Adenoid cystic carcinoma of the retromolar pad region: A case report.

INTRODUCTION: Adenoid cystic carcinoma (ACC) is one of the most common salivary gland malignancies, mostly occurs in the major and minor salivary glands in the oral and maxillofacial region. The development of ACC in the retromolar pad is extremely rare, which limits establishing proper diagnosis and management. PRESENTATION OF CASE: A patient described a 2-month history of finding a mass behind the lower left posterior teeth. Based on the physical examination and radiographic findings, we got an initial impression of a benign mucocele, the nature of which was to be investigated further. Pathological examination of the resected tissue resulted in a diagnosis of ACC. Follow-up visits showed no recurrence during the subsequent 54 months. DISCUSSION: In cases with an uncertain diagnosis based on medical history, clinical features and imaging examinations, it is important to proceed carefully with the possibility of a tumor in mind. CONCLUSION: ACC in the retromolar pad is rare and can be easily misdiagnosed. Clinical, radiographic, and pathological evidence confirm a definitive diagnosis. Long-term follow-up is important for the full analysis of ACC treatment.

Spatial transcriptomics reveals that metabolic characteristics define the tumor immunosuppression microenvironment via iCAF transformation in oral squamous cell carcinoma.

Tumor progression is closely related to tumor tissue metabolism and reshaping of the microenvironment. Oral squamous cell carcinoma (OSCC), a representative hypoxic tumor, has a heterogeneous internal metabolic environment. To clarify the relationship between different metabolic regions and the tumor immune microenvironment (TME) in OSCC, Single cell (SC) and spatial transcriptomics (ST) sequencing of OSCC tissues were performed. The proportion of TME in the ST data was obtained through SPOTlight deconvolution using SC and GSE103322 data. The metabolic activity of each spot was calculated using scMetabolism, and k-means clustering was used to classify all spots into hyper-, normal-, or hypometabolic regions. CD4T cell infiltration and TGF-ß expression is higher in the hypermetabolic regions than in the others. Through CellPhoneDB and NicheNet cell-cell communication analysis, it was found that in the hypermetabolic region, fibroblasts can utilize the lactate produced by glycolysis of epithelial cells to transform into inflammatory cancer-associated fibroblasts (iCAFs), and the increased expression of HIF1A in iCAFs promotes the transcriptional expression of CXCL12. The secretion of CXCL12 recruits regulatory T cells (Tregs), leading to Treg infiltration and increased TGF-ß secretion in the microenvironment and promotes the formation of a tumor immunosuppressive microenvironment. This study delineates the coordinate work axis of epithelial cells-iCAFs-Tregs in OSCC using SC, ST and TCGA bulk data, and highlights potential targets for therapy.

Application of digital guide plate with drill-hole sharing technique in the mandible reconstruction.

Background/purpose: With the development of computer-assisted surgery, digital guide plate was widely used in vascularized bone flap grafts for mandibular reconstruction. The purpose of this study was to design and manufacture a digital guide plate with drill-hole sharing for mandibular reconstruction and assess for surgical accuracy. Materials and methods: 17 patients that required mandibular reconstruction using fibula free flap or iliac crest free flap were included in the study. The computed tomography (CT) data of the patient's mandible and pelvis or fibula were acquired preoperatively. A surgical simulation was then performed using computer-aided surgical simulation (CASS) technology based on above date, which allowed the design of two cutting guide and a repositioning guide for mandibular reconstruction. After surgery, the accuracy of reconstruction was evaluated by superimposing the postoperative image onto the preoperative image of mandible, recording the linear and angular deviation of landmarks, measuring the differences between the planned and actual outcomes. Results: The osteotomy and repositioning of fibula or iliac crest segments were successfully performed as planned using surgical guides. The digital guide plate with drill-hole sharing showed excellent accuracy, When the iliac crest or the fibula free flap were used for mandibular reconstruction, the largest mean differences between the preoperative and postoperative were 1.11 mm and 2.8° or 1.3 mm and 3.87°. Conclusion: The digital guide plate with drill-hole sharing designed preoperatively provides a reliable method of for the mandibular reconstruction. This can assist surgeons in accurately performing osteotomy and repositioning fibula or iliac crest segments during the mandibular reconstruction.

