Evaluation of joint kinematics in patients with condylar reconstruction using mandibular motion simulation based on intraoral scanning registration.

AIM: To summarize the features of condylar kinematics in patients with condylar reconstruction using a mandibular motion simulation method based on intraoral scanning registration. MATERIALS AND METHODS: Patients undergoing unilateral segmental mandibulectomy and autogenous bone reconstruction as well as healthy volunteers were enrolled in the study. Patients were grouped based on whether the condyles were reconstructed. Mandibular movements were recorded using a jaw tracking system, and kinematic models were simulated after registration. The path inclination of the condyle point, margin of border movement, deviation, and chewing cycle were analyzed. A t test and one-way analysis of variance (ANOVA) were carried out. RESULTS: A total of 20 patients, including 6 with condylar reconstruction and 14 with condylar preservation as well as 10 healthy volunteers were included. The patients with condylar reconstruction showed flatter movement paths of the condyle points. The mean inclination angle of the condylar movement paths of the patients with condylar reconstruction (0.57 ± 12.54 degrees) was significantly smaller than that of those with condylar preservation (24.70 ± 3.90 degrees, P = 0.014) during both maximum opening and protrusion (7.04 ± 12.21 degrees and 31.12 ± 6.79 degrees, respectively, P = 0.022). The inclination angle of the condylar movement paths of the healthy volunteers was 16.81 ± 3.97 degrees during maximum opening and 21.54 ± 2.80 degrees during protrusion; no significant difference compared with the patients. The condyles of the affected side tended to deviate laterally in all patients during mouth opening and protrusion. Patients with condylar reconstruction showed more severe symptoms of mouth opening limitation and mandibular movement deviation as well as shorter chewing cycles than patients with condylar preservation. CONCLUSION: Patients with condylar reconstruction showed flatter movement paths of the condyle points, greater lateral motion range, and shorter chewing cycles than those with condylar preservation. The method of mandibular motion simulation based on intraoral scanning registration was feasible to simulate condylar movement.

Clinicopathological study of malignant peripheral nerve sheath tumors in the head and neck: Case reports and review of literature.

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is a rare and aggressive soft tissue sarcoma that poses a major diagnostic and therapeutic challenge. CASE SUMMARY: We retrospectively reviewed patients with head and neck MPNSTs treated in our hospital from 2000 to 2021. The clinical features, pathological manifestations, treatments, and prognoses were summarized. We also reviewed the literature, focusing on MPNST in the mandible and maxilla. The study population consisted of five women and five men aged 22-75 years (mean age, 49 years). Of the 10 patients, 7 were initial cases and 3 were recurrent cases. All lesions were sporadic. The most common site was the mandible. The most frequently encountered symptoms were a progressive mass and local swelling. Complete or partial loss of trimethylation at lysine 27 of histone H3 (H3K27me3) was evident on staining in four of nine cases (one case was excluded due to lack of tissue for evaluation of loss of H3K27me3). The 2- and 5-year disease-specific survival rates were 86% and 43%, respectively. The average survival time was 64 mo. CONCLUSION: MPNST is a highly malignant tumor with a poor prognosis, prone to a high risk of recurrence and distant metastasis. Complete surgical resection is the main treatment.

The application of an intraoral banana peel suturing model in surgical training of dental students.

OBJECTIVES: This study investigated the application of an intraoral banana peel suturing model in helping students to acquire intraoral surgical techniques. METHODS: This is a self-control study conducted from January 2021 to March 2021. An intraoral banana peel suturing model was implemented to provide oral suture experience for undergraduates majoring in stomatology. The sutures students placed in the model were photographed and evaluated blindly by a professional team using an established scoring system. Training scores were recorded before (training 1) and after 2 months of training (training 2). Linear regression was used to examine factors related to the scores. Suturing training was conducted in the School and Hospital of Stomatology at Peking University. A total of eighty-two students in Peking University School and Hospital of Stomatology were in their fourth pre-clinical year and followed a workshop on surgical sutures according to the curriculum. All students who should take this course were included, and the response rate was 100%. RESULTS: The mean training 2 score (23.04 ± 3.83) was higher than the mean training 1 score (13.94 ± 3.15). The training 1 score was not significantly correlated with any of the students' general characteristics. The training 2 score was correlated with the training 1 score and the cumulative duration of practice outside of class. CONCLUSION: The intraoral banana peel suturing model can be used for suture training, and dental students' suture ability was improved after using the banana peel for suture practice.

