The aim of this study was to compare treatment modalities, pathological and clinical characteristics, and outcomes in patients with metastasis in a parotid gland. The medical records of 34 patients who received treatment for metastasis in the parotid gland over a twenty-year period were evaluated. Patients with head and neck cutaneous squamous cell carcinoma (HNcSCC) metastasis were retrospectively reclassified using the P/N and N1S3 staging system. Patients with neck metastasis showed a significantly poorer prognosis (P = 0.025). Univariate analysis also revealed that extent of parotidectomy and type of neck dissection did not influence recurrence free survival (RFS) and overall survival (OS). When comparing the usefulness of the P/N and S1N3 staging systems, a positive correlation was observed between the P stage and the N1S3 stage in both RFS and OS. The extent of parotidectomy and concomitant neck dissection is still under discussion. Total parotidectomy and modified radical neck dissection did not improve RFS and OS. N1S3 is a less complex classification and possesses a higher predictive value when compared to the P/N staging system.

Excessive compression after parotidectomy can lead to flap necrosis, while inadequate pressure can cause fluid accumulation. This study aimed to determine the optimal pressure and compression properties of different types of dressings. Initially, pressure measurements were taken for conventional Barton\'s dressing and a pre-fabricated facial garment. In the subsequent phase, patients were randomly assigned to receive one of three types of pressure dressings: conforming bandage Barton\'s dressing, elastic bandage Barton\'s dressing or pre-fabricated facial garment. The dressing types were randomly crossed over the following day. The mean pressure exerted by conventional Barton\'s dressing and the pre-fabricated facial garment was 15.86 and 14.81 mmHg, respectively. There was no significant difference in the proportion of optimal pressure among the three types of pressure dressing (p-values of 0.195, 0.555 and 0.089 at pre-auricular, angle of mandible and post-auricular sites, respectively). The pre-auricular area demonstrated the highest proportion of optimal pressure, while suboptimal pressure was noted at the angle of the mandible and post-auricular area. Dressing types had no effect on pressure stability (p = 0.37), and there was no significant difference in patient preference (p = 0.91). Conforming bandage Barton\'s dressing, elastic bandage Barton\'s dressing and pre-fabricated facial garment exhibit comparable compressive properties, with no significant difference in patient preference and pressure stability.

Traditional open head and neck surgery often leaves permanent scars, significantly affecting appearance. The emergence of surgical robots has introduced a new era for minimally invasive surgery. However, the complex anatomy of the head and neck region, particularly the oral and maxillofacial areas, combined with the high costs associated with established systems such as the da Vinci, has limited the widespread adoption of surgical robots in this field. Recently, surgical robotic platform in China has developed rapidly, exemplified by the promise shown by the KangDuo Surgical Robot (KD-SR). Although the KD-SR has achieved some results comparable to the da Vinci surgical robot in urology and colorectal surgery, its performance in complex head and neck regions remains untested. This study evaluated the feasibility, effectiveness, and safety of the newly developed KD-SR-01, comparing it with standard endoscopic systems in head and neck procedures on porcine models. We performed parotidectomy, submandibular gland resection, and neck dissection, collected baseline characteristics, perioperative data, and specifically assessed cognitive workload using the NASA-TLX. None of the robotic procedures were converted to endoscopic or open surgery. The results showed no significant difference in operation time between the two groups (P = 0.126), better intraoperative bleeding control (P = 0.001), and a significant reduction in cognitive workload (P < 0.001) in the robotic group. In conclusion, the KD-SR-01 is feasible, effective, and safe for head and neck surgery. Further investigation through well-designed clinical trials with long-term follow-up is necessary to establish the full potential of this emerging robotic platform.

UNASSIGNED: To evaluate the effectiveness of MRI-based radiomics models in distinguishing between Warthin tumors (WT) and misdiagnosed or ambiguous pleomorphic adenoma (PA).
UNASSIGNED: Data of patients with PA and WT from two centers were collected. MR images were used to extract radiomic features. The optimal radiomics model was found by running nine machine learning algorithms after feature reduction and selection. To create a clinical model, univariate logistic regression (LR) analysis and multivariate LR were used. The independent clinical predictors and radiomics were combined to create a nomogram. Two integrated models were constructed by the ensemble and stacking algorithms respectively based on the clinical model and the optimal radiomics model. The models\' performance was evaluated using the area under the curve (AUC).
UNASSIGNED: There were 149 patients included in all. Gender, age, and smoking of patients were independent clinical predictors. With the greatest average AUC (0.896) and accuracy (0.839) in validation groups, the LR model was the optimal radiomics model. In the average validation group, the radiomics model based on LR did not have a higher AUC (0.795) than the clinical model (AUC = 0.909). The nomogram (AUC = 0.953) outperformed the radiomics model in terms of discrimination performance. The nomogram in the average validation group had a highest AUC than the stacking model (0.914) or ensemble model (0.798).
UNASSIGNED: Misdiagnosed or ambiguous PA and WT can be non-invasively distinguished using MRI-based radiomics models. The nomogram exhibited excellent and stable diagnostic performance. In daily work, it is necessary to combine with clinical parameters for distinguishing between PA and WT.

