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At least 127 records · Page 7Linked to original sources
PubMed1999

The iliopubic tract: an important anatomical landmark in surgery.

A band of fascial thickening, termed the iliopubic tract, lies on the posterior aspect of the inguinal region and has been described in the surgical literature as playing an important role during herniorraphy. This study was undertaken to examine the gross and microscopic anatomy of the iliopubic tract in 12 cadavers. The results confirmed that the iliopubic tract can be readily identified as a thickening of the transversalis fascia running deep and parallel to the inguinal ligament. It attaches to the superomedial part of the pubic bone medially, but laterally its fibres fan out within the fascia transversalis and fascia iliaca without bony attachment to the iliac spines. In contrast to the inguinal ligament, the histological analysis of the iliopubic tract shows a high elastin to collagen ratio. The functional significance of this structure merits further study, but there is no doubt that it is important in many approaches to inguinal herniorraphy. For this reason it is considered that the iliopubic tract deserves greater emphasis in the anatomy teaching of the inguinal region.

Aged↗
PubMed2000

Inter-examiner and intra-examiner agreement for assessing sacroiliac anatomical landmarks using palpation and observation: pilot study.

Despite the paucity of research into the reliability of static palpation, it is still employed extensively as a diagnostic tool by manual medicine practitioners. This study tested the inter- and intra-examiner agreement of ten senior osteopathic students using static palpation on ten asymptomatic subjects. Four assessments of the posterior superior iliac spine (PSIS), sacral sulcus (SS), and the sacral inferior lateral angle (SILA) on every subject by all examiners resulted in 1200 assessments in total. Kappa (Kg) yielded intra-examiner agreement that ranged between less-than-chance to substantial for the SILA (Kg=-0.05 to 0.69; mean Kg=0.21), and slight to moderate for the PSIS (Kg=0.07 to 0.58; mean Kg=0.33) and the SS (Kg=0.02 to Kg=0.60; mean Kg=0.24), with 50% significant beyond the 0.05 level. Inter-examiner agreement was slight (PSIS Kg=0.04; SILA Kg=0.08; SS Kg=0.07) and significant at the 0.01 level. Intra-examiner agreement was greater than inter-examiner agreement, which was consistent with existing palpation reliability studies. The poor reliability of clinical tests involving palpation may be partially explained by error in landmark location.

Adolescent↗
PubMedDate not supplied

An anatomical landmark for the supplementary eye fields in human revealed with functional magnetic resonance imaging.

Together with the frontal and parietal eye fields, the supplementary eye field (SEF) is involved in the performance and control of voluntary and reflexive saccades and of ocular pursuit. This region was first described in non-human primates and is rather well localized on the dorsal surface of the medial frontal cortex. In humans the site of the SEF is still ill-defined. Functional imaging techniques have allowed investigation of the location and function of the SEF. However, there is great variability with regard to the published standardized coordinates of this area. We used here the spatial precision of functional magnetic resonance imaging (fMRI) in order to better localize the SEF in individuals. We identified as the SEF a region on the medial wall that was significantly activated when subjects executed self-paced horizontal saccades in darkness as compared to rest. This region appeared to be predominantly activated in the left hemisphere. We found that, despite a discrepancy of >2 cm found in the standardized Talairach coordinates, the location of this SEF-region could be precisely and reliably described by referring to a sulcal landmark found in each individual: the upper part of the paracentral sulcus.

Adult↗
PubMed2004

Morphological measurements of anatomic landmarks in human maxillary and mandibular molar pulp chambers.

The aim of this in vitro study was to measure critical morphology of molar pulp chambers. One hundred random human maxillary and mandibular molars (200 teeth in total) were used. Each molar was radiographed mesiodistally on a millimeter grid. Using a stereomicroscope, the measurements were read to the nearest 0.5 mm. Results were as follows (mean, mm): pulp chamber floor to furcation, maxillary = 3.05 +/- 0.79, mandibular = 2.96 +/- 0.78; pulp chamber ceiling to furcation, maxillary = 4.91 +/- 1.06, mandibular = 4.55 +/- 0.91; buccal cusp to furcation, maxillary = 11.15 +/- 1.21, mandibular = 10.90 +/- 1.21; buccal cusp to pulp chamber floor, maxillary = 8.08 +/- 0.88, mandibular = 7.95 +/- 0.79; buccal cusp to pulp chamber ceiling, maxillary = 6.24 +/- 0.88, mandibular = 6.36 +/- 0.93; and pulp chamber height, maxillary = 1.88 +/- 0.69, mandibular = 1.57 +/- 0.68. The pulp chamber ceiling was at the level of the cementoenamel junction in maxillary, 98%, and mandibular, 97% of the specimens. The measurements showing the lowest percentage variance were buccal cusp to furcation (approximately 11%) and buccal cusp to pulp chamber ceiling (approximately 14%). The measurements were similar for both maxillary and mandibular molars.

