Anatomical variations of coronary ostia, aortocoronary angles and angles of division of the left coronary artery of the human heart.

Classic anatomical dissection of 150 heart specimens from adults aged 18 - 80 years was performed. Anatomical variations were studied in: (i) the position of the ostium of the left coronary artery; (ii) the angle between the proximal segment of the left coronary artery and the longitudinal axis of the aorta and between the circumflex and the anterior descending branches; (iii) the angle between the anterior descending artery and the diagonal branches, and between the diagonal and circumflex branches in trifurcation of the left coronary artery; (iv) the position of the ostium of the right coronary artery in the right coronary sinus of Valsalva; (v) the angle between the initial part of the right coronary artery and the longitudinal axis of the aorta; and (vi) the position of the initial part of the left coronary artery relative to the coronary groove. Knowledge of and the ability to recognize and identify the variety of sites of origin of coronary arteries, aortocoronary angles and angles of division of the left coronary artery of the human heart may help to overcome potential difficulties in cardiosurgical procedures, such as aortic valve replacement and reinsertion of coronary arteries.

Anatomical aspects of the arterial blood supply to the sinoatrial and atrioventricular nodes of the human heart.

Classic anatomical dissection of 150 hearts from adults aged 18 - 80 years was performed. The sinoatrial (SA) node artery was most frequently a large atrial branch of the right coronary artery (63%), arising at a mean distance of 1.2 cm (range 0.2 - 2.2 cm) from its beginning, with a mean external diameter of 1.7 mm (range 1 - 3 mm). In 37% of cases the SA node artery was a branch of the left coronary artery or one of its branches, with an initial mean external diameter of 2.2 mm (range 2 - 3 mm). The origin of the SA node artery was not related to coronary arterial dominance. The atrioventricular (AV) node artery was the first and longest inferior septal perforating branch of the right (90%) or left (10%) coronary artery, arising from the U- or V-shaped segment of the corresponding artery at the level of the crux cordis. Mean external diameter was 2 mm (range 1 - 3.5 mm). The origin of the AV node artery was dependent on coronary arterial dominance. Identification of the anatomical variants of the arterial blood supply to the SA and AV nodes may help in overcoming potential difficulties in treating arrhythmias and in mitral valve surgery.

Anatomical variations of the coronary sinus ostium area of the human heart.

Classic anatomical dissection of 150 heart specimens from adults aged 18 - 80 years was performed. The Thebesian valve was absent in 20% of cases and, in these, 4% had a large ostial valve of the middle cardiac vein in front of the coronary sinus ostium. Fibres of Chiari were found in 10% of cases. Ostia of the middle cardiac vein, posterior veins of the left ventricle, small cardiac vein and deep cardiac veins were present in the distal 10 mm of the coronary sinus. Some samples had ostial and/or parietal valves or antivalves that sometimes contained muscular fibres. Distal accessory parietal valves (2%) and antivalves (1%) of the coronary sinus wall were found at a distance of 4 - 7 mm from its ostium. The frequency and variability of anatomical structures in the area of the coronary sinus ostium probably influence the haemodynamics of this area. Knowledge of and being able to identify these anatomical variations may help in identifying and overcoming potential difficulties in treating arrythmias and in cardiosurgery.

Morphometric analysis of mandibular canal: clinical aspects.

Results of morphometric analysis of the mandibular canal (MC), carried out on 105 conserved mandibles, 70 being dentate and 35 edentate, was performed. The analysis was carried out on consecutive sections, at mutual intervals of 0.5 cm. In the mandibular ramus sections were carried out obliquely, approximately in the frontal plane, and horizontally, from mandibular foramen to the lowest region of the vertical part of the MC (all together two sections). In the mandibular corpus, consecutive transversal sections were carried out between existing teeth, or at mutual intervals of 0.5 cm in edentate regions. The obtained results pointed out the very close relationship between the MC and lingual cortical plate of the mandibular ramus. In its horizontal part, the average diameter of the MC was 2.6 mm. It was situated more lingually in the molar region; towards the front, it approached the vestibular cortical plate, being closest to it in the region of the second premolar. Similar relationships of the MC and both cortical plates existed in edentate jaws. Relationships of the MC and tooth root apices varied; however, the MC was closest to the apices of the third molar. Mesially from the mental foramen, a clearly defined incisive canal was present in 92% of the dentale mandibles, but only in 31% of the edentate ones. The nearest to the incisive canal was the apex of the first premolar. The authors point out the importance of presented results in everyday practice, especially in oral and maxillofacial surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

