Dentofacial deformities secondary to condylar hyperplasiais a kind of disease presenting facial asymmetry, malocclusion, temporomandibular joint dysfunction, and other symptoms caused by non-neoplastic hyperplasia of the condyle. The etiology is still unknown, and currently, pre- and post-operative orthodontics accompanied by orthognathic surgery, temporomandibular joint surgery and jawbone contouring surgery are the main treatment methods. A personalized treatment plan was developed, considering the active degree of condyle hyperplasia, the severity of the jaw deformity, and the patient’s will, to correct deformity, obtain ideal occlusal relationship, and regain good temporomandibular joint function. Combined with the author’s clinical experience, the etiology, clinical and imageological features, treatment aims, and surgical methods of condylar hyperplasia and secondary dentofacial deformities were discussed in this paper.

Orthognathic surgery, which involve osteotomy and repositioning of the maxillomandibular complex, has recently emerged as a crucial method of correcting dentofacial deformities. The optimal placement of the maxillomandibular complex holds utmost significance during orthognathic surgery because it directly affects the surgical outcome. To accurately achieve the ideal position of the maxillomandibular complex, with the rapid advancements in digital surgery and 3D-printing technology, orthognathic surgery has entered an era of “Precision Surgery” from the pervious “Empirical Surgery.” This article provides comprehensive insights into our extensive research and exploration of the treatment modality known as “precision orthognathic surgery” over the years. We also present the technical system and application in“Ortho+X” treatment modality to offer valuable references and assistance to our colleagues in the field.

More than 30 years of rapid development of endoscopic surgery has led to the mainstreaming of this procedure in many surgical departments in China. Since the first report on endoscopy, it has been used in salivary gland resection for more than 20 years. The overall development of endoscopic surgery indicates that its use in oral and maxillofacial surgery is still in the early exploration stage; it has not yet been maturely developed or applied. Owing to the advancement of other disciplines and corresponding widening experiences in those fields, the development of endoscopic technology in oral and maxillofacial surgery will likely achieve a leapfrogging. Learning from the general development pattern of endoscopy, this research explores the application history, current situation, and future direction of the application of endoscopy in salivary gland surgery.

Implant treatment in the esthetic area requires stable osseointegration and successful esthetic outcomes. Achieving this goal requires careful consideration of accurate implant axis and ideal three-dimensional position. Owing to the high esthetics and the special anatomical structure of the maxillary, a successful implant means a synthesized deli-beration of the residual bone dimensions, soft-tissue thickness, and the relationship of the residual alveolar ridge with the planned restoration. This article offers an in-depth analysis of the clinical decisions and key factors affecting the implant direction in the esthetic area.

Crown replacement has remained one of the difficult methods for installing fixed prosthesis but is often performed because of aesthetic factors and invasion of biological width. This article focuses on the clinical scenario in which preexisting crown margin has defects. Given that clinical decisions regarding restoration management and perio-dontal tissues have to be made with caution, a decision tree of the decision making process for natural abutments in aesthetic area with preexisting defected crown margin is presented. The re-establishment of a new crown margin is the key to the success of a new restoration, and the new margin should be located at the proper esthetic position and right biological position. It should have fine, smooth, and continuous morphology.

Traditionally, vital pulp therapy (VPT) is mainly indicated for young permanent teeth. However, in recent years, VPT has been increasingly applied to mature permanent teeth. VPT was previously thought to be effective only for teeth with normal pulp or reversible pulpitis. However, an increasing body of evidence has demonstrated that VPT can successfully manage permanent teeth with irreversible pulpitis or apical periodontitis. This work discusses which teeth with irreversible pulpitis or apical periodontitis are suitable for VPT, the recommended method to evaluate and select this kind of case, and the clinical procedure involved to operate such a case.

Objective This study aims to evaluate the correlation between differences in intraoperative jumping gaps and soft tissue changes around immediate implant placement and provisionalization (IIPP) in the maxillary anterior region. Results will provide a basis for clinical evaluation of the change trend and long-term stability of the labial soft tissue contours of patients with different jumping gaps. Methods Thirty-two patients with single tooth loss in the maxillary aesthetic area were enrolled, and they all received immediate implant placement and restoration. All patients were divided into three groups: A, B, and C according to the size of the jumping gap, group A: horizontal defect dimension (HDD) ≤2 mm; group B: 2 mm<HDD≤3 mm; group C: HDD>3 mm. Geomagic studio 2013 was used to quantitatively analyze the contour volume of the soft tissue around the implant and the level of the labial gingival margin. The pink esthetic score (PSE) was used for the final aesthetic evaluation. Results All implants had osseointegration within 6 months after the surgery. The average thickness of soft tissue contour volume changed by 0.62 mm±0.15 mm, and the average PES was 11.09±0.99. The changes in the gingival mucosa levels in the three groups at 6 months after operation were 0.45 mm±0.11 mm, 0.40 mm±0.12 mm, and 0.35 mm± 0.11 mm, respectively. The changes in the average thickness of the soft tissue contour volume in the three groups at 6 months after the operation were 0.77 mm±0.16 mm, 0.63 mm±0.17 mm, and 0.54 mm±0.11 mm. A moderate negative correlation was found between the jumping gap size and the gingival mucosa level, and the average thickness changed. No significant correlation was found between size of jumping gap and PES. Conclusion Although the contour volume of the labial soft tissue continuously decreased within 6 months after IIPP in the maxillary anterior region, the surgical procedure can achieve a satisfactory aesthetic effect, and the level of soft tissue around the implant can be well maintained.

