A glimpse of past, the temporo-buccinator band of Hovelaque, or the buccotemporal fascia of Zenker.

Only a few studies published until now have described the fascial-tendinous complex between the temporal and the buccinator muscles, which will be reviewed here. In 1957, the "temporo-buccinator band" (TBB) was described by Gaughran, who gave credit to Hovelaque for its first description in 1914. Zenker coined it in 1955 as the "buccotemporal fascia" (BTF). A buccal extension of the temporal muscle tendon extends from the temporal crest of the mandible to insert within the buccinator muscle, anterior to the pterygomandibular raphe, and posterior to the parotid duct that perforates the buccinator. That tendinous expansion is embedded within the buccotemporal fascia, which is oriented antero-infero-medially and joins the buccopharyngeal fascia, forming the TBB/BTF, above which we find the buccal fat pad. The buccal nerve and artery cross this anatomical structure. The TBB/BTF is an additional layer closing the pterygomandibular space anteriorly, and its knowledge is needed for practitioners performing inferior alveolar nerve blocks.

Global, Regional, and National Levels and Trends in Burden of Oral Conditions from 1990 to 2017: A Systematic Analysis for the Global Burden of Disease 2017 Study.

Government and nongovernmental organizations need national and global estimates on the descriptive epidemiology of common oral conditions for policy planning and evaluation. The aim of this component of the Global Burden of Disease study was to produce estimates on prevalence, incidence, and years lived with disability for oral conditions from 1990 to 2017 by sex, age, and countries. In addition, this study reports the global socioeconomic pattern in burden of oral conditions by the standard World Bank classification of economies as well as the Global Burden of Disease Socio-demographic Index. The findings show that oral conditions remain a substantial population health challenge. Globally, there were 3.5 billion cases (95% uncertainty interval [95% UI], 3.2 to 3.7 billion) of oral conditions, of which 2.3 billion (95% UI, 2.1 to 2.5 billion) had untreated caries in permanent teeth, 796 million (95% UI, 671 to 930 million) had severe periodontitis, 532 million (95% UI, 443 to 622 million) had untreated caries in deciduous teeth, 267 million (95% UI, 235 to 300 million) had total tooth loss, and 139 million (95% UI, 133 to 146 million) had other oral conditions in 2017. Several patterns emerged when the World Bank's classification of economies and the Socio-demographic Index were used as indicators of economic development. In general, more economically developed countries have the lowest burden of untreated dental caries and severe periodontitis and the highest burden of total tooth loss. The findings offer an opportunity for policy makers to identify successful oral health strategies and strengthen them; introduce and monitor different approaches where oral diseases are increasing; plan integration of oral health in the agenda for prevention of noncommunicable diseases; and estimate the cost of providing universal coverage for dental care.

The unusually lower position of the mandibular foramen and the canal of the neck of mandible.

BACKGROUND: The inferior alveolar nerve (IAN) courses through the mandibular foramen (MF) to enter the first segment of the mandibular canal (MC) in the mandibular ramus, to further supply with trigeminal fibers the lower teeth of that hemimandible. As the IAN also supplies the mylohyoid nerve, it is a mixed nerve. METHODS: Unusual morphologies of the mandibular ramus were encountered during a retrospective study of archived CBCT files. RESULTS: A previously unreported anatomic variation was found bilaterally in an edentulous mandible, consisting of a lowered position of the MF, with seemingly compensatory lengthening and enlargement of the sulcus colli, thus shortened MCs. Also, a rare neurovascular canal of the neck of the mandible was incidentally found unilaterally in another case and is reported here. CONCLUSIONS: Such possibilities of variation could justify the individual effect of the IAN block.

Anatomic variation in the pterygopalatine angle of the maxillary sinus and the maxillary bulla.

Bulges of the most posterior ethmoid air cells into the maxillary sinus were termed maxillary bullæ by Onodi. With few exceptions, they have since been ignored by anatomists through time. Likewise, Sieur cells-the spheno-ethmoido-maxillary air cells-are uncommonly found in anatomical texts. We therefore aimed to perform a retrospective cone beam computed tomography study on 50 patients to document the possibilities of anatomic variation in the situs of the orbital process of palatine bone-a variation related anatomically with the pterygopalatine fossa (PPF) and the respective angle of the maxillary sinus. Commonly occurring pneumatizations in this situs were the Sieur cell (58 %/64 % right/left side), and the maxillary recess of the sphenoidal sinus (20 %/22 % right/left side). Alone or in combination, these determined, but not exclusively, the maxillary bullæ. Uncommon pneumatizations in the anterior wall of the PPF were also found, such as a sphenoidal recess of the maxillary sinus, and lateral (maxillary, or pterygopalatine) recesses of the middle and superior, respectively, nasal meatuses. In two different cases, non-Haller, and non-Sieur posterior ethmoid air cells were found extruded posterior to the maxillary sinus. Significant statistical association indicated bilateral symmetry of Sieur's cell and of the maxillary recess of the sphenoidal sinus. It is important to identify such variant pneumatizations on a case-by-case basis in different surgical procedures and endoscopic corridors.

