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Table of Content

    25 June 2025, Volume 34 Issue 3 Previous Issue   
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    Original Articles
    Study on the therapeutic effect and potential mechanisms of astaxanthin electrospun patches on oral mucosal ulcers in rats
    Wang Huan, Sun Pei, Liu Zhaochen, Zhang Hui, Guo Yiqing, Zhao Houping, Wang Peiyan, Deng Jing
    2025, 34 (3):  225-232.  doi: 10.19439/j.sjos.2025.03.001
    Abstract ( 39 )   PDF (2324KB) ( 34 )  
    PURPOSE: To investigate the effect and underlying mechanism of astaxanthin electrospun patches in treating oral ulcers in rats. METHODS: An oral ulcer model of rats was established by mechanical trauma, then the rats were randomly divided into astaxanthin electrospun patch group, chitosan patch group, metronidazole patch group and blank control group. The ulcer healing time and the area healing rate of each group were observed. The pathological changes of ulcer tissues in each group were observed and scored by H-E staining 2, 4 and 6 days after drug administration. Meanwhile, the toxic effects of the drugs on the rat organs were detected. The changes in the levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in ulcer tissues were detected by WST-1 and TBA methods. Tumor necrosis factor-α (TNF-α) and Interleukin 6 (IL-6) were analyzed through immunohistochemistry experiments. RESULTS: Compared with the other groups, the astaxanthin electrospun patch could significantly accelerate the reduction of the ulcer area, promote its pathological healing, reduce the expression levels of TNF-α and IL-6, and significantly decrease the content of MDA in the ulcer tissue while increasing the activity of SOD. Six days after administration, there were significant differences in the levels of SOD and MDA compared with the blank control group and the metronidazole patch group(P<0.05), while there was no significant difference compared with the chitosan patch group(P>0.05). CONCLUSIONS: The astaxanthin electrospun patches have better performance in promoting ulcer healing, which may be related to their strong antioxidant and anti-inflammatory properties. It is expected to provide a natural marine preparation with better efficacy for the treatment of oral ulcers.
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    Effect of Er:YAG laser combined with NaClO on the removal of root canal smear layer and dentin microhardness
    Bai Xue, Wang Xiao
    2025, 34 (3):  233-236.  doi: 10.19439/j.sjos.2025.03.002
    Abstract ( 31 )   PDF (809KB) ( 13 )  
    PURPOSE: To evaluate the effects of Er:YAG laser combined with NaClO on the removal of root canal taint layer, calcium hydroxide clearance and dentin microhardness. METHODS: A total of 318 single-rooted extracted teeth collected from March 2021 to January 2024 were selected, the 13 mm root was taken and mechanically prepared and randomly divided into three groups, with 106 teeth in each group. The control group was rinsed with NaClO, the experimental group 1 was rinsed with NaClO combined with ultrasonic washing, and the experimental group 2 was treated with Er:YAG laser on the basis of NaClO. The removal of the smear layer was observed under electron microscope, and the microhardness of dentin post-treatment was assessed using a microhardness tester. RESULTS: The clearance rate of calcium hydroxide in experimental group 2 was significantly higher than that in experimental group 1 and control group, and the stain layer scores of crown formula 1/3, root middle 1/3 and root tip 1/3 were significantly lower than those in the other 2 groups(P<0.05). There was no significant difference between the initial and final microhardness of the three groups(P>0.05). CONCLUSIONS: Er: YAG laser combined with NaClO can effectively enhance the removal effect of stain layer in root canal therapy, and has little effect on dentin microhardness.
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    Three-dimensional finite element analysis of stress distribution and influence of stainless steel preformed crown on temporomandibular joint in children
    Zhang Yulu, Liu Jia
    2025, 34 (3):  237-243.  doi: 10.19439/j.sjos.2025.03.003
    Abstract ( 30 )   PDF (1333KB) ( 27 )  
    PURPOSE: To study the stress effect and distribution pattern of the first and second primary molars on temporomandibular joint in the restoration of upper and lower teeth with stainless steel precrown using three-dimensional finite element method, in order to provide theoretical basis for clinical diagnosis and treatment. METHODS: CBCT data from one male and one female aged 3, 6, and 8 years old were collected, and the first and second maxillary molar teeth, upper and lower mandible, dentition and temporomandibular joint(TMJ) data were obtained respectively. Three-dimensional finite element method was used to create the finite element models of the first and second maxillary molar teeth, upper and lower mandible, dentition and TMJ, respectively. The stress distribution of the TMJ with the stainless steel prefabricated crown raised at different heights was analyzed by applying the load force. RESULT: After stainless steel crown repair, different loads were applied to the TMJ, and the maximum stress values generated by the condyle were analyzed and compared. The stress difference analysis results of the condyle in children aged 3, 6, and 8 under different genders, ages, and load angles were statistically significant(P<0.01), while the stress difference analysis results of different groups were not statistically significant(P>0.05). CONCLUSIONS: After restoring primary molars with stainless steel preformed crowns, applying three angle loads results in a more uniform distribution of stress in the TMJ at normal occlusal height. Therefore, using stainless steel crowns to restore normal occlusal height in clinical restorative treatment is beneficial for reducing stress concentration in TMJ and improving the efficacy and long-term prognosis of primary molars restoration.
