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.

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.

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.

Objective This study aims to determine the effects of low-level laser (LLL) on the expression of interleukin-6 (IL-6), tumor necrosis factor (TNF)-α, osteoprotegerin (OPG), and receptor activator of nuclear factor-κB ligand (RANKL) in human periodontal ligament cells (HPDLCs) stimulated by high glucose; and identify the molecular mechanism of LLL therapy in the regulation of periodontal inflammation and bone remodeling during orthodontic treatment in diabetic patients. Methods HPDLCs were cultured in vitro to simulate orthodontic after loading and irradiated with LLL therapy. The cultured cells were randomly divided into four groups: low glucose Dulbecco’s modification of Eagle’s medium (DMEM)+stress stimulation (group A), high glucose DMEM+stress stimulation (group B), hypoglycemic DMEM+LLL therapy+stress stimulation (group C), and hyperglycemic DMEM+LLL therapy+stress stimulation (group D). Groups C and D were further divided into C1 and D1 (energy density: 3.75 J/cm²) and C2 and D2 (energy density: 5.625 J/cm²). Cells in groups A, B, C, and D were irradiated by LLL before irradiation. At 0, 12, 24, 48, and 72 h, the supernatants of the cell cultures were extracted at regular intervals, and the protein expression levels of IL-6, TNF-α, OPG, and RANKL were detected by enzyme-linked immunosorbent assay. Results 1) The levels of IL-6 and TNF-α secreted by HPDLCs increased gradually with time under static pressure stimulation. After 12 h, the levels of IL-6 and TNF-α secreted by HPDLCs in group A were significantly higher than those in groups B, C1, and C2 (P<0.05), which in group B were significantly higher than those in groups D1, and D2 (P<0.01). 2) The OPG protein concentration showed an upward trend before 24 h and a downward trend thereafter. The RANKL protein concentration increased, whereas the OPG/RANKL ratio decreased with time. Significant differen-ces in OPG, RANKL, and OPG/RANKL ratio were found among group A and groups B, C1, C2 as well as group B and groups D1, D2 (P<0.05). Conclusion 1) In the high glucose+stress stimulation environment, the concentrations of IL-6 and TNF-α secreted by HPDLCs increased with time, the expression of OPG decreased, the expression of RANKL increased, and the ratio of OPG/RANKL decreased. As such, high glucose environment can promote bone resorption. After LLL therapy, the levels of IL-6 and TNF-α decreased, indicating that LLL therapy could antagonize the increase in the levels of inflammatory factors induced by high glucose environment and upregulate the expression of OPG in human HPDLCs, downregulation of RANKL expression in HPDLCs resulted in the upregulation of the ratio of OPG/RANKL and reversed the imbalance of bone metabolism induced by high glucose levels. 2) The decrease in inflammatory factors and the regulation of bone metabolism in HPDLCs were enhanced with increasing laser energy density within 3.75-5.625 J/cm². Hence, the ability of LLL therapy to modulate bone remodeling increases with increasing dose.

Objective To investigate possible cross-talk genes, associated pathways, and transcription factors between chronic periodontitis (CP) and chronic obstructive pulmonary disease (COPD). Methods The gene expression profiles of CP (GSE10334 and GSE16134) and COPD (GSE76925) were downloaded from the GEO database. Differential expression and functional clustering analyses were performed. The protein‑protein interaction (PPI) network was constructed. The core cross-talk genes were filtered using four topological analysis algorithms and modular segmentation. Then, functional clustering analysis was performed again. Results GSE10334 detected 164 differentially expressed genes (DEGs) (119 upregulated and 45 downregulated). GSE16134 identified 208 DEGs (154 upregulated and 54 downregulated). GSE76925 identified 1 408 DEGs (557 upregulated and 851 downregulated). The PPI network included 21 nodes and 20 edges. The final screening included seven cross-talk genes: CD79A, FCRLA, CD19, IRF4, CD27, SELL, and CXCL13. Relevant pathways included primary immunodeficiency, the B-cell receptor signaling pathway, and cytokine-cytokine receptor interaction. Conclusion This study indicates the probability of shared pathophysiology between CP and COPD, and their cross-talk genes, associated pathways, and transcription factors may offer novel concepts for future mechanistic investigations.