Periodontitis is a chronic inflammatory disease that destroys the integrity of tooth-supporting tissue. Periodontitis is listed as a major oral disease by the World Health Organization and is a public-health problem affecting global oral and systemic health. The fourth national oral health epidemiological survey has revealed that periodontitis is one of the most common oral problems in China. With the development of science and medicine, increased attention is being paid to the importance of oral health and its influence on general health. Accordingly, stomatologists are required to master more relevant information on clinical diagnosis and treatment, as well as to pay more attention to the diagnosis and treatment methods of patients with different systemic diseases. This article expounds the diagnosis and treatment strategy of patients with systemic disease periodontitis. We aimed to help stomatologists make more reasonable diagnosis and treatment decisions.

Objective This study aims to analyze and summarize the characteristics of supernumerary teeth by using cone-beam computed tomography (CBCT). Methods A total of 718 patients with 1 138 supernumerary teeth were retrospectively collected. Age, gender, number, location, morphology, eruption status, and accompanying symptoms of the supernumerary teeth were statistically analyzed. The relationship relative to jaws, gender, and eruption status were analyzed and discussed. Results The average age of the patients was 9.54±5.32 years, and the male to female ratio was 2.88∶1. About 77.02% of the patients sought medical advice during the mixed dentition period, and 50.70% had one supernumerary tooth. These supernumeraries were most commonly conical in shape, and 85.76% of them were in the incisor region, 92.09% in the upper jaw, 46.75% in inverted position, and 86.20% unerupted. Overall, 65.29% of them had fully developed roots, and 60.63% had an impact on adjacent structures. Significant differences were found in eruption status, morphology, zoning, direction, root development, and impact on adjacent structures between the supernumerary teeth located in the upper and lower jaws (P<0.05). Significant differences were also detected in gender, morphology, zoning, orientation, root development, and impact on adjacent structures between erupted and unerupted teeth (P<0.05). The incidence of supernumerary teeth in the incisor region was higher in males than that in females. Moreover, the root of supernumeraries was more completely developed in males than in females (P<0.05). Conclusion For supernumerary teeth, CBCT images can provide accurate three-dimensional radiographic data and are valuable for clinical diagnosis and treatment planning.

Zirconia crown has been widely used in the field of prosthodontics. Traditional zirconia exhibits excellent mechanical properties but lacks translucency. The introduction of transparent zirconia significantly enhances its aesthetic performance. In clinical applications, factors affecting the aesthetic results of full zirconia crown should be comprehensively considered, and the most suitable restoration should be chosen. Additionally, clinicians need to design appropriate tooth preparation dimensions and methods based on an individual patient’s actual situation. During the clinical bonding process of zirconia, proper surface treatment of the tooth and restoration is essential. The selection of suitable adhesives is crucial for achieving optimal bonding strength and aesthetics.

Using digital technologies in concurrently performing missing tooth implantation and preparation of remaining teeth is a solution to reduce the number of visits and improve efficiency. This paper proposes a digital process for simultaneously implanting and preparing teeth. It integrates implant surgical guide and 3D-printed tooth preparation guide into a single guide and completes guided implant placement and precise tooth preparation. Based on “repair-oriented” virtual implant planning, the implant surgical guide can improve the efficiency and predictability of implant placement, and its linear accuracy is about 1 mm. The tooth preparation guide precisely guides tooth preparation and restoration space visualization, ensuring the quality of the tooth preparation. The two guides have different design accuracy requirements, and thus their combination improves the overall guiding accuracy requirements. The concurrent application of the two guides minimizes the clinical operation time, number of visits, and economic burden of patients.

Objective This study aimed to explore the stress distribution of surface-mounted inlays with two ceramic materials and different strategies for fiber post-restoration on pulp-penetrating non-carious cervical lesion in a maxillary first premolar to provide minimally invasive and reasonable restorative methods. Methods The cone beam computed tomography data of the standard right upper first premolar were selected. Healthy control (HC) and defective control (DC) finite element models were established. Then, eight experimental models were established according to two different ceramic materials (IPS e.max CAD [LD] and Lava Ultimate [LU]) and different locations of fiber post (without fiber post [NP], fiber post in buccal root canal [B], fiber post in palatal root canal [P], fiber post in both root canals [BP]), namely, LD_NP, LD_B, LD_P, LD_BP, LU_NP, LU_B, LU_P, and LU_BP. Axial load F1 and lateral load F2 were applied. Maximum principal stress and displacement of the buccal tip were investigated using finite element analysis software. Then, the percentage change of the following indicators in each experimental group was analyzed: stress of defective tip with group DC, stress of enamel and dentine, and displacement of buccal tips with group HC. It was considered similar when the percentage change was less than 5%. Results LD and LU groups could effectively reduce the stress of the defective tip, but the decreasing amplitude in the former was greater than that of the latter. For the stress of surface-mounted inlays and resin adhesive layer, LD groups were higher than LU groups, and no significant difference in stress peak was found among different experimental groups in the same material. In addition, fiber posts in double root canals could significantly reduce buccal tip displacement. Conclusion For pulp-penetrating non-carious cervical lesions, the restorative strategy of surface-mounted inlays could be applied. Compared with Lava Ultimate, IPS e.max CAD could better protect the defective tip tooth. Furthermore, fiber posts in double root canals could decrease overall deformation and increase the retention of surface-mounted inlays.