Combination of niclosamide and quinacrine inactivates Akt/HK2/Cyclin D1 axis mediated by glucose deprivation towards the inhibition of melanoma cell proliferation.

Malignant melanoma is one of the most aggressive and lethal skin cancer. At present, the treatment methods for melanoma have shortcomings. Glucose is the primary energy source of cancer cells. However, it is unclear whether glucose deprivation can be used to treat melanoma. Herein, we first found glucose played an essential role in melanoma proliferation. We then further found a drug combination of niclosamide and quinacrine could inhibit melanoma proliferation and glucose intake. Thirdly, we revealed the mechanism of anti-melanoma effect of the drug combination, which suppressed the Akt pathway. In addition, the first-rate limiting enzyme HK2 of glucose metabolism was inhibited. This work also disclosed that the decrease of HK2 inhibited cyclin D1 by reducing the activity of transcription factor E2F3, which further suppressed the proliferation of melanoma cells. The drug combination treatment also resulted in significant tumor regression in the absence of obvious morphologic changes in primary organ in vivo. In summary, our study demonstrated that the drug combination treatment created glucose deprivation to inactive the Akt/HK2/cyclin D1 axis, thereby inhibited the proliferation of melanoma cells, providing a potential anti-melanoma strategy.

Prognosis and Nomogram Prediction for Patients with Oral Squamous Cell Carcinoma: A Cohort Study.

The TNM staging system is often used to predict the prognosis of patients with oral squamous cell carcinoma (OSCC). However, we have found that patients under the same TNM staging may exhibit tremendous differences in survival rates. Therefore, we aimed to investigate the prognosis of postoperative OSCC patients, establish a nomogram survival prediction model, and verify its effectiveness. Operative logs were reviewed for patients who underwent surgical treatment for OSCC at the Peking University School and Hospital of Stomatology. Patient demographic and surgical records were obtained, and they were followed up for overall survival (OS). A total of 432 patients with oral squamous cell carcinoma were included in the study, with a median follow-up time of 47 months. Based on the results of the Cox regression analysis, we constructed and verified the nomogram prediction model, which includes gender, BMI, OPMDs, pain score, SCC grade, and N stage. The C-index value of the 3-year and 5-year prediction models was 0.782 and 0.770, respectively, proving that the model has a certain level of prediction stability. The new nomogram prediction model has potential clinical significance for predicting the postoperative survival of OSCC patients.

Extracapsular dissection by the sternocleidomastoid muscle-parotid space approach reduces the risks of postparotidectomy sialocele and salivary fistula.

BACKGROUND: Postoperative sialoceles and fistulas are frequent surgical complications of parotid tumor resection. Extracapsular dissection by the sternocleidomastoid muscle-parotid space approach (ECD-SMPSA) is a minimally invasive technique. To our knowledge, the characteristics of sialoceles and fistulas secondary to ECD-SMPSA have not been reported. METHODS: This prospective study enrolled 52 patients who underwent ECD-SMPSA without sialocele/fistula prevention measures. Postoperative sialoceles and fistulas were evaluated during 2 months of follow-up. RESULTS: Among the 52 patients, only one male patient developed a mild sialocele. No salivary fistulas occurred. The overall rate of sialocele/fistula formation was 1.92%. CONCLUSIONS: When treating clinically benign tumors that involve the sternocleidomastoid muscle-parotid space, ECD-SMPSA may prevent postoperative formation of sialoceles and salivary fistulas.

A new mammal from the Lower Cretaceous Jehol Biota and implications for eutherian evolution.

