上海口腔医学最新文献

Purpose: To observe the long-term clinical effect of implants retained complete overdentures with Locator attachments.

Methods: A total of 48 patients with edentulous jaws treated with implants retained complete overdentures with Locator attachments were selected from the Outpatient Department of Peking University School and Hospital of Stomatology from 2016 to 2017. Among them, 21 patients underwent double-maxillary complete overdentures restoration and 27 patients underwent single-maxillary restoration. A total of 230 implants were implanted. The clinical observation indicators included the implant survival rate, peri-implant mucosal bleeding on probing(BOP), the change in the vertical height of alveolar bone absorption around the implants, overdenture base fracture rate, artificial tooth fall off and fracture rate and other complications. The change of the locator attachment retention force of the implant-supported overdentures was evaluated. SPSS 13.0 software package was used for data analysis.

Results: During the five-years clinical observation period, 5 implants fell off, 1 narrow dimeter implant in the anterior zone was broken, and 12 implants were lost to follow-up. The implant survival rate was 97.25%. One year after the restoration therapy finished, peri-implant mucosal bleeding on probing (BOP+) was detected in 48 (21.4%) implants. The average BI was 0.21±0.42, which was higher in the anterior zone than that in the posterior zone. The vertical alveolar bone absorption height around the implants was (0.21±0.35) mm, 2 implants-supported complete overdenture bases were broken. After 5 years of restoration, 163(76.89%) implants had peri-implant mucosal bleeding on probing(BOP+). The average BI was 1.00±0.70, and the vertical alveolar bone absorption height around the implants was (0.58±0.85) mm. There was no significant difference between males and females. There was no significant difference in the peri-implant mucosal bleeding index and the alveolar bone vertical absorption height between the anterior zone and the posterior zone(P＞0.05). The mean BI of peri-implant mucosa and the vertical absorption height of peri-implant alveolar bone were significantly different between the 1-year observation period and the 5-year observation period respectively(P＜0.01). There were 17(26.15%) cases with overdenture bases fracture, and the fracture rate of artificial teeth was 16.92%. Most of them occurred in the midline area of the anterior zone and the location of the overdenture base on the locator attachments. The average first replacement time of the locator attachment nylon retainer washer was 34.2±10.3 months.

Conclusions: Implants retained complete overdentures with Locator attachments are effective in long term clinical observation. Complications are mainly found in peri-implant mucosal bleeding on probing and vertical alveolar bone absorption, and tended

Purpose: To observe the anti-caries effect of transgenic tomato anti-caries vaccine after immunization with SD rats by gavage and to explore its immunity mechanism initially.

Methods: SD rats were used to establish an experimental caries model. The transgenic anti-caries tomatoes expressing the target protein were cultivated and identified. The SIgA and IgG contents of specific anti-PAcA in saliva and blood samples of SD rats were detected by ELISA. Then, the SD rats were sacrificed, the maxillary and mandibular bones were taken for Keyes dental caries score, and spleens were taken for the analysis of RNA-seq. Statistical analysis was performed with SPSS 18.0 software package.

Results: The target protein concentration in the transgenic tomato anti-caries vaccine was 36.28 μg/mL. After vaccine immunization of SD rats, group D (8 mL/kg) produced the highest levels of specific SIgA and IgG antibodies at week 6 and was significantly different from the other groups(P＜0.05), and caries counting score was also significantly different than the other groups (P＜0.05). The spleen mRNA of SD rats in group D was extracted and sequenced by RNA-seq, and 40 genes with significant differences in mRNA expression were obtained(P-adjust＜0.05, |Fold Change|≥1.5). 26 genes were significantly upregulated, including IGFBP6 and COL15A1. The upregulated gene GO enrichment was enriched to humoral immune response, B-cell activation, and immunoglobulin receptor binding; KEGG enrichment was enriched to 56 signaling pathways, including PI3K-AKT and NF-κB, and F＜0.001. Fourteen genes were significantly downregulated, but the analysis of downregulated gene GO and KEGG enrichment was not statistically significant(F＞0.1).