Post-and-core crown is one of the most common forms of restoration of tooth after root canal therapy (RCT). Infection control is the core objective of RCT, which is usually well realized by endodontists. However, many prosthodontists often neglect the infection control of the tooth and the maintenance of the curative effect of RCT during the process of post-and-core crown, which may lead to the failure of the final restoration. The concept of integrated crown-root treatment advocated recently requires clinicians to consider the RCT and final restoration as a whole, rather than simply divided into two parts—endodontic treatment and restorative treatment. As the core content of integrated crown-root treatment, infection control should be taken seriously by clinicians and implemented throughout the whole treatment process, especially in the restorative treatment that is easily overlooked after RCT. Therefore, this article describes the infection control of post-and-core crown restoration, classifies the tooth requiring post-and-core crown restoration, and puts forward the measures of infection control before and during post-and-core crown restoration, in order to provide reference and guidance for clinical practice.

Orthodontics is a discipline that is based on aesthetics. It coordinates the relationship among nose, lip, and chin through the movement of teeth and the adjustment of jaw relationship. Orthodontists need to fully analyze the patient’s soft tissue profile before treatment. They also need to analyze the existing problems and those that may be solved or caused during orthodontics to guide the design of orthodontic treatment and effectively improve the clinical effect of orthodontics. This article reviews the aesthetic preconditions that guide the design of orthodontic treatment from the perspective of orthodontists.

In the field of prosthodontics, the use of virtual patients for biomimetic restoration holds great promise for various applications. Virtual patients consist of digitized data that encompasses details on the morphology, structure, and spatial relationships within the maxillofacial and intraoral regions. Nonetheless, there are several challenges associated with acquiring digital data, achieving accurate alignment, and recording and transferring dynamic jaw movements. This paper aims to concentrate on the process of constructing virtual patients, highlight the key and challenging aspects of virtual patient construction, and advocate for the extensive adoption and utilization of virtual patient technology.

Objective This study aimed to remove occlusal veneers of varied thicknesses and compositions by Er:Yag laser in vitro and analyze the interfacial microstructure between veneers and tooth that irradiated by laser, by which experimental evidence could be provided to support the non-invasive removal of occlusal veneerby laser. Methods Fresh mandibular premolars extracted for orthodontic requirements were collected for tooth preparation. Three kinds of ceramic materials (Vita Suprinity, Vita Mark Ⅱ, and Upcera Hyramic) were selected to fabricate occlusal veneer with different thicknesses (1.0, 1.5, and 2.0 mm). One week later, Er:Yag laser (2.5 W and 3.5 W) was used to irradiate and remove the occlusal veneer and recorded the timespan. After the removal operation, the micro-morphologies of samples were examined by scanning electron microscope. Results Upcera Hyramic veneer failed to be removed (>20 min); the operation span at 2.5 W, Vita Suprinity (96.0 s±16.0 s) was longer than Vita MarkⅡ(84.5 s±19.5 s) in the 1.0 mm group (P<0.05), and Vita Suprinity (246.5 s±13.5 s) was longer than Vita MarkⅡ(170.0 s±14.0 s) in the 1.5 mm group (P<0.05). At 3.5 W, Vita Suprinity (381.0 s±24.0 s) was longer than Vita MarkⅡ(341.5 s±26.5 s) in the 2.0 mm group. Conclusion Increasing laser power could shorten the operation span and facilitate the removal of occlusal veneers with the same thickness and composition. The occlusal veneer was sustained when insufficient laser power was applied. With the same laser power and ceramic thickness, laser penetration could interfere with the integral of the ceramic structure when the laser interacted with the bonding layer. With the same ceramic composition and laser power, the operation span and laser power increased with the thickness of the occlusal veneer. However, the laser was incapable of removing occlusal resin veneer directly.

Postoperative infection is one of the most common complications of tooth extraction. It may manifest as localized infection or develop to systemic infection. Clinically, oral surgeons can prevent postoperative infections by urging patients to strengthen oral hygiene, applying antibiotics in a rational and compliant manner, and choosing appropriate surgical methods for tooth extraction. For the treatment of infection, the oral surgeon should formulate a response strategy on the basis of different diagnoses. For local infections such as dry socket, delayed alveolar osteitis, gap infection, and marginal osteomyelitis of the jaws, the infection can be controlled by local debridement, therapeutic use of antibiotics, and incise and drain if necessary. For patients suspected of necrotizing fasciitis, timely extensive debridement should be made to reduce the area of tissue necrosis. For those who have received radiotherapy or anti-resorptive drugs, tooth extraction should follow the recommendations of the relevant clinical guidelines or expert consensus to minimize the risk of osteonecrosis of the jaws. For patients with poor systemic health or dysfunction of the immune system, attention should be paid to identifying infective endocarditis and intracranial infection to ensure the life safety of patients. In this study, the author intends to combine literature review and clinical experience to tackle postextraction infection and its prevention to provide a reference for colleagues on oral and maxillofacial surgery.