Canalicular adenoma (CA) is a rare benign tumor of the salivary glands, predominantly affecting elderly females, with a strong predilection for the upper lip. While CA commonly arises in the minor salivary glands, its occurrence in the parotid gland is exceptionally rare. In this report, we present a unique case of CA in the parotid gland, adding to the scant literature with only 8 documented instances. The patient, a 57-year-old Asian male, presented with a painless swelling in the left parotid gland that had been persisting for 8 years. Clinical examination and imaging studies identified a lobulated mass, prompting surgical intervention. The patient underwent a superficial parotidectomy, and pathological examination of the excised tissue confirmed the diagnosis of CA, with no signs of malignancy. This case illustrates the diagnostic and management challenges associated with CA, particularly given its rare presentation in the parotid gland. Accurate diagnosis is reliant on surgical biopsy, and careful surgical planning is imperative, especially considering the proximity of the facial nerve. Our case underscores the need for heightened awareness of CA\'s unique presentations, particularly within the Asian population. Given the potential for recurrence, long-term follow-up is essential. Further research is needed to elucidate the biological behavior of CA and to refine management strategies for optimal patient outcomes.

BACKGROUND: Anatomical preservation and functional integrity of the facial nerve (FN) are the main concerns of parotid surgery. Even though a variety of anatomical landmarks have been proposed and widely utilized, temporal or permanent postoperative FN palsy is still a significant comorbidity of parotid surgery. Therefore, the literature must fully elucidate the consistency of the anatomical relationship between the FN and the retromandibular vein (RMV).
METHODS: We conducted a cadaveric study of 24 hemifaces to map the relationship between the FN and the RMV. Three distinct patterns were identified. Fourteen of the hemifaces were males, and 10 were females. Thirteen cadaveric dissections were performed on the right side and 11 on the left side.
RESULTS: Our study found three distinct patterns and proposed a classification system. Type I (66.7%) is when the nerve lies exclusively lateral to the RMV. Type II (29.2%) is when the FN lies superficial to the RMV, but its mandibular branch lies deep to the anterior branch of the RMV, and type III (4.1%) is when the FN lies exclusively medial to the RMV.
CONCLUSIONS: The FN and RMV relationship is not constant, and surgeons should be aware of every anatomical variation. Especially in cases where the FN is estimated to lie more in-depth to the level of the RMV, a retrograde approach may be required to avoid a FN injury.

OBJECTIVE: This study assessed the effect of cevimeline and different concentrations of gum arabic on the parotid gland of rats being given xerostomia-inducing methotrexate.
METHODS: One hundred twenty-five rats were divided into five equal groups of twenty-five each. The rats in Group I received basic diets, while those in Groups II, III, IV, and V received 20 mg/kg MTX as a single intraperitoneal dose on day one. Group III received 10 mg/kg CVM dissolved in saline orally and daily, and the other two groups received a 10% W/V aqueous suspension of GA. Therefore, Group IV received 2 ml/kg suspension orally and daily, while Group V received 3 ml/kg suspension orally and daily. After 9 days, the parotid glands were dissected carefully and prepared for hematoxylin and eosin (H&E) staining as a routine histological stain and caspase-3 and Ki67 immunohistochemical staining. Quantitative data from α-Caspase-3 staining and Ki67 staining were statistically analysed using one-way ANOVA followed by Tukey\'s multiple comparisons post hoc test.
RESULTS: Regarding caspase-3 and Ki67 immunohistochemical staining, one-way ANOVA revealed a significant difference among the five groups. For Caspase-3, the highest mean value was for group II (54.21 ± 6.90), and the lowest mean value was for group I (15.75 ± 3.67). The other three groups had mean values of 31.09 ± 5.90, 30.76 ± 5.82, and 20.65 ± 3.47 for groups III, IV, and V, respectively. For Ki67, the highest mean value was for group I (61.70 ± 6.58), and the lowest value was for group II (18.14a ± 5.16). The other three groups had mean values of 34.4 ± 9.27, 48.03 ± 8.40, and 50.63 ± 8.27 for groups III, IV, and V, respectively.
CONCLUSIONS: GA, rather than the normally used drug CVM, had a desirable effect on the salivary glands of patients with xerostomia.

