Relationship between impaired parasympathetic vasodilation and hyposalivation in parotid glands associated with type 2 diabetes mellitus.

We examined the relationship between hemodynamics in the three major salivary glands and salivary secretion in urethane-anesthetized and sympathectomized type 2 diabetic and nondiabetic rats via laser speckle imaging and by collecting the saliva. Lingual nerve stimulation elicited rapid increases in glandular blood flow and induced salivary secretion from the three glands in both diabetic and nondiabetic rats. In the parotid gland, the magnitude of blood flow increase and salivary secretion was significantly lower in the diabetic rats when compared with the nondiabetic rats; however, this was not observed in the other glands. Although the intravenous administration of acetylcholine increased blood flow in the parotid gland in a dose-dependent manner, the response was significantly lower in the diabetic rats when compared with the nondiabetic rats. Similarly, mRNA expression levels of M1 and M3 muscarinic acetylcholine receptors in the parotid gland were relatively lower in the diabetic rats compared with the nondiabetic rats. Our results indicate that type 2 diabetes impairs parasympathetic vasodilation and salivary secretion in the parotid gland and suggest that disturbances in the cholinergic vasodilator pathway may contribute to the underlying mechanisms involved in the disruption of parasympathetic nerve-mediated glandular vasodilation.

The diagnostic value of Superb Microvascular Imaging in identifying benign tumors of parotid gland.

BACKGROUND: We compared the ultrasound features, superb microvascular imaging (SMI) and micro vessel density (MVD) of pleomorphic adenoma (PA), Warthin's tumor (WT) and basal cell adenoma (BCA) to explore the clinic value of SMI in differential diagnosis of benign tumors of parotid gland. METHODS: The vascular distributions and grade by color doppler flow imaging (CDFI) and SMI, as well as vascular index (VI) of 249 parotid gland masses from 217 patients were analyzed. RESULTS: The internal echogenicity of BCA are more homogeneous in comparing with WT and PA(P < 0.05). By SMI, the vascular distribution and vascular grade in PA were mainly peripheral (33.1%) and avascular (25.7%), Grade 1 (27.8%) and Grade 0 (25.7%). WT were mainly central (31.3%) and mixed distribution (34.9%), in Grade 3 (37.3%) and Grade 2 (36.2%). BCA was mainly peripheral (33.3%) and mixed distribution (33.3%), in Grade 2 (33.3%) and Grade 3 (33.3%). The overall detection rate of SMI for vascular Grade 2 and 3 was significantly higher than that of CDFI (P < 0.05). Both VI and MVD were lowest in PA, highest in WT (P < 0.001). The VI by SMI was correlated with MVD (P < 0.001). The correlation index between vascular distribution and grade by SMI and MVD were significantly higher than CDFI. CONCLUSION: SMI can provide low-velocity blood flow information, which is helpful for the differential diagnosis of common benign tumors of parotid gland, and is expected to be more widely used.

Evaluation of parotid glands in healthy children and adolescents using shear wave elastography and superb microvascular imaging.

OBJECTIVES: We aim to determine parotid gland elasticity values from healthy children and adolescents using shear wave elastography (SWE). We also define the degree of vascularity using superb microvascular imaging (SMI), power Doppler (PD), and color Doppler (CD) and compare SMI with CD and PD. MATERIALS AND METHODS: A total of 100 cases, comprising 50 girls and 50 boys, with ages ranging from 3 to 17 years were included in this prospective study. SWE, SMI, PD, and CD measurements were taken from both parotid glands, and the relationships with sex, age, and body mass index (BMI) were determined. The SMI was compared with the PD and CD. RESULTS: The median elasticity values measured with SWE were 8.37 ± 2.09 kPa and 1.68 ± 0.26 m/s on the right and 8.33 ± 2.04 kPa and 1.69 ± 0.26 m/s on the left. There were significant positive correlations present for those aged below and above 10 years and for BMI with elasticity values. The median vascular spot numbers measured using SMI, PD, and CD were 5 ± 1.70, 3.5 ± 1.45, and 2 ± 1.1 on the right and 4 ± 1.7, 4 ± 1.43, and 2 ± 1.05 on the left, respectively. The median values obtained with SMI were significantly higher than the median values obtained with both PD and CD. CONCLUSION: This study determined the reference SWE, SMI, PD, and CD values for normal parotid glands in healthy children and adolescents. Elasticity values were affected by age and BMI. There was no correlation between vascularity values and age, sex, or BMI. SMI provided more detailed information about vascularity compared with the other methods.

