Neck dissection of cN0 maxillary oral squamous cell carcinoma: A study based on SEER database.

OBJECTIVE: For patients with clinical nodal-negative (cN0) maxillary oral squamous cell carcinoma (MOSCC), neck dissection (ND) and clinical observation are the main two management strategies for the neck. However, the indications corresponding to these two options remain controversial. This study aimed to elucidate the clinical factors affecting ND treatment and to identify clinical characteristics of the population that may benefit from ND based on a retrospective analysis of cN0 MOSCC patient data from the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: 8846 MOSCC patients were identified in the SEER database from 2000 to 2020. The Kaplan-Meier method was utilized to examine overall survival (OS) and disease-specific survival (DSS), while the hazard ratio (HR) was estimated using the stepwise multivariate Cox regression model. Furthermore, multi-subgroup analyses of DSS and OS were performed to compare ND and No ND. RESULTS: We included 2,512 cN0 MOSCC patients. Basic survival analysis and Cox regression modeling showed that ND was an independent prognostic factor that promoted DSS and OS. Additional subgroup analyses revealed that the primary site and T-stage might influence the efficacy of ND modality. Moreover, patients with T3/T4 stage of upper gingival squamous cell carcinoma (UGSCC) (DSS p = 0.009, OS p = 0.004), hard palate squamous cell carcinoma (HPSCC) (DSS p = 0.001, OS p < 0.001), and soft palate squamous cell carcinoma (SPSCC) (p = 0.029) showed a better survival benefit with ND in OS and DSS. Nonetheless, no differences were observed in OS and DSS between ND and No ND at the T1/T2 stage of the abovementioned primary tumor sites. Additionally, the DSS outcomes for T1/T2 stage upper lip squamous cell carcinoma (ULSCC) patients were significantly worse in the ND group than in the No ND group (p = 0.018). However, no significant differences were noted in OS (p = 0.140) as well as OS (p = 0.248) and DSS (p = 0.627) for T1/T2 and T3/T4 patients, respectively. CONCLUSION: Active surveillance might be a feasible strategy for managing all T-staged ULSCC as well as early-stage (T1/T2) UGSCC, SPSCC, and HPSCC, provided regular and meticulous follow-up is performed. Hence, concurrent ND is recommended for patients with intermediate to advanced (T3/T4) stage UGSCC, SPSCC, and HPSCC.

The clinical efficacy of Er:YAG lasers in the treatment of peri-implantitis: a systematic review and meta-analysis.

BACKGROUND: Erbium-doped yttrium aluminum garnet (ER:YAG) lasers have been used to treat peri-implant, but there are some disputes. To dispel these negative views, our study aims to compare the efficacy and safety of Er:YAG lasers versus conventional mechanical debridement in the treatment of peri-implantitis. METHODS: Seven databases were used to search for relevant studies and full-text articles which evaluate the comparisons of Er:YAG lasers and mechanical debridement for patients with peri-implantitis. Review Manager 5.4 was employed to assess the effects of the results among the selected studies. Forest plots, subgroup analyses, and on the included articles were also completed. Cochrane risk of bias assessment tool was used to assess the risk of bias. RESULTS: Our study focused on 10 previously conducted studies which included 294 patients with peri-implantitis and a total of 461 implants. No significant differences in clinical attachment level (CAL) (MD =0.17, P=0.25, at 6 months; MD =0.23, P=0.15, at 12 months), reduction in bleeding on probing (BOP) (MD =9.54%, P=0.18, at 6 months; MD =11.28%, P=0.24, at 12 months), or plaque index (PI) (MD =-0.02, P=0.75, at 6 months; MD =-0.07, P=0.66, at 12 months) were observed between the Er:YAG laser group and the mechanical debridement group. However, in reducing probing depth (PD) (MD =0.28, P=0.03, at 6 months; MD =0.35, P=0.002, at 12 months) and gingival recession (GR) changes (MD =-0.12, P=0.04, at 6 months; MD =-0.16, P=0.03, at 12 months), the Er:YAG laser group showed some advantages at 6-month and 12-month intervals following treatment. No significant publication bias existed in our meta-analysis by using funnel plot and Egger's test (PD: P=0.65; CAL: P=0.73). DISCUSSION: Our research supported the premise that Er:YAG lasers offer health benefits to patients with peri-implantitis and can effectively reduce PD and GR. Due to the limitations of the included studies, further studies should be carried out to validate our findings.