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    Role of minocycline-loaded silica nanospheres in the regulation of periodontitis inflammation in rats
    Yang Jinxin, Ding Kexin, Sun Zhe, Cui Yawen, Liu Zongxiang
    2025, 34 (3):  244-250.  doi: 10.19439/j.sjos.2025.03.004
    Abstract ( 29 )   PDF (1751KB) ( 21 )  
    PURPOSE: To investigate the effect of minocycline hydrochloride(MH) loaded nano-silica microspheres(MSNion) on the inflammatory regulation of periodontitis in rats. METHODS: Mesoporous silica(MSN) was prepared by classical Stöber method and MSNion was obtained by doping hydroxyapatite. MH was loaded into MSNion by magnetic stirring, and chitosan (COS), which had anti-inflammatory and antibacterial effect, was adsorbed on its surface by using charge interactions, forming MH@MSNion@COS microspheres. The microspheres were characterized by electron microscopy and X-ray diffraction. The experiments were divided into control, MH, MSNion@COS and MH@MSNion@COS groups. The cytotoxicity of each group was assessed using the CCK-8 cell assay and the optimal concentration was determined. The expression levels of inflammatory factors(TNF-α, IL-6, IL-1β, iNOS, IL-10) were determined in each group using ELISA kits. In periodontitis model, the rats were treated according to the grouping of cell experiments, periodontal probing depth (PD) and gingival index (GI) of the rats were measured at 0, 1, 2, 4 weeks. At 4 weeks of the experiment, the peripheral blood of each group of rats was collected, and the levels of inflammatory factors in serum were detected by ELISA kits. RESULTS: Nanoparticles with a particle size of about 110 nm were prepared and observed as regular spheres by electron microscopy. MH@MSNion@COS degraded into fragments with unclear structure at the 8th day. In vitro drug release assay showed a slow release of MH, and the MH release rate reached 80% at about the 15th day. In cell experiment, MH@MSNion@COS showed the best cell proliferation activity at 50 μg/mL (P<0.05), and the cell activity was higher than that of MH group and MSNion@COS group(P<0.05). There was no significant difference between MH group and MSNion@COS group. ELISA results showed that the expression of inflammatory factors in MH@MSNion@COS group was significantly lower than that in LPS group at the first day(P<0.01), and there was no significant difference between MH group and MSNion@COS group. At the 3rd day, the expression of M1 inflammatory factors in MH@MSNion@COS group was lower than that in control group, and the expression of M2 inflammatory factors was higher than that in control group(P<0.05). PD and GI of MH@MSNion@COS group were significantly decreased after administration compared with other groups(P<0.05), and the amount of inflammatory factors was lower than other groups(P<0.05). CONCLUSIONS: MH@MSNion@COS has a good inflammatory regulation effect on experimental periodontitis in vitro and in vivo.
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    Maxillary sinus floor wall typing and three-dimensional finite element modelling of maxillary sinus internal elevation
    Zhu Kai, Cheng Lidi, Zheng Yuqing, Sun Qijun
    2025, 34 (3):  251-256.  doi: 10.19439/j.sjos.2025.03.005
    Abstract ( 35 )   PDF (1080KB) ( 17 )  
    PURPOSE: To evaluate the equivalent stress and displacement of maxillary sinus floor mucosa by three-dimensional finite element analysis under different types of maxillary sinus floor. METHODS: Three-dimensional finite element models of three different maxillary sinus floor shapes (shallow concave, deep concave and convex) were established by three-dimensional reconstruction of maxillary sinus bones and mucosa. The process of applying dynamic impact load to the maxillary sinus floor was simulated by using the ejector during maxillary sinus lifting operation, and the biomechanical characteristics of different maxillary sinus floor mucosa during ejection was analyzed. RESULTS: The equivalent stress and displacement of maxillary sinus floor mucosa were deep concave (0.518 90 MPa/0.002 955 mm), shallow concave (0.590 25 MPa/0.003 515 mm) and convex (0.623 56 MPa/0.003 660 mm). In the process of axial displacement of the ejector from 1-10 mm, the stress of the mucosa at the bottom of maxillary sinus increased uniformly. CONCLUSIONS: The equivalent stress level of mucosa is related to the morphology of sinus floor. Under the same load condition, the tension on mucosa increases obviously during internal lifting of convex maxillary sinus floor, which has an adverse effect during internal lifting operation.
