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Background: The supraspinatus muscle, one of the four rotator cuff muscles, initiates abduction of the arm, simultaneously stretching the articular capsule at the glenohumeral joint, and also contributes to exorotation of the arm. In the present study we aimed to evaluate the age-specific normative values for morphometric parameters of the supraspinatus muscle in human fetuses at varying ages and to elaborate their growth models. Materials and methods: Using anatomical dissection, digital image analysis (NIS Elements AR 3.0) and statistics (Student’s t-test, regression analysis), the length, width, circumference and projection surface area of the supraspinatus muscle were measured in 34 human fetuses of both sexes (16 males, 18 females) aged 18–30 weeks of gestation. Results: Neither sex nor laterality differences were found in numerical data of the supraspinatus muscle. In the supraspinatus muscle its length and projection surface area increased logarithmically, while its width and circumference grew proportionately to gestational age. The following growth models of the supraspinatus muscle were established: y = –71.382 + 30.972 × ln(Age) ± 0.565 for length, y = –2.988 + 0.386 × Age ± 0.168 for greatest width (perpendicular to superior angle of scapula), y = –1.899 + 0.240 × Age ± 0.078 for width perpendicular to the scapular notch, y = –19.7016 + 3.381 × Age ± 2.036 for circumference, and y = –721.769 + 266.141 × ln(Age) ± 6.170 for projection surface area. Conclusions: The supraspinatus muscle reveals neither sex nor laterality differences in its size. The supraspinatus muscle grows logarithmically with reference to its length and projection surface area, and proportionately with respect to its width and circumference. [ABSTRACT FROM AUTHOR]

Background: In the present study we aimed to quantitatively evaluate the growth of the psoas major in human fetuses., Materials and Methods: Using anatomical dissection, digital-image analysis (NIS Elements AR 3.0), volumetric hydrostatic method, and statistical analysis (Student's t-test, regression analysis), the 10 direct morphometric parameters (4 lengths, 2 widths, 3 projection surface areas, and volume) of the psoas major were evaluated, and then the 5 morphometric indexes (belly width-to-length ratio, tendon width-to-length ratio, belly-to-muscle projection surface area ratio, tendon-to-muscle projection surface area ratio, and tendon-to-belly projection surface area ratio) were calculated in 67 human fetuses of both sexes (31♂, 36♀) aged 16-28 weeks., Results: Neither male-female nor right-left significant differences were found in relation to numerical data of the growing psoas major. Both the total muscle length and tendon length increased logarithmically, the belly length followed the third-degree polynomial function, both the maximal belly width and midway tendon width followed inverse functions, while the distance from the muscle origin to the widest part of the muscle belly, 3 (muscle, belly and tendon) projection surface areas, and volume increased commensurately to fetal age., Conclusions: In terms of morphometric parameters, the psoas major displays growth dynamics diverse to four functions: from a gradual inhibition of growth which is typical of both natural logarithmic functions (total length and tendon length) and a reverse model (belly width and tendon width) through a linear growth (distance between the origin and the widest belly level, muscle projection surface area, belly projection surface area, tendon projection surface area, and volume) to a hyperbolic growth (belly length).

Objectives: The aim of the present study was to examine the growth dynamics of the first sacral vertebra and its ossification center in the human fetus, based on their linear, planar, and volumetric parameters., Methods: The examinations were carried out on 54 human fetuses of both sexes (26 males and 28 females) aged 18-30 weeks of gestation, which had been preserved in 10% neutral formalin solution. Using CT, digital image analysis software, 3D reconstruction, and statistical methods, the size of the first sacral vertebra and its ossification center was evaluated., Results: The first sacral vertebra and its ossification center grew proportionately according to fetal weeks., Conclusions: The numerical data obtained from computed tomography and the growth patterns of the body of the first sacral vertebra and its ossification center may serve as age-specific normative intervals relevant for gynecologists, obstetricians, pediatricians, and radiologists during fetal ultrasound screening. Our findings on the growth of the body of the first sacral vertebra and its ossification center may be useful in daily clinical practice, particularly in ultrasonic monitoring of normal fetal growth and in screening for congenital defects and skeletal dysplasias.

