The standardized workflow of computer-aided static guided implant surgery includes preoperative examination, data acquisition, guide design, guide fabrication and surgery. Errors may occur at each step, leading to irreversible cumulative effects and thus impacting the accuracy of implant placement. However, clinicians tend to focus on factors causing errors in surgical operations, ignoring the possibility of irreversible errors in nonstandard guided surgery. Based on the clinical practice of domestic experts and research progress at home and abroad, this paper summarizes the sources of errors in guided implant surgery from the perspectives of preoperative inspection, data collection, guide designing and manufacturing and describes strategies to resolve errors so as to gain expert consensus. Consensus recommendation: 1. Preoperative considerations: the appropriate implant guide type should be selected according to the patient's oral condition before surgery, and a retaining screw-assisted support guide should be selected if necessary. 2. Data acquisition should be standardized as much as possible, including beam CT and extraoral scanning. CBCT performed with the patient’s head fixed and with a small field of view is recommended. For patients with metal prostheses inside the mouth, a registration marker guide should be used, and the ambient temperature and light of the external oral scanner should be reasonably controlled. 3. Optimization of computer-aided design: it is recommended to select a handle-guided planting system and a closed metal sleeve and to register images by overlapping markers. Properly designing the retaining screws, extending the support structure of the guide plate and increasing the length of the guide section are methods to feasibly reduce the incidence of surgical errors. 4. Improving computer-aided production: it is also crucial to set the best printing parameters according to different printing technologies and to choose the most appropriate postprocessing procedures.

Objective To investigate the osteogenic properties of a methacrylated gelatin (GelMA) / bone marrow mesenchymal stem cells (BMSCs) composite hydrogel applied to the skull defect area of rats and to provide an experimental basis for the development of bone regeneration biomaterials. Methods This study was approved by the Animal Ethics Committee of Nanjing University. A novel photocurable composite biohydrogel was developed by constructing photoinitiators [lthium phenyl (2,4,6-trimethylbenzoyl) phosphinate, LAP], GelMA, and BMSCs. The surface morphology and elemental composition of the gel were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The compressive strength of the gel was evaluated using an electronic universal testing machine. After in vitro culture for 1, 2, and 5 days, the proliferation of the BMSCs in the hydrogels was assessed using a CCK-8 assay, and their survival and morphology were examined through confocal microscopy. A 5 mm critical bone deficiency model was generated in a rat skull. The group receiving composite hydrogel treatment was referred to as the GelMA/BMSCs group, whereas the untreated group served as the control group. At the 4th and 8th weeks, micro-CT scans were taken to measure the bone defect area and new bone index, while at the 8th week, skull samples from the defect area were subjected to H&E staining, van Gieson staining, and Goldner staining to evaluate the quality of bone regeneration and new bone formation. Results SEM observed that the solidified GelMA showed a 3D spongy gel network with uniform morphology, the porosity of GelMA was 73.41% and the pore size of GelMA was (28.75 ± 7.13) μm. EDX results showed that C and O were evenly distributed in the network macroporous structure of hydrogel. The hydrogel compression strength was 152 kPa. On the 5th day of GelMA/BMSCs culture, the cellular morphology transitioned from oval to spindle shaped under microscopic observation, accompanied by a significant increase in cell proliferation (159.4%, as determined by the CCK-8 assay). At 4 weeks after surgery, a 3D reconstructed micro-CT image revealed a minimal reduction in bone defect size within the control group and abundant new bone formation in the GelMA/BMSCs group. At 8 weeks after surgery, no significant changes were observed in the control group's bone defect area, with only limited evidence of new bone growth; however, substantial healing of skull defects was evident in the GelMA/BMSCs group. Quantitative analysis at both the 4- and 8-week examinations indicated significant improvements in the new bone volume (BV), new bone volume/total bone volume (BV/TV), bone surface (BS), and bone surface/total bone volume (BS/TV) in the GelMA/BMSCs group compared to those in the control group (P<0.05). Histological staining showed continuous and dense formation of bone tissue within the defects in the GelMA/BMSCs group and only sporadic formation of new bone, primarily consisting of fibrous connective tissue, at the defect edge in the control group. Conclusion Photocuring hydrogel-based stem cell therapy exhibits favorable biosafety profiles and has potential for clinical application by inducing new bone formation and promoting maturation within rat skull defects.