Conclusions: Transgenic tomato anti-caries vaccine may reduce caries occurrence by upregulating the activation of PI3K-AKT signaling pathway mediated by IGFBP6 in SD rats.

Purpose: To investigate the inhibitory effect of paeoniflorin(PF) with different concentrations on CAL27 cells of tongue squamous cell carcinoma in vitro and its possible mechanism.

Methods: CCK-8 technique and clone formation trial were used to detect the effect of PF on the proliferation and clone formation of CAL27 cells. Scratch test and Transwell method was used to detect the effects of PF on migration and invasion of CAL27 cells. Staining of Hoechst33342 was employed to evaluate the influence of PF on apoptosis of CAL27 cells, while Western blot was utilized to investigate the effect of PF on the expression of NF-κB pathway related proteins and EMT related proteins. The effect of PF on NO production in CAL27 cells was detected by nitric oxide detection kit. Statistical analysis was performed with SPSS 27.0 software package.

Results: PF inhibited proliferation, migration, and invasion of CAL27 cells in vitro in a concentration-dependent way. Moreover, PF caused apoptosis of CAL27 cells. PF impeded NF-κB pathway activity, decreased the expression of P-P65, further reduced the expression of iNOS and MMP-9, suppressed the production of NO, and concurrently inhibited Vimentin,promoted E-cadherin.

Conclusions: Paeoniflorin inhibits the proliferation, migration and invasion of CAL27 cells, which may play an anti-cancer role by inhibiting the activation of NF-κB pathway and EMT.

Purpose: To measure the cortical bone thickness of zygomatic alveolar ridge in adolescents and explore the correlation between cortical bone thickness and cervical vertebral bone age.

Methods: Cone-beam CT data of 80 adolescents were collected, including 20 adolescents with cervical vertebral bone ages of Cvs3, Cvs4, Cvs5 and Cvs6, respectively. CBCT images were reconstructed with the maxillary occlusal plane as the reference plane. Cortical bone thickness of different slices in the left maxillary zygomatic alveolar ridge area was measured in the direction parallel to and 60° from the reference plane, and the measured data were statistically analyzed by SPSS 21.0 software package.

Results: When the measurement direction was parallel to the reference plane and at 60°, the cortical bone thickness in the zygomatic alveolar ridge area of Cvs3-Cvs6 adolescents was (0.90±0.09) -(1.72±0.21) mm and (1.35±0.44)-(3.98±1.48) mm, respectively. There was significant difference in cortical bone thickness between Cvs4 and Cvs5 group(P＜0.05). Spearman correlation analysis showed a strong positive correlation(P＜0.01) between cortical bone thickness of zygomatic alveolar ridge and cervical vertebral bone age in adolescents.

Conclusions: The cortical bone thickness of zygomatic alveolar ridge in adolescents increases with the increase of cervical vertebral bone age, and the cortical bone thickness may increase significantly during Cvs4-Cvs5. In terms of cortical bone thickness, all slices of zygomatic alveolar ridge of CVS3-CVS6 adolescents are suitable for implanting miniscrews, and the anterior slices should be selected for implantation as far as possible for Cvs3 and Cvs4 adolescents.

Purpose: To investigate the prognosis of advanced oral squamous cell carcinoma (AOSCC) patients undergoing neck dissection with sternocleidomastoid muscle (SCM) preservation and resection.

Methods: From January 2013 to June 2017, a total of 235 AOSCC patients(stage Ⅲ and stage Ⅳ) who were diagnosed and underwent neck dissection at the Department of Oral and Maxillofacial Surgery, College and Hospital of Stomatology, Guangxi Medical University, were collected and followed-up. The differences in overall survival（OS）, local recurrence-free survival (LRFS) and regional recurrence-free survival (RRFS) were compared between different surgical procedures. SPSS 25.0 software package was used for statistical analysis.