Using a Siemens-Biograph 128 mCT camera the morphometric analysis of the L4 vertebral body and its ossification center were done in 55human fetuses aged 17 to 30weeks. No sex differences were found. The mean height, transverse and sagittal diameters of L4 vertebral body followed the logarithmic functions: y = -11.797+ 5.208 × ln(age) ± 0.372, y = -23.462 + 9.428 × ln(age) ± 0.702, y = 2.770 + 13.521 × ln(age) ± 1.722, respectively. The mean cross-sectional area of L4 vertebral body followed the linear function: y = -30.683 + 1.976 × age ± 2.701. The mean volume of L4 vertebral body followed the second-degree polynomial function: y = -93.983+ 0.385 × (age)² ± 23.707. The mean transverse and sagittal diameters of the ossification center of L4 vertebral body followed the natural logarithmic function: y = -27.106 + 10.178 × ln(age) ± 0.769 and y = -13.345 + 5.458 × ln(age) ± 0.424, respectively. The mean cross-sectional area and the volume of the ossification center of L4 vertebral body followed the linear function: y = -30.683 + 1.976 × age ± 2.701 and y = -43.214 + 2.760 × age ± 4.085, respectively.

Background: The study presents one of the six scapulohumeral muscles, which occupies most of the osteofibrous infraspinatus compartment. Along with the supraspinatus, teres minor and subscapularis muscles, the infraspinatus muscle contributes to the rotator cuff. It protects the posterior aspect of the articular capsule of the shoulder joint, adducts and externally rotates the arm. The aim of the study was to perform the quantitative analysis of the infraspinatus muscle in human fetuses and to elaborate growth dynamics for its morphometric parameters., Materials and Methods: Using anatomical dissection, digital image analysis (NIS Elements AR3.0) and statistics (Student's t-test, regression analysis), the vertical, transverse and oblique diameters, muscle circumference and projection surface area of the infraspinatus muscle were measured in 36human fetuses of both sexes (17♂, 19♀) aged 18-30weeks. The infraspinatus muscle revealed neither sex nor laterality differences., Results: All examined morphometric parameters of the infraspinatus muscle increased commensurately in accordance with the following linear functions: y=-4.024 + 0.903×Age ± 0.621 (R²=0.96) for transverse diameter, y=-3.089 + 1.321×Age ± 0.897 (R²=0.97) for vertical diameter, y=-1.161 + 0.632×Age ± 0.444 (R²=0.97) for oblique diameter, y=-13.575 + 3.851×Age ± 1.938 (R²=0.98) for muscle circumference and y=-293.512 + 23.228×Age ±19.650 (R²=0.95) for projection surface area.

Background: Operative treatment of fragility fractures of the pelvis has become a gold standard. Preoperative planning, including the assessment of the pathway for iliosacral screws, is crucial. The anchorage of the screw depends on the bone quality. Some recent studies have concentrated on assessing bone mineral density (BMD) with the use of Hounsfield unit (HU) values obtained from CT scans. The aim of the present study is to determine the best sacral levels of S1-S3 on the pathway of iliosacral screws for sacroiliac joint fixation. Methods: Patients admitted to the Independent Public Healthcare Center in Rypin between 1 of September and 1 of December in 2023, who had CT scans of the pelvis performed on them for different reasons, were included in this study. In total, 103 patients-56 men and 47 women-were enrolled in the study and consecutively separated into two groups of different ages: 18-60 years old (group A) and above 60 years old (group B). The volumetric bone density expressed in HU values was measured with sacral levels of S1, S2 and S3. Apart from the bodies of sacral vertebrae S1-S3, our measurements involved the ala of the ilium in the vicinity of the sacroiliac joint and the wing of the sacrum. All the measurements were performed on the pathway of presumptive iliosacral screws to stabilize the sacroiliac joint. Results: In group A (58 patients) the highest bone density in sacral bodies was found in S1 that gradually decreased to S3, while the opposite tendency was demonstrated in the ala of ilium. The HU values in the wing of the sacrum did not display statistical significance. In group B (45 patients), the highest bone density was also found in the sacral body S1 that decreased toward S3 but in the ala of ilium, the highest bone density was found with level S1 and lowest with level S2. In both groups, the highest bone density referred to the wing of the sacrum. Conclusion: While the perfect construct for posterior pelvic ring fixation remains unclear, our findings may imply that sacroiliac joint screws inserted into the wing of the sacrum of greater bone density could provide much more successful fixation in comparison to those anchored in the body of sacral vertebra of lesser bone density.