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    Three dimensional finite element analysis of different restoration types and materials for maxillary first premolar with large defect
    Li Xiaoman, Tian Benjian, Mirealimu·Miadili, Gao Yiming
    2025, 34 (3):  257-261.  doi: 10.19439/j.sjos.2025.03.006
    Abstract ( 29 )   PDF (1012KB) ( 10 )  
    PURPOSE: To provide references for the selection of restoration types and materials for the first premolar with large defect in clinical practice. METHODS: A large area defect model of the maxillary first premolar was established and repaired with different types and materials, including group A (inlay group), group B (endocrown group), group C (fiber post core crown group), and group D (pure titanium post core crown group). And then, according to different repair materials, it was divided into 3 subgroups, namely group 1 (zirconia), group 2 (glass ceramic), and group 3 (resin based ceramic), totaling 12 groups. The stress distribution and magnitude were investigated using finite element analysis software. RESULTS: In the inlay group, the stress concentration area was large and tended to spread along the neck of tooth; in the post core crown group and endocrown group, the stress distribution was more uniform. In terms of restorative materials for endocrown, resin based ceramic materials had the lowest stress, followed by glass ceramic materials, and zirconia materials had the highest stress. CONCLUSIONS: Large defects of the first premolar can be repaired with endocrowns and post core crowns, and endocrowns have good applicability and advantages. Resin based ceramic materials are recommended for the selection of the endocrown materials for the least stress of the remaining tooth.
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    Evaluation of the effect of simultaneous implantation of alveolar process dilation and guided bone regeneration in patients with severe deficiency of alveolar bone horizontal width
    Yu Miao, Jin Rong
    2025, 34 (3):  262-266.  doi: 10.19439/j.sjos.2025.03.007
    Abstract ( 28 )   PDF (575KB) ( 51 )  
    PURPOSE: To explore the influence of alveolar process expansion, guided bone regeneration (GBR) and bone grafting for simultaneous dental implantation therapy on bone resorption volume, retention and masticatory function in patients with severe deficiency of alveolar bone horizontal width. METHODS: Eighty patients with severely insufficient alveolar bone width who received dental implantation therapy in Hangzhou Stomatology Hospital were selected from January 2021 to January 2023. Totally 40 patients (55 teeth) who received alveolar process expansion combined with GBR bone grafting were included in the experimental group, while 40 patients (51 teeth) with traditional alveolar bone splitting were enrolled as the control group. Both groups were treated with dental implantation at the same time. The repair effect [bone healing time, diameter and implant stability quotient (ISQ)], occurrence of complications and subjective feeling scores (retention, pain and tooth aesthetics) 1 year after surgery, alveolar bone resorption volume (mesial and distal), periodontal related indicators [gingival sulcus depth (SPD), gingival sulcus bleeding index (SBI) and gingival index(GI)] and masticatory function (masticatory efficiency, occlusal force) before surgery and 1 year after surgery were compared between both groups. RESULTS: The bone healing time in the experimental group was significantly less than that in the control group(P<0.05). The total incidence rate of complications was significantly lower in the experimental group than that in the control group(P<0.05). At 1 year after surgery, the alveolar bone resorption volume, SPD, SBI and GI in both groups were significantly reduced than those before surgery, and the indicators in the experimental group were much lower(P<0.05). The masticatory efficiency and occlusal force in the experimental group were significantly enhanced compared to before surgery(P<0.05), and the two indicators were significantly higher than those in the control group(P<0.05). At 1 year after surgery, the retention function and pink esthetic score(PES) in the experimental group were significantly higher (P<0.05) while the visual analogue scale(VAS) score was significantly lower than the control group (P<0.05). CONCLUSIONS: Simultaneous dental implantation with alveolar process expansion combined with GBR bone grafting has good repair effect and safety for patients with severe bone width deficiency. It can help to reduce bone resorption volume, enhance retention stability after bone grafting, relieve pain and improve tooth aesthetics.
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    Clinical anatomy of the islanded pedicled nasolabial flap and its application in reconstruction of postoperative defects of T1-T2 stage carcinoma of the floor of mouth
    Zhou Xue, Wang Weihong, Luo Zhengpeng, Zhou Zhirong, Liu Yu, Zhang Jian
    2025, 34 (3):  267-270.  doi: 10.19439/j.sjos.2025.03.008
    Abstract ( 22 )   PDF (933KB) ( 10 )  
    PURPOSE: To investigate the anatomic features of nasolabial flap pedicled with a facial artery and its application in repairing the defect after surgery of stage T1-T2 carcinoma of the floor of mouth. METHODS: Dissections of the maxillofacial region were performed on 8 specimens of national adults fixed with 10% formaldehyde, and the anatomical pictures were analyzed using Image-Pro Plus 6.0 software. Nine patients were retrospectively reviewed from August 2015 to January 2024 for the repair of postoperative defects of stage T1-T2 carcinoma of the floor of mouth using nasolabial fold flaps with a facial artery perforator branch as vascular pedicle. RESULTS: The external diameter of the facial artery at the lower border of the mandible was (2.05±0.98) mm. The main trunk of the facial artery traveled along the line from the beginning of the facial artery to the nasal blade and had a length of (90.89±3.79) mm. The main facial vein run along the line from the beginning of the facial artery to the medial canthus, and its length is (118.10±2.57) mm. The longest distance between the facial artery and the facial vein was (25.92±1.96) mm. Nine patients had a favourable postoperative outcomes without obvious complications. CONCLUSIONS: Repair of postoperative defects in middle-aged and elderly patients with T1-T2 stage carcinoma of the floor of mouth using a nasolabial fold flap can achieve satisfactory clinical outcomes.