Objective To deposit degradable amino-hybrid mesoporous silica (AHMS) in situ on the surface of titanium nanotube (TNT) and explore its protective effect on nanomorphology and osteogenesis. Methods TNT and TNT@AHMS were sequentially prepared via an anodizing method: the oil-water two-phase method (experimental group) and the acid-etched titanium method [control group (Ti)]. The parameters for synthesis were explored by changing the silicon source dosage ratio (3∶1, 1∶1, 1∶3); the surface morphology was observed by scanning electron microscope(SEM), hydrophilicity was detected by Water Contact Angle Tester, elemental composition was detected by X-ray photoelectron spectroscopy (XPS); nanoindentation test and ultrasonic oscillator were used to observe the morphological holding effect as mechanical strength of TNT@AHMS in vitro; simulated immersion experiments in vitro was used to observe the degradation behavior of the material. the MC3T3-E1 cell line was used to observe the effect of cell adhesion, proliferation and differentiation on the material; and an SD rat femoral implant model and micro-CT were used to verify the protective effect and osseointegration effect of AHMS on TNT morphology. Results The morphologies of TNT and TNT@AHMS were successfully prepared, and the silicon source ratio was 1:3. SEM showed that the titanium nanotubes were uniformly covered with AHMS coating, and the mesoporous pore size was about 4 nm. After AHMS was incorporated, the surface of the material was hydrophilic (12.78°), the presence of amino groups (NH₂-) was detected, the material was completely degraded within 12 h in vitro, and the active morphology of the TNT was re-exposed with a cumulative silicon release of 10 ppm. Nanoindentation test showed that TNT@AHMS exhibited more ideal surface mechanical strength. SEM revealed that TNT maintains its own morphology under the protection of AHMS, and the TNT group suffered severe exfoliation. In addition, the early adhesion and proliferation rates, ALP activity, and bone volume fraction of cells on the TNT@AHMS surface 4 weeks after implantation were significantly higher than those in the TNT group. Conclusion By depositing AHMS on the surface of TNT, the nanotopography can be protected. It not only prevents the active base topography from exerting subsequent biological effects but also further endows the material with the ability to promote bone regeneration, laying a foundation for the future development of nanotopography-modified titanium implants.

Objective To explore the clinical efficacy and imaging changes of minimally invasive nonsurgical periodontal therapy (MINST) assisted by endoscopy for deep intrabony defects and to compare its effectiveness with that of traditional scaling and root planning (SRP) to therefore provide a reference for clinical periodontal treatment. Methods Patients with deep intrabony defects ≥ 4 mm in size were selected and divided into two groups: the MINST (MINST, 20 cases, 81 sites) group and the classic scaling and root planing (SRP, 20 cases, 80 sites) group. Before treatment and 12 and 24 months after treatment, probing depth (PD) and clinical attachment loss (CAL) were examined. Moreover, changes in the depth and angle of the intrabony defects were analyzed. Follow-up examination and maintenance treatment should be conducted every 3 months for 12 months after the initial treatment and every 6 months thereafter until 24 months. Results The PD and CAL of patients in both groups continued to decrease (P<0.001), and imaging examinations revealed a decrease in defect depth and an increase in intrabony defect angle (P<0.001). The changes in the first 12 months were significantly greater than those in the last 12 months in both groups (P<0.001). The decreases in PD, CAL, and depth of intrabony defects and increase in angle in the MINST group were significantly greater than those in the SRP group (P<0.001). At 12 and 24 months after treatment, the PD and CAL in the MINST group were lower than those in the SRP group (P<0.001). The defect height of the MINST group decreased more than that of the SRP group (P<0.001), and the defect angle of the MINST group increased more than that of the SRP group (P<0.001). Conclusion Minimally invasive nonsurgical periodontal therapy can significantly promote the healing of deep intrabony defects and the regeneration of alveolar bone. Imaging reflects that alveolar bone healing is rapid at first and then slows. Compared with traditional SRP, endoscopically assisted MINST can yield better clinical indicators and imaging changes in intrabony defects.