Here we report on a new Early Cretaceous eutherian represented by a partial skeleton from the Jiufotang Formation at Sihedang site, Lingyuan City, Liaoning Province that fills a crucial gap between the earliest eutherians from the Yixian Formation and later Cretaceous eutherians. The new specimen reveals, to our knowledge for the first time in eutherians, that the Meckelian cartilage was ossified but reduced in size, confirming a complete detachment of the middle ear from the lower jaw. Seven hyoid elements, including paired stylohyals, epihyals and thyrohyals and the single basihyal are preserved. For the inner ear the ossified primary lamina, base of the secondary lamina, ossified cochlear ganglion and secondary crus commune are present and the cochlear canal is coiled through 360°. In addition, plesiomorphic features of the dentition include weak conules, lack of pre- and post-cingula and less expanded protocones on the upper molars and height differential between the trigonid and talonid, a large protoconid and a small paraconid on the lower molars. The new taxon displays an alternating pattern of tooth replacement with P3 being the last upper premolar to erupt similar to the basal eutherian Juramaia. Parsimony analysis places the new taxon with Montanalestes, Sinodelphys and Ambolestes as a sister group to other eutherians. This article is part of the theme issue 'The impact of Chinese palaeontology on evolutionary research'.

Is This Novel Incision for Benign Parotid Tumors the Answer for Improved Esthetics and Access?

Background: Incision scars and postoperative cosmesis are critical in the management of benign parotid tumors. Traditional incisions have a typical visible scar in the retromandibular area or require wide skin flaps. Purpose: In this study, we introduced a new surgical approach called the tri-split flap approach and evaluated its technical feasibility and surgical outcomes. Materials and Methods: Eleven patients with clinically benign parotid gland tumors underwent the tri-split flap approach and were followed for six to ten months postoperatively. Facial weakness, salivary fistula formation, first bite syndrome, earlobe numbness, and the subjective cosmetic results were evaluated. Results: All tumors were completely excised, and the patients were highly satisfied with the esthetic outcome of the surgery. No patients developed wound dehiscence, facial nerve injury, or first bite syndrome during the follow-up period. One patient developed a minor salivary fistula that resolved after three weeks. Conclusion: The tri-split flap approach not only provides adequate exposure of the surgical site to achieve complete resection of benign parotid gland neoplasms but also results in a very short and highly concealed post-operative scar. This technique is a potential surgical approach in parotidectomy. Supplementary Information: The online version contains supplementary material available at 10.1007/s12663-021-01605-1.

Clinical application of double-layer soft tissue closure technology based on pedicled buccal fat pad in repairing maxillary defects after medication-related osteonecrosis of jaw surgery.

OBJECTIVES: This study aimed to analyze the clinical application effect of the double-layer soft tissue closure technique (DLST) based on pedicled buccal fat pad in repairing maxillary defects after medication-related osteonecrosis of the jaw (MRONJ) surgery. METHODS: Ten patients with maxillary MRONJ were diagnosed and treated via DLST based on pedicled buccal fat pad. Partial maxillary resection was conducted to remove the MRONJ lesion, and the inflammatory soft tissue in the maxillary sinus cavity was removed but the maxillary sinus mucosa was retained. Patients also underwent resection of the lower segment of the sphenoid pterygoid process. A pedicled buccal fat pad was used to line the maxillary sinus floor and oral mucosa to achieve double-layer soft tissue closure of the wound. The characteristics of the medication for the primary disease, the clinical characteristics and imaging characteristics of osteonecrosis, the surgical treatment effects, pain score, and functional status evaluation of the 10 patients were all reviewed and analyzed. RESULTS: Among the 10 patients, there were 5 cases of breast cancer, 2 cases of lung cancer, 1 case of prostate cancer, 1 case of multiple myeloma, and 1 case of kidney cancer. All 10 patients received zoledronic acid, and the average time of application of zoledronic acid was 34 months. Six patients had upper jaw exposure, and 4 patients had gingival soft tissue fistula; the average time to clinical symptoms was 5.6 months. Among them, 5 patients had a history of tooth extraction, 3 patients with apical periodontitis, 1 patient with periodontitis, and 1 patient with spontaneous teeth loss. The lesions of 10 patients were all located in the maxillary posterior area. CT images can often show sequestration near the maxillary sinus floor, and the maxillary sinus cavity was full of soft tissue inflammation in most patients. During the follow-up period, 8 patients healed by the first intention, and the other patient had partial liquefaction of the buccal fat pad 2 weeks after the operation, and the oral mucosa fistula closed 1 month after the operation. In another patient, MRONJ symptoms recurred 2 months after the operation, and the surgical site occasionally swelled and discharged pus. The patient's symptoms were completely relieved after another operation. The patient's pain and functional status improved significantly after the operation. CONCLUSIONS: Maxillary MRONJ is commonly found in the posterior area. The buccal fat pad-based DLST is used to repair the defect after maxillary resection, which is beneficial to seal the oral-maxillary sinus fistula and improve the clinical symptoms of patients with MRONJ.