Subsets of telocytes: Myocardial telocytes.

Telocytes (TCs) are morphologically defined as small-sized cells with long, thin, moniliform processes called telopodes (Tps). Numerous papers imply that TCs are a distinctive cell type, and that transmission electron microscopy (TEM) is the gold standard tool for their identification. We aimed to reproduce previous studies on myocardial TCs to check their validity. For this purpose we performed an immunohistochemical study on human cardiac samples from six autopsied donor cadavers, using antibodies against CD10, CD31, CD34, CD146, Ki67, alpha-smooth muscle actin (α-SMA), Platelet-Derived Growth Factor Receptor-alpha (PDGFRα) and laminin. Additionally we performed a TEM study on cardiac samples from three human autopsied donor cadavers and five adult Sprague-Dawley rats. We found endothelial cells (ECs), cords, and filopodia-projecting endothelial tip cells (ETCs) that expressed CD10, CD31, CD34, CD146, and PDGFR-α. Often, endothelial cells closely neighbored the sarcolemmal basal laminae. Endothelial progenitor cells, as well as nascent capillaries, were CD31+/CD34+. Proliferative endothelial cells expressed Ki67. In larger vessels we found pericytes that expressed CD146 and α-SMA; scarce α-SMA-expressing spindle-shaped cells lining cardiomyocytes were suggestive of a pericytic role in angiogenic sprout guidance. The TEM study showed that endothelial tubes are almost exclusively found in the narrow myocardial interstitia. ECs that built them up appeared identical to the cells that previous TEM studies have suggested to be myocardial telocytes. A subset of stromal cells with TC-like phenotype and telopodes-like processes actually seem to configure blood vessels, and therefore belong to the endothelial lineage. This study shows that data presented in previous studies on myocardial telocytes is not enough to allow the reproducibility of the results. At least a subset of cells considered to be TCs might belong to the endothelial lineage.

Altered Mitochondrial Anatomy of Trigeminal Ganglia Neurons in Diabetes.

Neurons from sensory ganglia are exposed to oxidative attack in diabetes. Altered mitochondrial morphologies are due to impaired dynamics (fusion, fission) and to cristae remodeling. This study aimed to evaluate using transmission electron microscopy mitochondrial changes in diabetic trigeminal ganglia suggestive for ignition of apoptosis, in absence of "classical" morphological signs of apoptosis. We used samples of trigeminal ganglia (from six type 2 diabetes human donors and five streptozotocin (STZ)-induced diabetic rats). In human diabetic samples we found three main distributions of mitochondria: (a) small "dark" normal mitochondria, seemingly resulted from fission processes; (b) small "dark" damaged mitochondria, with side-vesiculations (single- and double-coated), large matrix vesicles and cytosolic leakage of reactive species, mixed with larger "light" mitochondria, swollen, and with crystolysis; (c) prevailing "light" mitochondria. In STZ-treated rats a type (c) distribution prevailed, except for nociceptive neurons where we found a different distribution: large and giant mitochondria, suggestive for impaired mitochondrial fission, mitochondrial fenestrations, matrix vesicles interconnected by lamellar cristae, and mitochondrial leakage into the cytosol. Thus, the ultrastructural pattern of mitochondria damage in diabetic samples of sensory neurons may provide clues on the initiation of intrinsic apoptosis, even if the classical morphological signs of apoptosis are not present. Further studies, combining use of biochemical and ultrastructural techniques, may allow a better quantification of the degree in which mitochondrial damage, with membrane alterations and cytosolic leaks, may be used as morphological signs suggesting the point-of-no return for apoptosis. Anat Rec, 299:1561-1570, 2016. © 2016 Wiley Periodicals, Inc.

Diabetes and collision risk. A meta-analysis and meta-regression.

