation of peri-implant soft tissues and bone resorption,severely compromising long-term implant survival.To address this issue,the European Federation of Periodontology(EFP)published the S3-level clinical practice guideline for the prevention and treatment of peri-implant diseases based on evidence-based medicine in June 2023.The guideline deeply explores the surgical treat-ment strategies for peri-implantitis,including preoperative evaluation,surgical modality selection,postoperative manage-ment,and efficacy assessment criteria,thereby offering a sys-tematic and standardized pathway for surgical treatment of peri-implantitis.However,persistent controversies in surgical technique prioritization and heterogeneity in outcome evalua-tion metrics remain unresolved in contemporary practice.This review,drawing on the latest research findings,integrates and interpretes the clinical key points of the guideline,in order to offer a practical reference for the standardized treatment of peri-implantitis.

Abstract:Objective To analyze the economic burden and the regional disparities of deciduous dental caries among 5-year-old Chinese children in 2005 and 2015.Methods The study was conducted at Peking University School of Stoma-tology(Jan.-Apr.2025).Based on data from China's 3rd(2005)and 4th(2015)National Oral Health Epidemiological Surveys(5-year-old group),the demographic and economic data of China Statistical Yearbooks in 2005 and 2015,the current medical service pricing regulations issued by the medical security bureaus of provinces,autonomous regions and municipalities and the guidelines for the initiation of dental medical service price projects(Trial)issued by the National Medical Security Bureau in March 2025,and World Bank open data,the direct economic burden calculation model was established by setting Low-Cost Treatment Plan(LCTP)and Medium-to-High-Cost Treatment Plan(MHCTP)via unit-cost approach,while indirect economic burden calculation model was established using human capital approach,in order to quantify the economic burden and regional dispar-ities caused by untreated deciduous caries.Results The total direct economic burden of deciduous dental caries among 5-year-old children was approximately ¥4.62 bil-lion in 2005 and ¥4.63 billion in 2015 based on the LCTP.Based on the MHCTP,the total direct economic burden remained at approximately ¥6.23 billion for both years.The indirect economic burden increased from ¥1.97 billion in 2005 to ¥4.44 billion in 2015.Notably,central/western/re-mote regions exhibited higher per-capita direct burdens and there was significant indirect burden growth,and most rural children faced heavier direct burdens than urban counterparts.Conclusion The total economic burden of deciduous dental caries among 5-year-old children in China in 2005 and 2015 remains enormous.Children in the central and west-ern regions,remote areas and rural areas face greater economic burden challenges.

Abstract:Peri-implantitis is one of the primary causes of implant failure,and non-surgical treatment plays a crucial role in the early intervention and control of the disease.The S3-level clinical practice guideline issued by the European Federation of Periodontology provides clear evidence-based recommendations and standardized protocols for the non-sur-gical treatment of peri-implantitis.This article systematically interprets the core content of the guideline,focusing on treat-ment objectives,mechanical debridement,biofilm manage-ment,risk factor control,and evaluation criteria for treatment outcome.It emphasizes the evidence-based support of various treatment measures and their clinical application values.By thoroughly analyzing the guideline,this article aims to assist implantologists in comprehensively understanding the key as-pects of implementing non-surgical treatment and to improve their operational standardization and the therapeutic outcomes in clinical practice.