The aim of the present study was to examine the growth dynamics of the two ossification centers of the body of sphenoid bone in the human fetus, based on their linear, planar and volumetric parameters. The examinations were carried out on 37 human fetuses of both sexes aged 18-30 weeks of gestation, which had been preserved in 10% neutral formalin solution. Using CT, digital image analysis software, 3D reconstruction and statistical methods, we evaluated the size of the presphenoid and postsphenoid ossification centers. The presphenoid ossification center grew proportionately in sagittal diameter, projection surface area and volume, and logarithmically in transverse diameter. The postsphenoid ossification center increased logarithmically in sagittal diameter, transverse diameter and projection surface area, while its volumetric growth followed proportionately. The numerical findings of the presphenoid and postsphenoid ossification centers may be considered age-specific reference values of potential relevance in monitoring the normal fetal growth and screening for congenital disorders in the fetus. The obtained results may contribute to a better understanding of the growing fetal skeleton, bringing new numerical information regarding its diagnosis and development., (© 2024. The Author(s).)

Introduction Age-specific reference intervals for the extensor digiti minimi muscle (EDMM) in the human fetus may be relevant in the detailed evaluation of the musculoskeletal systems with potential relevant aspects for surgical treatment. The aim of the study was to examine the age-specific reference intervals and growth dynamics of the EDMM in relation to its length, width, projection surface area and volume. Material and methods The examined material included 70 human formalin-fixed fetuses of both sexes (37♀, 33♂) aged from 17 to 29 weeks. With the use of anatomical dissection every EDMM was visualized, recorded in a form of JPG formats and analyzed by the digital image analysis system and statistical methods. Results No variability of the EDMM was found. All the morphometric parameters of the EDMM revealed neither sex nor laterality differences. With fetal age most linear parameters of the EDMM concerning its examined lengths and widths increased in accordance with natural logarithmic functions. The only two exceptions to this referred to the belly width of EDMM measured at its mid-length and the tendon width of EDMM measured proximal to the extensor retinaculum of wrist, which both followed square root functions. The projection surface areas of the EDMM followed natural logarithmic functions, while the volumetric growth of the EDMM was proportionate to fetal age. Conclusions The variability of the EDMM in the human fetus is minimal. The morphometric data of the EDMM represents age-specific reference intervals of clinical significance. Morphometric parameters of the EDMM reveal neither sex nor laterality differences. The EDMM displays three different growth dynamics: from gradual growth deceleration according to both natural logarithmic functions (total length of the muscle and its tendons, belly length, tendon lengths, belly width at its origin, tendon width at its insertion, and projection surface areas) and square root functions (belly width at its mid-length and tendon width in the pre-retinacular segment) to a proportionate growth (total volume).