Results: Among 235 patients with postoperative follow-up, 101 patients retained the SCM during operation, and 134 patients had SCM removed. There was no significant difference in 5-year survival rate and 5-year regional recurrence rate between the SCM preservation group and the SCM resection group. Kaplan-Meier method of univariate analysis showed that SCM preservation or resection had no significant difference in OS, LRFS and RRFS. Cox multivariate regression analysis results showed that there was no significant difference between different surgical procedures in OS, LRFS and RRFS, while N stage and postoperative chemoradiotherapy were independent influencing factors for OS, LRFS and RRFS in AOSCC patients.

Conclusions: Neck dissection with SCM preservation in AOSCC patients has no effect on survival and recurrence (including local recurrence and regional recurrence). It is feasible for AOSCC patients to undergo SCM-preserving neck dissection when metastatic cervical lymph nodes do not invade SCM. N stage and postoperative chemoradiotherapy affect the prognosis of AOSCC patients.

Purpose: To investigate protein and genetic status of BRAF V600E in ameloblastomas, ameloblastic carcinomas and cysts, and to explore if recurrence and malignant transformation of ameloblastomas depends on BRAF status.

Methods: Twenty cysts, 25 primary ameloblastomas, 25 recurrent ameloblastomas and 8 ameloblastic carcinomas were analysed by immunohistochemistry, and 2 cysts, 5 primary ameloblatomas, 5 recurrent ameloblastomas, 3 atypical ameloblastomas and 6 ameloblastic carcinomas were analysed by quantitative real-time PCR(qPCR). SPSS 26.0 software package was used for data analysis.

Results: There was no correlation between BRAF V600E expression and recurrence. Cysts and carcinomas had lower frequencies of BRAF V600E mutations than ameloblastomas. There was a concordance between positive staining of BRAF V600E protein and BRAF V600E mutation.

Conclusions: BRAF V600E mutation may be useful in the differential diagnosis of ameloblastomas with cysts and ameloblastic carcinomas. Immunohistochemistry may be a beneficial method to screen for BRAF V600E mutation in ameloblastoma.

Purpose: To compare the debonding time of IPS e.max CAD lithium disilicate glass-ceramic veneers in different thickness and transparency using Er:YAG laser, and evaluate the effect of Er:YAG laser on the surface topography of the veneers and the underlying tooth.

Methods: A total of twelve maxillary first premolar teeth were collected and prepared, then veneers were made by computer aided design and computer aided manufacture(CAD/CAM) system. The veneers were divided into four groups according to different thicknesses and transparency: e.max HT with 0.5 mm and 1.0 mm thickness, e.max LT with 0.5 mm and 1.0 mm thickness. Three veneers of each group were cemented to prepared premolar with resin cement and then stored in normal saline solution at room temperature for 7 days. All veneers were debonded with Er:YAG laser and the debonding time of all-ceramic veneers of all groups was recorded. Scanning electron microscopy(SEM) observation was performed to detect the surface topography of the veneers and the underlying tooth. SPSS 19.0 software package was used for statistical analysis.

Results: The debonding time of 1.0 mm-thick groups were longer than 0.5 mm-thick groups. When the veneer thickness was 0.5 mm, the average debonding time of e.max LT group was longer than e.max HT. Consistent with the finding of 0.5 mm, the longer debonding time was found in the e.max LT group of 1.0mm. No cracks and crater structure were found in SEM observation of veneers after Er:YAG laser irradiation. Teeth surface was covered with bonding cement with no signs of ablation or damage of the enamel.

Conclusions: Er:YAG laser can completely debond lithium disilicate glass-ceramic veneers, and the debonding time depends on the transparency and thickness of the veneers. The lower translucent porcelain veneers (e.max LT) and thicker ones (1.0 mm-thick) had a longer debonding time. Moreover, Er:YAG laser does not damage the morphology and topography of the veneer and the teeth surface.

Purpose: To evaluate the applicability and accuracy of Demirjian and Chaillet method in estimating the actual age of Uygur and Han children and adolescents in Urumqi.

Methods: A total of 1144 orthopantomograms were included in the study, and the seven permanent teeth in the left jaw were divided into different stages according to two dental age estimation methods, and the dental age was converted to tooth age after checking the table and assigning points, and the dental age and its chronological age were compared with t test or rank sum test using SPSS 21.0 software package, and the accuracy of the two methods was evaluated by comparing the mean absolute error of the two methods.