Objective To review the effectiveness of secondary alveolar bone grafting using iliac cancellous bone in patients with unilateral complete alveolar cleft and to investigate the factors influencing it. Methods A retrospective study of 160 patients with unilateral complete alveolar clefts who underwent iliac cancellous bone graft repair at the Department of Cleft Lip and Palate Surgery, West China Hospital of Stomatology, Sichuan University, was conducted. Eighty patients in the young age group (6-12 years) and 80 in the old age group (≥13 years) were included. Bone bridge formation was determined using Mimics software, and the volume was measured to calculate the iliac implantation rate, residual bone filling rate, and resorption rate. The factors that affected bone grafting in both subgroups were investigated. Results Using bone bridge formation as the clinical success criterion, the success rate for the entire population was 71.25%, with a significant difference of 78.75% and 63.75% for the young and old age groups, respectively (P=0.036). The gap volume in the latter was significantly larger than that in the former (P<0.001). The factors that influenced bone grafting in the young group were the palatal bone wall (P=0.006) and history of cleft palate surgery (P=0.012), but only the palatal bone wall affected the outcome in the old age group (P=0.036). Conclusion The results of alveolar bone grafting for the old age group were worse than those for the young age group. The palatal bone wall was an important factor that affected alveolar bone grafting, and alveolar bone grafting in the young patients was influenced by the history of cleft palate surgery.

With the development of periodontal regenerative technology, an increasing number of scholars reported that advanced periodontitis involving teeth can be preserved through intentional replantation. Intentional replantation has become the last possible method to preserve natural teeth for advance periodontitis with signs of tooth extraction. However, the indications of intentional replantation are strict, and the success of the operation is closely related to the condition of cases and the operation skills of doctors. In this article, the operation steps and criteria of intentional replantation were summarized by introducing three success cases of advanced periodontitis involving teeth preserved by intentional replantation. The relevant factors that affect the prognosis of intentional replantation in advanced periodontitis involving teeth preservation were analyzed to help clinicians preserve natural teeth.

Objective This study aimed to investigate the feasibility of measuring the soft tissue height of bone cristae around implant by digital method. Methods A total of 36 patients with dental implants were selected from the Dental Medicine Center of the First Affiliated Hospital of University of Science and Technology of China (Anhui Provincial Hospital) from August 2022 to December 2022. A total of 43 dental implants were enrolled. All postoperative cone beam CT (CBCT) imaging data and intraoral digital impressions obtained before surgery were immediately obtained by the patients on the day of completion of oral implant surgery and they were imported into oral implant surgery planning software for image fitting. Then, virtual implants of the same specification were placed in the planting area, and the implant position was adjusted to overlap with the implant shadow in the CBCT image. Supracrestal tissue height (STH) was measured at the implant view interface (digital group). During the operation, implant holes were prepared step by step in accordance with the standard preparation method, and implants were implanted. The upper edge of the implant was flushed with the crest of the alveolar ridge. STH was measured by perio-dontal probing (periodontal probe group). Paired t-test was used to compare the STH differences between the digital and periodontal probe groups. Bland-Altman test was used to analyze the consistency of the two methods. Intra-group correlation coefficient (ICC) was used to verify the reliability of the results measured by different surveyors using di-gital methods. Results No statistical significance was observed in the STH difference between the two methods (P>0.05). Bland-Altman test showed good consistency between the two methods, but the measurement of mandibular posterior teeth showed that the results of periodontal probe were greater than those of digital method. The ICC and 95%CI of the STH results measured digitally by different surveyors are 0.992 (0.986-0.996). Conclusion The digital me-thod is in good agreement with the periodontal probe method in measuring the soft tissue height of the bone cristae around the implant.

Pregnancy is a special period for developing and treating oral diseases. Oral emergencies during pregnancy need to be handled appropriately. Changes in the physiological environments and personal habits of pregnant women increase susceptibility to some oral diseases. However, clinical treatment strategies are limited due to the need to ensure the safety of pregnant women and fetuses. Pregnant women should obtain oral health knowledge and enhance their awareness. Dentists should adhere to the principle of “prevention before pregnancy, controlling symptoms during pregnancy, and treating diseases after pregnancy” for different pregnancy periods. They should also formulate appropriate treatment plans to control emergencies, prevent disease progression, and avoid harmful effects on pregnant women by using the safest, simplest, and most effective strategies that avoid adverse effects on fetuses. Pregnant women and dentists should combine prevention and treatment while collaborating in maintaining oral health during pregnancy. This article focuses on the principles of treatment during pregnancy, and the treatment timing, clinical management, and treatment strategies of different diseases causing oral emergencies during pregnancy are reviewed.

Objective This study aimed to observe the outcomes of iRoot BP Plus full pulpotomy in primary molars with partial irreversible pulpitis retrospectively. Methods Collect 102 cases of primary molars with partial irreversible pulpitis undergoing iRoot BP Plus full pulpotomy from January 2019 to August 2023, with a follow-up period of 24-47 months. Based on the presence of irreversible pulpitis symptoms before surgery, the included cases will be divided into asymptomatic group (n=53) and symptomatic group (n=49). Observe the clinical and imaging success rates of both groups. Results Clinical success rates were 96.2% and 97.9% in asymptomatic and symptomatic groups, and radiographic success rates were 96.2% and 93.9% respectively. Conclusion iRoot BP Plus full pulpotomy can be used for the treatment of primary molars with partial irreversible pulpitis under an enhanced pulpotomy protocol.

Congenital orofacial cleft, the most common birth defect in the maxillofacial region, exhibits a wide range of prognosis depending on the severity of deformity and underlying etiology. Non-syndromic congenital orofacial clefts typically present with milder deformities and more favorable treatment outcomes, whereas syndromic congenital orofacial clefts often manifest with concomitant organ abnormalities, which pose greater challenges for treatment and result in poorer prognosis. This consensus provides an elaborate classification system for varying degrees of orofacial clefts along with corresponding diagnostic and therapeutic guidelines. Results serve as a crucial resource for families to navigate prenatal screening results or make informed decisions regarding treatment options while also contributing significantly to preventing serious birth defects within the development of population.