Intravoxel incoherent motion imaging measurement of perfusion changes in the parotid gland provoked by gustatory stimulation: A pilot study.

PURPOSE: To demonstrate the feasibility of intravoxel incoherent motion imaging (IVIM) for quantification of perfusion changes in the parotid gland after gustatory stimulation. MATERIALS AND METHODS: Eight healthy volunteers underwent diffusion-weighted magnetic resonance imaging (MRI) of the neck at 3T with 11 dynamic acquisitions (9 b-values between 0 and 980 s/mm2 , 2:40 min each). After 5:20 minutes, a lemon-mint-drop was administered orally. Perfusion fraction (Fp ), pseudodiffusion (D*), tissue diffusion (Dt ) coefficients, and optimal b-value threshold were measured using a multistep variable b-value threshold fitting approach. Dynamic changes in the coefficients between three exemplary timepoints (baseline, after stimulation, after dissolution) were compared using a Mann-Whitney U-test with Bonferroni correction (P < 0.016 significance level). RESULTS: Mean values (95% confidence interval [CI]) for IVIM parameters at baseline were Fp : 0.11 (0.08-0.15), D*: 56.48 mm2 /s (39.71-98.27), Dt : 1.01 mm2 /s (0.84-1.06), b-value threshold: 30 s/mm2 (21.25-105). After stimulation: Fp 0.16 (0.15-0.24; P < 0.01), D* 93.83 mm2 /s (77.98-129.53, P = 0.25), Dt 0.93 mm2 /s (0.87-1.08, P = 0.94), b-value threshold 20 s/mm2 (13.75-26.25 s/mm2 , P = 0.10), reflecting the increase in tissue perfusion. After dissolution of the drop: Fp : 0.13 (0.11-0.18, P = 0.38), D*: 101.61 mm2 /s (90.68-144.55, P = 0.07), Dt : 0.91 mm2 /s (0.85-1.05, P = 0.64), b-value threshold: 15 s/mm2 (11.25-40, P = 0.38). CONCLUSION: The IVIM method allows for simultaneous quantification of changes in perfusion and diffusion effects after gustatory stimulation of the parotid gland. LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:570-578.

Modified temporomandibular joint disc repositioning with miniscrew anchor: part I--surgical technique.

Anterior disc displacement is one of the most common conditions affecting the temporomandibular joint. In the authors' previous publications, they reported on the basic technical elements of disc repositioning surgery. However, the present article presents some critical modifications that have allowed the safe and successful performance of this procedure during the past 3 years.

Vascular malformations that were diagnosed as or accompanied by malignant tumors.

BACKGROUND: Vascular malformations can mimic malignant tumors, and the coexistence of both types of lesions can limit and interfere with treatment. A consecutive series of vascular malformations that were treated and evaluated in a single institute and cases involving vascular anomalies combined with malignancies or malignancies that were treated as vascular anomalies were analyzed. OBJECTIVE: Absolute ethanol is used in the treatment and management of vascular malformations and is sometimes administered before a definitive diagnosis has been obtained, despite the fact that some vascular lesions are subsequently revealed to be malignant tumors. This study discusses such cases. MATERIALS AND METHODS: From January 2006 to August 2012, 139 patients were treated for vascular malformations at Nagasaki University Hospital and were followed up for a minimum of 1 year. RESULTS: Four malignant lesions coexisted with or were misdiagnosed as vascular malformations, including a malignant peripheral nerve sheath tumor located in the chest, a hemangiopericytoma of the palate, an adenoid cystic carcinoma of the cheek, and a squamous cell carcinoma of the cheek. Thus, malignant lesions were detected in 2.88% of cases in which vascular malformations were preoperatively diagnosed. CONCLUSION: When treating vascular malformations, it is advisable to be aware of the possibility of malignancy.

