Evaluation of the anterior processes of the parotid gland: an ultrasonographic study.

OBJECTIVES: 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. STUDY DESIGN: 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. CONCLUSION: This study can raise awareness among clinicians about the presence of AEPG in the differential diagnosis of mid-cheek masses.

Anatomical Insights on the Cervical Nerve for Contemporary Face and Neck Lifting: A Cadaveric Study.

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. OBJECTIVES: 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.

The anterior lobe of the parotid gland: a CT sialographic study.

OBJECTIVES: To investigate the imaging and anatomic features of the anterior lobe (AL) of the superficial parotid gland (SPG). METHODS: Computed tomographic sialography examinations were undertaken for 142 parotid glands in 77 patients. Whole computer tomography (CT) data were analyzed using multi-planar reformation and maximum intensity projection to generate sialographic CT images. The tributary ducts of the SPG were analyzed to classify the parotid morphology. Three-dimensional analyses were used to investigate the AL and its relationship with adjacent anatomic landmarks. RESULTS: Four major types (I-IV) and 2 minor types (V-VI) of the AL and the superficial parotid gland were observed. Type I AL (83/142) was contiguous and not separated from the retromandibular parotid gland. Type II AL (16/142) was detached from the retromandibular parotid gland with 1-4 tributary ducts. Type III AL (12/142) showed a small isolated lobe above the Stensen duct around the anterior edge of the masseter. Type IV (28/142) showed the absence of the AL. Type V (3/142) shows the absence of the retromandibular parotid gland. Type VI (3/142) showed the presence of ectopic salivary gland beneath the Stensen duct anterior to the retromandibular parotid gland. CONCLUSIONS: The AL gives rise to the morphological variations of the superficial parotid gland. AL also gives rise to the accessory parotid gland when it is detached from the retromandibular parotid gland.

Facial nerve dissection in parotid surgery: a microscopic investigation study.

In parotid surgery, it is crucial to identify and preserve the facial nerve, which runs through the parotid gland. The purpose of this study was to histologically clarify two clinical questions: whether "superficial" and "deep" lobes exist anatomically and what are the structures surrounding facial nerve. Parotid gland tissues were obtained from dissection of donated cadavers. The gland was cut perpendicular to the facial nerve plane at 5 mm intervals, and the pieces were embedded in paraffin, thinly sliced, and stained. The morphology of the nerve was observed at each site, and the relationships between the thickness of the perineural tissue (defined as the tissue between the groups of nerve fasciculi and the glandular parenchyma), nerve diameter, and distance from the proximal end of the nerve were examined. In addition, the dissection layer was examined histologically in isolated parotid tissues. The interlobular connective tissue was spread like a mesh within the parotid gland and subdivided the glandular parenchyma. The facial nerve was located in the interlobular connective tissue, and its course was not restricted to the boundary plane between the superficial and deep lobes. The thickness of the perineural tissue decreased with increasing distance from the proximal end of the nerve. The dissection layer was clarified that located in the perineural tissue. The perineural tissue is thinner in more distal regions, which may make dissection more difficult there. No particular anatomical structure appears to separate the superficial and deep lobes.

Positional deformation of the parotid gland: Application to minimally invasive procedures.

Anatomical studies of the parotid gland are important for mid- and lower face filler, botulinum toxin, and thread lifting procedures. The purpose of this study was to observe the topographic anatomy of the parotid gland using cadaveric dissections. The superficial lobe of the parotid gland was studied in 30 hemisected heads. Reference lines were made on the lateral aspect of the face. A reference line (the line connecting the mandibular angle to the upper margin of the zygomatic arch, along the posterior border of the ramus) was divided into four sections (P1, P2, P3, and P4). The superior, inferior, anterior, and posterior borders of the parotid gland were measured using the reference lines and sections. Using these measurements, we categorized the superficial lobe of the parotid gland into two types: type Ia, pistol-shaped; Ib, pistol-shaped with an accessory lobe; and type II, oval-shaped. The superior border of the parotid gland started just below the inferior margin of the zygomatic arch. The parotid gland covered the posterior part of the masseter muscle near P1 and P2, but at P3 and below P3, the tail of the parotid gland was located posterior to the ramus and covered the anterior part of the sternocleidomastoid muscle. The topographic anatomy of the parotid gland serves as a reliable reference for esthetic procedures in the lower face and neck region.