Accuracy of 18 F-FDG PET/CT in Detection of Neck Metastases of Oral Squamous Cell Carcinoma in Patients Without Large Palpable Lymph Nodes.

OBJECTIVE: To measure the efficacy of positron emission tomography/computed tomography (PET/CT) in the diagnosis of neck metastases of oral squamous cell carcinoma (OSCC) in patients without enlarged lymph nodes and to determine the threshold of maximum standardized uptake values (SUVmax) in diagnosis. STUDY DESIGN: In total, 78 OSCC patients without large palpable lymph nodes were included. PET/CT findings were compared with histopathologic neck status. RESULTS: Neck dissection was performed in 78 patients with 98 neck sides, and 31 neck sides harbored metastases. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PET/CT were 83.9%, 73.1%, 76.5%, 59.1%, and 90.7%, respectively. The area under the curve in receiver operating characteristic analysis was 0.76, which indicated that SUVmax of lymph nodes was useful in diagnosis of pathologic neck status. The threshold SUVmax was 2.21, which was the best diagnosis threshold of neck metastasis. CONCLUSIONS: PET/CT is valuable in diagnosis of neck status. The probability of neck metastasis increased with increasing SUVmax values, but the threshold SUVmax should not be the sole criterion for determining the presence of neck metastases. Fluorodeoxyglucose PET/CT is recommended for evaluation of neck status in OSCC patients without large palpable lymph nodes.

Extracapsular dissection via sternocleidomastoid muscle-parotid space approach-a new operative technique for treating clinically benign tumor in the parotid tail.

OBJECTIVE: The aim of this study was to introduce extracapsular dissection via the sternocleidomastoid muscle-parotid space approach (ECD-SMPSA) as a modified operative technique for removal of clinically benign tumors from the parotid tail. STUDY DESIGN: The study included 52 patients with clinically benign tumors in the parotid tail, and the patients were divided into 2 groups: one group was treated with ECD-SMPSA and the other with extracapsular dissection (ECD). All of the patients were followed up for at least 2 years. RESULTS: The ECD-SMPSA group had lower incidence of subjective Frey syndrome (P = .03) and higher satisfaction with the cosmetic result after the surgery (P = .023) compared with the ECD group. All of the patients were free of salivary fistulae. Facial palsy (P = .234) and earlobe numbness (P = .291) were not significantly different between the groups (P < .05). CONCLUSIONS: With careful preoperative assessment, ECD-SMPSA may be a more suitable approach for the treatment of clinically benign tumors in the parotid tail.

Microfluidic Analyzer Enabling Quantitative Measurements of Specific Intracellular Proteins at the Single-Cell Level.

This paper presents a microfluidic instrument capable of quantifying single-cell specific intracellular proteins, which are composed of three functioning modules and two software platforms. Under the control of a LabVIEW platform, a pressure module flushed cells stained with fluorescent antibodies through a microfluidic module with fluorescent intensities quantified by a fluorescent module and translated into the numbers of specific intracellular proteins at the single-cell level using a MATLAB platform. Detection ranges and resolutions of the analyzer were characterized as 896.78⁻6.78 × 105 and 334.60 nM for Alexa 488, 314.60⁻2.11 × 105 and 153.98 nM for FITC, and 77.03⁻5.24 × 104 and 37.17 nM for FITC-labelled anti-beta-actin antibodies. As a demonstration, the numbers of single-cell beta-actins of two paired oral tumor cell types and two oral patient samples were quantified as: 1.12 ± 0.77 × 106/cell (salivary adenoid cystic carcinoma parental cell line (SACC-83), ncell = 13,689) vs. 0.90 ± 0.58 × 105/cell (salivary adenoid cystic carcinoma lung metastasis cell line (SACC-LM), ncell = 15,341); 0.89 ± 0.69 × 106/cell (oral carcinoma cell line (CAL 27), ncell = 7357) vs. 0.93 ± 0.69 × 106/cell (oral carcinoma lymphatic metastasis cell line (CAL 27-LN2), ncell = 6276); and 0.86 ± 0.52 × 106/cell (patient I) vs. 0.85 ± 0.58 × 106/cell (patient II). These results (1) validated the developed analyzer with a throughput of 10 cells/s and a processing capability of ~10,000 cells for each cell type, and (2) revealed that as an internal control in cell analysis, the expressions of beta-actins remained stable in oral tumors with different malignant levels.

