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Successful closed transatrial coronary sinus cannulation is dependent on a proper catheter insertion site and proper catheter direction. Accurate anatomic landmarks are described to provide a reproducible cannulation site and catheter direction. This results in consistent successful cannulation of the coronary sinus.
The radial artery was proposed and then abandoned as a coronary artery bypass graft in the 1970s. Development of new pharmacologic antispasmodic agents and minimally traumatic harvesting techniques has led to a revival of the use of the radial artery in coronary artery bypass procedures. Unlike the saphenous vein in the lower extremities, the radial artery in the volar forearm is not a subcutaneous structure. Safe harvest of the artery requires an understanding of volar forearm anatomy. Based on review of anatomy, cadaver dissection, and clinical experience with 40 patients, we have developed a technique for radial artery harvest. The volar forearm is divided into three zones: the proximal zone, the middle zone, and the distal zone. In each zone, important anatomic landmarks are identified. Our harvesting technique has resulted in minimal postoperative morbidity and no postoperative ischemic complications. Although the pedicled internal thoracic artery graft remains the primary arterial conduit for myocardial revascularization, the radial artery is an excellent additional bypass conduit.
Transverse sections of postnatal rat spinal cord have been cultured using the organotypic roller tube method. These explant cultures retain identifiable anatomical landmarks, allow identification of individual neurons, can be maintained for up to 8 weeks, and undergo maturational changes in vitro. Putative ventral horn motoneurons were identified in these cultures by localization to ventral horn regions analogous to those of motoneurons in vivo and by staining for choline acetyltransferase (ChAT) immunoreactivity and acetylcholinesterase (AChE) activity. Morphometric studies of the photomicrographic areas of cell bodies of these ventral horn neurons in intact cultures show a range of sizes up to 1635 microns 2 with the average size being 245 +/- 7 microns 2 (n = 724) (average +/- S.E.M.). The size ranges are roughly comparable to cross-sectional areas determined previously for ventral horn motoneurons in vivo. Dorsal horn regions of these cultures also developed prominent AChE activity that was absent at explantation. Biochemical analysis of ChAT and AChE activity in pooled samples of whole cultures showed ChAT activity to be 0.48 +/- 0.08 (n = 7) mumol/min/g protein and AChE activity to be 12.2 +/- 2.0 (n = 7) mumol/min/g protein at 37 degrees C (averages +/- S.E.M.). These values are comparable to previously reported values for neonatal rat spinal cord in situ. Organotypic roller tube cultures of postnatal rat spinal cord provide an attractive system for studies of survival, morphology, growth and differentiation of mammalian ventral horn neurons in vitro.
This report describes an integrated anatomical, electrophysiological and data management system for presenting cortical surface distribution maps. Approximately equal area projections (lateral and top) were constructed from a cross-sectional whole head atlas. Anatomical landmarks (major sulcus and gyrus locations) were also located on the outline. The outline and weights for interpolation are stored in the computer, with software for map generation directly from multilead EEG or evoked potential data. Electrode position and number can be easily varied and mapped onto any shaped space using the same program. Data derived from other sources such as xenon blood flow, brain scans or positron emission tomography can similarly be presented. The program uses a laboratory computer and emphasizes simplicity of data management and a mapping algorithm which is applicable to many forms of data.
Changes in spinal posture between the erect and flexed positions were calculated using angular measurements from lateral photographs and radiographs of ten adult male subjects. For photographic measurements, the thoracolumbar vertebral column was modelled as either a single segment or as three segments. In the three-segment model, there was a non-significant correlation between the decrease in lumbar concavity and intervertebral motion. In addition, there was a non-significant negative correlation between the increase in thoracic convexity and lumbar motion determined radiographically. In the single-segment model, the decrease in angulation between the thoracolumbar spine and pelvis was a good representation of lumbar spine flexion as determined by the mean lumbar intervertebral angular change. Therefore, modelling the thoracolumbar vertebral column as a single segment allowed better estimation of lumbar intervertebral angular change during flexion than a three-segment model. The results indicate that large range dynamic motion of the lumbar vertebral column can be represented using photographic analysis of the positions of three easily identified anatomical landmarks: the anterior superior iliac spine, posterior superior iliac spine and the spinous process of the first thoracic vertebra.
Dynamic changes in the geometric shape and dimensions of a left coronary artery tree were extracted from the computer-tomographically reconstructed three-dimensional images of an in situ beating heart of an anesthetized dog. Wireframe models of the left coronary artery tree at 16 different instants of a cardiac cycle were constructed for the study of its flexing motion. For quantifying the local bending and twisting of the left coronary artery tree, the anatomic landmarks of the bifurcation points are selected as focussed locations. At these points, the space curves of the tree at different cardiac instants were first derived in parametric forms. Curvature and torsion expressions are next obtained in terms of the derivatives with respect to the parameter. This analysis revealed that during the initial contraction of the heart wall, a 2% reduction per millisecond in the radius of curvature occurred near the bifurcation point where the left circumflex coronary artery descends toward the apex of the heart. When the left ventricular chamber reached a maximum value, the radius of curvature was found to decrease at a rate of 2.3% ms-1. At the end of diastole, an increase in the radius of curvature at a rate of 5.7% ms-1 was observed. The twisting rates per unit length of artery near the bifurcation point of the selected artery were found to range from -0.62 to 0.63 degrees ms-1.