Abstract:Objective To evaluate changes in clinical parameters of mechanical debridement with Nd:YAG laser thera-py for peri-implantitis.Methods A randomized controlled clinical trial was conducted,enrolling 22 patients(22 im-plants)with peri-implantitis who visited the Department of Periodontology at Peking University Hospital of Stomatology between July 2024 and January 2025.The patients were randomly allocated into two groups:the test group(n=11,11 im-plants),treated with titanium curette debridement combined with Nd:YAG laser,and the control group(n=11,11 im-plants),treated with titanium curette debridement alone.Clinical examinations were performed at baseline(pre-treatment)and 3 months after treatment,recording peri-implant probing depth(PPD),modified sulcus bleeding index(mSBI),and modified plaque index(mPLI)at six sites of each implant(buccal/facial and palatal/lingual sides,including mesial,middle,and distal sites).The mean PPD,deepest PPD(dPPD),maximum mSBI,and maximum mPLI,as well as the percentages of sites with PPD ≥ 5 mm and ≥ 7 mm were compared between the two groups.Results At baseline,no statistically significant differences were observed between the two groups in mean PPD,dPPD,mSBI,mPLI,or the percentages of sites with PPD ≥ 5 mm and ≥ 7 mm(all P＞0.05).At 3 months after treatment,both groups showed significant improvements in mean PPD,dPPD,and mSBI compared to baseline(all P＜0.05),with no significant intergroup differences(all P＞0.05).The control group exhibited a significant reduction in the percentage of sites with PPD ≥ 5 mm(P＜0.05),while the test group demonstrated a significant decrease in the percentage of sites with PPD ≥7 mm(P＜0.05).However,no significant intergroup differences were observed(all P＞0.05).Conclusion Both me-chanical debridement alone and its combination with Nd:YAG laser therapy can effectively improve PPD,dPPD,and mS-BI.The combined approach may reduce the percentage of deep peri-implant pockets(PPD ≥ 7 mm).

Abstract:Objective To study the clinical effect of digital guide plate combined with bone slice preservation technology in the treatment of jaw cysts.Methods Totally forty patients who needed jaw cyst enucleation in the outpatient depart-ment of oral surgery of the First Affiliated Hospital of Xinjiang Medical University(Affiliated Stomatological Hospital)from October 2023 to October 2024 were randomly divided into the study group and the control group(20 cases in each group).In the study group,digital guide plate combined with bone slice preservation technology was used during cyst enucleation,and concentrated growth factors(CGF)were filled;the control group was treated with conventional cyst enu-cleation and then CGF were filled.The operation time,the content of C-reactive protein(CRP)and white blood cell(WBC)at 1 d before operation and 1 d and 3 d after opera-tion,the visual analogue scale(VAS)score of pain at 1 d,3 d and 7 d after operation,the Landry wound healing in-dex at 3 d,7 d and 14 d after operation,the degree of post-operative swelling,complications and recurrence at 1 year after operation,the gray value of bone mineral density in the operation area before operation and at 3 months,6 months and 12 months after operation,and the volume of lesion bone cavity before operation and at 6 months and 12 months after operation were compared between the two groups.Re-sults The operation time was(31.40±5.34)min in the study group and(29.40±4.78)min in the control group,and there was no significant difference between the two groups(t=1.247,P=0.220).There was no significant difference in the preoperative CRP and WBC content,gray value of bone mineral density in the operation area,or volume of lesion bone cavity between the two groups(all P＞0.05);in the study group,the CRP content at 1 d after operation and the volume of the lesion bone cavity at 6 months and 12 months after operation were significantly reduced compared with the control group,and the gray value of bone mineral density at 3 months and 6 months after operation was significantly increased compared with the control group,with statistically significant differences(all P＜0.05).Compared with the control group,the VAS score of the study group at 1 day and 3 days after operation was significantly reduced,and the Landry wound healing index at 7 days and 14 days after operation was significantly increased,with statistically significant differences(all P＜0.05).There was no significant difference in the degree of postoperative swelling,complications or recurrence at 1 year after operation between the two groups(all P＞0.05).Conclusion Digital guide plate combined with bone slice preservation technology in the treatment of jaw cysts can achieve precise positioning,reduce surgical trauma,reduce post-operative pain,and help the soft and hard tissue healing in the operation area,which is worthy of clinical application.