Objective This study aimed to analyze the application value of a modified tragus edge incision and transmasseteric anteroparotid approach to condyle reconstruction. Methods Condyle reconstruction was performed in 16 patients (9 females and 7 males) with modified tragus edge incision and transmasseteric anteroparotid approach. After regular follow-up, the function of condyle reconstruction was evaluated by clinical indicators, such as parotid salivary fistula, facial nerve function, mouth opening, occlusal relationship, and facial scar. The morphology of rib graft rib cartilage was evaluated by imaging indicators, such as panoramic radiography, CT, and three-dimensional CT image reconstruction. Results At 6-36 months postoperative follow-up, all patients had good recovery of facial appearance, concealed incisional scar, no parotid salivary fistula, good mouth opening, and occlusion. One case had temporary facial paralysis and recovered after treatment. Radiographic evaluation further showed that costochondral graft survived in normal anatomic locations. Conclusion The modified tragus edge incision and transmasseteric anteroparotid approach can effectively reduce parotid salivary fistula and facial nerve injury in condylar reconstruction. The surgical field was clearly exposed, and the incision scar was concealed without increasing the incidence of other complications. Thus, this approach is worthy of clinical promotion.

Root canal therapy is the primary treatment method for pulpal and periapical diseases. Various advanced endodontic instruments for mechanical preparation have been marketed. The emergence of nickel-titanium rotary instruments has greatly improved the efficiency of root canal preparation. New demands have been put forward for nickel-titanium rotary instruments as a result of the deepening of clinicians’ awareness of root canal anatomy system as well as the purpose and prognosis of root canal treatment. These clinical-oriented demands accelerate instrument reform and innovation. This work presents new marketed nickel-titanium systems and discusses the advantages and limitations of these systems and how they perform in terms of the efficiency and outcome of root canal preparation.

At present, the commonly used clinical protocols of oral cosmetic restoration are mostly based on the oral aesthetic indexes proposed by Western developed countries (referred to as Western aesthetics), which are different from the oral aesthetic indexes unique to Chinese people (referred to as Chinese aesthetics). In the design of restoration schemes and the evaluation of restoration effects, these differences have a large or small effect on the doctor-patient-technology triad. Improper handling could directly weaken the cooperation efficiency of the three parties, reduce patient satisfaction, and even lead to medical disputes in serious cases. From doing a good job of oral cosmetic restoration in China, the connotative characteristics of Chinese oral aesthetics are introduced in this paper, and the value of oral aesthetic analysis in diagnosis and treatment is discussed. The process and method of aesthetic analysis and assessment through the modified Chinese psychosocial impact of dental aesthetics questionnaire and the evaluation ruler of the expected value of oral cosmetic restoration are further introduced in detail.

Anterior diastema is a common esthetic defect in China. The general treatment for a patient with diastemata, including orthodontics and direct and indirect restorations, is a multidisciplinary clinical procedure covering the orthodontics, operative dentistry, general dentistry, and prosthodontics department. Given the diversity of departments and the complex etiology of this defect, decision-making regarding the closing methods and time selection is undefined and unintegrated, which makes the long-term stability of closure unpredictable. This article proposed an etiology-based decision tree with actual measurement of diastemata width for diastemata closure. The decisional steps include classifying the etiological factors based on patients' medical history and clinical manifestation to evaluate the stability of diastemata. After maintaining the stability of diastemata, contemporary and multidisciplinary treatment plans were selected in accordance with the measured width of diastemata and patients' cosmetic psychology, economics, and available time. These decision trees focus on the challenges of collaboration among dental departments, propose an objective and efficient ways for connections, and promote efficient and effective diastemata closure.

Biodegradable magnesium-based metal-guided bone regeneration (GBR) membranes possess excellent mechanical properties, biodegradability, and osteopromotive capabilities, making them ideal implants for the treatment of maxillofacial bone defects. This review summarizes the current status and future research trends related to magnesium-based GBR membranes. First, the research history and application fields of magnesium-based metals are introduced, and the advantages of the use of magnesium-based materials for GBR membranes, including their mechanical properties, biocompatibility, osteopromotive performance, and underlying mechanisms are discussed. Finally, this review addresses the current limitations of magnesium-based GBR membranes and their applications and prospects in the field of dentistry. In conclusion, considerable advancements have been in fundamental and translational research on magnesium-based GBR membranes, which lays a crucial foundation for the treatment of maxillofacial bone defects.