A model of left ventricular (LV) kinematics is essential to identify the fundamental physiological modes of LV deformation during a complete cardiac cycle as observed from the motion of a finite number of markers embedded in the LV wall. Kinematics can be described by a number of modes of motion and deformation in succession. An obvious mode of LV deformation is the ejection of cavity volume while the wall thickens. In the more sophisticated model of LV kinematics developed here, seven time-dependent parameters were used to describe not only volume change but also torsion and shape changes throughout the cardiac cycle. Rigid-body motion required another six parameters. The kinematic model employed a deformation field that had no singularities within the myocardium, and all parameters describing the modes of deformation were dimensionless. Note that torsion, volume and symmetric shape changes all require the definition of a cardiac coordinate system, which has generally been related to the measured cardiac geometry by reference to approximate anatomical landmarks. However, in the present study the coordinate system was positioned objectively by a least-squares fit of the kinematic model to the measured motion of markers. Theoretically, at least five markers are needed to find a unique set of parameters.(ABSTRACT TRUNCATED AT 250 WORDS)
Tensorial morphometric assessments of form difference can aid in the understanding of the cause of the form difference by providing reference frame independent, anisotropic, non-homogenous descriptions. The majority of biological and prosthetic structures cannot be adequately analyzed by current methods due to the paucity of anatomical landmarks and methodological requirements of subdivision through the domain. Internal subdivisions can be eliminated with the boundary element method (BEM). A non-landmark (NL) method can be developed by the combination of elliptical Fourier analysis (EFA) and BEM. The appropriateness of NL and BEM was investigated. The growth of the female rat neural skull from 7 to 14 postnatal days was calculated with respect to increase in area. Linear and quadratic BEM landmark analysis were made using 10 and 5 elements, respectively. Five hundred linear BEM elements were constructed from the EFA equations for NL. The form change tensors were obtained by the solution of the Laplace equation using boundary displacements as the essential boundary conditions. For comparison, simplex triangular finite element analysis (FEA), quadrilateral FEA and macroelement analysis were made on the same structure. Results correspond well to the two major growth process in this time period; (1) high cerebellar growth, and (2) relatively higher facial versus neural growth. The results in other regions are close to the biologically observed 36% increase in area. The average difference between BEM, NL versus FEA is 1.9 and 2.8%. Trends in results with position are almost identical for BEM, NL, MEM and quadrilateral FEA. The morphometric landmark BEM technique requires an additional numerical scheme to eliminate the singularities near the boundary.(ABSTRACT TRUNCATED AT 250 WORDS)
Completed dentures should demonstrate the beneficial effects of an ordered, disciplined approach to the "try-in" appointment. The proposed design of the trial dentures for this appointment allows accurate verification of spatial positions, and easy access to changes in position and arrangement of the teeth. Two phases of the verification appointment should be recognized: laboratory and clinical. In the laboratory phase, the teeth are arranged according to anatomic landmarks, and the trial denture is designed to allow accurate verification of previous records. In the clinical phase, the intermaxillary dimensions are verified or corrected, and the teeth are rearranged for support of the lips and optimal esthetics. The design permits simple and effective changes in the spatial position of the teeth. When the try-in or verification appointment is carefully planned and the list of verification checks made in a disciplined and orderly manner, this appointment can progress to a meaningful and predictable conclusion.
A investigation of 64 Angle Class I, skeletal Class I dental students showed that the interalar nasal width is a reliable guide for selecting the mold of anterior teeth, and that the incisive papilla provides a stable anatomic landmark for arranging the labial surfaces of the central incisors at 10 mm anterior to the posterior border of the papilla. The mesiodistal width of the set of anterior teeth (four incisor and the mesial halves of the canines) should be determined by adding 7 mm to the patient's nasal width (Fig. 8). The tips of canines on the horizontal plane, should be set on a line which passes through the posterior border of the incisive papilla (Fig. 9). The distance between them should equal the patient's nasal width, so that from the frontal view they would each seem to lie on a perpendicular line drawn from each of ala of the nose (Fig. 6).
The positions that the maxillary right and left first molars occupy when a maxillary cast is mounted in the three-dimensional space of a semiadjustable articulator (Hanau H2) were studied. Mountings were made by using four face-bows, the Hanau Kinematic Face-bow, the Hanau Facia-bow, the Hanau 159 Earpiece Face-bow, and the Hanau Twirl Earpiece Face-bow. A kinematically determined hinge-axis was used arbitrarily as the baseline for comparisons among the three other bows. Deviations from the baseline were measured along the X, Y, and Z axes by using a contour meter (Fig. 1). The deviations showed great variability (Table I), and because maxillary casts are mounted in relation to anatomic landmarks that differ from subject to subject, it was not possible to establish clinical superiority of one face-bow over another.
