Morphometrics of the Southern Green Stink Bug [Nezara viridula (L.) (Hemiptera: Pentatomidae)] Stylet Bundle

The southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae), is a cosmopolitan pest of high-value cash crops, including cotton (Gossypium hirsutum L.; Malvales: Malvaceae). The pest can ingest and transmit disease-causing bacterial and fungal pathogens of cotton. We hypothesized that the size of the food canal may contribute to selective transmission, as observed in previous reports. The objective of this study was to examine food canal size and other morphometric parameters of the southern green stink bug stylet bundle at two locations (labium and head) to improve our understanding of factors that may contribute to pathogen transmission. For the food canal, females possessed significantly larger canals than males, major axes were significantly longer than minor axes, and canal sizes were numerically higher at the labium compared with the head. For salivary canal, mean axes lengths were similar between sexes and the head and labium. For both food and salivary canals, axes lengths were longer and area was larger at the labium compared with the head. These findings indicate the presence of a "funnel effect" with canals becoming narrower proximally. Sex and location significantly affected the size of the intact stylet bundle. Results indicate the food canal size was not a factor affecting previously observed selective passive transmission. Major and minor axes measurements, coupled with morphological observations of canal shapes and observed "funnel effect" in the food and salivary canals, improve our understanding of the hemipteran stylet bundle and its relationship with the insect's internal morphology.

[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).

Study of human adult parotid duct in the area of penetration through buccinator muscle and their functional relationship as a sphincter

The adult human parotid duct is roughly 6-8 cm long. From the parotid gland, parotid duct traverses through masseter muscle, penetrates through buccinator muscle, and opens into the oral cavity. This unique form of the parotid duct is likely correlated with the function of the duct, directly affected by the movement of the buccinator muscle during mastication and swallowing. Histological structure of the duct is known to be different in each region, and details of smooth muscle present in the parotid duct are mostly unclear. In this study, we conducted SEM and histological observations of the area where the parotid duct penetrates the buccinator muscle, and an observation of smooth muscle to investigate its existence using alpha-smooth muscle antibody. We confirmed the presence of an abundance of skeletal muscle bundles likely originating from the buccinator muscle under the epithelium of the parotid duct wall in the region where it penetrates the buccinator muscle. We also observed that some of the muscle fibers were completely attached to the epithelium. We observed a lack of smooth muscle in this region of the duct wall. From these results, we suggest that the area of the duct penetrating buccinator muscle plays a role in regulating the salivary passage through the contraction of the surrounding buccinator muscle fibers.

3D MR sialography as a tool to investigate radiation-induced xerostomia: feasibility study

PURPOSE

To evaluate whether magnetic-resonance (MR) sialography can be used to investigate radiation-induced xerostomia. Preradiotherapy (pre-RT) and postradiotherapy (post-RT) MR sialographic images of the major salivary ducts (parotid and submandibular) were compared.

METHODS AND MATERIALS

Magnetic-resonance sialography was performed pre-RT, and 6 weeks and 6 months post-RT on 9 patients with T1-4N0-2M0 naso- or oropharyngeal tumors, on a 1.5-T MR scanner. Patients were positioned in the scanner, using a radiotherapy immobilization mask. Image registration of the MR sialograms pre- and post-RT with each other and with the CT and consequently the dose distribution was performed. A categorical scoring system was used to compare the visibility of ducts pre-RT and post-RT.

RESULTS

Good-quality MR sialographic images were obtained, and image registration was successful in all cases. The visibility score of the parotid ducts and submandibular ducts was reduced at 6 weeks post-RT, which means that the full trajectory of the salivary ducts, from the intraglandular space to the mouth cavity, was only partially visualized. For some of the parotid ducts, the visibility score improved at 6 months post-RT, but not for the submandibular ducts. The mean dose for the parotid glands was 35 Gy (1 standard deviation [SD] 3 Gy), and for the submandibular glands it was 62 Gy (SD, 8 Gy).

CONCLUSION

Three-dimensional MR sialography is a promising approach for investigating xerostomia, because radiation-induced changes to the saliva content of the ducts can be visualized.