Multidisciplinary approach to lethal bleeding from an arteriovenous malformation in the external auditory canal.

Arteriovenous malformations (AVMs) are composed of abnormally connecting feeding arteries as well as draining veins and lack a regulatory system. Frequent recurrences and unpredictable behavior are their main problems. Potential mortality and morbidity associated with therapeutic procedures must be considered with these patients. Improper treatment often aggravates the condition, potentially rendering therapy more complex. A multidisciplinary approach, including an endovascular approach, surgical excision, and flap reconstruction, is considered to completely eradicate an AVM. This study introduces a complicated case of AVM with massive bleeding through the external auditory canal that was treated with a multidisciplinary approach.

Impairment of acetylcholine-mediated endothelium-dependent relaxation in isolated parotid artery of the alloxan-induced diabetic rabbit.

The aim of this study was to assess the effect of type 1 diabetes mellitus (induced by a single intravenous injection of 100 mg kg(-1) of alloxan) on acetylcholine (ACh)-induced relaxation in isolated rabbit parotid gland feeding artery. Isometric force measurements and quantification of inducible nitric oxide synthase (iNOS) mRNA by real-time RT-PCR were made in parotid artery rings from diabetic and control rabbits. Acetylcholine induced concentration- and endothelium-dependent vasorelaxation that was significantly decreased in parotid artery rings from diabetic rabbits. Schild analysis of the ACh vasorelaxant effect, in the presence of selective muscarinic receptor antagonists, revealed involvement of the M(3) receptor subtype in parotid artery rings from both control and diabetic rabbits, with no change in antagonist affinity constants. The inhibitory effects of indomethacin, a non-selective inhibitor of cyclooxygenase, and of high potassium, an inhibitor of hyperpolarization, on ACh vasorelaxation were increased. The effect of N(G) -nitro-l-arginine, a non-selective inhibitor of NOS, was decreased in diabetes. S-methylisothiourea, a selective inhibitor of iNOS, significantly reduced ACh vasorelaxation only in parotid artery rings from diabetic rabbits. Also, up-regulation of iNOS mRNA expression was detected in parotid artery rings from diabetic rabbits. These results suggest that in parotid artery rings from diabetic rabbits, impaired endothelium-dependent vasorelaxation to ACh appears to be caused by the loss of a nitric oxide-mediated component and increased iNOS expression, and is unlikely to be caused by a change at the M(3) receptor level.

Parotid Gland Venolymphatic Malformation Presentation As Macroglossia.

Venolymphatic malformations (VLM) are the rare congenital disorders but the parotid gland VLMs are the rarest. Most of the parotid lesions present with unilateral swellings. Aetiology is unknown. Interestingly, this case came in OPD with the macroglossia and only complaint was cosmetic problem. Diagnosis was confirmed on the basis of Magnetic resonance imaging which is gold standard. Doppler ultrasonography showed low flow. Intra lesion electro cautery was done. There is need to focus on malformations and work to find out the causes.

Perfusion characteristics of late radiation injury of parotid glands: quantitative evaluation with dynamic contrast-enhanced MRI.

We aimed to quantitatively investigate the alteration of parotid perfusion after irradiation using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) based on a two-compartment tracer kinetic model. This study enrolled 19 patients (53.2 +/- 14.9 years) treated by head and neck radiotherapy and 19 age-relevant and sex-matched subjects as a control group. Perfusion parameters (K ( el ), k (21) and A) of parotid glands were analyzed based on the Brix model from T1-weighted DCE-MRI. Suitability of the Brix model was evaluated via Monte Carlo simulation for the goodness-of-fit. Analysis of nonlinear goodness-of-fit showed that the Brix model is appropriate in evaluating the parotid perfusion (R(2) = 0.938 +/- 0.050). The irradiated parotid glands showed significantly lower K ( el ) (P < 0.0005) and k (21) (P < 0.05) and consequently significantly higher value of peak enhancement (P < 0.0005) and time-to-peak (P < 0.0005) compared with non-irradiated ones, suggestive of gradual and prolonged accumulation and delayed wash-out of contrast agent due to increased extracellular extravascular space and decreased vascular permeability in the irradiated glands. Linear regression analysis showed dose-dependent perfusion changes of the irradiated parotid glands. We conclude that quantitative DCE-MRI is a potential tool in investigating parotid gland perfusion changes after radiotherapy.

