Lymph nodes in oral squamous cell carcinoma: a comprehensive anatomical perspective.

Oral squamous cell carcinoma (OSCC) often exhibits a propensity for metastasis to lymph nodes (LNs), significantly influencing prognosis. Neck dissection (ND) is an important part in the treatment of OSCC. Variations in the preference for and pathways of lymph node metastasis (LNM) in different regions of the oral cavity have been observed. Currently, there is a lack of sufficient emphasis on the anatomical perspectives of LNM and ND. This review elucidates the lymphatic system of the maxillofacial regions from an anatomical standpoint, details the distribution of the sentinel LNs across different subsites, and summarizes the various classifications of the cervical LNs. Additionally, we elaborate on the methods used to study the lymphatic system, particularly imaging techniques. Furthermore, we investigate the pathways of cervical LNM and evaluate the efficacy of ND from an anatomical viewpoint. The overall objective of this review is to provide essential anatomical knowledge for managing LNs in OSCC, in the hope of providing patients with effective treatment modalities to enhance their quality of life.

Frequency of lymph node metastases at different neck levels in patients with oral squamous cell carcinoma: a systematic review and meta-analysis.

BACKGROUND: Currently, neck dissection is a standard treatment for the majority of oral squamous cell carcinoma (OSCC) patients. However, the procedure can lead to a series of complications, significantly reducing patient quality of life and even affecting the antitumor immune response in patients undergoing immunotherapy. Therefore, in the era of precision surgery, gaining a deeper understanding of the patterns of lymph node metastasis (LNM) in OSCC is crucial. MATERIALS AND METHODS: Literature searches were performed on PubMed, Embase, Web of Science, Cochrane Library, WANFANGDATA and China National Knowledge Infrastructure (CNKI) (inception to April 10, 2024). In addition, a manual searching was conducted in Scopus, Google Scholar, and Education Resources Information Center (ERIC). We included observational studies that evaluated the frequency of LNM in OSCC patients. Systematic review and a random effects model meta-analysis were performed. RESULTS: The search identified 4694 articles, of which 17 studies included in our study. We calculated the frequency of LNM according to the data reported in the articles. Frequency of LNM=number of patients with positive lymph node / number of patients with OSCC. The frequency of LNM was 12% in level I (95%CI: 0.11 to 0.15, I2=38.01%), 20% in level II (95%CI: 0.17 to 0.22, I2=47.71%), 10% in level III (95%CI: 0.08 to 0.12, I2=49.10%), 2% in level VI (95%CI: 0.01 to 0.03, I2=27.58%), 1% in level V (95%CI: 0.00 to 0.01, I2=11.37%). CONCLUSION: The frequency of LNM is consistent with the "cascade theory" and appears to be no significant difference from different primary sites. The frequency of LNM were low in levels I-III and were very low in level IV-V which implicated that more conservative treatments may be considered for OSCC in the future. This study will help clinicians better determine the extent of surgery and preserve lymph nodes during neck dissection.

Adjuvants for cancer mRNA vaccines in the era of nanotechnology: strategies, applications, and future directions.

Research into mRNA vaccines is advancing rapidly, with proven efficacy against coronavirus disease 2019 and promising therapeutic potential against a variety of solid tumors. Adjuvants, critical components of mRNA vaccines, significantly enhance vaccine effectiveness and are integral to numerous mRNA vaccine formulations. However, the development and selection of adjuvant platforms are still in their nascent stages, and the mechanisms of many adjuvants remain poorly understood. Additionally, the immunostimulatory capabilities of certain novel drug delivery systems (DDS) challenge the traditional definition of adjuvants, suggesting that a revision of this concept is necessary. This review offers a comprehensive exploration of the mechanisms and applications of adjuvants and self-adjuvant DDS. It thoroughly addresses existing issues mentioned above and details three main challenges of immune-related adverse event, unclear mechanisms, and unsatisfactory outcomes in old age group in the design and practical application of cancer mRNA vaccine adjuvants. Ultimately, this review proposes three optimization strategies which consists of exploring the mechanisms of adjuvant, optimizing DDS, and improving route of administration to improve effectiveness and application of adjuvants and self-adjuvant DDS.

Postoperative volume maintenance rate of microvascular free flap in oral and maxillofacial region: Systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: The resorption of flap's volume can be frequently observed in the transplantation of microvascular free flaps, which could significantly affect postoperative function. Therefore, it's essential to comprehend the postoperative flap volume and the mechanisms behind before making clinical decisions. METHODS: Literature search was conducted from database on PubMed, EMBASE, Cochrane Library, Chinese database and Google Scholar. A random effects model meta-analyses and descriptive systematic review were performed. RESULTS: The search identified 420 articles, of which 9 studies included in meta-analysis and 14 studies included in descriptive systematic review. Postoperative flap volume maintenance rate is used to represent the volume change. The pooled mean postoperative flap volume maintenance rate was 62.82 % for soft tissue flap (95 %CI: 58.83 to 66.82, p = 0.076, I2=56.3 %) and 85.96 % for bone flap (95 %CI: 84.19 to 87.73, p = 0.274, I2=20.4 %). Weight loss, muscle atrophy, and decreased serum albumin levels are risk factors for postoperative volume reduction of soft tissue flaps. The bone resorption rate of bone flaps in women is higher than that in men. CONCLUSION: When designing microvascular free flaps for oral and maxillofacial surgery, soft tissue flaps should consider an anticipated postoperative shrinkage of 37 %, while bone flaps should consider an anticipated postoperative shrinkage of 14 %.

Quantification of the Masseter Muscle Hardness of Stroke Patients Using the MyotonPRO Apparatus: Intra- and Inter-Rater Reliability and Its Correlation with Masticatory Performance.

BACKGROUND Chewing dysfunction is one of the most common serious complications after a stroke. It may be influenced by the hardness of the masseter muscle and masticatory performance; however, the association between these 2 factors is not explicit. Thus, it is meaningful to explore the functional status of the masseter muscle among stroke patients. The main objectives of this study were to examine the intra- and inter-rater reliability of the MyotonPRO apparatus in measuring masseter muscle hardness in stroke patients and to investigate the correlation between the bilateral masseter muscle hardness and masticatory performance in these patients. MATERIAL AND METHODS A total of 20 stroke patients participated in our study. The hardness of the masseter muscle was measured by 2 physiotherapists using the MyotonPRO apparatus. Overall, each patient masticated 2 pieces of red-blue bicolor chewing gum for 20 chewing cycles each. The chewing pieces were analyzed using ViewGum software for masticatory performance. RESULTS The intra- and inter-rater reliability of the MyotonPRO apparatus for measuring bilateral masseter hardness of stroke patients was excellent. The correlation analysis showed that the hardness index of the masseter muscle on the affected side was moderately correlated with the masticatory performance of the same side. CONCLUSIONS The MyotonPRO device can be used for measuring the masseter muscle hardness of stroke patients, with excellent reliability. This study established the construct validity between the stiffness of the masseter muscle and masticatory performance.

The effects of the magnetopolaron on the energy gap opening in graphene.

The magnetopolaron is formed via electron-acoustic deformation phonon coupling in the presence of a magnetic field in monolayer graphene. We find that an energy gap (EG) is opened due to the electron-phonon coupling. Both linear and square-root forms for the dependence of the EG on the magnetic field are obtained, which are in agreement with experimental measurements. Furthermore, we suggest that the EG can be estimated through observing the variation of Fermi velocity in cyclotron resonance experiments. The relation of the EG with the Debye cut-off wavenumber is also discussed.