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    Evaluation of the effect of cruciform tooth division and T-type crown amputation in extraction of mandibular middle and low impacted teeth
    Liu Jie, Wang Ying, Liu Zhenfei
    2025, 34 (3):  271-275.  doi: 10.19439/j.sjos.2025.03.009
    Abstract ( 25 )   PDF (592KB) ( 41 )  
    PURPOSE: To evaluation the effect of cruciform tooth division and T-type crown amputation in extraction of mandibular middle and low impacted teeth. METHODS: A total of 81 patients with mandibular middle and low impacted teeth treated in Bozhou People's Hospital from September to November 2024 were selected. According to the different extraction methods,they were divided into the control group(n=40, T-type crown amputation) and experimental group(n=41, cross tooth extraction). The operative time, intraoperative complications(anxiety, broken root), postoperative complications (pain, swelling and restricted mouth opening), healing of tooth extraction socket 1 week after surgery, and quality of life before and 1 week after surgery[oral health impact scale 14(OHIP-14)] were compared between the two groups. RESULTS: The operative time of the experimental group was significantly shorter than that of the control group, the total incidence of intraoperative complications(4.88%) was significantly lower than that of the control group (20.00%), the score of postoperative pain and mouth opening restriction was significantly lower than that of the control group, the degree of postoperative swelling was significantly less than that of the control group, and the total incidence of postoperative complications(4.88%) was significantly lower than that of the control group(32.43%). The healing score of tooth socket 1 week after operation was significantly lower than that of the control group (P<0.05). One week after surgery,the OHIP-14 score of both groups was decreased,and the experimental group was significantly lower than the control group(P<0.05). CONCLUSIONS: Compared with T-type crown amputation, cruciform tooth division can shorten the operation time of mandibular middle and low impacted tooth extraction, reduce the occurrence of intraoperative anxiety, broken root, postoperative pain, swelling and restricted mouth opening, and is conducive to the healing of tooth extraction wound.
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    Evaluation of the effect of concentrated growth factor membrane and Haiao oral repair membrane on the preservation of tooth extraction site in the posterior tooth region
    Hu Shaoguang, Wu Cuiling, Wang Quan, Yin Meihong, Lin Houxue
    2025, 34 (3):  276-280.  doi: 10.19439/j.sjos.2025.03.010
    Abstract ( 30 )   PDF (847KB) ( 43 )  
    PURPOSE: To evaluate the effect of concentrated growth factor (CGF) membrane and Haiao oral repair membrane on the preservation of extraction sites in the posterior area of teeth. METHODS: A total of 96 patients requiring site preservation after posterior tooth extraction from January 2020 to December 2022 were selected and divided into groups A and B by random number table method, with 48 cases in each group. After tooth extraction, Bio-Oss bone powder was used to cover tooth extraction wound in group A with CGF membrane, and in group B with Haiao oral repair membrane. The healing of the operative area, the changes of vertical height and horizontal width of alveolar bone, visual analog scoring (VAS) of pain, the changes of buccal and palatal tissue thickness and the rate of bone replantation were compared between the two groups. RESULTS: One week after operation, the tooth extraction wound in group A healed well, while 2 cases in group B healed poorly, but there was no significant difference between the two groups(P>0.05). Before surgery, there was no significant difference in vertical height and horizontal width of alveolar bone between the two groups(P>0.05); at 6 months after operation, the vertical height of alveolar bone was significantly increased and the horizontal width was significantly decreased(P<0.05), but there was no significant difference between the two groups(P>0.05).The VAS score of pain 1 week after surgery in 2 groups was lower than that 3 days and 24 hours after surgery, and the VAS score of pain in group A was lower, and the interaction between groups, and time points were significantly different(P<0.05).There was no significant difference in the thickness of buccal and palatal tissues between the two groups before and 6 months after surgery(P>0.05); at 6 months after surgery, the tissue thickness of the palatal side in group B was significantly lower than before surgery(P<0.05). Six months after surgery, the bone replantation rates in group A and group B were 4.17% and 6.25%, respectively, with no significant difference between the two groups(P>0.05). CONCLUSIONS: Both CGF membrane and Haiao oral repair membrane have good efficacy in the preservation of tooth extraction sites in the posterior region, which can effectively delay alveolar bone mass absorption, and CGF has a better effect in reducing short-term postoperative pain in patients.