The relationship of the parotid duct to the buccal and zygomatic branches of the facial nerve; an anatomical study with parameters of clinical interest

There have been studies concerning the protection of the facial nerve during plastic surgery intended for the parotid gland. The close relationship between the parotid duct and the buccal and zygomatic branches of the facial nerve is studied here. The dissections were performed on 10 fixed cadavers at the Anatomy Dissection Laboratory of Ankara University in 2004. The reference points used for surgery of this region were taken into consideration as the landmarks for morphometric measurements. In 7 of the cases the zygomatic branch was double and in 3 it was single. In 4 of the 7 cases with a double zygomatic branch both superior and inferior branches crossed the parotid duct. In the remaining 3 cases the superior branches of the zygomatic nerve coursed through the zygomatic major and minor muscles. In 9 of all the cases the zygomatic branch of the facial nerve crossed the duct anteriorly and in one it did so posteriorly (case 10). The buccal branch was single in 4 of the cases and double in 6. Among these one of the most precise measurements was the distance between the lateral canthus and the intersection point of the zygomatic branch and the duct with a coefficient of variation of 9.9%. With the use of this reliable measurement the intersection point of the zygomatic branch and the duct may be estimated to be within 5.16+/-1.01 centimetres of the lateral canthus. Facial nerve paralysis is the most important complication of superficial face surgery and the anatomy of this region must thus be taken into detailed consideration by surgeons.

Microscopic anatomy of pycnogonida: II. Digestive system. III. Excretory system

The digestive system of several species of sea spiders (Pycnogonida, Arthropoda) was studied by electron microscopy. It is composed of the foregut inside a long proboscis, a midgut and a hindgut. Lips near the three jaws at the tip of the proboscis receive several hundred ductules originating from salivary glands. These previously undetected glands open on the lips, a fluted, projecting ridge at the external hinge line of the jaws, i.e., to the outside of the mouth. This disposition suggests affinities to the chelicerate line. The trigonal esophagus within the proboscis contains a complex, setose filter device, operated by dedicated muscles, that serves to reduce ingested food to subcellular dimensions. The midgut has diverticula into the bases of all legs. Its cells differentiate from the basal layer and contain a bewildering array of secretion droplets, lysosomes and phagosomes. In the absence of a hepatopancreas, the midgut serves both digestive and absorptive functions. The cuticle-lined hindgut lies in the highly reduced, peg-like abdomen. Traditionally, pycnogonids have been claimed to have no excretory organ at all. Such a structure, however, has been located in at least one ammotheid, Nymphopsis spinosissima, in which a simple, but standard, excretory gland has been found in the scape of the chelifore. It consists of an end sac, a straight proximal tubule, a short distal tubule, and a raised nephropore. The end sac is a thin-walled and polygonal chamber, about 150 microm in cross section, suspended in the hemocoel of the appendage, its edges radially tethered to the cuticle at more than half a dozen locations. This wall consists of a filtration basement membrane, 1-4 microm thick, facing the hemocoel, and internally of a continuous carpet of podocytes and their pedicels. The podocytes, measuring maximally 10 by 15 microm, have complex contents, of which a labyrinthine system of connected intracellular channels stands out. These coated cisternae open into a central vacuole that often rivals the nucleus in size. The design of the organ closely approximates that of the primitive crustacean Hutchinsoniella macracantha.