[The bone structure of the ramus of the mandible]. / La structure osseuse de la branche montante de la mandibule.

Osseous structure of the ramus of mandible (RM) is of a practical clinical significance. Osteosynthesis of fractured segments and the success of the sagittal or the horizontal ramus split osteotomy depends on the cortical bone disposition and thickness. After morphometric investigations of the RM, conducted on 70 mandibles of adults, consecutive horizontal and frontal sections were made. On these sections, the cortical layer was studied and the cortical bone thickness was measured at four previously marked points. In the regard of morphometry, the significant datum is that nearly half of all the cases is grouped round the mean value of any parameter. Cortical bone is continuous and its two main sheets are the buccal and the lingual cortical plates. In its entirety, the buccal cortical plate is thicker than the lingual. The thickness of both cortical plates increases in the direction from the coronoid process to the angle of mandible.

The great cardiac vein.

The great cardiac vein is the longest venous vessel of the heart; in the majority of our cases it originated at the lower third of the anterior interventricular sulcus (58%). The great and the middle cardiac veins merge at the apex of the heart, forming together with the coronary sinus into which they both empty, a complete venous ring around the left ventricle (13%). On reaching the area of the coronary sulcus, the great cardiac vein crosses the anterior interventricular branch and the circumflex branch of the left coronary artery forming the triangle of Brocq and Mouchet in which the vein is mainly superficial (61%). One, two or three anterior ventricular branches of the left coronary artery traverse this triangle; the relations of the vein and these arteries are very variable and practically unpredictable in 30% of the cases.

[The relations of the mandibular canal with the outer surfaces of the body of the mandible and the risks which arise from its injury]. / Les rapports du canal mandibulaire avec les faces externes du corps de la mandibule et risques qui en découlent de le léser.

The investigations of relations and position of the mandibular canal (CM) were carried out on 80 mandibles (33 dentulous, 27 partly edentulous and 20 completely edentulous). The studies of relations of CM to the sides of mandibular body were accomplished by morphometric analysis of CM on consecutive transversal sections of mandibular body (54 preparations). The relation of the CM to be buccal or to the lingual side is expressed as the distance from the surface of the correspondent side of the mandibular body, which is shown in Table 1. According to these data, the position of the canal is at first proximate to the lingual side, and from the first molar tooth (M1) it approaches the buccal surface of the mandibular body. The position of the entire CM was determined by analysis of mandibular preparations (26) after removing the buccal osseous lamina. These investigations revealed that the position of the CM is predominantly buccal. Reconstruction of relations of the CM to the sides of mandibular body, according to the data obtained from transversal sections, and the real position of the CM are presented in Scheme I. The difference in direction lines of relations and of predominant position of the CM is a consequence of morphological characteristics of mandibular body.

[Ostium of the collection stem of the anterior cardiac veins (vv. cardiacae anteriores) in the vena cava, inferior]. / L'orifice du tronc collecteur des veines cardiaques antérieures (vv. cardiacae anteriores) dans la veine cave inférieure.

In 1 of 150 studied cases, we found the collection stem of anterior cardiac veins that emptied into the inferior vena cava. This collection stem had eight tributaries: two right atrial veins, five anterior cardiac veins and a right marginal vein. The caliber of the collection stem was increasing gradually from its beginning (2.8 mm) to its orifice (4.5 mm). The orifice of the collection stem was in the inferior vena cava, at a distance of 10 mm from its ostial valve, and was itself provided with a semilunar valve.