Objective To investigate the value of the peripheral blood neutrophil to lymphocyte ratio (NLR) before nimotuzumab combined with neoadjuvant chemotherapy in predicting the short-term efficacy of neoadjuvant therapy for advanced oral squamous cell carcinoma (OSCC). Methods With the approval of the Ethics Committee and the informed consent of the patients, 59 patients with stage Ⅲ and Ⅳ OSCC who were admitted to the Oral and Maxillofacial Surgery Department of the First Hospital of Shanxi Medical University from September 2020 to June 2023 were enrolled. All the patients had complete clinical data, were pathologically diagnosed with squamous cell carcinoma, and received preoperative and received preoperative nimotuzumab + TP (docetaxel + cisplatin) neoadjuvant chemotherapy. The clinical data were analyzed, and the neutrophil and lymphocyte counts in peripheral blood were collected before and after nimotuzumab combined with neoadjuvant chemotherapy. The NLR was calculated, and the threshold value was calculated using the receiver operating characteristic (ROC) curve. Patients were divided into a high NLR group and a low NLR group according to the NLR threshold before nimotuzumab combined with neoadjuvant chemotherapy with TP. The clinical efficacy after nimotuzumab combined with neoadjuvant chemotherapy with TP was evaluated according to the evaluation criteria for solid tumor efficacy, and the correlation between the NLR and recent neoadjuvant therapy efficacy was analyzed. Immunohistochemical staining was used to detect the expression of epidermal growth factor receptor (EGFR) in OSCC tissues before and after nimotuzumab combined with neoadjuvant chemotherapy with TP and to analyze whether the expression of EGFR differed among the different NLR groups. Results A total of 59 patients with advanced OSCC were included. According to the ROC curve, the NLR threshold was 2.377, and the patients were divided into a <2.377 group (low NLR group), with 24 patients, and a>2.377 group (high NLR group), with 35 patients. The short-term neoadjuvant therapy effect was significantly greater in the lower NLR group than in the higher NLR group (P<0.05); EGFR expression in both the low NLR group and the high NLR group decreased after nimotuzumab combined with neoadjuvant chemotherapy with TP, and the decrease in the low NLR group was significantly greater than that in the high NLR group (P<0.05). Conclusion A low NLR before nimotuzumab combined with neoadjuvant chemotherapy with TP is associated with better neoadjuvant therapy outcomes, and such patients are more likely to benefit from preoperative nimotuzumab combined with neoadjuvant chemotherapy.

Objective To evaluate the clinical efficacy of invisible orthodontic appliances without brackets for the distal movement of maxillary molars to improve the ability of orthodontists to predict treatment outcomes. Methods Web of Science, Cochrane Library, Embase, PubMed, Wanfang Database, CNKI Database, and VIP Database were searched for studies investigating the efficacy of invisible orthodontic appliances for distal movement of maxillary molars in adult patients and published from database inception to August 1, 2023. A total of three researchers screened the studies and evaluated their quality and conducted a meta-analysis of those that met quality standards. Results This study included 13 pre- and postcontrol trials with a total sample size of 281 patients. The meta-analysis revealed no significant differences in the sagittal or vertical parameters of the jawbone after treatment when compared with those before treatment (P>0.05). The displacement of the first molar was MD=-2.34, 95% CI (-2.83, -1.85); the displacement was MD=-0.95, 95% CI (-1.34, -0.56); and the inclination was MD=-2.51, 95% CI (-3.56, -1.46). There was a statistically significant difference in the change in sagittal, vertical, and axial tilt of the first molar before and after treatment. After treatment, the average adduction distance of the incisors was MD=-0.82, 95% CI (-1.54, -0.09), and the decrease in lip inclination was MD=-1.61, 95% CI (-2.86, -0.36); these values were significantly different from those before treatment (P<0.05). Conclusion Invisible orthodontic appliances can effectively move the upper molars in a distal direction and control the vertical position of the molars. When the molars move further away, there is some degree of compression and distal tilt movement, which is beneficial for patients with high angles. The sagittal movement of incisors is beneficial for improving the patient's profile.

Objective To investigate the clinical characteristics, diagnosis and treatment of severe combined periodontal-endodontic lesions in a double-rooted maxillary lateral incisor with a palatal radicular groove and to provide a reference for clinical diagnosis and treatment. Methods A patient with a double-rooted left maxillary lateral incisor with a palatal radicular groove and severe combined periodontal-endodontic lesions underwent complete root canal therapy and intentional replantation, and a retrospective analysis of the management of this type of patient was performed based on the literature. Results The 3-year follow-up examination revealed no discomfort, good healing of the upper left lateral incisor, no pathological loosening, and a palatal gingival sulcus was found at a depth of approximately 1 mm. Review of the literature showed that the prognosis of the affected tooth and the choice of treatment plan were correlated with the length and depth of extension of the lingual groove toward the root, the periodontal condition and the pulpal status of the affected tooth. For minor PRGs or for affected teeth with no loss of pulpal viability, flap surgery and odontoplasty can be used to avoid endodontic treatment or retreatment. For deep or long lingual grooves that result in significant loss of periodontal tissue, endodontic treatment, odontoplasty, or closure of the grooves and guided tissue regeneration are needed. In the case of PRGs with double root formation, the affected tooth can be preserved via root canal therapy, removal of the small root and filling with apical restorative material, and intentional replantation. Conclusion In cases of severe combined periodontal-endodontic lesions due to palatal radicular grooves occurring in double-rooted maxillary lateral incisors, clinical presentation and imaging can prevent missed diagnoses, and appropriate treatment should be based on the length and depth of lingual grooves extending toward the roots, periodontal conditions, and pulpal status of the affected teeth.