AIMS: The main objective of this study was to see whether diabetes is associated with an increased collision risk and to test the effect of age and gender on the overall collision risk for diabetes drivers. MATERIALS AND METHODS: Twenty-eight studies were included in meta-analysis, using mean age, gender, continent and the prevalence of fatal road incidents as covariates. RESULTS: The collision risk for diabetes drivers was small and not statistically significant - RR = 1.11 (1.01-1.23) with a prediction interval (PI) or 0.77-1.65. Age and gender were not associated with an increased overall risk. Insulin-dependent diabetes patients had a slightly increased effect size compared with the overall diabetes population, but the effect was not statistically significant. European diabetes drivers had a lower collision risk compared with their North American counterparts, the main cause being the difference of collision risk in the countries in which the studies were performed. CONCLUSIONS: Overall, diabetes patients do not have a statistically significant increased risk for unfavourable traffic events. Old age and insulin-dependent patients tend to have a higher risk. Advances in diabetes care, associated with advances in road safety regulations, and automotive industry have not decreased significantly the collision risk in the last 50 years for drivers with diabetes.

High Grade Penetrating Pancreatic Trauma - Case Report and Review of the Literature.

INTRODUCTION: The pancreatic injuries have fortunately a low frequency, but when present associate multiple intraabdominal lesions, and carry a significant morbidity and mortality. The aim of this study is to underline the significant morbidity associated with high grade pancreatic injuries. CASE REPORT: Female patient, 36 years old, with penetrating abdominal trauma due to domestic violence was referred to our center from a regional county hospital, after multiple laparotomies, hemodynamically unstable, with multiple organ failure. Abdominal clinical exam revealed evisceration, with massive pancreatic leakage at the level of the median laparotomy and through the stabbing wounds from the right flank. Emergency Computed Tomography showed multiple intraabdominal collections, with laceration of the liver, right kidney and pancreatic head. Abdominal exploration was decided. After a thorough abdominal debridement was revealed a deep laceration of the pancreatic head, with active extravasation of pancreatic secretion, correlating with a grade IV injury. Peritoneal lavage and large drainage of the lesser and greater peritoneal cavity was performed. The postoperative recovery was uneventful, with progressive decrease in pancreatic fistula output and discharge after 35 days. CONCLUSIONS: High grade pancreatic traumas associate a significant morbidity. Efficient drainage of the pancreatic head injuries and patients management in high volume centers for pancreatic surgery maximize the survival rate.

Brown adipocytes, cardiac protection and a common adipo- and myogenic stem precursor in aged human hearts.

New data on adult stem cells (ASCs) are continuously added by research for use in regenerative medicine. However organ-specific ASC markers are incompletely explored. It was demonstrated that in non-cardiac brown adipose tissue (BAT) CD133+ cells differentiate in cardiomyocytes, and such BAT-derived cells induce bone marrow-derived cells into cardiomyocytes, thus being a promising source for cardiac stem cell therapy. During embryogenesis the subepicardial fat derives from BAT. Although it was not specifically investigated in human adult or aged hearts, it is actually known that metabolically active BAT can be found in many adult humans, is related to antiobesity effects, and it may derive from stem/progenitor cells. Stro-1 can safely identify in situ cardiac stem cells (CSCs) with myogenic and adipogenic potential. It was therefore raised the hypothesis of subepicardial differentiation of CSCs in BAT in adult/aged hearts, which could be viewed, such as in infants, as a mechanism of protection. This could be determined by the reactivation of an embryologic differentiation pattern in which brown adipocytes and muscle cells derive from a common stem ancestor. Such quiescent common stem ancestors could be suggested in adult, or aged, human hearts, when subepicardial BAT is found, and if a Stro-1+/CD133+/Isl-1+ phenotype of CSCs is determined.

Intrinsic neuroendocrine cells in the outer wall of the human pyriform recess.

The extrinsic neural supply of the hypopharynx is well established. However, little is known about the intrinsic neurons and neuroendocrine cells (NECs) of the human hypopharynx that are under the influence of the extrinsic nerves. We aimed to identify and characterize such cell populations within the outer wall of the pyriform recess. We applied antibodies for neuron-specific enolase (NSE), calretinin (CR) and neurofilaments (NF) to autopsy samples from four donor cadavers. Within the lamina propria and the muscle layer of the pyriform recess outer wall, usually in perivascular areas, we found NSE-, CR- and NF-positive cells, mostly apolar, that were considered on a histological and immunohistochemical basis to be NECs. Although these cells have not, to our knowledge, been described previously in this anatomical location, their presence within the hypopharynx wall may explain the appearance of rare forms of local primary neuroendocrine carcinomas.