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.

Objective This study aimed to compare the effectiveness of ultrasound and acoustic and laser cleaning of curved root canals. Methods A total of 92 molars with independent root canals with a curvature of 20°-40° were prepared and standardized at 04 25# and stained with gentian violet solution for 72 h. Among them, 52 were randomly divi-ded into four groups for final rinsing (n=13): NI group, PUI group, EDDY group, and PIPS group. Ten samples in each group were cut horizontally along the long axis perpendicular to the root and divided into curved upper, curved, and apical segments. Images were taken with a stereomicroscope and Image J measurements were taken to calculate the depth of rinse penetration. The remaining three samples from each group were split along the long axis of the dentin, photographed by scanning electron microscope to record the dentin tubule exposure and staining layer, and scored for staining layer by double-blind method. SPSS 26.0 software was used to perform statistical analysis and select the best flushing method. An extra 40 samples were randomly divided into four groups for detection of flushing fluid penetration depth (n=10): 10, 20, 30, and 40 s. Results In the upper part, the mean depth of infiltration was not significantly different between the experimental and control groups (P>0.05). The PIPS group had a significantly lower smear layer score than the control group and the EDDY group (P<0.01). In the curved segment, the mean depth of infiltration was significantly greater in the PUI group than in the control group (P<0.05); the tarnish layer score was lower in each experimental group than in the control group. At the top, the mean depth of infiltration was greater in the PUI and PIPS groups than in the control group (P<0.05), and the smear layer score was lower in the PIPS group than in the other groups (P<0.05). After the time was changed, the depth of infiltration of PUI increased only in the apical segment as the flushing time increased. Conclusion The PUI and PIPS methods facilitate the penetration of irrigation solution into the dentin canal in curved root canals, especially in the apical segment. The PIPS technique is effective in removing the smear layer in curved root canals.

Objective The long-term effect of muscular force balance reconstruction technique combined with intranasal fixation for correcting secondary nasolabial deformity after unilateral cleft lip was evaluated. The aim was to provide a basis for further improving the surgical treatment effect of secondary nasolabial deformity of acleft lip. Methods A total of 40 patients aged 4-28 years with secondary nasal deformity and unilateral cleft lip were selected as research subjects. The two-dimensional photo measurement analysis method was used in comparing the surgical results before and immediately after the operation (7 d) and 1 year after the operation. Results Columellar angle, nostril height ratio (NHR), alar rim angle, alar rim angle ratio, and nostril shape (NS) increased dimmediately after the operation, whereas alar base width ratio (ABWR) and nostril width ratio decreased (NHR) immediately after the operation (P<0.01). The ABWR, NHR, and NS immediately after the operation were not significantly different from those 1 year after the operation (P>0.05). Conclusion Muscular force balance reconstruction technique combined with intranasal fixation is effective in the repair of unilateral secondary nasolabial deformity, and stable results can be obtained 1 year after surgery.

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.