The present article concentrates on an innovative analysis that was performed to assess the development of the femur in human fetuses using artificial intelligence. As a prerequisite, linear dimensions, cross-sectional surface areas and volumes of the femoral shaft primary ossification center in 47 human fetuses aged 17-30 weeks, originating from spontaneous miscarriages and preterm deliveries, were evaluated with the use of advanced imaging techniques such as computed tomography and digital image analysis. In order to ensure the data representativeness and to avoid introducing any hidden structures that may exist in the data, the entire dataset was randomized and separated into three subsets: training (50% of cases), testing (25% of cases), and validation (25% of cases). Based on the collected numerical data, an artificial neural network was devised, trained, and subject to testing in order to synchronously estimate five parameters of the femoral shaft primary ossification center, thus leveraging fundamental information such as gestational age and femur length. The findings reveal the formulated multi-layer perceptron model denoted as MLP 2-3-2-5 to exhibit robust predictive efficacy, as evidenced by the linear correlation coefficient between actual values and network outputs: R = 0.955 for the training dataset, R = 0.942 for validation, and R = 0.953 for the testing dataset. The authors have cogently demonstrated that the use of an artificial neural network to assess the growing femur in the human fetus may be a valuable tool in prenatal tests, enabling medical doctors to quickly and precisely assess the development of the fetal femur and detect potential anatomical abnormalities., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Badura et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The popliteal fossa presents an extensive diamond-shaped topographical element on the posterior aspect of the knee. With the use of classical anatomical dissection, digital image analysis of NIS Elements AR 3.0 and statistics we morphometrically analyzed the size of the popliteal fossa in human fetuses aged 17-29 weeks of gestation. Morphometric parameters of the popliteal fossa increased logarithmically with fetal age: y = -44.421 + 24.301 × ln (Age) for length of superomedial boundary, y = -41.379 + 22.777 × ln (Age) for length of superolateral boundary, y = -39.019 + 20.981 × ln (Age) for inferomedial boundary, y = -37.547 + 20.319 × ln (Age), for length of inferolateral boundary, y = -28.915 + 15.822 × ln (Age) for transverse diameter, y = -69.790 + 38.73 × ln (Age) for vertical diameter and y = -485.631 + 240.844 × ln (Age) for projection surface area. Out of the four angles of the popliteal fossa the medial one was greatest, the inferior one the smallest, while the lateral one was somewhat smaller than the medial one and approximately three times greater than the superior one, with no difference with fetal age. In terms of morphometric parameters the popliteal fossa in the human fetus displays neither male-female nor right-left differences. In the popliteal fossa, growth patterns of its four boundaries, vertical and transverse diameters, and projection surface area all follow natural logarithmic functions. All the morphometric data is considered age-specific reference intervals, which may be conducive in the diagnostics of congenital abnormalities in the human fetus.

Detailed numerical data about the development of primary ossification centers in human fetuses may influence both better evaluation and early detection of skeletal dysplasias, which are associated with delayed development and mineralization of ossification centers. To the best of our knowledge, this is the first report in the medical literature to morphometrically analyze the primary ossification center of the squamous part of temporal bone in human fetuses based on computed tomography imaging. The present study offers a precise quantitative foundation for ossification of the squamous part of temporal bone that may contribute to enhanced prenatal care and improved outcomes for fetuses with inherited cranial defects and skeletodysplasias. The examinations were carried out on 37 human fetuses of both sexes (16 males and 21 females) aged 18-30 weeks of gestation, which had been preserved in 10% neutral formalin solution. Using CT, digital image analysis software, 3D reconstruction and statistical methods, the size of the primary ossification center of the squamous part of temporal bone was evaluated. With neither sex nor laterality differences, the best-fit growth patterns for the primary ossification center of the squamous part of temporal bone was modelled by the linear function: y = -0.7270 + 0.7682 × age ± 1.256 for its vertical diameter, and the four-degree polynomial functions: y = 5.434 + 0.000019 × (age)4 ± 1.617 for its sagittal diameter, y = -4.086 + 0.00029 × (age)4 ± 2.230 for its projection surface area and y = -25.213 + 0.0004 × (age)4 ± 3.563 for its volume. The CT-based numerical data and growth patterns of the primary ossification center of the squamous part of temporal bone may serve as age-specific normative intervals of relevance for gynecologists, obstetricians, pediatricians and radiologists during screening ultrasound scans of fetuses. Our findings for the growing primary ossification center of the squamous part of temporal bone may be conducive in daily clinical practice, while ultrasonically monitoring normal fetal growth and screening for inherited cranial faults and skeletodysplasias., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Grzonkowska et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Dislocations of the sacroiliac joint (SIJ) are treated with iliosacral screws or anterior plating. The study aimed to investigate the course of the lumbosacral trunk with reference to SIJ and determine whether is there sufficient space for two screws through the sacrum while performing anterior plating. Sixty patients, who underwent an MRI of the lumbar spine were included in our study. The three transverse LT-SIJ distances were measured at the three points (A, B, and C). We also analyzed 60 CT pelvic scans at points A, B, and C in order to measure: the vertebral canal-to-SIJ distance, the sacrum's pelvic-to-dorsal surface sagittal distance, and the median plane-to-SIJ angle. The mean transverse LT-SIJ distances at points A, B, and C were 20.0 ± 3.05 mm, 17.9 ± 3.20 mm, and 12.3 ± 2.49 mm, respectively. Based on CT analyses, the vertebral canal-to-SIJ distances were 30.5 ± 7.65 mm at point A, 21.4 ± 5.05 mm at point B and 15.7 ± 6.05 mm at point C. The sacrum's pelvic-to-dorsal surface sagittal distances reached values: 35.1 ± 11.62 mm at point A, 52.5 ± 10.58 mm at point B, and 57.5 ± 7.79 mm at point C. The median plane-to-SIJ angles measured 31.4 ± 4.82 degrees at point A, 26.6 ± 3.77 degrees at point B and 21.3 ± 3.25 mm at point C. Proximally, the safe zone for applying an anterior plate of SIJ is 20.0 mm. Since both the safe zone and safe corridor taper distally, surgeons may securely use one screw of gradually increased length towards the distal direction of SIJ, with inclination of 30 degrees in relation to the median plane of the lesser pelvis., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Kułakowski et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