Sudden cardiac death due to triple myocardial bridging associated with atypical coronary topography.

Myocardial bridging (MB) is defined as the presence of an intramural course of a coronary artery, most likely caused by a defect in resorption of the musculature that encircles the epicardial arteries during morphogenesis. We present a case of the young man who died suddenly while playing professional football and whose cause of death was acute myocardial infarction associated with multiple myocardial bridges (1.8 cm on the anterior interventricular artery, 1.3 cm on the circumflex artery, and an intramyocardial trajectory of the posterior interventricular artery), and discuss the causes of death and possible consequences of this pathology.

Current strategies in the therapeutic approach for adenocarcinoma of the ampulla of Vater.

INTRODUCTION: Ampulla of Vater tumors, neoplastic diseases located at the confluence of the common bile duct with the main pancreatic duct; represent 0.2% of all gastrointestinal cancers. METHOD: Retrospective study of all patients admitted in the Emergency Hospital of Bucharest Romania between January 2008 and January 2013, the only selection criterion used being a pathology report which describes an ampulla of Vater carcinoma. We have also performed a review of the medical literature up to 2013, using the PubMed/Medline, Proquest Hospital Collection, Science Direct, Cochrane Library and Web of Science databases. We have used different combinations of the following keywords: "ampulla of Vater", "carcinoma", "resection", reviewing the reference list of retrieved articles for further relevant studies. RESULTS: Forty eight patients with ampulla of Vater carcinoma were identified, of whom 59.6% men, 71% from urban areas, and a mean age of 66 ± 13.3 years. Most patients were admitted for obstructive jaundice (49%), right upper quadrant abdominal pain (19%), nausea and loss of appetite in 13%, loss of weight (13%) and upper digestive obstruction in 6% of cases. All patients were evaluated with abdominal transparietal ultrasonography and double contrast, pancreatic protocol, Mutidetector Row Computed Tomography. The abdominal Magnetic Resonance Imaging was performed in 10 cases, upper gastrointestinal endoscopy in 9 cases, and Endoscopic Retrograde Cholangiopancreatography in 39 cases. According to the AJCC Cancer Staging 9% were into stage I, 47% into stage II, 40% into stage III and 4% into stage IV of the disease. The therapeutic approach was surgical for 44 patients and an endoscopic palliation with stent insertion in 4 cases. The surgical procedure was represented by Whipple pancreatoduodenectomy in 27 cases, pylorus preserving pancreatoduodenectomy in 15 cases and exploratory laparotomy in 2 cases. Early morbidity was represented by pancreatic leakage in 4 cases. CONCLUSIONS: There are clinical scenarios in which it is quite challenging to distinguish a primary ampullary adenocarcinoma based on a preoperative workup. Nevertheless, an aggressive approach should be performed, knowing the higher resectability rates and a five-year survival for these patients. Complete surgical resection should be performed in all medically fit patients, candidates for pancreatoduodenectomy, by a high volume, trained surgeon, able to offer a low morbidity and mortality.

Conventional vs unconventional assisted reproductive technologies: opinions of young physicians.

In the last three and a half decades, an increasing number of assisted reproductive technologies (ARTs) have been developed, some of them already being used in clinical practice, while others will probably remain purely theoretical due to their associated ethical issues. The purpose of this study was to analyse the opinions of medical residents regarding various ARTs, both classical and unconventional. We conducted a multi-institutional survey among 142 medical residents in order to assess the views of young physicians of regarding ARTs. Most responders were in favour of medical procedures like gamete donation and surrogacy. When asked about more controversial procedures such as posthumous sperm procurement or reproductive cloning, most were against. Progress in reproductive medicine is made at a fast pace, as more and more couples are found infertile and as the birth rate in developed countries becomes smaller and smaller. If not carefully followed and regulated, this can easily lead to the development of highly controversial procedures, which can significantly alter the way we see human reproduction. As the law has a very traditional approach, it is often left behind by progress in this field, leaving potentially controversial procedures unregulated for long periods of time. During these periods, physicians have the very important role of analysing what is good and what is not and when to recognise procedures that go against general ethical and medical principles.

Electrical conduction system apoptosis in type II diabetes mellitus.