Objective This study aims to compare the effects of two orthodontic treatment modalities for skeletal class Ⅲ malocclusion on specific changes in airway volume, morphology, palatal angle, mandibular rotation, and bone displacement. Results provide scientific evidence for the selection of orthodontic treatment plans and reduce the risk of developing obstructive sleep apnea hypopnea syndrome (OSAHS). Methods Thirty-six patients diagnosed with skeletal class Ⅲ malocclusion at the Department of Orthodontics, the Affiliated Stomatological Hospital of Nanjing Medical University from September 2018 to December 2023 were divided into two groups: orthodontic-orthognathic treatment group (18 patients) and camouflage orthodontic treatment group (18 patients). Changes in airway volume, cross-sectional area, palatal angle, mandibular, and tongue positions were observed through pre- and post-operative cone beam computed tomography and 3D cephalometric measurements. Results In the camouflage orthodontic treatment group, nasopharyngeal volume and oropharyngeal volume statistically increased after treatment (P<0.05). In the orthodontic-orthognathic treatment group, changes in nasopharyngeal volume, nasopharyngeal airway, distance from posterior tongue to pharyngeal wall, palatal angle, mandibular rotation, and hyoid bone displacement were statistically significant after surgery (P<0.05). In the comparison between the two groups after treatment, changes in the distance from posterior tongue to pharyngeal wall, palatal angle, and distance from hyoid bone to sella turcica point were statistically significant (P<0.05). Conclusion Patients in the orthodontic-orthognathic treatment group showed significantly greater changes in oropharyngeal cross-sectional area, palate angle, and tongue position compared with patients in the camouflage orthodontic treatment group. As individuals susceptible to OSAHS often exhibit mandibular retrusion and decreased minimum airway cross-sectional area, special attention should be paid to airway morphology changes when adopting orthodontic-orthognathic treatment to avoid adverse consequences.

At present, the commonly used clinical protocols of oral comestic restoration are mostly based on the aesthetic indicators proposed by Western developed countries (referred to as Western aesthetics). Mechanically copying the Western aesthetic scheme, ignoring the difference between it and the Chinese oral aesthetic indicators (referred to as Chinese aesthetics), is unable to effectively support personalized cosmetic restoration diagnosis and treatment. In addition, new technologies and new solutions for cosmetic restoration, which are developing rapidly in recent years, are emerging one after another, but many popular concepts are confusing and lack of proper hierarchical diagnosis and treatment norms, and there is indeed an urgent need for discussion and clarity. From the perspective of serving clinical application, this paper discusses the deficiencies of the Chinese translation of the word “aesthetics”, the diffe-rence and connection between aesthetics and cosmetology, and the relationship between cosmetic restoration and fixed restoration. It also discusses the difference between anterior teeth, esthetic zone and exposed zone, the diagnostic and therapeutic value of oral aesthetic analysis, as well as the application methods of desensitization, suggestion, and other therapies in difficult oral cosmetic restoration cases. We further introduce the decision tree and the clinical pathway for restoration and reconstruction of teeth in exposed zone guided by aesthetic analysis, and introduce the clinical process of aesthetic analysis and evaluation, the clinical triclassification of oral cosmetic restoration, and the corresponding clinical classification diagnosis and treatment points.

Robotic surgery is known as the “third technological revolution” in the field of surgery, and is an important milestone in the development of modern surgery. However, our country’s innovative surgical robot industry is still in its early stages, and it is only being utilized in certain surgical fields. To explore the effectiveness of the application of domestic surgical robot in oral and maxillofacial surgery, the author successfully completed a case of benign parotid tumor resection with the assistance of a domestic autonomous robot. The operation was successful, facial nerve function was preserved, and postoperative wound healing was good.

Objective This study aimed to compare the differences among four kinds of mechanical Ni-Ti files including T-Flex, Reciproc Blue (RB), ProTaper Gold (PTG), and ProTaper Universal (PTU) in dentinal microcrack generation after root canal preparation in vitro by using micro-computed tomography (micro-CT) analysis. Methods A total of 32 freshly extracted double-root-canal premolars with an angle not exceeding 10° were selected and established as root canal preparation models in vitro. Then, the specimens were randomly assigned to four experimental groups (n=8) according to the different Ni-Ti systems used for root canal preparation: group T-Flex, group RB, group PTG, and group PTU. The voxel size of the micro-CT was set at 17.18 μm. Pre- and post-operative cross-sectional images of roots (n=56 940) were scanned and analyzed to identify the presence of dentinal microcracks. The results of each group were expressed by the quantity and percentage of sectional images with microcracks. McNemar test was used to determine whether a significant difference existed in the existence of dentinal microcracks before and after instrumentation. The level of significance was set at P<0.05. Results Overall, 11.04% of the images presented dentinal defects (n=6 288). Dentinal microcracks were observed in 9.82%, 10.79%, 12.27%, and 11.25% of the post-instrumentation images from groups T-Flex, RB, PTG, and PTU, respectively. However, all these dentinal microcracks were already present in the corresponding pre-operative images. No new microcrack of premolars were generated after the root canal preparation utilizing the aforementioned systems. Conclusion Denti-nal microcracks already existed in advance in extracted teeth before root canal preparation. Root canal preparation using the T-Flex, RB, PTG, and PTU systems did not induce the formation of new dentinal microcracks on the straight root canals of premolars.

Complicated crown root fracture is a serious combined fracture of the enamel, dentin, and cementum in dental trauma. The treatment method is complicated. During the procedure, the condition of pulp, periodontal, and tooth body should be thoroughly evaluated, and a multidisciplinary approach combined with sequential treatment is recommended. This case reported the different treatment and repair processes of one case of two affected teeth after complicated crown root fracture of upper anterior teeth, including regrafting of broken crown after flap surgery at the first visit, direct resin repair to remove broken fragments, and pulp treatment and post-crown repair at the second visit. After 18 months of follow-up, the preservation treatment of the affected teeth with complicated crown root fracture was achieved. Therefore, fragment reattachment and post-crown restoration are feasible treatment options for children with complicated crown root fracture.