Abstract:In clear aligner therapy,orthodontists must consider the predictability of tooth movement when making clinical decisions and treatment plans.However,the predict-ability of different types of tooth movement varies,and the con-clusions of existing studies are not consistent.This paper re-views the researches on the predictability of tooth movement in clear aligner therapy in recent years and summarizes the is-sues that remain unsolved in current studies,aiming to pro-vide theoretical support and evidence for clinical application as well as to offer further recommendations for future research.

Abstract:With the deep integration of digital technology with orthodontic-orthognathic combined treatment,the tradi-tional diagnosis and treatment mode of orthodontic-orthogna-thic combined treatment has undergone significant changes,ensuring the efficiency and accuracy of the diagnosis and treat-ment process.The application of digital technology in the field of orthodontic-orthognathic combined treatment makes it pos-sible to acquire and integrate patients' dental and maxillofa-cial data,which not only ensures the accuracy of treatment,but also realizes the visualization effect of treatment results,fa-cilitating communication between clinical physicians and pa-tients.The analysis and design of orthodontic-orthognathic combined treatment plans through digital software have great-ly saved doctors' investment in analysis time.In addition,the clinical application of digital technology in orthodontic-orthog-nathic combined treatment simplifies the clinical operation process and is expected to promote further development of this discipline.

Abstract:Impacted tooth extraction is a relatively common procedure performed in oral and maxillofacial surgery clinics,which mainly focuses on the extraction of impacted mandibular third molar.Due to the complexity in the location and ana-tomical structure of the impacted mandibular third molar,the difficulty of extraction can differ significantly,leading to a higher incidence of postoperative complications.An accurate preoperative assessment of the difficulty associated with ex-tracting mandibular third molar is crucial for clinical decision-making,estimating operative time,and preventing postop-erative complications.Numerous studies have been conducted both domestically and internationally on the difficulty of mandibular third molar extraction,resulting in the development of various scoring systems for extraction difficulty.The ar-ticle reviews the research progress in the mandibular third molar extraction difficulty scoring system,aiming to summa-rize the advantages and disadvantages of various scoring methods and to provide guidance for future clinical application and gain better clinical benefits.

Abstract:Implant infra-position refers to the phenome-non that after dental implant restoration,the position of the im-plant changes in relation to the alveolar bone,causing the im-plant to move inward toward the alveolar bone.This situation may affect the integration between the implant and the sur-rounding bone tissue,thereby impacting the stability and func-tion of the implant.This article provides a review on the etio-logical research progress in the mechanisms and risk factors of implant infra-position,aiming to offer scientific guidance for the prevention and treatment of functional and aesthetic issues in oral implant denture restoration caused by this condition.

Abstract:Mendelian randomization(MR)is an analytical approach that utilizes genetic variants as instrumental vari-ables to assess causal relationships between exposures and outcomes.Its core principle is to leverage the random alloca-tion of genetic variants during gamete formation,effectively mitigating confounding factors,reverse causation,and mea-surement errors inherent in traditional observational studies,thereby enhancing the reliability of causal inference.Peri-odontal disease,as a multifactorial-mediated chronic inflammatory condition,relies predominantly on epidemiological observational studies to identify risk factors(e.g.,obesity,metabolic disorders),yet such methods struggle to establish de-finitive causal links.Furthermore,evidence regarding the impact of periodontal disease on systemic conditions(e.g.,car-diovascular diseases,diabetes)exhibits heterogeneity,and the reproducibility of conclusions remains incompletely estab-lished.Consequently,MR provides a novel causal inference paradigm for periodontal research,demonstrating unique ad-vantages,particularly in elucidating bidirectional associations between periodontal diseases and systemic disorders.This review summarizes the advances in MR applications in periodontology,encompassing studies on pathogenic mechanisms,risk factor analyses,and systemic implications of periodontal diseases.Nevertheless,MR findings still require validation through triangulation of multiple evidence sources(e.g.,experimental verification,prospective cohort studies)to strength-en robustness of conclusions.Future research should optimize instrumental variable selection,expand sample sizes,and integrate multi-omics data to deepen mechanistic exploration,thereby providing a theoretical foundation for precision prevention/control and interdisciplinary intervention of periodontal diseases.