Antimicrobial defence mechanisms of the human parotid duct

The parotid duct transports saliva from the gland into the oral cavity. However, its immune response properties, along with the secretion and moistening principles of the duct, have not yet been fully investigated. These properties may play an important role in protecting the parotid gland from infection and also prevent development of sialodocholithiasis, as the parotid duct -- in contrast to the submandibular salivary duct -- is often free of duct concrements. Up to now, only the parotid gland has been investigated, without regard to its duct. The present study analyses the structures of the parotid duct in their relations to antimicrobial defence mechanisms and rheological properties. Investigations were performed on 23 parotid ducts using histological, histochemical and immunohistochemical methods. Epithelial and goblet cells of the parotid duct synthesize a complex mucous layer that covers the epithelium. The viscosity is influenced by secreted mucins and TFF peptides. This layer contains carbohydrates including N-acetyl-glucosamine, N-acetyl-galactosamine, galactose, mannose, fucose and sialic acids. The lamina propria contains granulocytes, T lymphocytes and macrophages. IgA, produced by plasma cells in the subepithelial layer, is frequently integrated in the secretory product. Synthesized mucins, TFF peptides, carbohydrates and immunoglobulins form a complex layer that can be expected to prohibit infection and enables salivary flow. Our study demonstrates that the steady secretion of the parotid gland, together with the ductal cellular and biochemical immune protection system, is likely to thwart ascending infections in the parotid duct and gland.

An anatomical study of the buccinator muscle fibres that extend to the terminal portion of the parotid duct, and their functional roles in salivary secretion

Until now there has been no definitive anatomical study describing the area where the parotid duct enters the buccinator muscle. In this study, we performed anatomical and histological examinations to investigate the relationship between the parotid duct and the buccinator muscle. Thirty specimens (including the buccinator and the terminal portion of the parotid duct) were obtained from embalmed Korean cadavers. Dissection was performed on 22 of these specimens, and the remaining eight specimens were prepared for histological examination and stained with haematoxylin-eosin or Gomori trichrome. In all specimens, small, distinct muscle fibres originating from the buccinator muscle extended to and inserted into the terminal portion of the parotid duct. The topography of these fibres varied, and we classified them into three categories according to where they originated. Type I buccinator muscle fibres, which inserted into the terminal portion of the parotid duct, originated simultaneously from the anterior and posterior aspects of the duct (ten cases, 45.5%). Type II fibres originated from the anterior aspect of the duct and inserted into the anterior side of the duct (seven cases, 31.8%). Type III fibres originated from the posterior aspect of the parotid duct and ran anteriorly toward the duct (five cases, 22.7%). These results were confirmed in the histological examination of all eight specimens. Based on these findings, we have proposed a tentative description of the physiological role of the buccinator muscle fibres in salivary secretion and in the formation of the sialoliths.

Symmetry of the submandibular glands in humans—a postmortem study assessing the linear morphometric parameters

BACKGROUND

The analysis of morphometric right-left symmetry of the salivary glands is important for assessing unilateral changes discovered in these organs during diagnostic imaging.

STUDY DESIGN

A study was carried out on 18 adult human autopsy neck and maxillofacial specimens from both sexes (14 males, 4 females), with age range of 17 to 73 years (mean age 49.9 years). The submandibular duct was injected with contrast medium and images were made in two projection planes.

RESULTS

Morphometry performed using the obtained radiographs included: (a) caliber (mean proximal, middle, and distal = 1.73 mm, 1.82 mm, and 1.77 mm), (b) length (mean = 37.2 mm); (c) genu of the submandibular duct (mean = 114 degrees ); and (d) longitudinal and transverse diameters of the gland (mean = 44.1 mm and 25.9 mm). Comparison of these morphometric parameters between the right and the left glands revealed no statistically significant differences.

CONCLUSION

There is a high level of right-left symmetry in linear morphometric parameters of the submandibular gland.

The functional evaluation of salivary glands using dynamic MR sialography following citric acid stimulation: a preliminary study

OBJECTIVE

We introduce a new technique for the functional evaluation of the salivary glands using continuous magnetic resonance (MR) sialography before and after citric acid stimulation.

METHODS

In 10 volunteers, the time-dependent changes in the maximum area of the detectable parotid gland ducts on MR sialographic images taken every 30 seconds before and after citric acid stimulation were analyzed. The time period to the occurrence of the maximum duct area poststimulation was noted, and then the time for the area to return to its 50% value pre-citric acid stimulation was also observed. This new technique was clinically applied in 1 patient with an excessive supply impression of saliva and in 1 patient with a short supply impression with saliva.