Hypophosphatemia rickets is a rare disease that is divided into two categories, namely, hereditary and acquirability. Its clinical manifestations include growth disorders, limb deformities and dysfunction, poor mineralization of the teeth, and growth retardation in children as well as hyperparathyroidism, osteoarthritis, osteomalacia, and pseudofracture in adults. Oral manifestations include non-carious teeth with recurrent apical periodontitis, periapical abscess and even cellulitis, periodontitis, and early tooth loss. X-linked hypophosphatemia rickets (XLHR) accounts for approximately 80% of all hypophosphatemia rickets. We report a 3-year-old child with XLHR whose first diagnosis was apical periodontitis of multiple non-carious and non-traumatic teeth. Through medical history, clinical examination, laboratory examination, radiographic findings, genotype testing, and literature analysis, we analyze the pathogenesis, clinical manifestations, radiographic features, diagnosis and differential diagnosis, treatment, and follow-up. This work provides reference for clinical diagnosis and treatment and reduces missed diagnosis and misdiagnosis by dentists.

Objective The objective of this study is to measuring the morphology and position of bilateral temporomandibular joints in patients with unilateral and bilateral molar scissor bite and simulating the deformation of the mandible during occlusion, in order to provide thesis for the diagnosis of temporomandibular joint disease in patients with unilateral and bilateral molar scissor bite. Methods This study was a retrospective study. A total of 10 patients with unilateral molar scissor bite (the unilateral molar scissor bite group) and 10 patients with bilateral molar scissor bite (the bilateral molar scissor bite group) were selected as the experimental group, and 20 adult patients with classⅠ of angle classification of similar ages were selected as the control group. All patients underwent cone beam computed tomography scans, by measuring the width of the fossa, height of the fossa, articular eminence inclination, long axis of the condyle, minor axis of the condyle, horizontal angle of the condyle and the space of the temporomandibular joint, compare temporomandibular joint morphology and position. The three-dimensional finite element analysis of the mandible morphology was carried out to evaluate the force and deformation of the mandible by using software to simulate the occlusion of the patients. It was further explored the relationship between the force of the mandible morphology and the possible temporomandibular joint disorder symptoms of the patients. Results Intergroup comparisons for the unilateral molar scissor bite group and left sides of the other groups revealed that the superior articular space in the group with unilateral molar scissor bite was shorter than that in the control group (P<0.05); the long axis of the condyle in the unilateral and bilateral molar scissor bite group were both shorter than that of the control group (P<0.05); among which the unilateral group was larger than the bilateral group, and the minor axis of the condyle in bilateral molar scissor bite group was smaller than in the control group (P<0.05), and the unilateral and bilateral condylar groups were larger than the control group (P<0.05); and the condylar horizontal angle in the unilateral and bilateral groups were larger than that in the control group (P<0.05). The normal sides of the unilateral molar scissor bite group and right sides of the other groups had smaller superior articular space than the control group (P<0.05); and the condylar long-axis in bilateral group was smaller than the control group (P<0.05); and the normal side of the condylar short-axis unilateral group was larger than that of the bilateral condylar group. Three-dimensional finite element analysis: the condyle of patients with molar scissor bite was a concentrated area of deformation during the bite of the mandible, when the first molar occlusion of the scissors bite side was simulated, the maximum deformation was located in the condyle in the X-axis and Z-axis directions. The amount of deformation was greater than that of the scissor bite side in the X-axis direction, while in the Z-axis direction, the normal side was greater than the scissor bite side. The maximum sites of local deformation in the X-axis direction were located in anterior and posterior the transverse crest of scissor bite side, and the minimum sites of local deformation was at 1/3 of the anterior slope of the inner pole of the normal side, the maximum local deformation sites in the Z-axis direction were located in the outer pole and below the outer pole of the normal side. The X-axis deformation value was the largest in the molars occlusion on the normal side, the Y-axis deformation value was in the premolars occlusion on the normal side, and the Z-axis deformation value was the largest in the centric occlusion, the deformation value of the condyle was not most significant in molar scissor bite. Conclusion Unilateral and bilateral molar scissor bite resulting in a short condyle morphology, and the bilateral group had a shorter condylar morphology than the unilateral group. The condyle of the patient with molar scissor bite is a concentrated area of poor occlusal deformation, and the largest sites of deformation are distributed near the transverse ridge of the inner and outer poles of the condyle. Different occlusion conditions have an effect on condylar deformation values, but do not indicate whether there is a clear association between them.

Objective To study the clinical effect of the L-shape technique combined with concentrated growth factor on the horizontal bone defects of maxillary anterior teeth. Methods Twenty-five implants from 25 patients who underwent single maxillary anterior tooth implantation with simultaneous bone grafting were selected as the study subjects. Based on the bone grafting techniques, the patients were divided into a test group (L-shaped technique with guided bone regeneration combined with concentrated growth factor, 11 cases) and a control group (traditional guided bone regeneration combined with concentrated growth factor, 14 cases). The early discomfort and wound healing conditions in the two groups at two weeks after surgery were compared. The horizontal bone thickness, vertical bone thickness, and grayscale values in the augmentation area were measured immediately postsurgery and six months after surgery. Implant stability, hard tissue resorption within six months, and grayscale values were compared between the two groups. Results Differences in early discomfort, wound healing, implant stability, and grayscale values between the two groups were not statistically significant (P>0.05). Vertical bone thickness in the test group was significantly better than that in the control group at six months after surgery (P<0.05). The variation in horizontal bone thickness in the test group was significantly higher than that in the control group (P<0.05). Conclusion The application of the L-shape technique with concentrated growth factor for horizontal bone defects in the anterior maxillary area yielded satisfactory short-term results in terms of bone augmentation, early discomfort, wound healing, and implant stability at six months after surgery.