Effects of ethyl acetate extract of peony (Paeonia suffruticosa) seed coat on the proliferation and apoptosis of oral squamous carcinoma cells through miR-424-3p/STAT3/Survivin pathway.

Oral squamous cell carcinoma is one of the most common high malignant tumors. This experiment aimed to investigate whether ethyl acetate extract of peony (Paeonia suffruticosa) seed coat could affect the proliferation and apoptosis of oral squamous carcinoma cells by regulating the miR-424-3p/STAT3/Survivin pathway. For this purpose, oral squamous cell carcinoma cell CAL27 was cultured in vitro, and cells were treated with ethyl acetate extract of peony seed coat at different concentrations. MTT was used to detect cell proliferation. Flow cytometry was used to detect apoptosis. qRT-PCR was used to detect the expression level of miR-424-3p. The miR-424-3p mimics and anti-miR-424-3p were transfected into CAL27 cells respectively, and the cell proliferation and apoptosis were detected by the above method. Western blot method was used to detect the expression of PCNA, Bcl-2, Bax, p-STAT3 and Survivin protein. Results showed that ethyl acetate extract of peony seed coat could reduce cell proliferation rate and the protein levels of PCNA, Bcl-2, p-STAT3, Survivin and the expression level of miR-424-3p (P<0.05), increase apoptosis rate and the protein level of Bax (P<0.05). After transfection with anti-miR-424-3p, the cell proliferation rate, the protein levels of PCNA and Bcl-2 were significantly reduced (P<0.05), the apoptosis rate and the protein level of Bax were significantly increased (P<0.05), while the effect of miR-424-3p mimics was the opposite. Transfection of miR-424-3p mimics could significantly reduce the regulatory effect of ethyl acetate extract of peony seed coat on CAL27 cell proliferation, apoptosis and STAT3/Survivin pathway. It concluded that ethyl acetate extract of peony seed coat could inhibit the activation of the STAT3/Survivin signaling pathway by down-regulating the expression of miR-424-3p, thereby inhibiting the proliferation of oral squamous carcinoma cells and inducing apoptosis.

[Study on the relationships of the width of periodontal ligaments and the capacity ratio of collagen fibers with the elastic modulus of fresh bovine periodontal ligaments].

This experiment was aimed to shed light on the correlation and quantitative relationships between the width of bovine periodontal ligament (PDL) and the elastic modulus and, more over, between the width of bovine PDL and the capacity ratio of collagen fibers. The width and length of periodontal ligament of PDL were determined by stereomicroscope, and the elastic modulus by the materials testing systems. The collagen fibers in cross section of the specimen were stained with 1% Sirius Red F3B in saturated carbazotic acid, and the photo of stained PDL was collected by stereomicroscope. Image pro plus6.0 image analysis software was used to measure and calculate the capacity ratio of collagen fibers. It was found that there is a negative correlation between the width of bovine periodontal ligament and elastic modulus. The correlation coefficient is -0.21 and the simple linear regression model is Y = 71. 681-0.021x (Width of PDL); there is a positive correlation between capacity ratio of collagen fibers and elastic modulus. The coefficient correlation is 1.583 and the simple linear regression model is Y = -34.944 + 1.583x (The percentage of collagen fibers). Thus, the elastic modulus of bovine PDL increases while the width of bovine PDL decreases, and it increases while the capacity ratio of collagen fibers increases.

[Relationship between tissular structure and strength of fresh bull periodontal ligament].

OBJECTIVE: To study the relationship between the width and the content of fiber in peridontal ligament (PDL) and the strength of peridontal membrane. METHODS: Fresh mandible of bull was obtained to prepare for a 5 mm x 2 mm x 10 mm cuboid including teeth, peridontal membrane, and alveolar bone. The width of the PDL was measured under a stereomicroseope. Pull stress was loaded on the test piece until it broke. The stress-strain curve was recorded. The broken ends of the PDL was dyed with siriue to adalyze the content of fiber. RESULTS: The relationship between the width of the PDL and the maximum stress was expressed as Y = 9.786e(-3.6693x). The relationship between the width of the PDL and the physiological ultimate stress was expressed as Y = e((2.188(-3.953)x). The relationship between the percentage of fiber and maximum stress was expressed as Y = 20.788-0.755x + 0.007x(2). The relationship between the percentage of fiber and the physiological ultimate stress was expressed as Y = 1.39e(-14) x x(7.666). The initial physiological stress was 0.28 N/mm2. CONCLUSION: The strength of PDL increases with the decrease of PDL width and increase of fiber content.