Clinical Application of Individualized 3D-Printed Templates in the Treatment of Condylar Osteochondroma.

BACKGROUND: Osteochondroma (OC) is one of the most common benign tumors of the long bones, but it rarely occurs in the maxillofacial skeleton. However, mandibular condylar OC often leads to severe facial deformity in affected patients, including facial asymmetry, deviation of the chin, and malocclusion. This study aimed to explore the clinical application of individualized 3D-printed templates to accurately and effectively treat condylar OC. METHODS: A total of 8 patients with mandibular condylar OC were treated from July 2015 to August 2021. The enrolled patients (5 women and 3 men) had a median age of 27 years (range: 21-32 years). All patients exhibited symptoms of facial asymmetry and occlusal disorders preoperatively. The digital software used to virtually design the process consisted of three-dimensional reconstruction, 3D-cephalometry analysis, virtual surgery, individualized templates, and postoperative facial soft-tissue prediction. A set of 3D-printed templates (DOS and DOT) were used in all cases to stabilize the occlusion and guide the osteotomy. Then, pre- and post-operative complications, mouth opening, clinical signs, and the accuracy of the CT imaging analysis were all evaluated. All the measurement data were presented as means ± SD; Bonferroni and Tamhane T2 multiple comparison tests were used to examine the differences between the groups. RESULTS: All patients healed uneventfully. None of the patients exhibited facial nerve injury at follow-up. In comparing the condylar segments with T0p and T1, the average deviation of the condylar segments was 0.5796 mm, indicating that the post-operative reconstructed condyles showed a high degree of similarity to the reconstruction results of the virtual surgical plan. CONCLUSIONS: Individualized 3D-printed templates simplified surgical procedures and improved surgical accuracy, proving to be an effective method for the treatment of patients with slight asymmetric deformities secondary to condylar OC.

A novel clinical signature predicts the survival of elderly patients with oral squamous cell carcinoma.

BACKGROUND: The risk factors for the survival of elderly patients with oral squamous cell carcinoma (OSCC) are multifarious. Here, we developed a novel clinical signature to serve as an indicator of prognosis in these patients. MATERIALS AND METHODS: Clinicopathological data were collected for 554 patients aged ≥ 60 years who were treated for primary OSCC. Overall survival (OS), disease-specific survival, and disease-free survival were the primary outcomes. RESULTS: Multivariate cox regression analysis showed that high N stage, low hemoglobin level, low body mass index (BMI), and high neutrophil-to-lymphocyte ratio (NLR) showed a poor survival (P < 0.05). A nomogram was constructed with a c-index of 0.702. CONCLUSION: A novel clinical signature including hemoglobin level, BMI, and NLR, which are obtained through noninvasive examinations can be used as prognostic indicators in clinical practice for elderly patients with OSCC.

Application of the presentation-assimilation-discussion class in oral pathology teaching.

OBJECTIVES: The presentation-assimilation-discussion (PAD) class is a novel teaching method in which half the class time is allocated for the instructor's presentation and the other half for student's assimilation and discussion. This study evaluates and compares the teaching outcomes of the PAD class and traditional lecture-based method in oral pathology courses in School of Stomatology, Kunming Medical University. MATERIALS AND METHODS: The experimental and control groups included 88 undergraduates from Class 2017 and 72 undergraduates from Class 2016, respectively. The PAD method was applied on the experimental group in 2019, whereas the traditional lecture-based method was applied on the control group in 2018. The two groups' teaching outcomes were compared using final theory tests, biopsy diagnostic tests, and questionnaires. The Mann-Whitney U-test and independent-sample t-test were adopted for statistical analysis. RESULTS: In five multiple-choice questions examining the same knowledge point from final theory tests, the distribution of the final scores showed a statistically significant difference between the two groups (p < 0.05). In the biopsy diagnostic tests, the experimental group scored higher than the control group (p < 0.05). In the questionnaires, there was no statistically significant difference for the "enhancing knowledge mastery" item (p > 0.05). However, the experimental group showed significant superiority in the remaining nine items (p < 0.05). [Correction added on August 30, 2021, after first online publication: The data value p was corrected in the last sentence of result section.] CONCLUSIONS: Compared with the traditional lecture-based teaching, the PAD class stimulated a passion for learning among students and results in improved teaching outcomes. Therefore, the application of PAD class in oral pathology teaching should be recommended.