RESULTS

In all volunteers after citric acid stimulation, the maximum area of the detectable salivary gland ducts first increased and then decreased. A strong relationship was found between the maximum area of the detectable salivary gland ducts before citric acid stimulation and total saliva volume (Pearson r = 0.672, P = .031). Compared with all the volunteers, the ratio of change in the detectable ducts was the highest in the patient with an excessive supply impression of saliva, but lowest in the patient with a short supply impression with saliva.

CONCLUSIONS

This initial study suggests that dynamic MR sialography allows for functional and morphological evaluation of the salivary glands. This technique appears to have many possible applications and further investigation in this field is necessary.

Interrelated Buccal Fat Pad With Facial Buccal Branches and Parotid Duct

The facial nerve branches are vulnerable during manipulation of the buccal fat pad. The aim of this study is to describe the precise anatomical interrelation among the buccal fat pad, buccal branches of the facial nerve, and parotid duct. Nineteen hemifaces of Korean cadavers (11 male and 8 female) fixed in 10% formaldehyde solution were dissected. An average 3.6 buccal branches of the facial nerve were found. The facial buccal branches and parotid duct crossed each other within a semicircle with a 30-mm radius. The base (diameter) is parallel to a horizontal line passing the corner of the mouth and 12 mm above. Its center is located 53 mm lateral to it. The buccal branches of the facial nerve have two locations at the buccal fat pad: Type I, branches crossing superficial to the buccal fat pad in 14 of 19 (73.7%) specimens; and Type II, two twigs passing through buccal extension of the buccal fat pad in 5 of 19 (26.3%). An interrelation of parotid duct and buccal fat pad is as follows: parotid duct crossing superficial to the buccal extension of buccal fat pad in 8 of 19 (42.1%) specimens, crossing deep to the buccal extension of buccal fat pad in 5 of 19 (26.3%) specimens and crossing along the superior border of the buccal extension of buccal fat pad in 6 of 19 (31.6%) specimens. There is a 26.3% chance of injury to the buccal branch during total removal of buccal fat pad. The parotid duct runs deep to the buccal extension of buccal fat pad in 26.3% of cases.

Management of parotid duct injuries

Injuries to the buccal region of the face can carry multiple complications due to the complex anatomy that lies within. The facial nerve and the parotid duct can be easily injured by sharp or penetrating trauma to the cheek. The purpose of this paper is to present the full spectrum of current treatment modalities available to manage these injuries. The anatomy of the parotid gland and duct are described, and surgical techniques and therapeutic alternatives for the immediate and delayed treatment of the parotid duct injuries are reviewed. Clinical cases are presented to illustrate the treatment options outlined.

Utility of three dimension fast asymmetric spin-echo (3D-FASE) sequences in MR sialographic sequences: model and volunteer studies

OBJECTIVES

To evaluate the utility of 3D-FASE for the visualization of salivary gland ducts for use in MR sialographic sequences.

METHODS

We compared MR sialographic images and virtual endoscopic views from 3D-FASE with those from three kinds of sequences described by previous reports in a 3D parotid gland duct model and volunteer. The four sequences were two-dimension fast spin-echo (2D-FSE), three-dimension fast spin-echo (3D-FSE), two-dimension fast asymmetric spin-echo (2D-FASE), and three-dimension fast asymmetric spin-echo (3D-FASE).

RESULTS

In the 3D parotid gland duct model, image visibility on visual score was clearest with 3D-FSE, followed by 3D-FASE (P = 0.028). In the volunteers, the visualization of images improved in the following order: 3D-FASE > 3D-FSE > 2D-FSE > 2D-FASE.

CONCLUSIONS

The technique of 3D-FASE sequencing is more suitable and useful for MR sialography with an appropriate acquisition time.

Is there evidence of a sphincter system in Wharton's duct? Etiological factors related to sialolith formation

The exact cause of the formation of sialoliths is unknown. Detailed knowledge of the pathogenesis of sialolithiasis is necessary to define new therapeutic procedures. The possible presence of a sphincter system in Wharton's duct has been described frequently in the context of diagnostic sialendoscopy. Serial histological examination of the entire Wharton's duct in four samples revealed no anatomical correlation for the presence of a sphincter. Secretory disturbances and viscous secretions as well as microlith formation and ductal obstruction cannot fully explain the genesis of sialoliths. The coaction of those factors with participation of bacteria leads to the development of sialoliths.