The positioning of denture teeth in a completely edentulous patient is dependent on many factors. Anatomic landmarks are frequently valuable in complete denture fabrication. The topography of the palatal soft tissue in relationship to tooth position in dentate patients may be an aid in the placement of denture teeth. By using casts formed from irreversible hydrocolloid impressions, 50 subjects were examined to determine the orthographic distance from the posterior of the incisive papilla to a line intersecting the distal contact points of the maxillary canines. In 92% of subjects the posterior point of the incisive papilla was approximately 3 mm anterior to the line between the distal points of the canines. Neither gender, age, nor maxillary tooth arch form affected this distance.
A photographic technique was used to measure anatomic landmarks located on dental casts. The relationship of the maxillary anterior teeth to the incisive papilla in a Southern Chinese population living in Hong Kong was studied. The distances from the labial surface of the central incisors to the midpoint and the posterior border of the incisive papilla were measured. The area on the incisive papilla where the intercanine line crossed was noted. The data obtained were compared with those from previous studies of Caucasians. Results show that there is little difference between the Southern Chinese in this study and most other ethnic groups. The guidelines that use the incisive papilla as a reference for the setting of artificial teeth in denture construction recommended for Caucasians can be applied to Southern Chinese patients.
A procedure for placing a crush lesion in the sciatic and tibial nerve of the rat based on anatomical landmarks is described. These crush lesions are used to study the process of regeneration of peripheral nervous tissue and the beneficial effects of melanocortins on speed and quality of nerve regeneration. A new precise and rapid method for testing the return of sensory function by a locally applied electric stimulus is discussed.
The human brain and the brains of most mammals studied for this purpose demonstrate hemispheric asymmetry of gross anatomical landmarks and/or architectonic cortical subdivisions. The magnitude as well as the direction of these cortical asymmetries vary among individuals, and in some species there exist significant population directional biases. The magnitude, if not the direction, of cortical asymmetry is found to predict for relative numbers of neurons comprising a given pair of hemispheric architectonic homologues such that the more asymmetric the region is, the smaller the number of neurons. Similarly, the more asymmetric a region is, the smaller the density of interhemispheric connections and (probably) the greater the density of intrahemispheric connections. Developmentally, the decrease in the number of neurons characterizing the more asymmetrical regions appears to reflect mainly increased unilateral ontogenetic cell loss, and diminished callosal connectivity might signify increased developmental axonal pruning. These relationships between cell numbers, callosal connections, and presumed intrahemispheric relationships can be entertained to explain variability in anatomo-clinical correlations for language function and aphasia between left- and right-handers and men and women.
Herein is presented the first case of balanitis xerotica obliterans treated successfully by carbon dioxide-continuous wave (CW-CO2) laser vaporization. This method appears to be a safe addition to other well-known treatment modalities, offering minimal postoperative discomfort, preservation of anatomic landmarks and function, and excellent cosmetic results.
Ultrasound technology has not been used extensively in the study of normal and abnormal oral physiology and speech. Features such as soft tissue detail, real-time motion display, and subject safety make ultrasound ideal for imaging the tongue and the floor of the mouth. This study demonstrates visualization of the muscles of the tongue and floor of the mouth for a normal subject using ultrasound imaging. By employing submandibular transducer placement of realtime sector scanners, tongue anatomy and motion were continuously visualized in sagittal or coronal planes. In addition to the entire tongue surface, much of the intrinsic anatomy was identified including: the genioglossus, geniohyoid, mylohyoid, and digastric muscles; fascial boundaries such as the median fibrous septum, floor intermuscular septum, and paramedian septums; and the hyoid bone. A tongue excised from a human cadaver was scanned using ultrasound and dissected to confirm the anatomy seen in the live tongue. Tongue surface shape and configuration of the intrinsic tissue structures were observed and compared for the phonemes /k/, /u/, and /i/. Anatomical landmarks in the resting and speaking tongue are discussed as well as applications in the fields of speech science and speech pathology.
The intersegmental loads transmitted by the proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints of the index finger are presented in activities involving application of a twisting moment by the hand. Twenty normal subjects, ten males and ten females were included in the studies. A six component load transducer was incorporated in each of the two fixtures representing a water tap and a jar cap 70mm in diameter and the maximal loading on the fingers was monitered in applying an isometric twisting moment to these structures. Two different hand configurations were studied for each activity: the spatial position and orientation of the finger segments were determined using two orthogonally positioned still cameras, and specially designed stick markers were utilized to highlight anatomical landmarks. The results confirm the use of the finger in a complex three-dimensional manner with no significant differences between the male and female subjects. Forces recorded in the jar cap activity were larger than those applied in the tap activity, the maximum being around 100 N and in general the abduction/adduction moments developed at both joints were of comparable magnitude to flexion/extension. Torques as high as 0.6 Nm and 1.0 Nm were calculated at the PIP and MCP joints respectively.