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    Prediction value of miR-146a-5p, PI3K and Akt in gingival crevicular fluid on the severity of chronic periodontitis
    Gao Jiaming, Zhang Naixin, Yue Jiasheng
    2025, 34 (3):  281-285.  doi: 10.19439/j.sjos.2025.03.011
    Abstract ( 25 )   PDF (667KB) ( 20 )  
    PURPOSE: To investigate the predictive value of microRNA-146a-5p (miR-146a-5p), phosphatidylinositol 3 kinase (PI3K) and protein kinase B (Akt) in gingival crevicular fluid for the severity of chronic periodontitis (CP). METHODS: A total of 121 CP patients admitted to Qinhuangdao Hospital of Peking University Third Hospital from March 2021 to March 2024 were selected. According to the severity of the disease, the patients were divided into mild-to-moderate group(n=85) and severe group(n=36). The levels of miR-146a-5p, PI3K and Akt in gingival crevicular fluid were detected, and probing depth(PD), clinical attachment loss(CAL), sulcus bleeding index(SBI) were collected to analyze the factors affecting the severity of CP. Area under the curve (AUC) of receiver operating characteristic (ROC) was used to analyze the predictive value of miR-146a-5p, PI3K and Akt in CP severity. RESULTS: The miR-146a-5p, PI3K, Akt, probing depth(PD), the level of clinical attachment loss (CAL), the ratio of combined diabetes and the smoking history in the severe group were significantly higher than those in the mild-moderate group(P<0.05). Logistic regression analysis showed that diabetes mellitus(OR=3.252, 95%CI: 1.312-8.059), miR-146a-5p level(OR=5.273, 95%CI: 2.469-11.258), PI3K level (OR=4.877, 95%CI: 1.812-13.123) and Akt level (OR=4.421, 95%CI: 1.669-11.710) were independent risk factors affecting the severity of the disease(P<0.05). ROC results showed that the AUC of miR-146a-5p, PI3K, Akt and their combined prediction of CP severity were 0.801, 0.789, 0.772 and 0.898, respectively(P<0.05). CONCLUSIONS: The levels of miR-146a-5p, PI3K and Akt in gingival crevicular fluid are independent risk factors for CP severity, and combined detection of the three parameters can better predict the severity of patients' disease.
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    Application of 3D oral scanning combined with digital guide plate in implant restoration of mandibular posterior dentition defect
    Ye Shuhua, Zhu Jiadong, Deng Ningning
    2025, 34 (3):  286-290.  doi: 10.19439/j.sjos.2025.03.012
    Abstract ( 20 )   PDF (611KB) ( 17 )  
    PURPOSE: To investigate the value of 3D oral scanning combined with digital guide plate in implant restoration of mandibular posterior dentition defect. METHODS: A total of 96 patients with mandibular posterior dentition defects treated in Hangzhou Stomatology Hospital from March 2021 to October 2022 were randomly divided into control group (48 cases) and experimental group (48 cases). The control group was treated with conventional implant repair, while the experimental group was treated with 3D oral scanning combined with digital guide plate implant repair. The operation related indexes, implant accuracy, implant stability, alveolar ridge and parietal bone absorption of the two groups were compared, and the implant success rates, complication rates and patient satisfaction were also evaluated. RESULTS: There was no significant difference in postoperative pain time and swelling time between the two groups(P>0.05), but the surgical time in the experimental group was significantly shorter than that in the control group(P<0.05). The crown deviation, root deviation, depth deviation and angle deviation in the experimental group were significantly smaller than those in the control group(P<0.05). The success rate of the experimental group was significantly higher than that of the control group(P<0.05). There was no statistically significant difference in the planting success rate and stability coefficient between the two groups(P>0.05), and the absorption of alveolar crest bone in the experimental group was significantly lower than that in the control group(P<0.05). The total incidence of complications in the experimental group was significantly lower than that in the control group (P<0.05). The satisfaction of patients in the experimental group was significantly higher than that in the control group(P<0.05). CONCLUSIONS: The application of 3D oral scanning combined with digital guide plate in implant restoration of mandibular posterior dentition defect can effectively shorten the operation time, improve the accuracy of implant, reduce the complications, and improve patients' satisfaction.