Abstract:In June 2023,the European Federation of Peri-odontology(EFP)released guidelines for the prevention and treatment of peri-implant diseases.The content includes the definition and pathophysiology of peri-implant diseases,man-agement sequences,prevention,treatment for peri-implant mucositis,and surgical and non-surgical treatments for peri-implantitis.The management of peri-implant diseases involves specific interventions based on different treatment stages and the clinical status of peri-implant tissues.Furthermore,four-level prevention strategies are proposed for the pre-and post-implantation stages.This article aims to interpret the manage-ment sequence and prevention strategies for peri-implant dis-eases,providing standardized guidance for clinicians in the treatment and prevention of peri-implant diseases.

Abstract:A healthy temporomandibular joint is a prerequisite for the successful functioning of important oral and maxil-lary systems such as chewing,swallowing and speaking.In healthy people,when the jaw is in the intercuspal position,the condyle is located in the center of the articular fossa.Different diseases and treatments may lead to different degrees of differences in condylar position and morphology,and even lead to rattle and/or murmur in joint area,joint pain and/or masticatory muscle pain,abnormal jaw movement and other clinical symptoms.Cone beam CT,as a high resolution 3D imaging technology,can accurately measure the condylar changes,which provides an important basis for clinical diagno-sis and treatment.In this paper,the effects of age,related diseases and treatment methods on condylar position and mor-phological changes were reviewed,aiming to provide reference for clinical work and provide ideas for further research on the relationship between temporomandibular joint function and structure.

Abstract:Objective To evaluate the clinical efficacy of concentrated growth factors(CGF)-assisted guided bone re-generation(GBR)in the treatment of vertical alveolar bone defects of single teeth.Methods Totally sixty patients with vertical alveolar bone defects of a single tooth treated at the Department of Stomatology,Beijing Yanqing District Hospi-tal from January 2023 to December 2024 were selected.Using a random number table method,patients were allocated in a 1∶1 ratio to a control group(n=30)and a CGF group(n=30).The control group received conventional GBR,while the CGF group received CGF-assisted GBR.Probing depth(PD)of the deepest site of vertical bone defect,bleeding index(BI),and alveolar bone defect height were compared between the two groups at baseline and 6 months postoperatively.Mastication limitation and swelling and pain degree at 12 h,24 h,48 h,72 h and 96 h,and the differences in adverse re-actions at 2 weeks and 6 months after operation were also compared.Results There were no statistically significant dif-ferences in baseline data(PD,BI and alveolar bone defect height)between the two groups(all P＞0.05).At 6 months postoperatively,PD and alveolar bone defect height in both groups were significantly reduced from baseline,with a more pronounced reduction in the CGF group(both P＜0.05).The CGF group exhibited significantly lower degree of mastica-tion limitation at 48 h and 72 h,degree swelling degree at 48 h,72 h and 96 h,and lower pain degree at 12 h and 24 h,as compared to the control group(all P＜0.05).No adverse reactions occurred in either group during the follow-up period.Conclusion CGF-assisted GBR is significantly superior to conventional GBR in the treatment of vertical alveolar bone defects.It not only effectively promotes bone regener-ation and improves clinical parameters such as PD and bone defect height,but also significantly reduces patients' postop-erative discomfort,thereby improving their postoperative quality of life.As a safe and effective biomaterial,CGF is wor-thy of promotion and application in the treatment of alveolar bone defects.

Abstract:Clear aligner therapy is a modern orthodontic method that utilizes transparent,removable aligners for non-fixed correction.The rapid advancement of artificial intelligence and digital technologies has injected new impetus into this field,demonstrating significant potential in diagnosis,treatment planning,remote monitoring,and patient communi-cation.This review summarizes the application advantages,limitations and challenges of artificial intelligence in clear aligner therapy and look into the directions for future development.