Peri-implantitis is a pathologic condition associated with dental plaque that occurs in the implant tissue and is characterized by inflammation of the mucous membrane surrounding the implant, followed by the progressive loss of supporting bone. In this study, a case of guided bone regeneration therapy based on plaque control of peri-implant inflammation was reported. Four years after surgery for the left second premolar implant, the patient presented with “left lower posterior tooth swelling and discomfort for more than 2 years”. The X-ray periapical film showed a decrease in distal bone mineral density of implant, and the clinical diagnosis was peri-implantitis of the left second premolar. Implants underwent guided bone regeneration and regular periodontal maintenance treatment. Re-examination at 3.5 months, 11 months, 18 months, and 7 years showed that the alveolar bone height and bone mineral density were stable, and the periodontal depth became shallow. However, the gingival recession was mild. In the present case, follow-up at 7 years demonstrated that the clinical periodontal indexes could be remarkably improved after complete periodontal treatment for peri-implantitis, and the alveolar bone could be well restored and regenerated.

Objective This study aimed to construct the finite element model of the mandibular first molar with the invisible appliance and explore the dentition movement characteristics of the mandibular first molar when using micro-implant anchorage and different initial positions of the first molar. Methods Models of the mandible, tooth, periodontal membrane, and invisible appliance were constructed using cone beam computed tomography (CBCT) data. The two groups were divided into the non-anchorage group and the micro-implant group (between the roots of the first molar and the second molar) based on whether the elastic traction of the micro-implant was assisted or not. The two groups were divided into the following conditions based on the starting position of the first molar: Working condition 1: the distance between the first molar and the second premolar was 0 mm; working condition 2: the distance between the first molar and the second premolar was 1 mm; working condition 3: the distance between the first molar and the second premolar was 2 mm; working condition 4: the distance between the first molar and the second premolar was 3 mm. The data characte-ristics of total displacement and displacement in each direction of dentition were analyzed. Results In the non-ancho-rage group, all the other teeth showed reverse movement except for the first molar which was moved distally. Meanwhile, in the micro-implant group, except for a small amount of mesial movement of the second molar in wor-king condition 1, the whole dentition in other working conditions presented distal movement and anterior teeth showed lingual movement, among which the distal displacement of the first molar in working condition 4 was the largest. With the change of the initial position of the first molar to the distal, the movement of the first molar to the distal, the premolar to the mesial, and the anterior to the lip increased, while the movement of the second molar to the mesial decreased. Conclusion The micro-implant can effectively protect the anterior anchorage, increase the expression rate of molar distancing, and avoid the round-trip movement of the second molar. The initial position of the first molar movement is related to the amount of distancing and the remaining tooth movement.

Objective The objectives of this study were to assess the quality of prosthetic prescriptions of removable partial dentures (RPDs) and to analyze the current situation of the communication and information delivery between clinicians and technicians. Methods All RPD prosthetic prescriptions received by a major dental laboratory in 4 weeks were involved in a quality audit, and the prescriptions were divided into three groups in accordance with the grades of clients. The filling of prosthetic prescriptions was recorded. The items in the prescriptions for audit included the general information of the patient, the general information of the clinician, the design diagram information, other detailed information, and the return date. The prescriptions were categorized into four levels on the basis of their quality by two quality inspectors who have been working for more than 10 years. Results A total of 916 prescriptions were collected and assessed. The names in the general information of the patient and the clinician were filled out best, both at the rate of 97.6% (n=894). The return date was filled out worst, only at the rate of 6.4% (n=59). Of those prescriptions, 86.8% (n=795) exhibited inadequate design diagram information. The results of the quality assessment demonstrated that 74.2% of prescriptions were assessed as noncompliant ones and failed to meet the acceptable clinical quality standard. Conclusion At present, the overall quality of RPD prosthetic prescriptions is poor. The responsibilities of clinicians and technicians are unclear, and the communication between them is not ideal.

Objective To solve the current problems of loosening and dislodging caused by the high elastic modulus of solid implants, we attempted to study a gradient porous dental implant that can lower the stress concentration and reduce the elastic modulus. Methods SolidWorks software was utilized to design the abutment and mechanical structure of the gradient porous implant. The mechanical properties of the gradient porous implant were evaluated by an orthogonal experimental design from four aspects: pore shape, pore diameter, porous layer height, and circumferential distribution. ANSYS software was used to evaluate the distribution of Von-Mises stress in the implant and its surrounding bone tissues under different structural combination parameters to derive the optimal combination of gradient porous implant parameters. Results The effects of the four factors, namely, pore shape, pore diameter, porous layer height and pore distribution, on the maximum Von-Mises stress on the implant were as follows. As the pore shape became smaller and the circumferential distribution decreased, the Von-Mises stress decreased significantly. The pore diameter went from 500 μm to 600 μm and then to 700 μm. The Von-Mises stress decreased and then increased. It increased with the increase in the height of the porous layer. Conclusion The final optimal combination of parameters for the gradient porous implant was as follows: square pore shape, pore diameter of 600 μm, porous layer height of 3 mm, and quadratic step in pore distribution.