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    A new fixed Twin-block appliance in the treatment of adolescent patients with skeletal Class Ⅱ malocclusion
    Ding Meng, Zhang Wei, Shen Qun, Chen Yucheng, Zhang Hui, Ge Feifan, Hang Mengyue, Wu Jianhua
    2025, 34 (3):  291-297.  doi: 10.19439/j.sjos.2025.03.013
    Abstract ( 29 )   PDF (1507KB) ( 35 )  
    PURPOSE: To evaluate the clinical effect of a new fixed Twin-block on adolescent patients with skeletal ClassⅡ malocclusion. METHODS: Twenty-one patients aged 10-13 years with skeletal ClassⅡ malocclusion with mandibular retrusion were chosen for functional treatment using a new fixed Twin-block. Before and after treatment, panoramic and cephalometric films were taken, and the observation indexes were measured and recorded. RESULTS: There was no loosening or destruction of the appliance during treatment, the mean duration of treatment was (11.42±1.78) months. The position of the mandible(SNB), the length of the mandible (Co-Gn), nasolabial angle (Cm-Sn-UL), condylar sagittal position(Pcd-S), the lower labial protrusion distances (LL-SnPg') were significantly increased (P<0.05) after treatment, and the relative position of the maxilla and mandible (ANB), Y-axis angle(SGn/FH), the inclination of the maxillary incisors (U1/SN), and the depth of the mental-labial sulcus (Si-LLPg') reduced(P<0.05). Maxillary position(SNA), posterior mandibular position(S Vert-Co), mandibular length(Go'-Me), the mandibular incisor inclination (IMPA), and upper and lower mesial incisor angles(U1/L1), protrusion of the upper lip (UL-SnPg') were changed but without significant difference(P>0.05). The vertically orientated measurements of the vertical position of the lower dentition(Ll-MP), L6-MP, the vertical distance of the upper and posterior teeth (U6-PP), anterior height (N-Me), facial height index(S-Go'/N-Me), and mandibular plane angle (MP/SN) did not change significantly(P>0.05), while the posterior height(S-Go'), the vertical position of the upper dentition(U1-PP), occlusal plane angle (SN/OP), mandible height (Ar-Go'), the mandible ramus height(Co-Go) was increased significantly (P<0.05). CONCLUSIONS: New fixed Twin-block significantly promotes mandibular growth and provides effective vertical control, improves the facial profile by retracting the maxillary incisors, and the clinical effect is reliable.
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    Effect and prognosis of piezosurgery combined with 45°contra-angle turbine drill in extraction of impacted mandibular wisdom teeth
    Xie Xuemei, Yu Xiaojia
    2025, 34 (3):  298-302.  doi: 10.19439/j.sjos.2025.03.014
    Abstract ( 22 )   PDF (602KB) ( 20 )  
    PURPOSE: To investigate the clinical effect of piezosurgery combined with 45°contra-angle turbine drill in extraction of impacted mandibular wisdom teeth. METHODS: A total of 146 patients with impacted wisdom teeth at the median mandibular level admitted from June 2022 to June 2024 were randomly divided into control group and experimental group, with 73 cases in each group. The wisdom teeth in the control group were simply removed using 45° contra-angle turbine drill, while those in the experimental group were removed using piezosurgery combined with 45° contra-angle turbine drill. The treatment outcomes, postoperative pain, limited swelling and incidence of postoperative complications of the two groups were compared. RESULTS: There was no significant difference in operation time between the two groups(P>0.05), and the amount of blood loss in the experimental group was significantly lower than that in the control group(P<0.05). The visual analogue scale(VAS) of pain in the experimental group was significantly lower than that of the control group on the 1st and 3rd day after surgery(P<0.05). Immediately, 1 day and 3 days after surgery, the serum C-reactive protein (CRP) in the experimental group was significantly lower than that in the control group (P<0.05). The score of facial swelling degree and proportion in the experimental group were significantly lower than those in the control group (P<0.05), the reduction rate of mouth opening degree and the proportion of mouth opening restriction in the experimental group were significantly lower than those in the control group(P<0.05). There were no significant differences in the total incidence of postoperative complications such as tongue numbness, lower lip numbness, adjacent tooth injury, dry socket and root fracture between the two groups(P>0.05). CONCLUSIONS: Compared with only using 45° contra-angle turbine drill, the combination of piezosurgery for impacted mandibular wisdom teeth extraction can help reduce intraoperative bleeding, alleviate pain and swelling,improve the degree of limited mouth opening.