BACKGROUND: Despite the significant roles it plays in the functions of the platysma and lower lip, the cervical branch of the facial nerve is often overlooked compared to other branches, but its consideration is critical for ensuring the safety of neck surgeries.
OBJECTIVE: The aim of this study was to clarify the anatomical discrepancies associated with the cervical branch of the facial nerve to enhance surgical safety.
METHODS: The study utilized 20 fresh-frozen hemiheads. A 2-stage surgical procedure was employed, beginning with an initial deep-plane facelift including extensive neck dissection, followed by a superficial parotidectomy on fresh-frozen cadavers. This approach allowed for a thorough exploration and mapping of the cervical nerve in relation to its surrounding anatomical structures.
RESULTS: Upon exiting the parotid gland, the cervical nerve consistently traveled beneath the investing layer of the deep cervical fascia for a brief distance, traversing the deep fascia to travel within the areolar connective tissue before terminating anteriorly in the platysma muscle. A single branch was observed in 2 cases, while 2 branches were noted in 18 cases.
CONCLUSIONS: The cervical nerve\'s relatively deeper position below the mandible\'s angle facilitates a safer subplatysmal dissection via a lateral approach for the release of the cervical retaining ligaments. Due to the absence of a protective barrier, the nerve is more susceptible to injuries from direct trauma or thermal damage caused by electrocautery, especially during median approaches.

Parotid lumps are a heterogeneous group of mainly benign but also malignant tumors. Preoperative imaging does not allow a differentiation between tumor types. Multispectral optoacoustic tomography (MSOT) may improve the preoperative diagnostics. In this first prospective pilot trial the ability of MSOT to discriminate between the two most frequent benign parotid tumors, pleomorphic adenoma (PA) and Warthin tumor (WT) as well as to normal parotid tissue was explored. Six wavelengths (700, 730, 760, 800, 850, 900 nm) and the parameters deoxygenated (HbR), oxygenated (HbO2), total hemoglobin (HbT), and saturation of hemoglobin (sO2) were analyzed. Ten patients with PA and fourteen with WT were included (12/12 female/male; median age: 51 years). For PA, the mean values for all measured wave lengths as well as for the hemoglobin parameters were different for the tumors compared to the healthy parotid (all p < 0.05). The mean MSOT parameters were all significantly higher (all p < 0.05) in the WT compared to healthy parotid gland except for HbT and sO2. Comparing both tumors directly, the mean values of MSOT parameters were not different between PA and WT (all p > 0.05). Differences were seen for the maximal MSOT parameters. The maximal tumor values for 900 nm, HbR, HbT, and sO2 were lower in PA than in WT (all p < 0.05). This preliminary MSOT parotid tumor imaging study showed clear differences for PA or WT compared to healthy parotid tissue. Some MSOT characteristics of PA and WT were different but needed to be explored in larger studies.

OBJECTIVE: This study aimed to determine the prevalence of anterior extensions of the parotid gland (AEPG), namely the accessory parotid gland (APG) and the facial process of the parotid gland (FP), using ultrasonography.
METHODS: A total of 338 parotid glands were scanned bilaterally. APG was defined as a soft tissue mass with the same echogenic features as the main parotid gland (MPG) and not in contact with it, while FP was defined as an extension that exceeded the anterior border of the mandibular ramus and was continuous with the MPG. The anteroposterior, mediolateral, superoinferior dimensions and the mean distance from the MPG to the APG were measured.
RESULTS: The prevalence of APG and FP were 19.5% and 36%, respectively, resulting in an AEPG prevalence of 55.6%. The presence of APG was statistically higher in females than in males (p = 0.039). The mean anteroposterior, mediolateral, and superoinferior dimensions of the APG were 18.1 ± 0.57 mm, 0.35 ± 0.17 mm, and 12.3 ± 0.36 mm, respectively, and the mean distance from the MPG was measured as 12.1 ± 0.87 mm.
CONCLUSIONS: This study can raise awareness among clinicians about the presence of AEPG in the differential diagnosis of mid-cheek masses.