Deep Neck Contouring With a Focus on Submandibular Gland Vascularity: A Cadaver Study.

BACKGROUND: Opening the neck through a submental incision allows accurate management of deep neck structures and results in exceptional neck contours. OBJECTIVES: The authors aimed to evaluate the distribution of deep neck structures and investigate the detailed vascular anatomy of the submandibular gland. METHODS: A total of 26 fresh frozen cadaver heads (15 female, 11 male) were utilized. The authors evaluated the weights of the excised tissues simulating cosmetic resections, including subcutaneous fat, subplatysmal fat, the anterior belly of the digastric muscle, and submandibular glands. The vascular supply of the submandibular gland and intracapsular vessel diameters were also investigated. RESULTS: Whereas female cadavers had greater mean tissue weight removed from the supraplatysmal plane (mean 20.9 g, 56.6%) than the subplatysmal plane (16 g, 43.4%), male cadavers had higher mean tissue weight removed from the subplatysmal plane (10.5 g, 60.7%) than the supraplatysmal plane (mean 6.8 g, 39.3%). The mean subcutaneous (6.8 g) and subplatysmal (6.4 g) fat weights were almost equal in male cadavers; mean subcutaneous fat weight (20.9 g) was 3 times higher than subplatysmal fat weight (6.8 g) in female cadavers. There was a statistically significant relationship between body mass index and fat removed. The intraglandular vessel diameters increased as resections approached the main feeding vessels located posterosuperior (facial artery) and anterosuperior (submental artery) to the submandibular gland. CONCLUSIONS: The results suggest that to achieve exceptional neck contour the structures deep to the platysma often need to be addressed. The submandibular gland reduction can be safely performed with comprehensive understanding of its vascular anatomy.

Clinical Anatomy of Feeding Artery of the Submandibular Gland.

ABSTRACT: The purpose of this study was to investigate the clinical anatomy of the feeding artery of the submandibular gland (SMG). A total of 199 SMG removals were performed in extraoral or intraoral approach with/without endoscopic assistance by a single surgeon. The feeding artery of the SMG was always identified intraoperatively and recorded in the operation record. The clinical anatomy of the feeding artery of the SMG was investigated based on the intraoperative findings. The facial artery was ligated and transected for the involvement of tumor or severe inflammation in 16 (8.0%) procedures. The feeding artery was investigated in the remaining 183 procedures. The mean number of the glandular branch was 1.5. There were 1 branch in 98 procedures (53.6%), 2 branches in 80 procedures (43.7%), and 3 branches in 5 procedures (2.7%). Detailed anatomical knowledge of the feeding artery of the SMG is useful for proper dissection of the SMG and preservation of the facial artery.

Características morfocuantitativas de la glándula submandibular de ratón (Mus musculus) / Morphocuantitative characteristics of the mouse (Mus musculus) submandibular gland

El ratón (Mus musculus) es un buen modelo animal de experimentación, donde sus glándulas salivales han sido utilizadas en estudios, especialmente de tipo preclínico. Sin embargo, las diferencias en la morfología de estas glándulas y, en particular de las submandibulares, entre humanos y roedores no son de conocimiento común. Por lo anterior, el objetivo de este estudio fue conocer las características morfocuantitativos de la glándula submandibular del ratón macho C57BL/6. Se utilizaron cinco ratones macho, cepa C57BL/ 6, de 11 a 13 semanas de nacidos, con un peso promedio de 30 g. Luego de su ambientación, los ratones fueron eutanasiados. Para el análisis histológico, las glándulas fueron extraídas y fijadas en formalina tamponada por 48 horas, procesada para su inclusión en paraplast y teñidas con hematoxilina y eosina, azul alcián pH 2,5, ácido peryódico de Schiff y Picrosirius Red. Se determinaron las características estereológicas de densidad de longitud (LVcond), de volumen (VVcond) y de superficie (SVcond) de los conductos. En las células acinares se evaluó la densidad de número (NVcel) y la densidad de volumen (VVcel). Para cada variable se obtuvo la media ± desviación estándar. La glándula submandibular se encontraba organizada de manera lobulada, cuyo parénquima era de tipo túbuloacinar mixto con predominio seroso, que se conectaba a través de conductos. Las células acinares presentaban reacción positiva para azul alcián y ácido peryódico de Schiff. El estroma de la glándula contenía principalmente colágeno tipo 1. Los resultados de las mediciones estereológicas fueron: LVcond = 220,02 ± 50,51 mm/mm3; VVcond = 50,48 ± 9,55 %; SVcond = 26,39 ± 5,45 mm2/mm3; NVcel = 16,85 x 104 ± 9,13 × 104/mm3; VVcel = 24,98 ± 6,22 %. Con los análisis presentados es posible realizar investigaciones experimentales, considerando las similitudes y diferencias morfocuantitativas que presenta la glándula submandibular de ratón macho, cepa C57BL/6 con la del humano.