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    Clinical analysis of 309 patients with 2 supernumerary teeth in the upper incisor area
    Liu Xiaolin, Ren Qun, Liu Wenjing, Feng Xiaowei, Du Wenya, Ren Guiyun
    2025, 34 (3):  303-309.  doi: 10.19439/j.sjos.2025.03.015
    Abstract ( 22 )   PDF (1416KB) ( 13 )  
    PURPOSE: To analyze and summarize the clinical characteristics of patients with two supernumerary teeth in the upper incisor area, in order to provide reference for clinical diagnosis and treatment. METHODS: A total of 309 patients with two supernumerary teeth in the upper incisor area who were admitted to Hospital of Stomatology, Hebei Medical University from January 2017 to December 2021 were collected, their age, gender, reasons for medical treatment, and related information on supernumerary teeth were statistically analyzed. The growth direction, eruption status, morphology, and development of supernumerary teeth in different genders and age groups were grouped and analyzed. SPSS 21.0 software package was used for data analysis. RESULTS: Among 309 patients, the average age was (8.21±3.89) years old, and the male to female ratio was 3.83∶1. The 6-12 years old group had the highest number of visits, with 205 cases (66.34%); 204 cases (66.02%) had 2 supernumerary teeth with inconsistent growth directions, 223 cases (72.17%) had 2 supernumerary teeth with inconsistent morphology, 194 cases (62.78%) had 2 supernumerary teeth with fully developed roots, 174 cases (56.31%) had 2 supernumerary teeth in an unexpired state. There was no significant difference(P>0.05) in the growth direction, eruption status, development, treatment reasons, and impact on adjacent tissues between the two supernumerary teeth of different genders, but there was significant difference(P<0.05) in morphology. There was significant difference in the growth direction of two supernumerary teeth in different age groups(P>0.05), but there were significant differences in eruption status, morphology, development, medical reasons, and impact on adjacent tissues(P<0.05). CONCLUSIONS: Patients with two supernumerary teeth in the upper incisor area are mostly seen in the mixed dentition period. The incidence rate of males is significantly higher than that of females. Gender has certain impact on the morphology of supernumerary teeth, and age has certain impact on the eruption, morphology, and development of supernumerary teeth.
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    Clinical study of immediate placement at previously failed sites using simple taper-retained implants
    Dai Jieting, Xu Yehao, Ren Bihui, Wei Hongwu, Guo Shuigen
    2025, 34 (3):  310-317.  doi: 10.19439/j.sjos.2025.03.016
    Abstract ( 24 )   PDF (1698KB) ( 14 )  
    PURPOSE: To evaluate the clinical efficacy of immediate replantation using simple taper fixed implants at failed implantation sites. METHODS: Patients with implant failure at the Department of Stomatology, Fourth Affiliated Hospital of Nanchang University from January 2018 to December 2022 were collected. Simple taper-retained implants were used for immediate replantation at implant failure sites. Marginal bone loss, survival rate and complications were analyzed at immediate replantation(T0), immediately after repair(T1), and at the last follow-up(T2). RESULTS: A total of 33 implantation failure sites in 31 patients were included at an average of (13.27±21.92) months after primary implantation, 33.33% were early failures and 66.67% were late failures; the average follow-up after immediate reimplantation was (14.22±9.90) months, with an overall retention rate of 100%. History of periodontitis, smoking, systemic diseases, and nocturnal grinding conditions, occlusal relationship, and bone type at the implant site had no significant difference in the effect of peri-implant marginal bone resorption; the difference between the mean implant length and the implant length at primary implantation was not statistically significant, but there was significant difference in the implant diameter and implantation depth between the primary implantation and the reimplantation. Binary Logistic regression model showed that the diameter of the implant had no significant effect on the survival rate of the implant, but the deeper the implant depth, the higher the survival rate of the implant.There was significant bucco-lateral bone height resorption at T0 and T1, but no significant changes in proximal and distal mesial heights, lingual bone heights, and buccolingual bone thickness at T0, T1, and T2. Buccolingual lateral bone height had the least amount of resorption in the T2-T1 period, which was statistically different from the amount of bone resorption in the T1-T0 and T2-T0 periods. Buccolingual lateral bone thickness was statistically different from the amount of bone change in the T1-T0 and T2-T1 periods, but there was no significant change in proximal and distal mesial heights, buccolingual lateral bone heights, and lingual lateral bone thicknesses in the T1-T0, T2-T1, and T2-T0 periods. CONCLUSIONS: The application of simple taper fixed implant system for immediate replantation at failed implant sites has good short-term clinical effects, and immediate replantation can be considered in the event of implant failure.
