上海口腔医学最新文献

Purpose: To investigate the effect of dual-wavelength laser combined with bioceramics material iRoot SP on molar root canal treatment.

Methods: A total of 104 patients receiving root canal treatment from January 2020 to June 2023 were selected and divided into control group and experimental group according to random number table method, with 52 cases in each group. The control group was treated with iRoot SP paste, and the experimental group was treated with dual-wavelength laser(Nd:YAG and Er:YAG) combined with iRoot SP paste. The total effective rate, pain degree and complications were compared. Serum interleukin-6 (IL-6), interleukin-17(IL-17), tumor necrosis factor-α(TNF-α), bleeding index(BI), depth of periodontal probing(PD) and clinical attachment level(CAL) were observed before treatment, 6 weeks and 12 weeks after treatment. SPSS 22.0 software package was used for statistical analysis.

Results: The total effective rate of the experimental group was significantly higher than that of the control group, and the pain degree after root canal filling was significantly lower than the control group(P＜0.05). The levels of IL-6, IL-17, TNF-α, BI, PD and CAL in the experimental group were significantly lower than those in the control group at 6 and 12 weeks after treatment (P＜0.05).

Conclusions: Dual wavelength laser combined with bioceramic material iRoot SP has a better effect in the treatment of molar root canal, which is conducive to reducing periodontal inflammation and pain.

Purpose: To analyze the stress distribution of polyetheretherketone framework of implant-supported fixed maxillary prosthesis by three-dimensional finite element method.

Methods: Three dimensional finite element model of implant-supported fixed maxillary prosthesis was established. Polyetheretherketone as framework material, resin, zirconia, PEEK, baked plastic and lithium silicate were used to make crown prosthesis as experimental group, pure titanium and monolithic zirconia prosthesis model was used as control group. The feasibility of PEEK framework was analyzed by loading 150N axially and obliquely on the first molar, and the maximum compressive stress, minimum tensile stress and von Mises principal stress of the framework, crown, screw, implant, cortical and cancellous bone were measured and compared.

Results: Under axially loading, the von Mises stress in the monolithic zirconia and lithium silicate crowns were 361 MPa and 295 MPa, while the stress in resin and PEEK crowns were 35 MPa and 37 MPa, respectively. The screw von Mises stress of the experimental group was 694-724 MPa, which was much higher than 61 MPa of the control group.The maximum and minimum stresses of the screw appeared in the resin crown and PEEK crown group. Under oblique loading,von Mises stress of the framework in the experimental group was lower than that in the control group, but the maximum stress appeared in the resin crown and PEEK crown. von Mises stresses of monolic zirconia and lithium disilicate crowns in the experimental group were higher than that of resin and PEEK crowns. von Mises stress of the implant in the experimental group was twice that of the control group. von Mises stress in screw of the experimental group was much higher than that of the control group, and the maximum stress was 22 times that of the control group. The stresses of cancellous bone and cortical bone in the experimental group were twice that of the control group, and the differences were larger than that under vertical loading.

Conclusions: In order to reduce the stress of crowns,resin or PEEK materials are preferred to be used as the crown prosthesis when PEEK was framework of implant-supported fixed maxillary prosthesis. Reducing the cantilever and lateral force may avoid excessive stress in screw.

Purpose: To analyze the immune-related core genes differentially expressed in oral squamous cell carcinoma(OSCC) and construct an immune-related prognostic risk model for OSCC patients.

Methods: Weighted gene co-expression network analysis of RNA sequencing data from OSCC patients in the Cancer Genome Atlas (TCGA) database was conducted to identify immune-related modules and core genes. Core genes associated with immune prognosis were screened using univariate Cox regression analysis and survival analysis to construct an immune-related prognostic risk model for OSCC. The prognostic risk model's predictive ability was evaluated using Kaplan-Meier analysis, receiver operating characteristic curves, and external datasets from GSE41613. The expression of 8 immune prognostic core genes in tumor samples from OSCC patients was detected by real-time quantitative PCR assay(RT-qPCR), and the correlation between risk score and depth of invasion was assessed by calculating risk scores for OSCC patients. Statistical analysis was performed with SPSS 21.0 software package.