Comparison of sonographic appearance of normal and postradiotherapy parotid glands: a preliminary study.

This study was undertaken to evaluate and compare the grey-scale and Doppler sonographic features of postradiotherapy (RT) and normal parotid glands. A total of 10 patients with previous head and neck RT and with different degrees of xerostomia were included. Another 10 healthy subjects, who are age and gender-matched with the 10 patients, were also recruited. Grey-scale and Doppler ultrasound examinations of parotid glands were performed on both the patients and healthy subjects. The parotid glands were assessed for their size, echogenicity, echotexture, conspicuity of intraparotid ducts, blood flow velocity and vascular resistance. Results showed that post-RT parotid glands tended to be smaller than normal parotid glands with a significant difference in the transverse dimension (p < 0.05). Normal parotid glands appeared homogeneous, hyperechoic relative to the adjacent muscles and had marginally seen intraparotid ducts. Post-RT parotid glands were heterogeneous, isoechoic (50%) or hypoechoic (50%) relative to the adjacent muscles, and the intraparotid ducts were either marginally (50%) or obviously (50%) seen on ultrasound. The PSV, RI and PI of normal parotid glands were significantly higher than that of post-RT parotid glands (p < 0.05). However, the difference in EDV between normal and post-RT parotid glands was not significant (p > 0.05). In conclusion, ultrasound is useful in assessing parotid glands. To avoid image misinterpretation, post-RT changes in the sonographic appearance of parotid glands should be considered in examining patients with previous head and neck RT.

Differentiation of benign and malignant parotid tumors using deconvolution-based perfusion CT imaging: feasibility of the method and initial results.

AIM: We evaluated the feasibility of perfusion CT (CTP) of the parotid gland and attempted to differentiate benign from malignant tumors. MATERIALS AND METHODS: CTP was performed in 17 patients with benign tumors and 10 patients with malignant parotid tumors. Data were postprocessed by using deconvolution-based perfusion analysis. Postprocessing-generated maps showed blood flow (BF), blood volume (BV), mean transit time (MTT), and capillary permeability surface product (PS). Regions of interest were placed through the tumor site and the contralateral healthy parotid tissue. Ratios of the perfusion values between the tumors and the contralateral healthy structures were also calculated. Pearson correlation coefficients were determined to compare the agreement between the two readers. RESULTS: Perfusion maps of all tumors were successfully obtained. High Pearson correlation coefficients comparing the two readers' visually measured abnormalities were observed (r=0.79-0.86, P=0.001) for all perfusion maps, The MTT and PS values between malignant and benign tumors were not significantly different. The BF and BV values were statistically significant different between the benign and malignant tumors (0.00

An unusual position of retromandibular vein: a surgical challenge in parotid surgeries.

A 44-year-old man presented with swelling in the left parotid region. The swelling was firm and Fine Needle Aspiration Cytology report proved pleomorphic adenoma. In the CT scan, the tumour was confined to the superficial lobe of parotid. So, left superficial parotidectomy was planned. Modified Wilson Blair's incision was used. On course of identifying the facial nerve, a large calibre vein was identified running vertically through the parotid substance. Assuming it as retromandibular vein, further dissection was carried out more meticulously. Marginal mandibularbranch of facial nerve was identified near the angle of mandible and retrograde dissection showed the cervicofacial division running medial to retromandibular vein with the main facial nerve trunk lying unusually medial and posterior to it. Adding to it, the temporofacial division was found 'forked' between the branches of retromandibular vein. These variations in head and neck venous channels are not that rare as we believe. All these variations have an embryological basis. Therefore, knowledge and understanding of this complex anatomy will help us preventing devastating complications like bleeding and facial nerve injury in such cases.

Auricular complications in parotid, temporal bone, infratemporal fossa, and lateral skull base surgery.