The mouse (Mus musculus) is a good experimental animal model, where murine salivary glands have been widely used in research by their similarities with human glands. Stereology is a tool that has to demonstrated to be valuable in biomedical researc h. Therefore, the objective was to realize an analogy between morphology, function and morpho-quantitative characteristics of the C57BL/6 mouse submandibular gland. Five male mice, C57BL/6, from 11 to 13 weeks old were used, with an average weight of 30 g. After seven days, the mice were euthanized and the samples were extracted. Then, these were processed following the conventional histological processing protocol and stained with H&E, Picrosirius Red, AA and PAS. Finally, the histological and stereological analysis of the samples was performed. In the glandular ducts the length density (LVcond), volume density (VVcond) and surface density (SVcond) were determined; whereas, in the acinar cells the density of number (NVcel) and the density of volume (VVcel) were evaluated. For each stereological variable the mean ± standard deviation was obtained. The histological study revealed no discrepancies as previously described. Descriptive statistical analysis revealed the following: LVcond = 220.02 ± 50.51 mm/mm3; VVcond = 50.48 ± 9.55 %; SVcond = 26.39 ± 5.45 mm2/mm3; NVcel = 168467.38 ± 91288.67 /mm3 and VVcel = 24.98 ± 6.22 %. From this study, it will be possible to conduct comparative experimental research analyzing quantitative results from those presented in this research. From this study, it will be possible to carry out comparative experimental research, analyzing quantitative results from those presented in this investigation.

Deep cervical fascia as an anatomical landmark of lingual lymph nodes: An anatomic and histologic study.

OBJECTIVES: We aimed to discuss the definition of lingual lymph nodes based on the deep cervical fascia anatomy. METHODS: A total of 11 cadavers were histopathologically evaluated. Specimens were dissected into serial stepwise cross-sections. The deep cervical fascia and lymph nodes were evaluated by staining the cross-sections with Elastica van Gieson and hematoxylin and eosin stains, respectively. The gross anatomy of the deep cervical fascia was evaluated in 1 cadaver after bilateral dissection. RESULTS: A single severely degenerated medial lingual lymph node (MLLN) was identified in the lingual septum of 1 cadaver. A single lateral lingual lymph node (LLLN) was identified in 1 cadaver, between the genioglossus and the hyoglossus. The superficial layer of deep cervical fascia (SLDF) was found to split into two layers encapsulating the submandibular gland. The deeper portion of this fascia was in close contiguity with the hyoglossus and formed the boundary between the mouth and the neck. The SLDF was found to be discontinuous with the area between the sublingual space and the submandibular gland. CONCLUSIONS: The SLDF could serve as an anatomical landmark for lingual lymph nodes, since it is considered to be the demarcating boundary during neck dissection. When lymph nodes that are located deeper than the SLDF were defined as lingual lymph nodes, 1 MLLN and 1 LLLN were identified.

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.

Management of the Submandibular Gland in Neck Lifts: Indications, Techniques, Pearls, and Pitfalls.

Neck contour deformities are common among patients who present for facial rejuvenation. A thorough physical examination and photographic analysis, including an upward view of the flexed neck, enable the surgeon to determine which structures should be treated. Common causes of neck concerns include hypertrophy of the subplatysmal fat, the anterior belly of the digastric muscle, and/or the submandibular salivary glands. Partial removal of the submandibular salivary glands requires advanced knowledge of subplatysmal anatomy and surgical expertise but can be performed safely and reliably to yield favorable results of neck rejuvenation.