Application of digital guide plate based on drill-hole sharing in oral and maxillofacial surgery.

OBJECTIVES: This study aimed to investigate the application of digital guide plate based on the drill-hole sharing concept in orthognathic surgery and mandibular reconstruction. METHODS: Sixteen patients with maxillofacial deformity requiring orthognathic surgery and 10 patients requiring mandibular reconstruction were selected as the research objects. Patients with maxillofacial deformity were scanned by computed tomography (CT), gypsum mold of the maxilla and mandibular arch were scanned using a laser surface scanner, and the fibula or iliac bone of the patients who needed mandibular reconstruction were scanned by CT to create a 3D model. The osteotomy and repositioning guides based on the drill-hole sharing concept were manufactured by digital technology. The guide plate was used to guide osteotomy and reposition the bone segment. Postoperative CT scan was performed. The displacement error of the bone segment was compared between the preoperative virtual surgery and the actual surgery to evaluate the accuracy of the guide plate, by measuring the distance between the landmarks and three reference planes and the distance between the two landmarks. RESULTS: The wounds healed well in all patients, and no serious complications were observed. The maximum mean values of LeFort Ⅰ osteotomy, genioplasty, fibular reconstruction, and iliac reconstruction were 0.84, 0.64, 1.27, and 1.18 mm, respectively; these values were acceptable by clinical standards. CONCLUSIONS: The digital guide plate based on the drill-hole sharing concept has high accuracy and clinical application value in orthognathic surgery and mandibular reconstruction.

Design and manufacture of dental-supported surgical guide for genioplasty.

BACKGROUND/PURPOSE: Genioplasty were used widely to correct chin deformities. The purpose of this study was to design and manufacture a dental-supported surgical guide for genioplasty surgery and assess for surgical accuracy. MATERIALS AND METHODS: eleven patients with chin deformities were treated in this study. The computed tomography (CT) data of the patient's skull and the digital dental models of stone dental models were acquired preoperatively. For each patient, a virtual three-dimensional (3D) model of the skull was constructed and enhanced with digital dental models. A surgical simulation was then performed using computer-aided surgical simulation (CASS) technology based on clinical examination and 3D cephalometry. The surgery was simulated preoperatively which allowed the design of a cutting guide and a dental-supported repositioning guide for genioplasty, which was then 3D-printed and used during operation after disinfection. After surgery, the outcome was evaluated by superimposing the postoperative CT model onto the preoperative model, recording the linear and angular deviation of landmarks and plane, then measuring the differences between the planned and actual outcomes. RESULTS: The osteotomy and repositioning were successfully performed as planned using surgical guides. No inferior alveolar nerve damage was seen in this study. The dental-supported surgical guide showed excellent accuracy, with the largest differences between the planned and the postoperative chin segment being 0.9 mm and 3.2°. CONCLUSION: The dental-supported surgical guide designed preoperatively provided a reliable method of transfer genioplasty planning. This can assist surgeons in accurately performing osteotomy and repositioning bone segments during a genioplasty.

Drain fluid amylase as a predictor of postoperative salivary fistula in cases with benign parotid tumours.