Neoplasms located in the parotid region, temporal bone, infratemporal fossa, and lateral skull base represent a challenge due to their difficult anatomic location and surrounding neurovascular structures. A variety of surgical approaches are appropriate to access this area, although several of them can place the auricular blood supply in danger. If the auricular blood supply is compromised, ischemia and, eventually, avascular necrosis of the auricle can occur. Auricular necrosis often can cause patients a delay in adjuvant radiation therapy and result in the need for additional reconstructive procedures. Therefore, it is imperative to identify risk factors associated with the development of this disabling complication. We conducted a retrospective review of 32 individuals undergoing treatment of benign and malignant lesions in the parotid gland, infratemporal fossa, and lateral skull base. To identify potential risk factors for auricular necrosis, the patients were analyzed based on the type of neoplasm (malignant or benign), risk factors affecting blood flow (diabetes mellitus, smoking history, prior radiation, prior surgery), body mass index, and the length of surgery. In our population examined, 3 instances of auricular necrosis occurred. None of the potential risk factors proved to be statistically significant (although malignant pathology approached significance at p = 0.07). Two of the patients required an auriculectomy with reconstruction. The third had multiple postoperative clinic visits for surgical debridement. Although no potential risk factors were statistically significant, surgeons should remain cognizant of the auricular blood supply while performing surgery via preauricular and postauricular approaches to this area.

Influence of amplitude-related perfusion parameters in the parotid glands by non-fat-saturated dynamic contrast-enhanced magnetic resonance imaging.

PURPOSE: To verify whether quantification of parotid perfusion is affected by fat signals on non-fat-saturated (NFS) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and whether the influence of fat is reduced with fat saturation (FS). METHODS: This study consisted of three parts. First, a retrospective study analyzed DCE-MRI data previously acquired on different patients using NFS (n = 18) or FS (n = 18) scans. Second, a phantom study simulated the signal enhancements in the presence of gadolinium contrast agent at six concentrations and three fat contents. Finally, a prospective study recruited nine healthy volunteers to investigate the influence of fat suppression on perfusion quantification on the same subjects. Parotid perfusion parameters were derived from NFS and FS DCE-MRI data using both pharmacokinetic model analysis and semiquantitative parametric analysis. T tests and linear regression analysis were used for statistical analysis with correction for multiple comparisons. RESULTS: NFS scans showed lower amplitude-related parameters, including parameter A, peak enhancement (PE), and slope than FS scans in the patients (all with P < 0.0167). The relative signal enhancement in the phantoms was proportional to the dose of contrast agent and was lower in NFS scans than in FS scans. The volunteer study showed lower parameter A (6.75 ± 2.38 a.u.), PE (42.12% ± 14.87%), and slope (1.43% ± 0.54% s(-1)) in NFS scans as compared to 17.63 ± 8.56 a.u., 104.22% ± 25.15%, and 9.68% ± 1.67% s(-1), respectively, in FS scans (all with P < 0.005). These amplitude-related parameters were negatively associated with the fat content in NFS scans only (all with P < 0.05). CONCLUSIONS: On NFS DCE-MRI, quantification of parotid perfusion is adversely affected by the presence of fat signals for all amplitude-related parameters. The influence could be reduced on FS scans.

Spontaneous infarction of a pleomorphic adenoma in parotid gland: diagnostic problems and review.

Although infarction of parotid gland pleomorphic adenoma (PA) following fine-needle aspiration (FNA) has been well-documented, spontaneous infarction of PA has remained as an uncommon entity in the literature. To our knowledge, we report the second case of spontaneous infarction occurring in a parotid gland PA. A 44-yr-old man presented with a 2-yr history of slowly enlarging right parotid mass, which had become painful 1 mo before performing FNA biopsy. Smears revealed abundant necrotic debris, atypical squamous cells, and small cells with dark nuclei suggestive of a carcinoma. Histologic examination of the tissue fragments demonstrated degenerated clusters of cells and chondromyxoid matrix. The parotidectomy specimen had features consistent with those of an infarcted PA. Although appears to be rare, spontaneous infarction of PA should be considered in the differential diagnosis, since necrosis may mimic carcinoma and cause misinterpretation of necrosis as an indication of malignancy, in an otherwise benign salivary gland neoplasm.