A Study to Assess the Dosimetric Impact of the Anatomical Changes Occurring in the Parotid Glands and Tumour Volume during Intensity Modulated Radiotherapy using Simultaneous Integrated Boost (IMRT-SIB) in Head and Neck Squamous Cell Cancers.

BACKGROUND: Anatomical variations in head and neck cancer during IMRT leads to volume shrinkage, results in dosimetric variations in tumour and normal tissue including parotid glands, with a risk of radiation toxicities. METHODS: 30 patients with a stage II-IV head and neck squamous cell carcinoma (HNSCC) were treated with definitive IMRT-SIB and concomitant chemotherapy. Volumetric and dosimetric variations were evaluated during the period of IMRT by recalculating and obtaining dose-volume histograms of re-contoured target volumes and parotid glands on repeat CT scans taken multiple times during treatment (CT1, CT2, CT3 and CT4). RESULTS: Result showed significant (p < 0.001) mean decrease in both primary and nodal tumors volume with time whereas increase (p < 0.01 or p < 0.001) in respective V100 (%) and D2% (Gy). The mean parotid gland dose increased (p < 0.01 or p < 0.001) with time, whereas parotid gland volume and distance between plan isocenter and centre of mass of parotid glands decreased (p < 0.05 or p < 0.001) with time. Patient's mean weight and neck circumference both decrease (p < 0.001) with time whereas ECOG score increase (p < 0.001) with time. The mucosal toxicity increased significantly (p < 0.001) with time. The change in both weight and neck circumference showed significant (p < 0.001) and direct (positive correlation) association with change in parotid gland volume. CONCLUSION: If the PTV and normal anatomy are changing with time, adaptive IMRT would be beneficial radiation dose delivery where possible.

Comprehensive histochemical and stereological study of the parotid and sublingual salivary glands in Caucasian squirrel (Sciurus anomalus).

The present investigation tries to reflect histochemical and stereological properties of the parotid gland (PG) and sublingual gland (SLG) in the Caucasian squirrel. Totally, five male Caucasian squirrels were used. The glands were examind histochemical using PAS, Alcian blue (AB, pH = 2.5) and Aldehyde fucshin (AF) stainings. Total volume of the glands, acini, ducts as well as total length of ducts were estimated using streological procedures. The PG had a unique morphology and were connected to each other with an intermediated isthmus. The SLG was oval-shaped. Serous acini of PG exhibited strong, negative and weak reaction with AF, AB and PAS, respectively. While, mucous acini of SLG showed positive staining for AB and PAS, and negative staining for AF. The ductal system was consisted of intercalated (Id), striated (SD) and excretory ducts (Ed). The Sd in PG was lined with simple cuboidal to the columnar epithelium, while it was lined with simple cuboidal epithelium in SLG. The Ed was lined with stratified cuboidal epithelium in both glands. The striated duct was longest duct in both glands, the excretory and intercalated ducts were the shortest ones in PG and SLG, respectively. The maximum total volume in both gland were blonged to the acini and straited ducts. It concluded that PG and SLG in the Caucasian squirrel have some distinct structural properties in comparison to other rodents and mammalis species.

Discovery of new salivary gland - A substantial histological analysis.

Regardless of the COVID-19 pandemic in 2020, discovering a new salivary gland turned into all the rage among the medical fraternity. The significance of the disclosure has been correlated with its clinical relevance in radiotherapy of oropharyngeal carcinoma. However, there are views against this new revelation, owing to the lack of substantial evidence. We have endeavoured to illuminate Tubarial glands with potential shreds of evidence.

The Role of the Parotid-Mastoid Fascia in Identification of the Facial Nerve Trunk During Parotidectomy.

OBJECTIVE: We aim to describe the parotid fascia as a landmark that can help identify the immediately underlying facial nerve trunk. METHODS: Dissection of the parotid fascia and identification of the facial nerve trunk were carried out on 8 fresh cadaveric parotid glands. The attachments and arrangement of the parotid gland and its fascia were evaluated and histologically assessed, with special attention to the fascia overlying the facial nerve trunk. RESULTS: The parotid fascia envelops the posterior aspect of the parotid gland in an open-book fashion. Posteriorly, it connects to the anterior and medial aspect of the mastoid tip. Posterosuperiorly, it attaches to the inferior aspect of the tragal pointer. Directly medial to the fascia lies the facial nerve trunk. CONCLUSION: The parotid fascia, particularly the parotid-mastoid segment overlying the facial nerve trunk, can be utilized as an additional landmark of depth to help identify the facial nerve trunk during a parotidectomy in conjunction with other commonly used standard anatomic landmarks. The parotid fascia sling spans from the mastoid and tragal pointer to the parotid gland and can be easily palpated intraoperatively. Once the fascia is removed, the facial nerve trunk is identified.