Even though apoptosis is known to be associated with various cardiovascular pathologies, its presence in cardiac nodal tissue in adults was only scarcely researched. Cardiomyocyte apoptosis was associated with diabetic cardiovascular pathology. Our main objective was to test whether programmed cell death is present in nodal tissue in type II diabetes mellitus and, if present to characterize it. The study was designed as a qualitative one. We used autopsy samples of hearts from 10 patients (56 to 73-year-old, 6:4 male to female ratio), positive for type II diabetes mellitus. Samples from sinoatrial and atrioventricular nodes were stained with Hematoxylin-Eosin. For immunohistochemistry, we used primary antibodies for caspases 3 and 9, cathepsin B, and TRADD. Nodal tissue in all samples was characterized by diffuse interstitial fibrosis and chronic ischemic lesions; nuclear damage and foci of irreversible ischemic necrosis intermingled with isles of relatively morphologically normal myocytes. Sinoatrial and atrioventricular nodes were caspase-3 and -9 positive, and also cathepsin-B-positive, suggesting an overlap between apoptotic and necrotic mechanisms. Central area of the sinus node seemed to have the most severe lesions. As a conclusion, nodal apoptosis is present in nodal tissue in type II diabetes mellitus; it involves the intrinsic pathway and associated concomitant and/or post-apoptotic necrosis.

Prehospital trauma care: a clinical review.

INTRODUCTION: There are many controversies related to the trauma patient care during the pre-hospital period nowadays. Due to the heterogeneity of the rescue personnel and variability of protocols used in various countries, the benefit of the prehospital advanced life support on morbidity and mortality has been not established. METHOD: Systematic review of the literature using computer search of the Library of Medicine and the National Institutes of Health International PubMed Medline database using Entre interface.We reviewed the literature in what concerns the basic and advanced life support given to the trauma patients during the prehospital period. RESULTS: Although the organization of the medical emergency system varies from a country to another, the level of patient'scare can be classified into two main categories: Basic Life Support (BLS) and Advanced Life Support (ALS).There are many studies addressing what to be done at the scene.The prehospital care can be divided into two extremes: stay and play/treat then transfer or scoop and run/load and go. CONCLUSIONS: A balance between "scoop and run" and "stay and play" is probably the best approach for trauma patients. The chosen approach should be made according to the mechanism of injury (blunt versus penetrating trauma), distance to the trauma center (urban versus rural) and the available resources.

Telocytes form networks in normal cardiac tissues.

Telocytes (TC) are a class of interstitial cells present in heart. Their characteristic feature is the presence of extremely long and thin prolongations (called telopodes). Therefore, we were interested to see whether or not TCs form networks in normal cardiac tissues, as previously suggested. Autopsy samples of cardiac tissues were obtained from 13 young human cadavers, without identifiable cardiac pathology and with a negative personal history of cardiovascular disease. Immunohistochemistry on formalin-fixed paraffin-embedded tissues was performed using monoclonal antibodies for CD117/c-kit. Additionally, ventricular samples from 5 Sprague-Dawley rats were ultrastructurally evaluated under transmission electron microscopy. We found c-kit positive cells with TC features in subepicardium, as well in subepicardial arteries and in subepicardial fat. TCs were also present in the subendocardium. Light and electron microscopy revealed the existence of intramyocardial networks built up by bipolar TCs. Larger c-kit positive multipolar TCs were found between cardiac muscle bundles. Our results support the existence of a cardiac network of telocytes.

The human trigeminal ganglion: c-kit positive neurons and interstitial cells.

OBJECTIVES: The presence of c-kit positive neurons in sensory ganglia has been verified in various species but not in humans. Our aim has been to identify whether human primary trigeminal neurons label with c-kit/CD117 and thus, whether data gathered in animal studies can be extrapolated to humans. We also intended to establish whether, and which non-neuronal cells also label with c-kit in the trigeminal ganglion. METHODS: Human adult trigeminal ganglia from eight cadavers were processed for immunohistochemistry on paraffin embedded samples using monoclonal antibodies for CD117/c-kit, and three additional trigeminal ganglia were used for transmission electron microscopy (TEM). To evaluate which neuronal type (A or B) was labeled with c-kit, we evaluated the same neurons on adjacent sections labeled with antibodies for neurofilaments (NF). RESULTS: c-kit has labeled trigeminal neurons (TNs), mast cells and interstitial cells (ICs) within the trigeminal ganglion. c-kit+TNs were NF-and thus were strongly presumed to be nociceptive, as such neurons are known to be NF-poor. c-kit+ICs with long and moniliform processes intermingled with the satellite glial cells (SGCs) of the neuronal envelopes. TEM evaluations confirmed this mixed composition of the neuronal envelopes and demonstrated that the perineuronal ICs are in fact interstitial Cajal-like cells (ICLCs) and/or telocytes. CONCLUSIONS: c-kit+TNs were objectified in humans and strongly presumed to be nociceptive. TNs envelopes mostly consist of SGCs, but are also combined with ICLCs/telocytes.