Dental Pulp Cavity↗
PubMed2006

Regional differences in anatomical landmarks for placing anterior instrumentation of the thoracic spine in both normal patients and patients with adolescent idiopathic scoliosis.

STUDY DESIGN: A retrospective analysis of patients who had magnetic resonance imaging (MRI) of the thoracic spine, comparing those with a normal straight spine and those with a right thoracic adolescent idiopathic scoliosis (AIS). OBJECTIVE: To analyze the position of the rib head with respect to the spinal canal and vertebral body in normal patients and those with right thoracic AIS using MRI. SUMMARY OF BACKGROUND DATA: When placing anterior vertebral body screws in thoracic AIS, the most cephalad screws are most at risk for loosening because of smaller vertebral body size and the position of the rib heads, which may obscure more of the vertebral bodies. To our knowledge, there are no studies defining the relationship of the rib head to the vertebral anatomy in thoracic AIS. METHODS: Transverse MRIs of the vertebral bodies from the 4th thoracic (T4) vertebra to the 12th thoracic (T12) vertebra in normal patients (n = 21) and patients with AIS (n = 21) group were analyzed regarding the following parameters: (1) percent vertebra obscured by rib head (i.e., the percent of the sagittal plane vertebral body length obscured by the overlapping rib head); (2) posterior safe angle, defined as the most posterior angle a screw can be placed, which avoids the spinal canal; and (3) anterior safe angle, defined as the most anteriorly directed screw trajectory that safely obtained good screw purchase. RESULTS: In both the normal and AIS groups, the percent vertebra obscured by rib head significantly decreased from T4 (30% in normal group and 34.7% in AIS group) to T12 (-0.4% in normal group and 3.5% in AIS group) (P < 0.05). The rib head was positioned more anterior to the vertebral body in the cephalad-thoracic spine when compared to a more posterior position in the caudal thoracic spine. In each group, the posterior safe angle significantly decreased from T4 (23 degrees in normal group and 20.8 degrees in AIS group) to T12 (-0.9 degrees in normal group and 2.1 degrees in AIS group) (P < 0.05), while the anterior safe angle significantly increased from T4 (27.5 degrees in normal group and 26.6 degrees in AIS group) to T12 (38.3 degrees in normal group and 38.5 degrees in AIS group) (P < 0.05). CONCLUSIONS: It is important to understand the relationship of the rib head to the vertebral body to provide-excellent screw purchase within the vertebral body without risking penetration into the spinal canal. In both normal and AIS groups, the relationship of the rib head to the vertebral body and spinal canal changes so that the rib head is positioned more anteriorly in the cephalad-thoracic spine and more posteriorly in the caudal thoracic spine. When placing anterior thoracic screws, at the cephalad- thoracic spine (T4, T5, T6, and T7), removal of rib heads is recommended to allow for good screw purchase. However, at the caudal thoracic spine (T10-T12), staying anterior to the rib head is important to avoid penetration into the spinal canal.

Adolescent↗
PubMed2005

Morphological measurements of anatomic landmarks in pulp chambers of human maxillary furcated bicuspids.

The aim of this in vitro study was to measure key morphological features of pulp chambers from furcated maxillary bicuspid teeth. There were 107 random human maxillary bicuspid teeth used. Each bicuspid was radiographed using the Trophy RVG digital imaging system and a Belmont Acuray X-ray at 70 kVp. Measurements were made using the Digipan measuring mode of the Trophy system. Results were mean (mm): pulp chamber floor to furcation: 1.85 +/- 0.85; pulp chamber ceiling to furcation: 4.61 +/- 1.04; cusp to furcation: 11.55 +/- 1.12; cusp to pulp chamber ceiling: 6.94 +/- 0.70; pulp chamber height: 2.76 +/- 0.97. The measurements showing the lowest percentage variance were: cusp to furcation (9.70%) and cusp to pulp chamber ceiling (10.09%). The only measurement that was statistically the same across maxillary molars, mandibular molars and bicuspids was measurement "B," pulp chamber ceiling to furcation. The critical distance from cusp tip to pulp chamber ceiling in bicuspids was approximately 7.00 mm.