Objective To discuss the possible etiology, pathogenesis, clinical features, diagnosis and treatment of epidermoid cysts of the jaw and to provide a reference for clinical diagnosis and treatment. Methods A case of an epidermoid cyst in the right mandible with retained deciduous teeth and succedaneous impacted teeth was reviewed and analyzed in combination with the relevant literature. Results A patient presented with a mass in the right mandible that had persisted for 1 month after being found at imaging examination. Tooth 83 was retained, and tooth 43 was unerupted. Swelling was characterized by no obvious tenderness, fluctuation, or table tennis sensation and was observed in the lingual alveoli of teeth 83, 44, and 45. Imaging revealed a low-density shadow in the apex of teeth 83, 44, 45, and 46, approximately 1.9 cm × 2.6 cm × 1.6 cm in size, which wrapped around the dental crown of tooth 43. Preliminary diagnoses were as follows: right mandibular mass thought to be a dentigerous cyst; impacted tooth 43; and retained primary tooth 83. The mass in the right mandible was removed, and teeth 43 and 83 were extracted under intravenous and inhalation anesthesia. During the operation, the mass was observed to have a thin cyst wall and contained bean-like residue. Histopathological examination indicated an epidermoid cyst in the right mandible. At the 1-week follow-up examination, the patient reported no discomfort, and the surgical area showed good recovery. According to the literature, epidermoid cysts are benign cysts originating from ectopic ectodermal tissue that can occur throughout the body but rarely in the oral cavity and are even extremely rarer in the jaw. Epidermoid cysts of the jaw, which have no specific clinical manifestations, can be confused with odontogenic cysts such as dentigerous cysts and odontogenic tumors. Dental pulp tests and other techniques can serve as a reference for clinicians. The diagnosis is confirmed via histopathology. Surgical removal is a common treatment, with a good prognosis and a low recurrence rate. Conclusion The principle of treatment for an epidermoid cyst of the jaw is similar to that for a jaw cyst. The prognosis is good when the cyst is removed completely.

Pediatric malocclusion is common in dentistry. Some children with malocclusion combined with obstructive sleep apnea-hypopnea syndrome (OSAHS) often fail to receive appropriate treatment due to a lack of multidisciplinary diagnosis and treatment. It can cause abnormal ventilation during sleep, affecting the central nervous system and cardiovascular development and even causing neurological and behavioral problems. Pediatric OSAHS is caused by the narrowing of the upper respiratory tract, characterized by specific facial bone characteristics and neuromuscular factors and correlated with malocclusion. Due to its diverse clinical manifestations and etiology, the diagnosis and treatment of pediatric OSAHS require an interdisciplinary, personalized, and specialized approach. Questionnaires and physical examinations can be used for preliminary screening. Moreover, children's stomatology and otorhinolaryngology examinations are the basis for disease diagnosis. Polysomnography (PSG) is currently the direct diagnostic method. There are various treatment methods for OSAHS in children, and for OSAHS caused by adenoid tonsil hypertrophy, adenoidectomy and tonsillectomy are the main treatments. Othodontic treatment including mandibular advancement and rapid maxillary expansion et al is also effective for OSAHS in children with malocclusion. Currently, there is limited research on the correlation between childhood malocclusion and OSAHS, and multidisciplinary combination therapy may improve the cure rate, but there is a lack of sufficient evidence. In the future, the pathogenesis of OSAHS should be further elucidated, and research on multidisciplinary combination therapy should be promoted to achieve early intervention and treatment for potential and existing patients.

After years of development, the advantages of computer-assisted orthognathic surgery have been widely recognized. However, the clinical application of this technology is challenging. Each step may generate errors from data acquisition, computer-assisted diagnosis, and computer-assisted surgical design, causing errors to be transferred from the virtual surgical plan to the operation. The accumulation and amplification of errors will affect the final surgical effect. Currently, digital devices, such as intraoral scanners, are being explored for error control, utilizing automation methods and algorithms, and implementing personalized bone positioning methods. Moreover, there are still many problems that have not been fully resolved, such as precise simulation of postoperative soft tissue, functional assessment of mandibular movement, and absorbable internal fixation materials. Fully understanding computer-assisted orthognathic surgery's limitations could provide direction for optimizing existing methods while helping clinicians avoid risks and maximize its advantages to achieve the best outcome. Many emerging and cutting-edge technologies, such as personalized titanium plates, artificial intelligence, and surgical robots, will further promote the development of this discipline. We can expect future optimization of digital orthognathic surgical technology by innovations in automation, intelligence, and personalization.