Objective This study aims to understand the prevalence and treatment status of dental caries in preschool children aged 3-5 years in China among the past five years. Methods Databases including CNKI, WanFang data, VIP, MEDLINE, EMBASE were systematically searched for the epidemiological literature of dental caries in preschool children in China from 2017 to 2022 for Meta-analysis. Subgroup analysis was carried out by sex, age, geographical region, ethnology, and residence. Results The Meta-analysis enrolled 27 literatures, including 72 788 preschool children; of which, 38 344 children had dental caries. The merged prevalence of dental caries in preschool children was 59.3% (95%CI: 54.6%-63.9%), and the merged filling rate of caries was 5.7% (95%CI: 2.5%-8.8%). In the subgroup analysis, the merged prevalence rates of caries in children aged 3, 4, and 5 years were 46.9% (95%CI: 42.5%-51.4%), 59.0% (95%CI: 55.1%-62.8%), and 67.3% (95%CI: 62.5%-72.2%), respectively, and the difference was significant. In addition, significant differences were found among different regions. The merged prevalence of dental caries in preschool children was the highest in northwest China (68.6%, 95%CI: 55.5%-81.8%) and the lowest in central China (49.1%, 95%CI: 47.3%-51.0%). The merged prevalence of dental caries was not significantly different among preschool children of different genders, ethnicities, and residence. Conclusion The prevalence of dental caries in preschool children aged 3-5 years in China is high and continuously increases. The oral health of preschool children should be comprehensively strengthened, and a three-level strategy should be implemented to prevent diseases.

Conventional periodontal regenerative surgery has limited effect on tooth with severe periodontitis-related alveolar bone defects. This article reported a case of regenerative treatment in severe distal-bone defect of mandibular first molar. The treatment involved applying 3D printing, advanced/injectable platelet-rich fibrin, and guided tissue-regeneration technology. After the operation, the periodontal clinical index significantly improved and the alveolar bone was well reconstructed.

Langerhans cell histiocytosis (LCH) is a group of unexplainable abnormal proliferation and aggregation of Langerhans cell. LCH can be classified into four clinical variants: Letterer-Siwe disease, Hand-Schüller-Christian disease, eosinophilic granuloma, and congenital self-healing LCH. LCH is most prevalent in children. Lesions can be localized in a single system or multiple organs, and clinical manifestations vary depending on the affected organs. The skin and mucocutaneous tissues are the starting point of the affected tissue. This study presents a LCH case characterized by transient self-healing. This case can further provide references for the clinical diagnosis and treatment of LCH.

Stevens-Johnson syndrome (SJS), also known as the multifactorial erythematous drug eruption, is a class of adverse reactions of the skin and mucous membranes primarily caused by drug allergy often involving the oral cavity, eyes, and external genital mucosa, generally accompanied by fever, and can be life-threatening in severe cases. In February 2022, the Department of Stomatology, the First Affiliated Hospital of Zhengzhou University admitted a patient with huge inflammatory hyperplasia of bilateral lingual margins secondary to SJS. Upon admission, no other obvious symptoms were observed except for tongue hyperplasia. The patient suffered from a severe adverse drug reaction caused by acetaminophen 2 months ago and was complicated by liver dysfunction and pulmonary infection. After 1 month of treatment and rehabilitation, he developed a secondary tongue mass and was subsequently admitted to Dept. of Oral and Maxillofacial Surgery Ward 2, the First Affiliated Hospital of Zhengzhou University. After completing the examination, the tongue mass was surgically removed. After a follow-up of 11 months, the patient’s condition was satisfactory and no temporary discomfort was observed. The case of tongue mass secondary to SJS is extremely rare. If a stomatologist encounters a similar case, we should carefully inquire about the drug allergy history and recent medication history, and be alert to whether or not they had adverse drug reactions recently.

Chinese medicine entered a significant period from foundation to maturity between Han and Tang dynasties when the Chinese traditional stomatology was a key stage. Sorting and analysis of existing literature and research outcomes have showed that current research on stomatology between Han and Tang dynasties focuses on oral physiology, pathology, diagnosis and treatment, and health care. It also involves stomatology history and explanation of termino-logies related to mouth and teeth recorded in medical books, use of simple methods, and thinking with citation and analysis of literature simply listed and reasoning preliminarily deducted. From the macro perspective, current research has not unveiled the whole picture of stomatology between the two dynasties and left a series of key issues unresolved. Thus, new methods should be developed and employed to carry out medical research on stomatology between Han and Tang dynasties given that is has a prosperous future.