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    Comparative quantitative analysis of palatal masticatory mucosal thickness between Han and Uygur in Xinjiang area
    Yipalamu·Tulajiang, Ma Ting, Maimaiti·Yasen
    2025, 34 (3):  318-325.  doi: 10.19439/j.sjos.2025.03.017
    Abstract ( 27 )   PDF (1335KB) ( 17 )  
    PURPOSE: To measure and compare the palatal masticatory mucosal thickness from maxillary canine to the second molar region of Han and Uygur periodontally healthy people in Xinjiang area by using CBCT, and to analyze the related factors. METHODS: CBCT images of 48 periodontally healthy subjects in each nationality were selected from the Dental Clinic of the First Affiliated Hospital of Xinjiang Medical University according to the inclusion and exclusion criteria. The thickness of the palatal masticatory mucosa, the height and width of the palatine fornices, and the location of the greater palatine foramen were measured at the distance of 3, 6, 9 and 12 mm from the gingival margin. RESULTS: There were significant differences in the average palatal mucosal thickness at the distance of 3, 6, 9 and 12 mm from the gingival margin, different anatomical shapes of the palatine fornices and different age groups between Han and Uygur(P<0.05). There was no significant difference in the distribution of the greater palatine foramen between Han and Uygur(P>0.05). However, the correlation between mucosal thickness and related factors in Han population was closer. The general trend was similar between the two groups: ①from 3mm to 12mm from the gingival margin, the mucosal thickness first increased and then decreased from the canine to the second premolar, decreased first and then increased from the first molar, and continued to increase from the second molar; ②the mucosal thickness of canine, first premolar and first molar was affected by age and the anatomical morphology of palatine fornix. The mucosal thickness of second premolar was affected by age, and the mucosal thickness of second molar was affected by the anatomical morphology of palatine fornix; ③the greater palatal foramen was mostly located in the distal region of the second molar, and the distance from the greater palatal foramen to the midpalatal suture was smaller in the HFT group than in the LFT group(P<0.05). CONCLUSIONS: The most suitable donor site for autologous connective tissue transplantation in both nationalities is the palatal masticatory mucosa when the distance between the gingival margin of the maxillary first and second premolars is 3-9 mm.
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    Clinical Reports
    A retrospective study on clinical outcomes of implant-supported rehabilitations in patients with alveolar cleft
    Lan Rong, Wu Yiqun, Huang Wei, Chen Zhenqi, Pan Xiaogang, Wang Feng
    2025, 34 (3):  326-331.  doi: 10.19439/j.sjos.2025.03.018
    Abstract ( 25 )   PDF (921KB) ( 27 )  
    PURPOSE: To retrospectively evaluate the clinical outcomes of implant-supported prosthesis in alveolar cleft patients. METHODS: A total of 14 patients with alveolar cleft underwent implant restoration in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from January 2015 to January 2023 were collected. Among them, 9 were male and 5 were female. The age ranged from 18 to 52 years, with a mean of (26.1±10.6) years. The sequence treatment history of patients with cleft lip and palate and the effect of implant repair were retrospectively analyzed. RESULTS: Bone grafting in the fissured area failed repeatedly in 1 patient and no implant was implanted. A total of 21 implants were implanted in the remaining 13 patients with alveolar cleft, all of which achieved good osseointegration. In 10 cases, one implant was implanted in each fissure area for single crown or single end bridge repair. In 3 cases, 11 implants were implanted in the non-fissure area for fixed bridge repair. Seven patients with single implant were followed up for 6 to 96 months, with an average of (39.4±29.2) months. During their visits, patients underwent various examinations, including pink aesthetic score (PES) averaging 10.16±0.98, white aesthetic score(WES) averaging 8.50±1.23, and probing depth(PD) with a mean of (2.68±0.61) mm. Additionally, gingival index(GI) was recorded with a mean of 1.33±1.10, and marginal bone loss(MBL) was measured with a mean of (0.17±0.35) mm. The width of the mid-labial keratinized mucosa was observed to be (5.14±2.10) mm. CONCLUSIONS: Implant-supported prosthesis in the alveolar cleft area after well-established multidisciplinary sequential treatments have predictable middle-term success rate, satisfactory aesthetic outcomes and stable peri-implant soft and hard tissue conditions.
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    Dental Education
    Application of the jigsaw classroom method in oral histology and pathology course
    Wang Yanjin, Qin Zhiming, Li Tiejun, Liu Tingjiao
    2025, 34 (3):  332-336.  doi: 10.19439/j.sjos.2025.03.019
    Abstract ( 26 )   PDF (1071KB) ( 20 )  
    PURPOSE: This study applied jigsaw classroom method to reform some contents of oral histology and pathology course, aiming at exploring new methods of undergraduate education in stomatology, achieving more dimensional learning goals and improving learning effects. METHODS: Twenty-four undergraduates from the School of Stomatology of Fudan University were selected as the study objects. Under the guidance of teachers, students studied oral squamous cell carcinoma cases online and offline for 3 weeks. The teaching effect was evaluated from the perspectives of teachers and students through subjective and objective examination, questionnaire survey and interview. RESULTS: The objective questions were tested before and 4 months after the final report, with an average of 7.17 and 7.41(out of 10 points). There was no significant difference between the two scores, indicating that the students achieved their knowledge goals and had a good long-term learning effect. The average scores of case report and report were over 90(out of 100 points). 75% of the students were satisfied with the learning effect, 37.5% preferred this method, and over 80% of the students thought that this method had exercised many abilities, improved their understanding of the importance and significance of oral pathology, and achieved the goals of ability and literacy. CONCLUSIONS: Compared with traditional teaching, jigsaw classroom can make students master knowledge more firmly, exercise their ability and accomplishment, and achieve better learning effect. The specific implementation can be adjusted according to the situation, and it needs further investigation.
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