Virtual endoscopic view of salivary gland ducts using MR sialography data from three dimension fast asymmetric spin-echo (3D-FASE) sequences: a preliminary study

OBJECTIVES

We performed magnetic resonance (MR) sialography of parotid gland and/or submandibular gland ducts using three-dimensional fast asymmetric spin-echo (3D-FASE) sequencing. The objective was to make three-dimensional (3D) reconstruction images and virtual endoscopic views of the parotid gland ducts using MR sialography data sets of 3D-FASE sequences.

METHODS

We reviewed the MR sialography data sets with 3D-FASE sequencing of 10 control volunteers and six patients. Three-dimensional reconstruction images and virtual endoscopic views of the parotid gland and/or submandibular gland ducts were generated with maximum intensity projection (MIP), shaded surface display (SSD), and volume rendering techniques (VRT).

RESULTS

The main parotid gland and/or submandibular gland ducts, large branches within the glands, and small branches were fairly well defined in a very short acquisition time on MR sialographic images with 3D-FASE sequencing in nine of the 10 healthy volunteers. The 3D-reconstruction images of the parotid gland ducts and/or submandibular gland ducts showed the entire length of the branch paths and complete images from all angles, and the virtual endoscopic views showed the endoluminal tracts of the main ducts and the large branches in nine. In the patient with Sjogren's syndrome, chronic sialoadenitis, and salivary calculi in the Wharton ducts, the MR sialographic images showed diffuse areas of punctate high signal intensity, dilatation of Stensen's duct, or stones of Wharton's duct, respectively. Furthermore, the 3D-reconstruction images of the salivary gland ducts showed the stenoses and stones in the branch paths and complete images from all angles, and the virtual endoscopic views showed the stenoses and stones in the endoluminal tracts of the main and large branches.

CONCLUSIONS

Our initial experience showed that virtual MR endoscopy could be performed to observe the endoluminal tracts of parotid and submandibular glands. The clinical use of the virtual MR endoscopy for salivary gland ducts has not been established yet. Future applications of the 3D-reconstruction images and virtual endoscopic views using MR sialography data sets of 3D-FASE sequences are very attractive and further expansion of this field is expected.

Vascular endothelial growth factor in minor salivary glands: effect of ageing

Morphological and physiological age changes are described in human salivary glands. Vascular endothelial growth factor (VEGF) is neoangiogenic growth factor found in normal salivary glands. Considering the neoangiogenic properties of VEGF and its important function in inflammation, repair and, probably, in oral mucosa homeostasis, the purpose of the present study was to evaluate the effect of ageing on the immunolocalization of VEGF in minor salivary glands. Paraffin-embedded tissue blocks containing normal labial salivary glands were retrieved and classified according to the patients' age in two groups (< 20 and > 40-year-old). The biotin-streptavidin-peroxidase system was used to detect the VEGF antigen. The results demonstrated that the mean level of VEGF immunoreaction in the young group was not statistically different from the old group when compared by the Mann-Whitney U-test (P = 0.54). This may indicate that although salivary flow reduction may develop in old patients, some properties of the salivary glands may not be affected.

The genu of the submandibular duct--is the angle significant in salivary gland disease?

OBJECTIVES

To investigate whether the angle of the genu of the submandibular duct is a significant contributory factor in the development of salivary calculi or sialoadenitis.

METHODS

A preliminary test with a phantom was performed, taking oblique lateral views with different vertical and horizontal beam angulations to assess the effect on the genu angle. The phantom comprised a dried mandible and a piece of wire bent to simulate the submandibular duct. There were no differences in the measured angle of the bend in the wire within the range of beam angulations used in the clinical study. One hundred and two sialographs were analysed from three separate groups of patients, normal controls (n=18), proven salivary calculi (n=61) and those with sialoadenitis (n=23). The oblique lateral radiographs were digitised and imported into the Denoptix digital system, and the angle measured using the VixWin 2000 software. Differences in angle between groups were investigated using analysis of variance.