Toxin variation among salamander populations: discussing potential causes and future directions.

Amphibians produce defensive chemicals which provide protection against both predators and infections. Within species, populations can differ considerably in the composition and amount of these chemical defenses. Studying intraspecific variation in toxins and linking it to environmental variables may help us to identify the selective drivers of toxin evolution, such as predation pressure and infection risk. Recently, there has been a renewed interest in the unique toxins produced by salamanders from the genus Salamandra: the samandarines. Despite this attention, intraspecific variation has largely been ignored within Salamandra-species. The aim of this study was to investigate whether geographic variation in profiles of samandarines exists, by sampling 4 populations of Salamandra atra over its range in the Dinaric Alps. In addition, we preliminary explored whether potential variation could be explained by predation (counting the number of snake species) and infection risk (cultivation and genomic analyses of collected soil samples). Salamanders from the 4 populations differed in toxin composition and in the size of their poison glands, although not in overall toxin quantity. Nor predation nor infection risk could explain this variation, as populations barely differed in these variables. Sampling over a much broader geographic range, using better estimators for predation and infection risk, will contribute to an improved understanding of how environment may shape variation in chemical defenses. Nevertheless, as the 4 populations of S. atra did differ in their toxin profiles, we propose that this species provides an interesting opportunity for further ecological and evolutionary studies on amphibian toxins.

Description and relationships of the parotid gland levels proposed by the European Salivary Gland Society staging system: an anatomical study.

OBJECTIVES: To perform an anatomical study to analyze the size, weight, and the relationships of the parotid levels proposed by the European Salivary Gland Society (ESGS). MATERIALS AND METHODS: Anatomical dissections of the parotid region in 19 human specimens were performed. All dissections were systematically carried out to study the dimensions and weight of each level. We also studied the facial nerve distribution between the different levels and the relative position of the facial nerve main trunk and parotid duct in regard to the Frankfort line plane. RESULTS: The facial nerve trunk and the parotid duct were identified in all the 19 specimens, which made it feasible to define the 4 principal levels of the parotid gland body (levels I-IV). Level V was identified in 9 out of 19 dissections (47.5%). For the whole gland, the mean for the height and width dimensions were 66.37 mm and 46.84 mm, respectively, and it weighted 18.13 g. In terms of relative weight regarding the whole gland, level II was always the heaviest, representing from 41 to 47% of the gland's weight, depending on the presence of level V. Levels I and III represent almost the same amount of relative weight as they range from 20 to 22% for each one. Level IV was the lightest body level representing 8-10% of the whole, and when present, level V represented less than 5% of the whole parotid weight. The temporal and zygomatic terminal branches were always found between the cranial levels, whereas the cervical and marginal nerves lie in all cases between the caudal levels. The buccal branches had multiple ramifications that lie between both cranial and caudal levels in 47% of the cases, being found exclusively between cranial levels in 21% and between the caudal levels in the remaining 32%. CONCLUSION: As traditionally reported, the caudal superficial portion of the gland represents the most voluminous portion of the gland, being labeled in our classification as level II. Levels I and III represent similar amounts of gland, though presenting a significantly different morphological disposition. Level IV is the smallest portion of the body gland and level V, when present represents a scarce 5% of the whole body gland weight. The ESGS levels have a clear anatomical basis and the basic references needed to define them are always present.

Normative measurements of parotid lymph nodes on CT imaging.

PURPOSE: The goal of this study is to characterize the normal size of parotid lymph nodes among healthy adult patients on CT. METHODS: This was a single-center retrospective observational study of 543 patients who underwent maxillofacial CT scans between January 2019 and July 2019. The long and short axis diameters of the largest lymph nodes in the bilateral superficial parotid glands were measured. RESULTS: Among the 543 patients, 407 subjects with a mean age of 47.0 ± 18.4 years had a total of 719 detectable intraparotid lymph nodes. The mean patient age was 47.0 ± 18.4 years. Of all 719 measured intraparotid lymph nodes, the measured long and short axis diameter means were 4.4 ± 1.4 mm and 3.3 ± 1.1 mm, respectively. In our study, 96% (689/719) of all lymph nodes had a long axis diameter of 7 mm or less and 93% (671/719) of all lymph nodes had a short axis diameter of 5 mm or less. Younger patients had significantly larger lymph nodes than older patients in both long axis (4.5 vs 4.3 mm; P = 0.03) and short axis (3.4 vs 3.1 mm, P = 0.01) measurements. CONCLUSION: Our findings suggest 5 mm as an upper limit of normal for the short axis diameter of superficial intraparotid lymph nodes.