Jaw Opening Decreases Window to the Deep Parotid Lobe.

To describe the relationship between jaw opening and access to the deep parotid window, we identified the following distances in 10 human skulls: symphysis to angle of mandible, mastoid tip to angle of mandible, angle of mandible to condylar process, and mastoid tip to condylar process. With the jaw closed and open, these distances were measured with 1 to 3 wooden blocks, each measuring 1 cm, between the upper and lower incisors. The triangular deep parotid area formed by the last 3 distances was calculated. A repeated measures analysis of variance showed a significant decrease in the deep parotid area with increasing interincisal distance ( P < .01). A generalized estimating equation model demonstrated a statistically significant decreasing area of the deep parotid window with increasing interincisal distance. These results suggest that nasal intubation may improve access to the parotid window.

Accessory Submandibular Salivary Gland Forming a "Horseshoe" With the Main Submandibular Salivary Gland: A Unique Variation.

Presence of accessory submandibular salivary gland (ASSG) is an extremely rare variation. Knowledge of its relations could be very useful to oral and maxillofacial surgeons, head and neck surgeons, and radiologists. During dissection classes, an ASSG was noted between the mylohyoid and hyoglossus muscles. The main submandibular salivary gland had superficial and deep parts. The deep part was narrow and measured about 5 cm. The lingual nerve passed between the superficial and deep parts. The accessory submandibular gland was situated below and parallel to the deep part of SSG. It also measured 5 cm. The ASSG had its own duct, which joined the duct of main gland. The ASSG and the deep part of the SSG were united at the lateral border of geniohyoid muscle to give a characteristic "horseshoe" appearance. The ASSG overlapped both lingual and hypoglossal nerves.

Effects of biodegradable hydrogel spacer injection on contralateral submandibular gland sparing in radiotherapy for head and neck cancers.

Xerostomia is the most common late toxicity after head and neck radiation. We demonstrate injection of a hydrogel spacer anteriorly displacing the submandibular gland. This procedure enables reduced dose to the displaced submandibular gland in cadaveric models of oropharynx cancer treated with IMRT, with potential implications in reducing xerostomia risk.

Effect of Biochanin A versus 17ß estradiol in rat submandibular salivary gland.

The epigenetic nature of development mandates the observation of the effect of any exogenous substance, especially those with estrogenic activities, during critical phases of development. The submandibular gland (SMG) presents as a great model due to extensive postnatal development, and is known to be regulated and affected by hormones as well as growth factors. Herein, we observed postnatal development following low doses of Biochanin A (BCA) and 17ß estradiol (E2) in rats. The pups were randomly divided into four groups: control, BCA, E2, and dimethyl sulfoxide (DMSO), and euthanized at the 6th, 15th, 30th, and 60th postnatal days (PND). SMG morphogenesis was assessed. The nuclear expression of estrogen receptor beta (ERß) was evaluated immunohistochemically; ERß expression was up-regulated by BCA and down-regulated by E2. Similarly, caspase three gene expression, assessed by real time polymerase chain reaction was increased in the BCA group but decreased in the E2 group. A significant decrease in epidermal growth factor gene expression was noted at PND 30. The results presented by this study provide evidence that the effect of a postnatal exposure of the SMG to Biochanin A during development could be linked to sex hormone-dependent disorders.

Subplatysmal Necklift: A Retrospective Analysis of 504 Patients.