RESULTS

The mean angle of the genu was 103 degrees (range 41 degrees-147 degrees) in the control group, 108 degrees (range 46 degrees-178 degrees) salivary calculi group, and 91 degrees (range 24 degrees-155 degrees) in sialoadenitis patients. There were no statistical differences in the angle between the groups.

CONCLUSIONS

There is a wide variation in the angle of the genu of the submandibular duct (24 degrees -178 degrees ). This angle does not appear to be associated with either sialolithiasis or sialoadenitis.

Secretion by striated ducts of mammalian major salivary glands: review from an ultrastructural, functional, and evolutionary perspective

In addition to their role in electrolyte homeostasis, striated ducts (SDs) in the major salivary glands of many mammalian species engage in secretion of organic products. This phenomenon usually is manifested as the presence of small serous-like secretory granules in the apical cytoplasm of SD cells. The composition of these granules is largely unknown, except in the case of the cat and rat submandibular gland, where the granules have unequivocally been shown to contain kallikrein. In some species, the apical cytoplasm of SD cells contains variable numbers of vesicles, both spherical and elongated, that vary in appearance from 'empty' to moderately dense. In the rat parotid gland, lucent vesicles transport glycoproteins to the luminal surface where they are incorporated into the apical plasmalemma and the glycocalyx. There is a strong possibility that in various species some of these vesicles are involved in transcytosis of antibodies to the saliva from their source (plasma cells) in the surrounding connective tissue. In addition, vesicles may engage in transfer of growth factors from the saliva to the interstitium. In a few species, conventional SDs have been replaced by ducts that are wholly given over to secretion, i.e., they entirely lack basal striations; although such ducts occupy the histological position of conventional SDs, it is not clear whether they represent a new type of duct or merely are modifications of SDs. Broad-based comparisons of ultrastructural and other data about SDs offer some insight into evolutionary history of salivary glands and their role in the adaptive radiation of mammals. Evolutionary patterns emerged when we made interspecific comparisons across mammalian orders. Among the bats, there is a clear relationship between SD secretion and general categories of diet.

H+ and HCO3- transporters in human salivary ducts. An immunohistochemical study

The presence and cellular distribution of key H+ and HCO3- transport proteins was studied in human salivary ducts. Immunofluorescence and immunoperoxidase light microscopy was applied, using specific antibodies against the NHE1 and NHE3 isoforms of the Na+/H+ exchanger, against the 31 and 70 kDa subunits of the vacuolar H+-ATPase and against the electrogenic Na+-HCO3- cotransporter. The results show basolateral NHE1 and apical NHE3 in human submandibular, parotid and sublingual duct cells. Vacuolar H+-ATPase was found predominantly in the apical membrane of parotid, submandibular and sublingual duct cells, although it was absent in certain parotid striated duct cells. The Na+-HCO3- cotransporter was predominantly expressed in the apical membrane of parotid and sublingual striated ducts, and intracellularly distributed in the distal parts of the gland tree and in submandibular ducts. The results indicate that HCO3- transport properties of salivary ducts may vary not only between gland and species, but even in different duct segments of the same gland as well.

Endoscopic Excision of the Submandibular Gland by an Intraoral Approach

The recent advent of endoscopic procedures has compelled both plastic and neck and head surgeons to reconsider the conventional methods by which the excision of submandibular gland is classically achieved. An endoscopic intraoral approach for excision of the submandibular gland is described. This procedure is anatomically safe and can be made with minimal morbidity; a transcervical incision is avoided. Both specific instruments and solid anatomical knowledge are necessary to perform a safe and efficient glandular endoscopic excision. The essential surgical steps are as follows: 1) Careful identification of the Wharton duct and lingual nerve; 2) Retraction of the mylohyoid muscle; 3) Protection of the sublingual gland and lingual nerve; 4) Extraoral manipulation of the submandibular gland obtaining intraoral protrusion; and 5) Careful dissection of the posterior third of gland, avoiding injury on the facial artery and vein. Two patients were operated on with this technique and were very pleased with their results. No complications were registered. With advanced endoscopic instruments, new surgical technique, and surgeon experience, endoscopic intraoral excision of the submandibular gland can be the method of choice in benign neoplasia, sialolith, sialoadenitis and plunging ranula.