Analysis of Variance↗
PubMed2005

The evaluation of vertical heights of maxillary and mandibular bones and the location of anatomic landmarks in panoramic radiographs of edentulous patients for implant dentistry.

The purpose of this study was to determine variations in the vertical height measurements in the edentulous maxilla and mandible, and to assess positions of the maxillary sinus, mandibular foramen, and the mandibular canal, which are important for implant length selection and planning using panoramic radiographs. The study sample included 346 edentulous alveolar ridges of 90 men and 83 women. Sixty-three dentate patients' panoramic radiographs were used for location of the first premolar and molar area. Panoramic radiographs were made with a Siemens Orthophos panoramic machine which had been standardized previously. All radiographs were made using a standardized manner by the same technician. Fourteen sites were measured on every panoramic radiograph whenever possible, eight sites in the maxilla and six sites in the mandible. Correlation analyses were performed between age groups and all measurements to determine if age is significant as a covariate. In order to examine the effect of gender the statistical analysis of differences between men and women was performed with Student t-test. The 5% significance level was used for statistical significancy. The height of the maxilla and the mandible in the anterior, first premolar, and first molar regions were significantly greater in men than in women. A majority of the most inferior border of the maxillary sinuses was located anterior to the first molar area (premolar regions) both in men (48.9%) and women (55.4%). Although, there was no statistically significant difference between edentulous men and women for the vertical distances from the mental foramen to the alveolar crest, and horizontal distances from mental foramen to midline, there were statistically significant differences between edentulous men and edentulous women for the vertical distances from the upper border of the mandibular canal to the alveolar crest in the first molar area. Mental foramens were located at the crest of the ridge in 7.2% of the edentulous women, and 6.7% of the edentulous men. The results of this study may guide clinicians to make primer decision of implant insertion area for implant supported prosthesis in edentulous patients.

Adult↗
PubMed1983

The fetal hippocampus. A possible pitfall and a useful anatomical landmark in evaluation of the biparietal diameter.

A well-demarcated hypoechoic region was seen just lateral to the collicular plate during measurement of the fetal biparietal diameter (BPD) in 101 (70%) of 144 ultrasound examinations and confirmed on postmortem sonographic water-bath studies of fetal brains. This structure was found to represent the hippocampus, with its lateral border formed by the trigone of the lateral ventricle. It should not be confused with an abnormal entity such as a ventricular cyst. Recognition of this hypoechoic region in conjunction with previously described structures is a useful method of obtaining consistent BPD measurements.

Cephalometry↗
PubMed1996

Comparison of portal vein anatomy and bony anatomic landmarks.

PURPOSE: To determine if a relationship exists between the right portal trunk (RPT) and bony structures that might aid guidance of needle passes into the RPT during transjugular intrahepatic portosystemic shunt (TIPS) placement. MATERIALS AND METHODS: Sixty-two TIPS portal venograms were reviewed. The distance of the mid-RPT from the lateral margin of the vertebral column was measured and calculated as a fraction of the adjacent vertebral body width. The cephalocaudal height of the RPT was compared with that of the posterior ribs and rib spaces. The cephalocaudal height was evaluated with frequency distribution, and scattergram plots were used to determine the most common location of the mid-RPT relative to bony structures. The height and lateral position were analyzed in relation to clinical parameters to determine the effect of these parameters on RPT position. RESULTS: The mean distance of the mid-RPT from the lateral vertebral margin was 0.9 vertebral widths (range, 0.1-1.5). Fifty-six of 62 (90%) mid-RPTs were between 0.5 and 1.5 vertebral widths to the right of the lateral margin of the vertebrae. Fifty-four of 62 (87%) mid-RPTs were below the 10th and above the 12th ribs. Clinical factors did not affect RPT position. CONCLUSION: Bony landmarks provide an approximation of the mid-RPT location and may aid in TIPS placement.

Adult↗