Results: Prognostic risk model for OSCC was successfully constructed based on 8 immune prognostic core genes(CSF2RA, CLEC4C, COL5A3, CTSG, EDNRA, GPC4, GUCY1A2, ANGPT2). The prognostic risk model demonstrated perfect predictive value validated using Kaplan-Meier analysis, receiver operating characteristic curve, and the GSE41613 dataset. The risk scores of OSCC patients calculated based on this model were positively correlated with the depth of invasion, indicating that the model have the ability to predict the potential risk of OSCC.

Conclusions: An OSCC prognostic risk model is constructed based on the signatures of 8 immune prognostic core genes, which may effectively predict the prognosis of OSCC patients, providing an important reference for immune prevention of OSCC.

Purpose: To evaluate the effect of bone nail and artificial periosteum combined with iliac cancellous bone grafting in repairing cleft lip and palate with alveolar cleft during dental replacement.

Methods: The clinical data of 82 children with cleft lip and palate with alveolar cleft during dental replacement period were retrospectively analyzed from January 2020 to December 2023, and were divided into control group (iliac cancellous bone grafting alone, n=42) and experimental group (combined iliac cancellous bone grafting with bone nail and artificial periosteum, n=40) according to the operation method. The viable bone volume in bone graft area, absorption rate of whole bone graft and different bone graft areas, success rate of bone graft, survival rate of bone graft and complications were compared between the two groups. SPSS 25.0 software package was used for statistical analysis.

Results: The surviving bone volume in the bone graft area was significantly larger in the experimental group 3 and 9 months after operation(P＜0.05). There was no significant difference in viable bone volume in bone graft area between the two groups 9 months and 3 months after surgery (P＞0.05). The bone graft absorptivity of the experimental group was significantly lower than that of the control group 3, 9 months and 3-9 months after surgery(P＜0.05), and there was no significant difference between the two groups at 3, 9 months after surgery(P＞0.05). The absorption rate of bone graft in 1/2 area of nasal cavity, 1/2 area of alveolar ridge, 1/2 area of lip and 1/2 area of palate in the experimental group was significantly lower than that in the control group 3 and 9 months after operation(P＜0.05). The absorptivity of bone graft in 1/2 area of alveolar ridge was significantly higher than that in 1/2 area of nasal cavity, and the absorptivity of bone graft in 1/2 area of palatal side was significantly higher than that in 1/2 area of lip in both groups (P＜0.05). The success rate and survival rate of bone grafting in the experimental group were significantly higher than those in the control group(P＜0.05). The complication rate of the experimental group was significantly lower than that of the control group (P＜0.05).

Conclusions: Bone nail and artificial periosteum combined with iliac cancellous bone graft can effectively repair cleft lip and palate with alveolar cleft during dental replacement, reduce bone absorption rate and complications, and improve bone formation effect. Meanwhile, postoperative bone mass absorption mainly occurs within 3 months after surgery, and mainly occurs in the alveolar crest area and palatine area.

Purpose: To analyze the correlation between the changes in salivary ion concentration, Streptococcus and Bifidobacterium in children with dental caries and the severity of the disease.

Methods: Eighty children with dental caries treated from May 2022 to April 2023 were selected as the experimental group. According to the DMFT, they were divided into mild group (DMFT≤15%, n=35) and severe group (DMFT>15%, n=45). Another 80 children without dental caries were selected as the control group. The calcium ion concentration in saliva was detected by methanol-permeabilized calciometric method, the level of Streptococcus and Bifidobacterium was detected by real-time single-quantity PCR technology, and the correlation between DMFT and salivary calcium ion concentration, Streptococcus and Bifidobacterium was analyzed by Pearson correlation analysis. The diagnostic value of salivary calcium ion concentration, Streptococcus and Bifidobacterium for the severity of dental caries in children was evaluated by the receiver operating characteristic curve(ROC), and the area under the curve(AUC) was calculated. SPSS 22.0 software package was used for statistical analysis.

Results: The level of salivary calcium ion concentration, Streptococcus mutans, Streptococcus sobrinus and Bifidobacterium in the experimental group was significantly higher than that in the control group(P＜0.05), and significantly higher in the severe group than in the mild group(P＜0.05). DMFT was significantly positively correlated with salivary calcium ion concentration, Streptococcus and Bifidobacterium (P＜0.05). Based on DMFT, ROC curve was prepared, and AUCs of salivary calcium ion concentration, Streptococcus mutans, Streptococcus sobrinus and Bifidobacterium for assessing the severity of dental caries in children were 0.760, 0.658, 0.718 and 0.705, respectively.