A Multicellular Model of Primary Saliva Secretion in the Parotid Gland.

We construct a three-dimensional anatomically accurate multicellular model of a parotid gland acinus to investigate the influence that the topology of its lumen has on primary fluid secretion. Our model consists of seven individual cells, coupled via a common lumen and intercellular signalling. Each cell is equipped with the intracellular calcium ([Formula: see text])-signalling model developed by Pages et al, Bull Math Biol 81: 1394-1426, 2019. https://doi.org/10.1007/s11538-018-00563-z and the secretion model constructed by Vera-Sigüenza et al., Bull Math Biol 81: 699-721, 2019. https://doi.org/10.1007/s11538-018-0534-z. The work presented here is a continuation of these studies. While previous mathematical research has proven invaluable, to the best of our knowledge, a multicellular modelling approach has never been implemented. Studies have hypothesised the need for a multiscale model to understand the primary secretion process, as acinar cells do not operate on an individual basis. Instead, they form racemous clusters that form intricate water and protein delivery networks that join the acini with the gland's ducts-questions regarding the extent to which the acinus topology influences the efficiency of primary fluid secretion to persist. We found that (1) The topology of the acinus has almost no effect on fluid secretion. (2) A multicellular spatial model of secretion is not necessary when modelling fluid flow. Although the inclusion of intercellular signalling introduces vastly more complex dynamics, the total secretory rate remains fundamentally unchanged. (3) To obtain an acinus, or better yet a gland flow rate estimate, one can multiply the output of a well-stirred single-cell model by the total number of cells required.

The Accessory Parotid Gland and its Clinical Significance.

PURPOSE: The accessory parotid gland is a collection of salivary tissue separate from the main parotid gland. When present, it may complicate parotidectomies, promote parotitis, and serve as a potential site for benign and malignant lesions to arise. The aim of this study was to provide a comprehensive and current overview of the anatomy of the accessory parotid gland, as there is a wide discrepancy in the literature regarding its prevalence. MATERIALS AND METHODS: The authors conducted a search in PubMed, Embase, ScienceDirect, Web of Science, SciELO, BIOSIS, Current Content Connect, Korean Journal Database, and Russian Citation Index to identify all studies which reported relevant data on the accessory, with no date or language restrictions applied. Data on prevalence, side of occurrence, and sex dimorphism of the accessory parotid gland were extracted and pooled into a meta-analysis. RESULTS: A total of 13 articles (n = 3115 subjects) were included in the study. The results revealed that the overall pooled prevalence of an accessory parotid gland was 32.1% (95% confidence interval: 21.2-44.0). It was more prevalent in cadaveric studies (35.8%) than in computed tomography studies (21.5%), had a higher prevalence in Asia (33.8%) as compared to North America (23.5%), and when present, it was most often found as an unilateral structure (77.8%). CONCLUSIONS: With respect to the findings presented, the accessory parotid gland may be considered an anatomical variation likely to encounter in the population. More anatomical studies on the structure and its prevalence are needed, in all regions of the world, to provide a representative global overview.

Anatomical Study of the Posterior Auricular Branch of the Facial Nerve: Application to Parotid Surgery.

The posterior auricular nerve (PAN) is the first branch of the facial nerve after it leaves the stylomastoid foramen. The literature describing the anatomy of the PAN is very sparse. Therefore, the purpose of this study was to clarify the detailed anatomical features of the PAN and consider its clinical and surgical applications. The authors examined 10 sides from 6 fresh frozen adult cadaveric Caucasian heads. The PAN was observed as the first branch of the facial nerve in all specimens. During the dissection of the PAN, the posterior auricular artery was constantly near the PAN. Moreover, the PAN was located under the investing layer of deep cervical facia covering the sternocleidomastoid and mastoid process in all specimens. The diameter of the PAN was 0.82 ±â€Š0.21 mm (range from 0.55 to 1.21). The distance from the stylomastoid foramen to where the PAN branched from the facial nerve was 0.40 ±â€Š1.25 mm (range from 0 to 4.35). The distance from the location of this branching point of the PAN to the entering point of the PAN to any muscles was 28.03 ±â€Š5.51 mm (range from 19.71 to 38.75). Understanding the anatomical features of the PAN is essential for performing surgical procedures in this region.