CT-based quantitative analysis of any ossification center in the cranium has not previously been carried out due to the limited availability of human fetal material. Detailed morphometric data on the development of ossification centers in the human fetus may be useful in the early detection of congenital defects. Ossification disorders in the cranium are associated with either a delayed development of ossification centers or their mineralization. These aberrations may result in the formation of accessory skull bones that differ in shape and size, and the incidence of which may be misdiagnosed as, e.g., skull fractures. The study material comprised 37 human fetuses of both sexes (16♂, 21♀) aged 18-30 weeks. Using CT, digital image analysis software, 3D reconstruction and statistical methods, the linear, planar and spatial dimensions of the occipital squama ossification center were measured. The morphometric characteristics of the fused ossification center of the occipital squama show no right-left differences. In relation to gestational age, the ossification center of the occipital squama grows linearly in its right and left vertical diameters, logarithmically in its transverse diameters of both the interparietal and supraoccipital parts and projection surface area, and according to a quadratic function in its volume. The obtained numerical findings of the occipital squama ossification center may be considered age-specific references of relevance in both the estimation of gestational age and the diagnostic process of congenital defects., Competing Interests: The authors have declared that no competing interests exist.

Purposes: Detailed morphometric data on the development of ossification centers in human fetuses is useful in the early detection of skeletal dysplasias associated with a delayed development of ossification centers and their mineralization. Quantitative analysis of primary ossification centers of cranial bones is sporadic due to limited availability of fetal material., Material and Methods: The size of the primary ossification center of the frontal squama in 37 human (16 males and 21 females) spontaneously aborted human fetuses aged 18-30 weeks was studied by means of CT, digital-image analysis and statistics., Results: With neither sex nor laterality differences, the best-fit growth dynamics for the primary ossification center of the frontal squama was modelled by the following functions: y = 13.756 + 0.021 × (age) 2  ± 0.024 for its vertical diameter, y = 0.956 + 0.956 × age ± 0.823 for its transverse diameter, y = 38.285 + 0.889 × (age) 2  ± 0.034 for its projection surface area, and y = 90.020 + 1.375 × (age) 2  ± 11.441 for its volume., Conclusions: Our findings for the primary ossification center of the frontal squama may be conducive in monitoring normal fetal growth and screening for inherited faults and anomalies of the skull in human fetuses.

This study aimed to examine age-specific reference intervals and growth dynamics of the best fit for liver dimensions on the diaphragmatic surface of the fetal liver. The research material consisted of 69 human fetuses of both sexes (32♂, 37♀) aged 18-30 weeks. Using methods of anatomical dissection, digital image analysis and statistics, a total of 10 measurements and 2 calculations were performed. No statistical significant differences between sexes were found (p>0.05). The parameters studied displayed growth models that followed natural logarithmic functions. The mean value of the transverse-to-vertical diameter ratio of the liver throughout the analyzed period was 0.71±0.11. The isthmic ratio decreased significantly from 0.81±0.12 in the 18-19th week to 0.62±0.06 in the 26-27th week, and then increased to 0.68±0.11 in the 28-30th week of fetal life (p<0.01). The morphometric parameters of the diaphragmatic surface of the liver present age-specific reference data. No sex differences are found. The transverse-to-vertical diameter ratio supports a proportionate growth of the fetal liver. Quantitative anatomy of the growing liver may be of relevance in both the ultrasound monitoring of the fetal development and the early detection of liver anomalies., Competing Interests: The authors have declared that no competing interests exist.