Abstract:Prevention and treatment of peri-implant dis-eases-the EFP S3 level clinical practice guideline has expound-ed on the prevention and treatment measures of peri-implant diseases and updated the definition and the overall prevention and treatment strategy for them.This review introduces the management strategies of peri-implant mucositis,including non-surgical treatment methods and the application of related auxiliary measures,so as to provide a new reference for clini-cians in diagnosis and treatment.However,some methods still need further experiments for verification.

Abstract:With the increasing demand for dental aesthet-ics,the role of researches on dental color difference thresholds has become prominent in clinical practice.Such researches of-fer a scientific basis for assessing dental aesthetics and serve as a critical reference for evaluating treatment outcomes,there-by holding practical value in increasing patient satisfaction and optimizing therapeutic efficacy.The article reviews the current research status of color difference thresholds in den-tistry,including color spaces and color difference formulas,the definition of color difference thresholds and their influenc-ing factors,and analyzes the research results of color differ-ence thresholds for major dental restorative materials.The aim is to provide some references for selecting dental color differ-ence thresholds in clinical and basic research to evaluate the clinical significance of research results.

Abstract:The oral health status of the Chinese population is poor,and the awareness of oral health knowledge is low.Therefore,the oral medical community has a very heavy task of strengthening oral hygiene education,popularizing the awareness of periodontal disease treatment and promoting regular maintenance of periodontal health among the public.Personalized oral hygiene education at the dental chair is the most effective approach and method for patients.It is neces-sary to provide basic education in oral hygiene for dental students.This paper reviews the course design and implementa-tion of"oral hygiene education"in the undergraduates during clinical pre-practice internship in the Department of Peri-odontology,Peking University School of Stomatology.It summarizes the teaching experience and methods,which is aimed to provide guidance for improving the oral health education ability of domestic dental students and contribute to promot-ing the oral health of the public and strengthening the prevention of periodontal diseases.

Abstract:Head and neck schwannomas are relatively uncommon benign tumors that may present with both cystic and solid components,with the potential for malignant transformation in rare instances.These tumors often develop bilaterally along the nerve axis and,upon aspiration,typically yield a brownish,blood-tinged,non-coagulated fluid.Schwannomas in the head and neck region generally exhibit slow growth and are frequently associated with symptoms such as tender-ness,radiating pain,and other neurological manifestations.Head and neck schwannomas are generally resistant to con-ventional radiotherapy,with surgical excision being the most commonly employed treatment modality.However,surgical intervention is often complicated by adhesion to adjacent tissues,which can result in damage to the nerve of tumor origin.Additionally,the recurrence rate following surgery is extremely high.In recent years,significant advancements in thera-peutic approaches have led to notable progress in the management of head and neck schwannomas.This article reviews current treatment approaches,including traditional surgical resection,minimally invasive techniques,radiofrequency ab-lation,stereotactic radiosurgery,and targeted therapies,discusses current research hotspots and looks forward to future research directions.

Abstract:Early orthodontic intervention is to prevent, guide,and treat occlusal and maxillofacial problems in prima-ry,mixed and permanent dentitions immediately in the earli-est available time. Early orthodontic interventions indicate all sorts of oral therapies through the construction of the occlu-sions,like oral therapy of dental diseases,the corrections of oral habits, the occlusal guidance treatments, orthodontic treatments and dental facial orthopedic treatments. The den-tist should use all kinds of methods,including preventive treatments,adjunctive orthodontic treatments and intercep-tive orthodontic treatments,to create a healthy oral environ-ment in order to achieve the good maxillofacial development and occlusal construction. Early orthodontic intervention is an important part of the modern pediatric dentistry and orthodon-tics. It is also the trend and direction of developing pediatric stomatology and orthodontics.