BACKGROUND: Improvement of neck contour is a primary goal of patients who seek rejuvenation of the face and neck. Subplatysmal structures, including fat, the digastric muscle, and the submandibular salivary glands (SMSGs), may contribute to the appearance of a disproportionately large neck. OBJECTIVES: The authors sought to evaluate the safety, effectiveness, and predictability of necklift combined with reshaping and repositioning of the subplatysmal structures. METHODS: The records of 504 patients were reviewed retrospectively. Surgical maneuvers for subplatysmal necklift were described comprehensively and supplemented with videos. The subplatysmal anatomy was detailed by means of 2 cadaver dissections. RESULTS: A total of 430 patients (85.3%) underwent subplatysmal necklift. The most commonly treated structures were fat (423 patients [83.9%]), the SMSGs (307 patients [60.9%]), and the digastric muscle (91 patients [18.1%]). The most common complications were weakness of the lower lip depressor (29 patients [5.7%]), followed by sialoma of the parotid gland (10 patients [2%]). No patients experienced subplatysmal hematoma. CONCLUSIONS: Subplatysmal necklift is a safe, effective, and reliable option for patients who desire improved cervical contour. LEVEL OF EVIDENCE: 4 Therapeutic.

[Topographic features of lingual nerve and its relationship with other anatomical structures in maxillolingual groove].

By surgical interventions in maxillolingual groove area one should consider anatomical variations and topography of vessels, glands ducts and lingual nerve to prevent their injury. At the Department of Operative Surgery and Topographic Anatomy of the First Moscow State Medical University named after I.M. Sechenov we carried out anatomical study on cadavers (men and women, n=30).The study revealed topographical features of the lingual nerve and its relationship to other anatomical structures in the maxillolingual groove. It was found out that at the level of the second molar (96%) lingual nerve "crosses" duct of submandibular salivary gland, at the level of the third molar lingual nerve is located under the duct and lateral to it, closer to the inner surface of the body of the mandible. At the level of the first molar lingual nerve is located above and medial to Wharton duct and passes along sublingual-lingual muscles (m.hyoglossus).

Should we use fingerbreadth measurements in submandibular gland surgery? A critical appraisal of the technique.

OBJECTIVES: Having observed variation in the breadth of surgeons' fingers whilst they are placing the incision for submandibular gland surgery, we aimed to examine this technique of incision siting, quantify the differences in fingerbreadths and consider any consequences of variability. METHODS: Surgeons trained in salivary gland surgery were questioned on their method of incision placement for submandibular gland surgery. The breadth of index and middle fingers were subsequently measured using Vernier calipers. RESULTS: The majority of surgeons use a measure of two fingerbreadths below the mandible in planning their approach to the submandibular gland. There is a significant difference in the size of surgeons' fingers, particularly between men and women (mean, 4.2 cm vs 3.6 cm). CONCLUSION: Fingerbreadth measurements are somewhat arbitrary, with significant inter-surgeon variability. However, based on the results of cadaveric studies, the findings indicate that the technique is safe for marking the incision in submandibular surgery.

3D printing of rat salivary glands: The submandibular-sublingual complex.

The morphology and the functionality of the murid glandular complex, composed of the submandibular and sublingual salivary glands (SSC), were the object of several studies conducted mainly using magnetic resonance imaging (MRI). Using a 4.7 T scanner and a manganese-based contrast agent, we improved the signal-to-noise ratio of the SSC relating to the surrounding anatomical structures allowing to obtain high-contrast 3D images of the SSC. In the last few years, the large development in resin melting techniques opened the way for printing 3D objects starting from a 3D stack of images. Here, we demonstrate the feasibility of the 3D printing technique of soft tissues such as the SSC in the rat with the aim to improve the visualization of the organs. This approach is useful to preserve the real in vivo morphology of the SCC in living animals avoiding the anatomical shape changes due to the lack of relationships with the surrounding organs in case of extraction. It is also harmless, repeatable and can be applied to explore volumetric changes occurring during body growth, excretory duct obstruction, tumorigenesis and regeneration processes. 3D printing allows to obtain a solid object with the same shape of the organ of interest, which can be observed, freely rotated and manipulated. To increase the visibility of the details, it is possible to print the organs with a selected zoom factor, useful as in case of tiny organs in small mammalia. An immediate application of this technique is represented by educational classes.