Immunohistochemical localization of C-type natriuretic peptide in the rat submaxillary salivary gland

To define the localization and characteristics of C-type natriuretic peptide (CNP) in the rat submaxillary gland, immunohistochemistry and gel permeation-high-performance liquid chromatography were used. Immunoreactive (IR)-CNP was localized in cells of the granular convoluted tubule, striated duct and endothelial cells of the capillary, where atrial natriuretic peptide (ANP) was colocalized in consecutive sections, but not in acini. Gland extracts co-eluted with synthetic CNP and its content was 60.3+/-4.9 pg/mg protein (n=4). Molecular profiles of immunoreactive material showed two peaks corresponding to synthetic CNP((1-53)) and CNP((1-22)). These results indicate that CNP is colocalized with ANP in the duct and endothelial cells of the rat submaxillary gland. Therefore, CNP may have a physiological role in the submaxillary gland by interacting with ANP and/or other biologically active substances in the ducts and granular convoluted tubule cells.

Morphological features of the minor salivary glands

The minor salivary glands are important components of the oral cavity, present in most parts of the mouth, and their secretions directly bathe the tissues. Individual glands are usually in the submucosa between muscle fibres, and consist of groups of secretory endpieces made up of mucous acinar cells and serous or seromucous demilune cells. The ductal systems comprise intercalated ducts, intralobular ducts usually lacking basal striations, and excretory ducts opening directly through the mucosa Minor glands secrete highly glycosylated mucins, containing blood group determinants, and probably active in tissue lubrication and bacterial aggregation. They also secrete several antimicrobial proteins and immunoglobulins, and the lingual serous (von Ebner's) glands secrete digestive enzymes and proteins with possible taste perception functions. Minor gland morphology and function can conveniently be studied in the rat. There are substantial differences between major and minor salivary glands, as well as among the minor glands, in the nature and composition of their mucous and serous secretory products. The role of minor salivary glands in the function and defence of the oral cavity may be better understood as a result of new physiological and molecular methods applicable to samples of limited size and availability.

Ultrastructure of major intraglandular ducts in the parotid gland of the African mole-rat

The parotid gland of a female African mole-rat, Tachyoryctes splendens, was examined by light and electron microscopy. A pure seromucous gland of conventional histology, its striated and excretory ducts contain prominent cytoplasmic inclusions that are lightly stained with toluidine blue. At the ultrastructural level, the inclusions are seen to consist of a light to moderately dense structureless matrix in which are suspended scattered, randomly oriented filaments that either are 4-7 nm or approx 14 nm thick. A few multivesicular bodies or putative lipid droplets are sparsely distributed in the inclusions. Even though the inclusions lack an encompassing membrane, all other formed cytoplasmic structures are excluded. These inclusions are not present in the ducts of the submandibular gland of the mole-rat. The inclusions may confer special properties on the parotid gland of this fossorial animal that permit it to cope with the exigencies of a subterranean existence.

Sialographic characterization of the normal parotid gland of the miniature pig

OBJECTIVE

To characterize the structure of the parotid gland of the miniature pigs (minipig).

METHODS

Sialographic, anatomical, histological and ultrastructural studies of the parotid gland were performed on 11 minipigs.

RESULTS

Sialograms showed a long main duct and a triangular shaped gland. All branching ducts extended from the inferior-posterior margin of the main duct. No accessory glands were found. Typical serous acini were found microscopically and histochemically.

CONCLUSION

This study provides basic structural information on the parotid gland of the minipig.