Ossifying Fibromyxoid tumor of soft parts in head and neck: case report and literature review.

BACKGROUND: Ossifying fibromyxoid tumor of soft parts (OFMT), is a rare but morphologically distinctive neoplasm of uncertain histogenesis that most frequently affects middle-aged male adults. Clinically, it usually presents as a slowly enlarging, small, circumscribed mass, which in most cases is painless. OFMT is most frequently found within the subcutaneous tissues of extremities or trunk, and rarely in the oral/head and neck region. We present an unusual case of this tumor in the submandibular region, and, based on the current medical literatures this is probably the first case described in this anatomical location. CASE PRESENTATION: A 32-year-old male presented to our outpatient clinic with a right submandibular mass with 1-year of evolution. Excisional biopsy showed that it was characterized by ossification along the periphery of the lesion. The neoplastic cells were spindle-like with scant eosinophilic cytoplasm. These cells were arranged with uniform cell-to-cell space in a fibromyxoid stroma. Small and large clusters of calcifications were present within the tumor. Immunohistochemically, the case showed positive staining of S-100 protein, vimentin, nestin, calponin, SMA, GFAF, desmin, INI-1, caldesmon, and CD34. It also showed negative staining of CK, CK7, CK8/18, NF, and EMA. About 2% of neoplastic cells showed positive staining of Ki67. Based on these features, the final pathological diagnosis was OFMT. CONCLUSIONS: It is hoped that a greater understanding of OFMT in the head and neck region will avoid potential misdiagnosis, and contribute to determining the correct management, which appears to be complete surgical excision with close follow-up for recurrence surveillance.

Clinicopathological characteristics and outcomes of squamous cell carcinoma of the tongue in different age groups.

BACKGROUND: The clinicopathological features and outcomes of squamous cell carcinoma (SCC) of the tongue in patients of different age groups remain debatable. METHODS: Medical records of 457 patients with tongue SCC were reviewed, grouped by age, followed up, and compared. RESULTS: Sex and TNM stage showed no intergroup differences. Tongue SCC in patients ≤30 years had the most advanced TNM classification and greatest proportion of poorly differentiation tumors. Both disease-free survival (DFS) and disease-specific survival (DSS) showed no statistically significant difference between the youngest and the oldest groups (P = .605 and P = .520). However, there was a tendency of higher death rate caused by recurrence or metastasis in the youngest group compared with the others (91.7% vs 75.4% and 77.4%). CONCLUSION: Young patients had a tendency of higher death rate caused by recurrence or metastasis than middle-age and older patients; therefore, a larger case sample is needed for further confirmation.

Imaging features of medicine-related osteonecrosis of the jaws: comparison between panoramic radiography and computed tomography.

OBJECTIVE: The current staging system of medicine-related osteonecrosis of the jaws (MRONJ) assigns patients to different stages based on clinical manifestations. The extent of bone disease cannot be fully determined without radiologic evaluation. Missing radiologic information may lead to incorrect classification of MRONJ, resulting in poor outcomes of treatment. The objective of this study was to compare computed tomography (CT) and panoramic radiography (PR) features of MRONJ in different stages to achieve accurate staging on the basis of combined findings from clinical staging and imaging. STUDY DESIGN: A retrospective study was carried out to analyze the differences in the radiographic features of various clinical stages in MRONJ, as shown by PR and CT. RESULTS: Both PR and CT could detect the typical syndrome of osseous sclerosis in grade 0 and grade 1. For the patients of grade 2, more features were observed on CT, such as periosteal reaction, cortical perforation, and periosteal bone deposition. CT was also conducive to analyzing the degree of the maxillary lesion and soft tissue involvement as compared with PR. CONCLUSIONS: This study showed that CT detects changes that may not be revealed by plain radiography in patients with MRONJ.