BACKGROUND: Late diagnosis of a salivary fistula increases the risk of wound infection and scarring. The purpose of the present study was to identify a quantitative predictor of postoperative salivary fistula for cases treated with surgery. METHODS: Demographic, intraoperative and postoperative parameters for 57 cases that received surgery for benign parotid tumours were recorded from June 2017 to June 2018, of which 18 cases developed salivary fistulas. These data were analysed using univariate and binary logistic regression analyses as well as receiver operating curve analysis. RESULTS: Drain fluid amylase concentration was positively correlated with salivary fistula development (p <  0.001), with an odds ratio of 1.14 for a 1 KU/L increase in concentration and an optimal receiver operating curve cut-off value of 51,100 U/L for predicting salivary fistula development. Cases wherein the parotid-masseteric fascia remained intact were associated with a lower risk of salivary fistula development (p = 0.006). CONCLUSION: Drain fluid amylase concentration may be a valuable predictor of postoperative salivary fistula in cases with benign parotid tumours.

Inflammatory myofibroblastic tumor in the head and neck-a neoplasm with both tumor features and inflammation.

OBJECTIVE: The aim of this study was to unveil the reciprocal relation of tumor characteristics and inflammation in inflammatory myofibroblastic tumor in the head and neck. STUDY DESIGN: The study included a retrospective cohort of patients with inflammatory myofibroblastic tumors treated between 2005 and 2017 in a tertiary hospital. Tumor features and inflammation were assessed through the expression of anaplastic lymphoma kinase (ALK), the degree of inflammation and cyclooxygenase-2 (COX-2) expression. The prognostic factors were analyzed for overall survival (OS) and disease-free survival (DFS) in univariate and multivariate analyses. RESULTS: Forty-one patients diagnosed with inflammatory myofibroblastic tumors were followed up, and 41 paraffin sections were obtained. The positive rate of ALK expression was 21 (51.2%) of 41 patients. Nineteen patients had high-grade ALK expression, and 22 patients had low-grade ALK expression. Thirty-nine patients had high-grade inflammation, and 2 had low-grade inflammation. The positive rate of COX-2 expression was 100%. Tumors with both high-grade ALK expression and inflammation had worse DFS (P = .015). The multivariate Cox analysis showed that the grades of ALK expression and inflammation (P = .004) were independent risk factors for DFS. CONCLUSIONS: Because of the latent synergistic effects of ALK and inflammation in the tumorigenesis of inflammatory myofibroblastic tumor, the combined therapy of ALK and COX-2 inhibitors shows promise.

GDNF secreted by nerves enhances PD-L1 expression via JAK2-STAT1 signaling activation in HNSCC.

Programmed death ligand 1 (PD-L1) functions as a key immune inhibitory factor by binding with its receptor, programmed death 1 (PD-1), to induce immune cell dysfunction and escape of the immune system. However, the mechanisms of PD-L1 expression under growth factor stimulation are not well characterized. Here, we demonstrate a novel role for glial cell line-derived neurotrophic factor (GDNF) in upregulating PD-L1 expression in head and neck squamous cell carcinoma (HNSCC). The expression and correlation of PD-L1, GDNF and perineural invasion (PNI) status were evaluated by bioinformatics analysis of TCGA database and IHC assays from 145 HNSCC patients. PD-L1 expression was investigated by flow cytometry, Western blot and real-time PCR analyses in HNSCC cells after GNDF incubation. The cell signaling pathways activated by GDNF were analyzed with an antibody array and blocked by specific signaling inhibitors in cancer cell lines. PD-L1 expression was significantly higher in cancer cells that exhibited PNI in the HNSCC specimens, and elevated PD-L1 expression was significantly correlated with GDNF levels. GDNF not only enhanced cancer cell PNI in a co-culture of dorsal root ganglions and cancer cells but also had a potent role in inducing PD-L1 expression through the JAK2-STAT1 signaling pathway. Moreover, a JAK2 inhibitor attenuated GDNF-induced PD-L1 and enhanced tumor cell susceptibility to NK cell killing. Our findings provide clinically novel evidence that nerve-derived GDNF can increase PD-L1 levels in cancer cells around the perineural niche and that regulatory signaling is critical for cancer cell escape from immune surveillance in the nerve-cancer microenvironment.

Clinical evaluation of a toothpaste containing lysozyme for removal of extrinsic stains on the tooth surface: An 8-week, double-blind, randomized study.