Conclusions: Increased salivary ion concentration, Streptococcus sobrinus, Streptococcus mutans and Bifidobacterium levels are related to dental caries in children, and are positively correlated with the severity of the disease, which has a certain value for assessing the severity of the disease.

Purpose: To investigate the biomechanical expression of different shapes of attachments on the maxillary anterior teeth during the lingual tooth movement process using clear aligners, providing new insights for orthodontists to improve the clinical design.

Methods: In this study, CBCT data were simulated using the three-dimensional finite element technique. Attachments of various shapes, including no attachment(A1), rectangular attachment(A2), wedge-shaped attachment(A3), and curved arc attachment(A4), were designed on the lateral incisors. Ansys software was employed to calculate the three-dimensional changes in the lateral incisors, dental arch, and clear aligners and the distribution of equivalent stress on the periodontal ligament(von Mises) under the same load conditions.

Results: The coronal displacement of the lateral incisors showed the following variations: A1＞A4＞A3＞A2. The sagittal displacement exhibited the following variations: A3＞A4＞A1＞A2. The vertical elongation demonstrated the following variations: A4＞A3＞ A1＞A2. The overall displacement of each dental arch displayed an arch-shaped trend. Different regions of the clear aligners exhibited variations in deformation. The von Mises distribution of the periodontal ligament in A1 and A2 group showed similarities, while A3 group exhibited stress concentration only in the lingual area of the root's one-third region. Group A4 experienced significantly higher stress in the cervical region compared to A1 and A2 group.

Conclusions: Rectangular attachments and curved arc attachments possess advantages in coronal control, with rectangular attachments exhibiting the best control effect in vertical control. The area of attachment force and actual displacement efficiency do not have an absolute correlation, as the shape of the force-bearing surface can significantly affect its specific biomechanical expression.

Purpose: Benign deep lobe parotid tumors(BDLPT) exhibit a wide range of clinical and imaging features, which closely correlated with the selection of appropriate surgical approaches. This study was aimed to explore variations in surgical management.

Methods: Seventy-five patients with primary BDLPT who underwent surgery in Peking University School and Hospital of Stomatology from August 2014 to August 2020 were included. The imaging data of all cases were retrospectively evaluated. BDLPTs were divided into four types according to the anatomical relationship between the tumor and various structures, and the surgical treatment of each type of tumor was studied. SPSS 24.0 software package was used for statistical analysis.

Results: TypeⅠBDLPT(14/75, 18.7%) was located entirely medial to the ramus and the stylomandibular space, with growth extending towards the parapharyngeal space. Type Ⅱ BDLPT(19/75, 25.3%) resided within the retromandibular space, bounded by the ramus, stylomandibular space, mastoid, and retromandibular vein. Type Ⅲ BDLPT(27/75, 36.0%) exhibited an expansive growth pattern, extending from the retromandibular vein to the parapharyngeal space while traversing the stylomandibular space. Type Ⅳ BDLPT(15/75, 20%) was situated inferior to the ear lobe, deep to the facial nerve and retromandibular vein. Transmandibular approach was predominantly employed in type I cases (10/14). Type Ⅲ cases utilized transparotid (14 cases), transmandibular(11 cases), and combined transparotid-transmandibular (2 cases) approaches. Type Ⅱ and Ⅳ cases involved transparotid approaches with concurrent parotidectomy.

Conclusions: The classification of BDLPT offers valuable insights and practical guidance for preoperative treatment planning.

Purpose: To exploring the clinical effect of lip muscle training combined with Frankel Ⅲ orthodontic appliances in correcting Class Ⅲ malocclusion during the mixed dentition period.

Methods: One hundred children with Class Ⅲ malocclusion during the mixed dentition period admitted to Hangzhou Greentown Stomatological Hospital from June 2018 to December 2022 were selected. The children were randomly divided into a combination group (treated with lip muscle training and Frankel Ⅲ orthodontic appliance) and a control group (treated with Frankel Ⅲ orthodontic appliance), with 50 cases in each group. X-ray cephalometric indicators, temporomandibular joint parameters, upper airway measurement parameters and 12 month follow-up of the two groups of children were compared before and after treatment. SPSS 21.0 software package was used for statistical analysis.