Vascular malformation with phleboliths involving the parotid gland: A case report with a review of the literature.

Phleboliths within the parotid gland are exceedingly rare. We report a case of a venous malformation with multiple phleboliths that involved the left parotid gland and extended into the extraparotid tissue in a 43-year-old woman. We also review 13 similar cases that have been reported since 1948, and we highlight the significance of distinguishing phleboliths from sialoliths because management of the two can be entirely different. Phleboliths in and around the salivary glands primarily affect the parotid and submandibular glands in adult women. Patients can present with recurrent, intermittent swelling that may be associated with food intake and hyposalivation. Any sialolithiasis located outside of its most common location in the submandibular glands must be investigated thoroughly before surgery.

Utility of (99m)Tc RBC Scintigraphy in Diagnosing Parotid Venous Malformations.

Venous malformations of the parotid glands are uncommon and can be difficult to confirm on routine anatomical imaging alone because of overlap of imaging features with other more common parotid lesions. (99m)Tc RBC scans combined with SPECT/CT offer a noninvasive way to diagnose parotid venous malformations without the need for biopsy. Combined with anatomical findings of phleboliths (when present), the diagnosis can be reliably determined. We present a case where MRI and biopsy were inconclusive, but the SPECT/CT was used to confirm the suspicion of a benign venous malformation.

Brief Report: Ultrasonographic Assessment of Salivary Gland Response to Rituximab in Primary Sjögren's Syndrome.

OBJECTIVE: To evaluate changes in salivary gland echostructure and vascularization after rituximab treatment in patients with primary Sjögren's syndrome (SS). METHODS: Twenty-eight patients with primary SS included in the multicenter, randomized, double-blind, placebo-controlled Tolerance and Efficacy of Rituximab in Primary Sjögren's Syndrome (TEARS) trial underwent salivary gland ultrasonography before the first placebo or rituximab infusion and then 6 months later. Trial inclusion criteria were scores of ≥50 mm on at least 2 of 4 visual analog scales (VAS) evaluating dryness, pain, fatigue, and global disease; and recent-onset (<10 years) biologically active primary SS and/or systemic primary SS. Patients were randomly assigned (1:1) to rituximab (1 gm at weeks 0 and 2) or placebo. Ultrasonography of both parotid and submandibular glands was performed to assess echostructure (using a semiquantitative score of 0-4, with improvement defined as a ≥1-point decrease), size of each gland, and vascularization based on the resistive index of the transverse facial artery of the parotid gland before and after lemon juice stimulation. RESULTS: Of the 28 patients, 5 (18%; 3 in the placebo group and 2 in the rituximab group) had clinically detectable bilateral parotid gland enlargement at baseline. Parotid parenchyma echostructure improved in 50% of the rituximab-treated patients versus 7% of the placebo-treated patients (P = 0.03). In the submandibular glands, echostructure also improved in a larger proportion of rituximab-treated patients, although the difference was not significant (36% versus 7% of placebo-treated patients; P = 0.16). Gland sizes and resistive index remained unchanged. CONCLUSION: Ultrasonography showed improved salivary gland echostructure in patients with primary SS receiving rituximab, with no changes in salivary gland size or vascularization, 6 months after the first infusion.

A fine structural demonstration that some benzopyrones act as vitamin P in the rat.

In rats fed a diet lacking flavonoids (but which had supplementary vitamin C) definite fine structural alterations were found in blood capillaries and tissues. These fine structural alterations were quite different from those reported in C-avitaminosis and imply a different deficiency. They were largely prevented by feeding the benzopyrones, coumarin or coumarin plus troxerutin, thus pointing to the specificity of the lesions. This implies that, for the rat, benzopyrones are vitamins and that vitamin C and "vitamin P"-deficiency states are qute distinct. In "P-avitaminosis" the basic lesion is the opening of some blood capillary endothelial intercellular junctions. Unlike in C-avitaminosis, the endothelial cells are intact, without pale, grossly swollen cytoplasms.