Results: Demirjian method was overestimated by an average of 0.46 years (0.47 years for males and 0.43 years for women) in the Han population, 0.36 years for men and 0.26 years for women in Uyghur population, the difference was significant between Uyghur and Han boys (P＜0.05). Chaillet method yielded an average underestimate of 0.01 years (0.04 years for men and -0.08 years for women) in the Han population, and 0.08 years(0.02 years for men and -0.21 years for women) in the Uyghur population, there was no significant difference between Uyghur and Han boys and girls(P＞0.05).

Conclusions: When assessing the age of Uyghurhan children and adolescents in Urumqi, Chaillet method is more accurate than the Demirjian method. When applying dental age estimation method in different regions, it is necessary to evaluate the accuracy of the estimation method and revise it if necessary to improve the accuracy.

Purpose: To explore how bone morphogenetic protein 9(BMP9) promotes the osteogenic differentiation of periodontal ligament stem cells(PDLSCs) via ERK5/KLF4 signaling pathway under an inflammatory environment.

Methods: Recombinant adenovirus to overexpress BMP9 in PDLSCs stimulated with TNF-α was used and the expression level of osteogenic-related genes and proteins in BMP9-treated cells was examined using RT-PCR and Western blot. Then, KLF4 was overexpressed in PDLSCs via transfection and subjected to inflammatory stimulation to observe its effects on osteogenic differentiation and the expression of osteogenic-related genes. overexpression of BMP9 under the condition of KLF4 knockdown was conducted and its effects on osteogenic differentiation and the expression of osteogenic-related genes was analyzed. ERK5 inhibitor BIX02189 was used to explore the role of ERK5 in BMP9-induced osteogenic differentiation. Statistical analysis was performed with SPSS 20.0 software package.

Results: BMP9 could promote the osteogenic differentiation of PDLSCs and the expression of KLF4 in an inflammatory environment. Moreover, the overexpression of KLF4 further promoted the osteogenic differentiation of PDLSCs. However, when KLF4 was knocked down, the osteogenic differentiation promotion effect of BMP9 on PDLSCs was weakened. After BMP9 treatment, the phosphorylation level of ERK5 significantly increased. However, after adding ERK5 inhibitor, the promoting effect of BMP9 on osteogenic differentiation was significantly reduced.

Conclusions: BMP9 can promote the osteogenic differentiation of PDLSCs via ERK5/KLF4 signaling pathway in an inflammatory environment.

Purpose: To observe changes of upper airway in three dimensions and tongue position after correction with Twin-block combined with maxillary expansion appliance in children with mandibular retrusion and history of mouth breathing.

Methods: Twenty children with Class Ⅱ malocclusion and mandibular retrusion were selected and treated with Twin-block combined with maxillary expansion appliance. Cone-beam CT(CBCT) data before and after treatment were imported into Mimics 21.0 software to measure the total volume of the upper airway (nasopharyngeal segment + oropharyngeal segment), as well as segmental airway volume of nasopharyngeal, glossopharynx and oropharyngeal space. The cross-sectional area and maximum sagittal diameter at the tip of uvula in glossopharyngeal airway,and maxillary width were measured, too. Anterior-posterior and height changes of tongue position were observed. SPSS 26.0 software package was used to perform paired sample t test and Wilcoxon signed rank test of the data.

Results: The total upper airway volume and the airway volume of the nasopharyngeal, oropharyngeal and glossopharyngeal segments increased significantly after correction. The cross-sectional area and maximum sagittal diameter at the tip of uvula in glossopharyngeal segment, and the maxillary width were increased significantly.Tongue position increased and moved forward. All the above data had significant different(P＜0.05).

Conclusions: Twin-block combined with maxillary expansion appliance can increase the total volume of the nasopharyngeal segment, oropharyngeal segment, glossopharyngeal segment and upper airway in children with Class Ⅱ malocclusion and mandibular retrusion and expand the anterior-posterior depth of oropharynx airway.In addition,the treatment can increase maxillary width and normalize the tongue position, and contribute to the improvement of airway patency.