Results: Before treatment, there was no significant difference of SNA, SNB, ANB, U1-NA, L1-NB, ANS-Ptm, S-Ptm, Co Po, Co-S, MP-SN, MP-FH and NP-FH between the combination group and the control group (P＞0.05). After treatment, ANB, U1-NA, L1-NB and MP-SN in the combination group were significantly higher than those in the control group, while NP-FH were significantly lower than that in the control group(P＜0.05). Before treatment, there was no significant difference of the joint space, anterior joint space and posterior joint space between the combination group and the control group patients(P＞0.05); after treatment, the joint space and the joint space in the combination group were significantly higher than those in the control group(P＜0.05). Before treatment, there was no significant difference of Ba PNS, Ad1 PNS, Ad2 PNS, Mc1 Mc2, SPP-SPPW, U-MPW, PAS and V-LPW between the combination group and the control group(P＞0.05); after treatment, Ad2-PNS in the combination group was significantly higher than that in the control group(P＜0.05). After 12 months of follow-up, the recurrence rate of the combination group was 2.00%, which was significantly lower than that (16.00%) of the control group (P＜0.05).

Conclusions: The combination of lip muscle training and Frankel III orthodontic appliances is more conducive to correcting Class III malocclusion during the replacement period, improving upper airway morphology, and reducing the recurrence rate after treatment.

Purpose: To explore the risk factors for mesioangular and vertical impactions of the mandibular third molars and to construct a predictive model based on logistic regression analysis.

Methods: Clinical data of 243 mandibular third molars collected from June 2021 to December 2023 at Tianjin Stomatology Hospital were classified into the eruption group and the impaction group, with the latter including mesioangular and vertical unilateral impactions. The clinical data were subjected to univariate analysis to screen for statistically significant factors, followed by multivariate analysis using logistic regression to further delineate risk factors for mandibular third molar impaction, with the construction of a nomogram for prediction.SPSS 27.0 software package was used for statistical analysis.

Results: Totally 243 mandibular third molars were included, and 75 (30.86%) were in the eruption group and 168 (69.14%) in the impaction group. No significant difference was found between the groups regarding age, gender, number of tooth roots, Co-Go, Co-Cop, W2, W3, W4 and L (P＞0.05). Significant differences were observed between the eruption and impaction group concerning Nolla, L-6 missing, L-E missing, Co-Pog, Co-Go/Co-Pog, L6-MP, α and W1(P＜0.05). Multivariate regression analysis revealed that Nolla, absence of L-6, absence of L-E, Co-Pog, Co-Go/Co-Pog, L6-MP, α and W1 were independent risk factors for mesioangular and vertical impactions of the mandibular third molars (P＜0.05). The construction of nomogram demonstrated high predictive accuracy. Analysis of the receiver operating characteristic curve(ROC) indicated that the area under the curve(AUC) for the joint prediction of mesial and vertical impaction of the mandibular third molar by independent risk factors was 0.924, with a 95%CI of 0.887 to 0.960. The sensitivity was reported to be 86.9%, and the specificity was 86.7%.

Conclusions: Nolla, absence of L-6, absence of L-E, Co-Pog, Co-Go/Co-Pog, L6-MP, α and W1 are major risk factors affecting the impaction of mandibular third molars. The use of logistic regression analysis and nomograms can effectively predict the risk of impaction, providing a scientific basis for clinical treatment.

Purpose: To investigate the feasibility and effect of free latissimus dorsi myocutaneous flap in the reconstruction of giant head and neck defects.

Methods: Free latissimus dorsi myocutaneous flap on the cadaver was simulated dissected, and measured by Image-Pro Plus 6.0 to assess the feasibility of repairing giant head and neck defects. Between May 2011 and September 2022, seven patients with giant head and neck defects of different causes repaired with the latissimus dorsi myocutaneous flap were retrospectively analyzed.

Results: The diameter of the initiating thoracodorsal artery was (4.03±0.56) mm, and the mean lengths of the arteriolar and venous pedicles of the latissimus dorsi myocutaneous flaps obtained from human specimens were (85.5±10.5) mm and (104±4.2) mm, respectively. Among 7 patients, 5 cases had scalp defects, the remaining 2 cases had neck defects. There were no substantial postoperative problems in the donor site, and all seven latissimus dorsi myocutaneous flaps were successfully transplanted.

Conclusions: For the treatment of considerable head and neck deformities, the latissimus dorsi myocutaneous flap is an optimal muscle flap due to its abundance of tissue, enough length of vascular pedicles, and sufficient venous drainage.