Purpose: The medical literature still lacks studies on the size of the radial shaft primary ossification center, thus preventing us from potentially relevant data in diagnosing skeletal dysplasias, i.e., TAR syndrome, VATER syndrome, Holt-Oram syndrome, Fanconi anemia and Edwards syndrome, frequently characterized by disrupted or retarded fetal growth., Materials and Methods: The size of the radial shaft primary ossification center in 47 (25 males and 22 females) spontaneously aborted human fetuses aged 17-30 weeks was studied by means of CT, digital image analysis and statistics., Results: With neither sex nor laterality differences, the best-fit growth dynamics for the radial shaft primary ossification center was modeled by the following functions: y = - 10.988 + 1.565 × age ± 0.018 for its length, y = - 2.969 + 0.266 × age ± 0.01 for its proximal transverse diameter, y = - 0.702 + 0.109 × age ± 0.018 for its middle transverse diameter, y = - 2.358 + 0.203 × age ± 0.018 for its distal transverse diameter, y = -189.992 + 11.788 × (age) 2  ± 0.018 for its projection surface area, and y = - 798.174 + 51.152 × age ± 0.018 for its volume., Conclusions: The morphometric characteristics of the radial shaft primary ossification center show neither sex nor bilateral differences. The radial shaft primary ossification center grows proportionately in length, transverse dimensions and volume, and quadratically in its projection surface area. The obtained numerical findings of the radial shaft ossification center are considered age-specific reference of relevance in both the estimation of fetal ages and the diagnostic process of congenital defects.

Purposes: Skeletodysplasiae and hereditary dysostoses constitute a group of over 350 disorders of the skeletal system. Knowledge about development of the pubic primary ossification center may be useful in both determining the fetal stage and maturity, and for detecting congenital disorders. The present study was performed to quantitatively examine the pubic primary ossification center with respect to its linear, planar, and volumetric parameters., Materials and Methods: Using methods of computed tomography (CT), digital-image analysis and statistics, the size of the pubic primary ossification center in 33 spontaneously aborted human fetuses (18 males and 15 females) aged 22-30 weeks was studied., Results: With no sex and laterality differences, the best-fit growth dynamics for the pubic primary ossification center was modeled by the following functions: y = - 13.694 + 0.728 × age ± 0.356 for its sagittal diameter, y = - 3.350 + 0.218 × age ± 0.159 for its vertical diameter, y = - 61.415 + 2.828 × age ± 1.519 for its projection surface area, and y = - 65.801 + 3.173 × age ± 2.149 for its volume., Conclusions: The size of the pubic primary ossification center shows neither sex nor laterality differences. The growth dynamics of the vertical and sagittal diameters, projection surface area, and volume of the pubic ossification centers follow proportionately to fetal age. The obtained numerical findings of the pubic ossification center are considered age-specific reference data with clinical implications in the diagnostics of congenital defects.