[Positive lymph node ratio is an important prognostic factor of oral squamous cell carcinoma].

OBJECTIVE: To investigate the cutoff value and significance of lymph node ratio (LNR) in oral squamous cell carcinoma. METHODS: This retrospective study included 286 patients with oral cancer and pathological positive lymph nodes. Used time-dependent receiver operating characteristic (ROC) curves to determine which LNR best defines different risk groups of oral squamous cell carcinoma (OSCC) patients. All the variables were subjected to the univariate analysis, then only the variables that had prognostic potential were subjected to multivariate analysis by the COX proportional hazards regression model. RESULTS: The cutoff value of LNR was 0.092. When LNR was greater than 0.092, the overall survival rate was 24.2%, when LNR was less than 0.092, the overall survival rate was 45.8% (P<0.05). CONCLUSIONS: Lymph node ratio is a predictor of outcome in patients with oral squamous cell carcinoma, and the cutoff value is 0.092.

[Clinical features of osteonecrosis of jaws after bisphosphonates therapy for bone metastasis of breast cancer].

OBJECTIVE: To understand the clinical features of osteonecrosis of the jaw after bisphosphonates use for therapy of breast cancer patients with bone metastasis. METHODS: The cases diagnosed as bisphosphonates-related osteonecrosis of the jaws (BRONJ) were retrospectively analyzed from January 2011 to August 2015 in the Peking University School and Hospital of Stomatology, and those breast cancer patients with bone metastasis were selected. The clinical symptoms, imaging characteristics and treatment results were summarized. RESULTS: A total of 14 cases of breast cancer patients with bone metastasis were selected, with an average age of 60.21 years. The average time of suffering from breast cancer was 9.77 years, and the average time of bone metastasis and bisphosphonates drugs use was 5.67 and 3.29 years individually. There was no patient with systemic application history of hormone therapy, and no history of diabetes. There were 9 patients with tooth extractions history, and the mean time of bone necrosis symptoms was 8.58 months. There were 10 cases with bone necrosis occurring on mandible, 3 cases on maxilla, and one case with both upper and lower jaws involved. Among the 10 patients with surgical treatment, there were 3 cases cured, and 6 cases improved. However, the clinical symptoms of 2 cases with conservative treatment were significantly aggravated. CONCLUSION: The medication time between the bisphosphonates use beginning and the occurrence of BRONJ is relatively long. The history of diabetes and long-time hormone use did not exist in this group. Tooth extraction itself does not determine the severity of BRONJ. Mandible is the most common site involved by BRONJ. Surgical treatment can alleviate the clinical symptoms of BRONJ with breast cancer to some extent.

[Application of three-dimensional tumor mapping technique in diagnosis and treatment of malignant maxillary cancer].

OBJECTIVE: To investigate the application efficacy of three-dimensional tumor mapping technique for diagnosis and treatment of maxillary cancer. METHODS: Seventeen patients (aged from 9 to 74 years with an average age of 44.2 years) diagnosed with maxillary malignant tumors (13 for primary cancer and 4 for recurrent cancer) in Peking University School of Stomatology from December 2012 to October 2014 were reviewed as experimental group, in whom three-dimensional tumor mapping was performed before surgery, and 18 patients underwent traditional surgery in the same period as control group. Three-dimensional tumor imaging was generated with conversion of CT data into DICOM format by a software. Virtual plan of tumor resection and osteotomy was also manipulated according to the three-dimensional position of the tumor. Surgical navigation was used in the operation to confirm the virtual plan. The real position and situation of tumor was evaluated in the operation and compared with the pre-operative design. The frozen section was applied to confirm the margin after tumor resection. All the patients were followed up and the prognosis was evaluated. RESULTS: The real situation of the tumor in the operation matched well with the result of pre-operative tumor mapping and positive margin was detected only in one case. While in the control group, 2 of 18 patients presented with positive margin in the operation. The mean follow-up time was 14.8 months (range from 2.0 to 22.0 months). Local recurrence occurred in 4 cases of experimental group and in 6 cases of controlled group, and all of them were with advanced malignant tumors. CONCLUSION: The three-dimensional tumor mapping technique is a feasible and reliable method for the diagnosis and treatment of maxillary malignant tumor, and use of this technique can significantly improve the clinical outcome.