Clinical significance of buccal branches of the facial nerve and their relationship with the emergence of Stensen's duct: An anatomical study on adult Taiwanese cadavers.

OBJECTIVE: This observational study on adult Taiwanese cadavers focused mainly on the intersection of buccal branches of the facial nerve with Stensen's duct, using the emergence of Stensen's duct as the reference landmark. MATERIALS AND METHODS: Thirty-five cadaveric hemifaces were included in our research. Samples with facial defects due to tumor, trauma, or surgery were all excluded. Buccal branches of the facial nerve were identified according to the Gray's Anatomy 40th edition definition. The distance was measured from the intersection to the emergence of Stensen's duct, running from the anterior border of the parotid gland. RESULTS: In the 35 hemifaces, the number of buccal branch/Stensen's duct intersections ranged from 1 to 5 (average 2.49 ± 1.15). Two-point intersections accounted for 37% (13 hemifaces) of the sample, forming the largest group. Samples of facial nerve buccal branches were divided into four types: Type 1, with two buccal branches, accounted for 37.15% (13/35); Type 2, with three buccal branches, made up 48.59% (17/35) of our samples - the biggest group (Type 2-a was the most frequent pattern among our samples, with two superior buccal branches and one inferior buccal branch, accounting for 34.31% of our samples); Type 3, with four buccal branches, accounted for only 5.7%. Three cases of double Stensen's duct were classified as Type 4, though this is supposed to be a very rare anatomical variation. With Type 2a, the most frequent pattern among our specimens, the distance from the emergence of the Stensen's duct to the emergence point of the first superior buccal branch along the anterior border of the parotid gland was 9.58 ± 5.68 mm. The distance from the emergence point to the emergence of the inferior buccal branch along the anterior border of the parotid gland was 11.03 ± 5.38 mm. The distance (D1) from Stensen's duct to the emergence of the first superiorly located buccal branch of the group Type 2-a was statistically different from the distance (D1) of the other groups (p = 0.02). No direct anastomoses or communicating fibers between upper and lower buccal branches were noted in 11 hemifaces (31%). CONCLUSION: The distribution of buccal branches was described using the emergence of Stensen's duct as a reference landmark. According to our observations, the relationship between the buccal branches and Stensen's duct was much more complicated than described in previous studies. This was the first study to investigate the complete distribution of buccal branches of the facial nerve emerging from the anterior of the parotid gland, and their relative locations and branching numbers.

Parotid gland comparative microscopic anatomy / Histología comparada de la glándula parótida

The frequent use of animal models in biomedical research means that the anatomy or histology of the animals is constantly analyzed so the results obtained can be extrapolated to human tissues; therefore, knowledge of the structures studied is truly important. This study compares the human parotid gland to that of three animal species from a histological point of view. Five parotid gland samples from each animal species were used: Sprague Dawley rats (Rattus norvegicus), C57BL/6 mice (Mus musculus) and male rabbits (Oryctolagus cuniculus). The samples were stained using H/E, Masson trichrome and van Gieson's techniques. The anatomical relations of the parotid glands in the three species were the facial nerve, master muscle and mandibular ramus among other anatomical elements. Histologically, the duct system in the three species is comprised of intercalated, striated, excretory ducts and main excretory ducts. Human, rodent and rabbit parotid glands are made of purely serous adenomeres. The intercalated and striated ducts are prominent. The human parotid gland is well characterized by intralobular adipose tissue, as is observed in rabbit, whereas the adipocytes are not prominent in the parotid gland in rats and mice. The tissue of the rat parotid gland contained a large number of serous acini that included a large area of gland tissue and few ducts, as observed in the rabbit and human. The glands studied present considerable morphological similarities with the human one that make them reliable candidates as experimental models of parotid tissue.