PURPOSE: To assess the efficacy and safety of application of a toothpaste containing lysozyme to remove extrinsic stains on the tooth surface in an 8-week trial. METHODS: 70 adult participants with extrinsic staining of the tooth surface were recruited to this randomized, parallel-controlled, double-blind clinical trial. Participants were allocated randomly to the test group or the control group and the study procedure and correct usage of the toothpaste were explained to them. Staining, measured by the Lobene stain index, and any side effects, were recorded over the course of the 8 weeks. All data were analyzed using SAS software version 8.0. RESULTS: 69 participants completed the study. The value of the Lobene stain index was significantly reduced (P< 0.05) in the treatment group compared with the control group after both 4 and 8 weeks. No obvious side effects were observed. CLINICAL SIGNIFICANCE: The results of this clinical study showed that the toothpaste containing lysozyme was effective in removing extrinsic staining on the tooth surface.

Recurrence and cancerization of ameloblastoma: multivariate analysis of 87 recurrent craniofacial ameloblastoma to assess risk factors associated with early recurrence and secondary ameloblastic carcinoma.

OBJECTIVE: The recurrence and progression of ameloblastoma are unpredictable. Therefore, we examined the influence of clinical factors on recurrence time and analyzed the clinical factors associated with early recurrence and cancerization. We then developed a staging system to predict early recurrence and cancerization. METHODS: All of the primary craniofacial ameloblastoma patients treated in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine were recorded. There were 87 recurrent cases used to create a staging system and tested in a Cox regression analysis for risk factors associated with early recurrence or cancerization following surgery. RESULTS: There were 890 craniofacial ameloblastoma patients, and 72 cases had recurrence. There were also 15 cases with cancerous recurrence. The overall recurrence rate was 9.78%, and the cancer rate was 1.69%. The primary cases were classified into the following 3 stages based on clinicopathological features: stage I, the maximum tumor diameter ≤6 cm; stage II, the maximum diameter of tumor >6 cm or tumor invasion to the maxilla sinus/orbital floor/soft tissue; and stage III, tumor invasion of the skull base or metastasis into regional lymph nodes. When the method of surgery was controlled by partial correlation, the staging had significance with recurrence time (P=0.004). The Cox analysis showed the tumor stage was correlated with recurrence time (P=0.027) and cancerization time (P=0.002). However, the surgical method did not influence the recurrence time when adjusted for cofounding variables. CONCLUSIONS: Tumor larger than 6 cm and invasion to soft tissues or adjacent anatomical structures are associated with early recurrence. This staging system can be used to predict the risk factors of early recurrence and cancerization in ameloblastoma patients.

Maxillary ameloblastoma: Factors associated with risk of recurrence.

BACKGROUND: Maxillary ameloblastomas are rare and associated with an aggressive course because of the anatomic composition of the maxilla and adjacent structures. The risk factors associated with recurrence were analyzed in this retrospective study. METHODS: Cases of maxillary ameloblastoma reported in a tertiary hospital from 2005 to 2015 were analyzed to identify clinicopathological and radiological factors associated with recurrence using univariate and multivariate Cox regression analyses. RESULTS: A total of 890 patients with ameloblastomas were treated in this study, of whom only 51 (5.7%) had maxillary ameloblastomas. The median follow-up period was 56 ± 28.65 months. Of the maxillary ameloblastomas, 29 (56.8%) were primary and 22 (43.1%) were recurrent. Soft tissue or maxillary sinus invasion and primary or recurrent tumor status were risk factors significantly associated with recurrence in the univariate analyses (p = .006 vs p = .025, respectively), whereas the association between recurrence and surgical methods was borderline significant (p = .08). The multivariate Cox regression analysis showed that soft tissue or maxillary sinus involvement was significantly associated with recurrence (p = .023). CONCLUSION: Recurrent tumors and tumors with soft tissue or maxillary sinus involvement were risk factors for recurrence among patients with maxillary ameloblastoma. © 2017 Wiley Periodicals, Inc. Head Neck 39: 996-1000, 2017.