Diameters of the main excretory ducts of the adult human submandibular and parotid gland: a histologic study

In assessing new minimally invasive diagnostic techniques (duct endoscopy) and therapy (lithotripsy), it is of importance to know the true dimensions of the excretory ducts. Twenty-five ducts of the parotid gland and 20 ducts of the submandibular gland were examined histologically at different points of their anatomic course, and their in vivo diameters were evaluated with the use of a previously determined formalin-induced shrinking-factor. The mean diameter of Stensen's duct at four different points along its length ranged between 1.4 mm and 0.5 mm, with a maximum of 2.3 mm and a minimum of 0.1 mm, depending on the site. A narrowing at the middle of the duct was striking. In all preparations examined, the minimum width of the excretory duct was located at the ostium. In Wharton's duct the narrowest duct diameter was also identified at the ostium. The mean values for the duct diameters ranged between 1.5 mm and 0.5 mm. The largest duct diameter reached 2.2 mm; the smallest one, 0.2 mm. For diagnostic and therapeutic purposes, endoscopes, balloon catheters, and stone-extraction-baskets probably should, despite the extensibility of the duct, conform as much as possible to the physiologic duct widths. A diameter of 1.2 mm should be aimed at as an upper limit for these instruments. Our findings also suggest that, in the case of salivary stone lithotripsy, the best results will be achieved when the maximum size of stone fragments does not exceed 1.2 mm.

Surgery of the salivary ducts

Successful surgery of the salivary ducts relies on an understanding of the surrounding anatomy and the delicate dissection of tissues in order to reduce morbidity. Trauma to the ducts should be assessed when lacerations or wounds encroach on their paths. Early diagnosis and treatment will reduce the complications of stricture and fistula formation from these injuries. Sialoliths can be located in several places along the length of the salivary ducts. The correct diagnosis and positioning of the stone in the duct is important in establishing the appropriate surgical approach. Imaging using plain films, ultrasonography, and endoscopy can be very valuable, with sialography and CT scans helpful in cases of radiolucent stones, glandular atrophy, or suspected tumor. As the condition becomes more chronic, resulting in glandular atrophy, excision of the diseased gland is often indicated. Treatment of excessive salivary flow in patients with cerebral palsy can be managed by a combination of ductal repositioning and glandular excision. Redirection of both the parotid and submandibular glands can be accomplished, either to reroute excess salivary flow or salvage the duct in cases of lesion excision.

MR sialography. Work in progress

PURPOSE

To develop a noninvasive method for demonstrating the main salivary gland duct systems.

MATERIALS AND METHODS

The authors developed a magnetic resonance (MR) imaging protocol that uses a heavily T2-weighted (echo time, 750 msec), fat-suppressed pulse sequence and rapid acquisition with relaxation enhancement. The technique was optimized to depict fluid within a two-dimensional thick slab. A preliminary evaluation was performed by examining the major salivary gland ducts in 10 asymptomatic volunteers and three symptomatic patients with known salivary duct abnormalities.

RESULTS

The main parotid gland ducts were clearly demonstrated in all volunteers. The submandibular ducts were visible in all cases, although not always on projection images. In the three patients, the MR technique clearly demonstrated bilateral sialectasis, a calculus obstructing the left submandibular duct, and a fluid-filled ranula, respectively.

CONCLUSION

Preliminary work indicates that this MR technique can successfully demonstrate both normal and abnormal parotid and submandibular gland duct systems and has several advantages over conventional x-ray sialography.

The relationship of the buccal branch of the facial nerve to the parotid duct

PURPOSE

This cadaver dissection studied the relationship of the buccal branch of the facial nerve to the parotid duct and its relevance to surgical procedures in this area.

MATERIALS AND METHODS

Ten cadaveric heads (twenty sides) were dissected. The superficial tissues were removed, and the buccal branch of the facial nerve and the parotid duct were identified. The vertical and horizontal relationships were recorded and analyzed.

RESULTS

Eighty-five percent of the cadavers had a single buccal branch of the facial nerve, whereas 15% had two branches. In 75% of cases, the nerve was inferior to the duct as it emerged from the parotid gland, whereas in 25% of cases the nerve crossed the duct, usually from superior to inferior.

CONCLUSION

The buccal branch of the facial nerve has a close relationship with the parotid gland for over 2.5 cm after it emerges from the parotid gland; it normally lies inferior to the duct. This relationship is of importance in performing parotid gland surgery, parotid duct surgery, and some facial cosmetic surgery.