Sialoadenitis purulenta submaxilar producida por cuerpo extraño en el conducto de Wharton / Submandibular sialoadenitis due to a foreign body in the Wharton duct

Una causa frecuente de infección crónica de la glándula submaxilar es la obstrucción de su conducto excretor que puede ser causada por litiasis, tapones de moco o a por la presencia de un cuerpo extraño. En las tres circunstancias se desarrollan cuadros de inflamación crónica del conducto (sialodoquitis) y de la glándula (sialoadenitis). Los estudios de imágenes radiográficas adecuadas son de gran utilidad para el diagnóstico, puesto que revelan el elemento obstructivo La presencia dentro del conducto salival de un cuerpo extraño es extremadamente rara. En este reporte se presenta un caso inusual de un paciente masculino de 23 años de edad que presentaba secreción purulenta debajo de la lengua y dolor crónico en la región submaxilar izquierda, de diez años de duración, donde el examen radiográfico convencional y la tomografía espiral multicorte contribuyeron al diagnóstico, identificando un mondadientes de madera alojado dentro del con ducto de Wharton. Se discute la importancia de la anamnesis y la interpretación de las imágenes en el manejo del caso.

One of the more frequent causes of submandibular sialoadenitis is the obstruction of its duct. The obstruction can be caused by lithiasis, mucus plug or a foreign body. The three circumstances produce inflammation and infection of the duct and the gland. Appropriated radiographic image techniques are very useful to demonstrate the obstructive object. The presence of a foreign body in the salivary duct is extremely rare. In this article is reported an unusual case of a 23-year-old male patient that presented purulent secre tion in the floor of the mouth and complained of chronic pain in the submandibular salivary gland, both lasting for ten years. Conventional radiographies and computed radiographs allowed to identify a wood toothpick inside the WhartonÆs duct. Data obtained during anamnesis and interpretations of radiographic findings are discussed for the adequate management of the case.

An anatomic basis for volumetric evaluation of the neck.

BACKGROUND: A better understanding of volume distribution between the superficial (subcutaneous) and deep (subplatysmal) planes of the neck may be useful when deciding on the best course of management for patients presenting for cervical contouring. OBJECTIVES: The authors investigate the normal distribution of fat in the superficial and deep planes of the neck in a cadaver model, to determine the proportion of the submandibular gland that contributes to submental fullness. METHODS: Fat in the superficial and deep neck planes of 29 adult cadavers was dissected and weighed. The submandibular glands were also dissected and the cervical portion of each gland was shaved off, weighed, and compared to the weight of the whole gland. RESULTS: The mean weight of superficial fat collected from the specimens was 15.0 g in males (n = 14; range, 2.2-35.7 g) and 14.3 g in females (n = 15; range, 1.6-37.3 g); the mean weight of subplatysmal fat was 5.5 g in males (range, 1.3-15.2 g) and 3.7 g in females (range, 0.6-15.1 g). Mean weight was not statistically significantly different between the sexes, nor between the 2 racial/ethnic groups (Caucasian, n = 14; Southeast Asian, n = 15). Approximately 40% of the submandibular gland was found to lie inferior to the lower border of the mandible in the specimens examined. The authors found no anatomical evidence of submandibular gland ptosis, even in the oldest specimens. CONCLUSIONS: The study provides a comprehensive analysis of the distribution of adipose tissue in the superficial and deep planes of the neck, as well as the contribution of the submandibular glands to submental volume. This objective evaluation of neck volume may help guide clinicians in the surgical planning process and provide a foundation for designing new cervicofacial rejuvenation techniques.

Removal of parotid, submandibular, and sublingual glands.

Surgical removal of the major salivary glands is a common task for the oral and maxillofacial surgeon. The major salivary glands have complex anatomic relationships with the surrounding neurovascular structures, and a thorough understanding of the surgical anatomy is essential for any surgeon involved in the management of salivary gland disease. This article reviews the indications, surgical anatomy, diagnostic evaluation, and surgical techniques for removal of the major salivary glands.

The historical evolution of the understanding of the submandibular and sublingual salivary glands.