El frecuente uso de modelo animal en investigación biomédica, hace que constantemente sea analizada la anatomía o histología de dichos animales, donde los resultados obtenidos deben ser extrapolables a tejidos humanos, por lo cual el conocimiento de las estructuras estudiadas, es realmente importante. El presente trabajo compara a la glándula parótida humana con las de tres especies desde un punto de vista histológico. Se utilizaron muestras de glándula parótida de ratas Sprague Dawley (Rattus norvegicus) (n=5), ratones (Mus musculus) cepa C57BL/6 (n=5) y conejos (Oryctolagus cuniculus) (n=5) machos, las cuales fueron teñidas con técnicas de H/E, Tricrómico de Masson y van Gieson. Las glándulas parótidas analizadas se relacionaron anatómicamente en todas las especies con elementos tales como nervio facial, músculo masetero, rama mandibular entre otros. Con respecto a la histología, el sistema de conductos de roedores así como de conejo se compone de conductos intercalados (ID), estriado (SD), excretor (ED) y conductos excretores principales. Las glándulas parótidas humanas, de roedores y conejos están compuestas de adenómeros serosos puros. La ID y SD son prominentes. La glándula parótida humana está bien caracterizada por tejido adiposo intralobular, al igual a lo encontrado en el conejo, mientras que los adipocitos no son prominentes en la glándula parótida en ratas y ratones. El tejido de la glándula parótida de la rata se observaron gran cantidad de acinos serosos que comprenden una gran área del tejido de la glándula y unos pocos conductos, al igual que el conejo y humano. Las glándulas estudiadas presentan semejanzas morfológicas considerables con la humana que las hacen candidatas confiables al momento de su elección como modelos experimentales del tejido parotídeo.

Chondroitin sulfate isolated from the secretion of the venom-producing parotoid gland of Brazilian bufonid.

The parotoid gland of bufonids is characterized as a specialized integument region, formed by different gland types. The secretion elaborated by the largest glandular alveoli has been related to animal chemical defense and is constituted by granular protein content, associated with a basophilic and alcianophilic material with features of glycoconjugates. This study aimed to identify and characterize the glycoconjugates in the secretion of the largest granular gland of the parotoid gland of Rinella icterica by histochemical and immunohistochemical techniques at light microscopy, biochemical methods, and nuclear magnetic resonance spectroscopy. Our results showed that the glycoconjugate content contains a mixture of chondroitin­6­sulfate (C6S) and chondroitin-non-sulfate (C0S). Thus, chondroitin sulfate probably plays an important role in gland physiology, probably protecting the protein content while inside the secretory portion.

Histological, SEM and three-dimensional analysis of the midfacial SMAS - New morphological insights.

INTRODUCTION: The superficial musculoaponeurotic system (SMAS) of the midface has a complex morphological architecture, and a multitude of controversial opinions exist regarding its in vitro appearance and clinical relevance. The aim of this study was to investigate the three-dimensional architecture of the midfacial SMAS. METHOD: Histological and SEM analyses were performed on tissue blocks of the skin, subcutaneous tissue and mimic musculature of the midfacial region between the anterior parotid gland pole and lateral to the nasolabial fold and tissue blocks of the skin, subcutaneous tissue and parotid fascia. Blocks were collected postmortem from six formalin-fixed donor bodies. Serial histological sections were made, stained with Azan and digitized. Three-dimensional reconstructions and visualization of the tissue blocks were performed using AutoCAD. RESULTS: Two different SMAS architectures were found in the midfacial region: parotideal (type IV) and preparotideal (type I) SMAS. Type I SMAS showed three-dimensional interconnecting fibrous chambers embracing fat tissue lobules that cushioned the space between the skin and mimic musculature. Fibrous septa divided the mimic musculature surrounding the muscular bundles. Beneath the mimic muscular level, SMAS septa were oriented parallel to the muscular plane. Above the mimic muscular plane, SMAS septa were oriented perpendicularly, inserted into the skin. Type IV SMAS showed a parallel alignment of the fibrous septa to the skin level, anchoring the skin to the parotid fascia, presenting lymphatic nodes in the fat tissue compartments. The fat cells of the SMAS were enveloped in a fibrotic membrane at the border of the fibro-muscular septa. The SMAS blood supply comprised two subcutaneously epimuscularly spreading anastomosing vascular systems. CONCLUSIONS: Midfacial SMAS represents a functional unit with physical and immunological tasks appearing in two different morphological architecture types. A well-defined nomenclature is needed to prevent controversy.

Reduction Neck Lift: The Importance of the Deep Structures of the Neck to the Successful Neck Lift.

A description of the deep structures of the neck that are responsible for submandibular fullness and a systematic surgical approach to reduce them are presented. The structures susceptible to surgical management include the subplatysmal fat, inter-sternocleidomastoid origin fat, anterior belly of the digastric muscle, hyoid bone, submandibular gland and the tail of the parotid gland. A thorough analysis of the key anatomic landmarks of the young and attractive neck is detailed in resting and dynamic positions. A clinical classification of parotid reduction in the face lift/neck lift patient is also presented.