Extrahepatic and intrahepatic human portal interstitial Cajal cells.

Portal interstitial cells of Cajal (PICCs), acting as vascular pacemakers, were previously only identified in nonhumans. Moreover, there is no evidence available about the presence of such cells within the liver. The objective of the study is to evaluate whether or not PICCs are identifiable in humans and, if they are, whether or not they are following the scaffold of portal vein (PV) branches within the liver. We obtained extrahepatic PVs and liver samples from six adult human cadavers, negative for liver disease, in accordance with ethical rules. They were stained with hematoxylin-eosin (HE) and Giemsa, and then we performed immunohistochemistry on formalin-fixed paraffin-embedded specimens for CD117/c-kit, a marker of the Cajal's cells. Immune labeling was also performed for S-100 protein, desmin, glial fibrillary acidic protein (GFAP), neurofilaments, α-smooth muscle actin (α-SMA), and CD34. c-kit-Positive PICCs were identified within the extrahepatic PV, in portal spaces, and septa. On adjacent sections, these PICCs were negative for all the other antibodies used. In conclusion, our study confirms the presence of extrahepatic PICCs on humans, which may act as a possible intrinsic pacemaker in the human PV. However, the intrahepatic PICCs, which were evidenced here for the first time, are in need for further experimental studies to evaluate their functional role. A promising further direction of the study is the PICCs role in the idiopathic portal hypertension.

Can subclinical hypothyroidism explain some sudden deaths due to pulmonary embolism without evident risk factors?

Thyroid pathology is rarely involved in the pathogenesis of sudden death in young people, and usually, when this is the case, is associated with acute changes of thyroid hormone blood levels. Three main thyroid causes of sudden death are known and used in tanathologic chains: thyrotoxicosis, myxedematous coma and, as of recently, lymphocytic thyroid infiltration. Coagulation disorders associated with thyroid disease are usually mild and not associated with sudden death. There are some studies showing an increased risk for unprovoked deep venous thrombosis in patients with hypothyroidism but there is none, to our knowledge, showing a correlation between hypothyroidism, deep venous thrombosis and sudden death. Our article suggests that subclinical hypothyroidism can lead to coagulation disorders and deep venous thrombosis which can explain some cases of sudden death associated with pulmonary embolism without other significant risk factors.

Morphological changes associated with hemodynamically significant myocardial bridges in sudden cardiac death.

UNLABELLED: Although myocardial bridging (MB) is a common coronary anomaly, its cardiovascular consequences are still disputed. A positive link between sudden cardiac death (SCD) and myocardial bridging has not yet been definitively proved, even though many case reports and small scale studies support this association. For myocardial bridging to be associated with sudden cardiac death it must exhibit certain specific characteristics involving coronary or myocardial changes sufficient to explain a terminal cardiac event. In this study we aimed to analyze the morphological changes (both myocardial and coronary) associated with hemodynamically significant myocardial bridging and the morphological differences between hemodynamically significant MB and MB considered to be non-hemodynamically significant. MATERIAL AND METHOD: We analyzed 53 cases of sudden cardiac death, of which 21 cases had hemodynamically significant myocardial bridging, 14 had non-hemodynamically significant myocardial bridging and 20 cases suffered sudden cardiac death without myocardial bridging, using a morphological score with seven histological parameters. RESULTS: Myocardial fibrosis and interstitial edema were found to be highly correlated with hemodynamically significant myocardial bridging (HSMB), as were interstitial edema and interstitial fibrosis. CONCLUSIONS: Hemodynamically significant myocardial bridging can be discovered during heart dissection by analyzing a series of morphological markers (width, distribution of atherosclerosis, distal hypoplasia). Our study showed that MB was associated with increased myocardial fibrosis and edema, both of which have an increased risk of electrical instability. Compared to non-hemodynamically significant myocardial bridging, HSMB shows a distinct histological pattern, with increased myocardial fibrosis and edema. The main cause of SCD in association with HSMB seems to be electrical due to increased electrical myocardial heterogeneity, but large scale studies are needed to test this.