The discovery of the major salivary glands was primarily a story of the establishment of the glands major excretory ducts. Occurring during the Renaissance: religious, political, and philosophical considerations played a role in defining the structure's function. We describe the history and background of these political, religious, and philosophical factors. Next, we present a translation of the original texts, describing the establishment of the submandibular and sublingual salivary glands. We place these translations into historical context and comment on their naming propriety. Initially we translate the works of the 15th century anatomists. Next, we look at the discovery and description of the submandibular gland's duct by Thomas Wharton (1614-1673) in his landmark book, Adenographia sive glandularum totius corporis descriptio (Adenographia or the description of the glands of the entire body) (1656). Next, the somewhat unexpected discovery of the duct of the parotid gland by Nicholas Stenson (1638-1686) and his publication, De glandulis oris et novis earundum vasis (On the glands of the mouth and their new ducts) (1661), done primarily for his discussion of the submandibular and sublingual gland anatomy. Finally we outline the description and discussion by Caspar Bartholin (1655-1738), in De ductu salivali, hactenus non descripto observatio anatomica (Anatomical observation of a salivary duct not hitherto described) (1685) of the origin of the complex drainage system of the sublingual gland. The honor of naming these glands rested with the discoverer of their ducts. All original works were published in Latin, and we have translated these texts to more fully understand the author's perspectives and historical context for a more interesting and complete story.

Volumetric change of selected organs at risk during IMRT for oropharyngeal cancer.

PURPOSE: To assess volumetric changes of selected organs at risk (OAR) during intensity-modulated radiotherapy (IMRT) for oropharyngeal carcinoma. MATERIALS AND METHODS: Twenty-six consecutive patients that were treated with definitive IMRT ± chemotherapy between November 2007 and November 2008 were selected for the present study. As part of an internal quality assurances program, a repeat kilovolt (KV) computed tomography was planned weekly during the 7-week treatment course. On each available scan, a single observer contoured the parotid submandibular, and thyroid glands (PG/SMG/TG), larynx (L), and constrictor, masticatory, and sternocleidomastoid muscles (CM/MM/SCM) as appropriate. The volume at each scan was compared with the one at planning CT in a pair-wise fashion. p values <0.05 after correction for multiple testing were considered significant. RESULTS: A total of 159 scans was obtained during treatment for a total of 185 scans, including the baseline imaging. All OARs showed statistically significant changes over baseline by week 5. At week 7, the PG showed the largest absolute change with an average reduction of ∼10 mL followed by both the SCM and MM (∼-5 mL). The largest (∼-30%) relative change was observed for the salivary glands. L and CM showed a ∼15% increase in volume during treatment. CONCLUSION: All selected OAR undergo significant volumetric changes during a course of IMRT for oropharyngeal squamous cell carcinoma.

Microanatomic study of the vascular and duct system of the submandibular gland.

PURPOSE: Autologous microvascular submandibular gland (SMG) transfer is an effective treatment for severe keratoconjunctivitis sicca (KCS). However, epiphora (excessive tear secretion) may occur after the successful transfer of whole submandibular gland because tear secretion level is closely related to the size of the transferred gland. The aim of this study was to investigate the microanatomy of SMG to explore the possibility of partial SMG transfer to prevent postoperative epiphora. MATERIALS AND METHODS: Sixty intact and histologically normal human SMGs from patients with benign tumor of the mandible who underwent vascularized mandibular reconstruction and removal of the SMG for anastomosis of the blood vessels were included in the study. SMGs were perfused with methacrylate to form resin casts of blood vessels and ducts. The length and diameter of the blood vessels and ducts in the casts were measured using a sliding caliper. The numbers of lobules, distribution of arteries, veins, and ducts, as well as the relationship among them, were analyzed. RESULTS: The resin cast of the gland showed a treelike structure, with the vessels gradually dividing into multiple branches. The arteries, veins, and ducts run in parallel and were roughly divided into 3 levels: from the stem extending into the main branches (level I), into the narrower secondary branches (level II), and then the secondary branches subsequently divided into terminal branches (level III). The structures of the blood vessels and ducts were similar at each level in the lobules. In the vein casts, communicating vessels were found between the anterior facial vein and the concomitant vein of the facial artery. CONCLUSION: The characteristic treelike structure of the SMG vascular and ductal system may provide useful information for partial gland transfers.