Purpose: There has been little information in the medical literature regarding the growing ulna in the human fetus, though such knowledge appears to be potentially useful in diagnosing skeletal dysplasias, characterized by a disrupted or completely halted growth of the fetus. Therefore, longitudinal measurements of long bones are extremely conducive in assessing both pregnancy and fetal anatomy., Materials and Methods: Using methods of CT, digital-image analysis and statistics, the size of the ulna's shaft primary ossification center in 48 (26 males and 22 females) spontaneously aborted human fetuses aged 17-30 weeks was studied., Results: With no sex differences, the best fit growth dynamics for the ulna's shaft primary ossification center was modeled by the following functions: y = - 8.476 + 1.561 × age ± 0.019 for its length, y = - 2.961 + 0.278 × age ± 0.016 for its proximal transverse diameter, y = - 0.587 + 0.107 × age ± 0.027 for its middle transverse diameter, y = - 2.865 + 0.226 × age ± 0.295 for its distal transverse diameter, y = - 50.758 + 0.251 × (age) 2  ± 0.016 for its projection surface area, and y = - 821.707 + 52.578 × age ± 0.018 ± 102.944 for its volume., Conclusions: The morphometric characteristics of the ulna's shaft primary ossification center show neither sex nor bilateral differences. The ulna's shaft primary ossification center grows linearly with respect to its length, transverse dimensions and volume, and follows a quadratic function with respect to its projection surface area. The obtained morphometric data of the ulna's shaft primary ossification center is considered normative for respective prenatal weeks and may be of relevance in both the estimation of fetal ages and the diagnostic process of congenital defects.

Purposes: Details concerning the normal growth of the pelvic girdle in the fetus are of importance in the early detection of congenital defects. This study was executed to quantitatively evaluate the primary ossification center of the ischium with relation to its linear, planar and volumetric parameters., Materials and Methods: Using methods of CT, digital-image analysis, and statistics, geometrical dimensions of the ischium's primary ossification center in 42 spontaneously aborted human fetuses (21 ♂ and 21 ♀) aged 18-30 weeks were calculated., Results: With no sex and laterality differences, the best fit growth dynamics for the ischium's primary ossification center were displayed by the following functions: y = - 10.045 + 0.742 × age ± 0.013 (R 2  = 0.97) for its vertical diameter, y = - 5.212 + 0.385 × age ± 0.008 (R 2  = 0.97) for its sagittal diameter, y = - 36.401 + 0.122 × (age) 2 ± 45.534 (R 2  = 0.96) for its projection surface area, and y = - 1052.840 + 368.470 × ln(age) ± 12.705 (R 2  = 0.91) for its volume., Conclusions: Neither male-female nor right-left differences are found for any of the morphometric parameters of the ischium's primary ossification center. With relation to fetal ages in weeks, the ischium's primary ossification center grows proportionately in vertical and sagittal diameters, second-degree polynomially in projection surface area, and logarithmically in volume. The quantitative findings of the ischium's primary ossification center are considered age-specific reference data of relevance in the diagnostics of innate defects.

Purposes: Precise morphometric data on the development of ossification centers in human fetuses may be useful in the early detection of skeletal dysplasias associated with delayed ossification center development and mineralization. The present study was performed to quantitatively examine the primary ossification center of the fibular shaft with respect to its linear, planar and volumetric parameters., Materials and Methods: Using methods of CT, digital-image analysis (Osirix 3.9 MD) and statistics (Student's t-test, Shapiro-Wilk, Fisher's test, Tukey's test, Kruskal-Wallis test, regression analysis), the size of the primary ossification center of the fibular shaft in 47 spontaneously aborted human fetuses (25 ♂ and 22 ♀) aged 17-30 weeks was studied. In each fetus, the assessment of linear dimensions (length, transverse diameters for: proximal end, middle part and distal end), projection surface area and volume of the fibular shaft ossification center was carried out., Results: With no sex and laterality differences, the best fit growth dynamics for the primary ossification center of the fibular shaft was modelled by the following functions: y = - 13.241 + 1.567 × age ± 1.556 (R 2  = 0.94) for its length, y = - 0.091 + 0.063 × age ± 0.073 (R 2  = 0.92) for its proximal transverse diameter, y = - 1.201 + 0.717 × ln(age) ± 0.054 (R 2  = 0.83) for its middle transverse diameter, y = - 2.956 + 1.532 × ln(age) ± 0.090 (R 2  = 0.89) for its distal transverse diameter, y = - 69.038 + 4.699 × age ± 4.055 (R 2  = 0.95) for its projection surface area, and y = - 126.374 + 9.462 × age ± 8.845 (R 2  = 0.94) for its volume., Conclusions: The ossification center in the fibular shaft follows linear functions with respect to its length, proximal transverse diameter, projection surface area and volume, and natural logarithmic functions with respect to its middle and distal transverse diameters. The obtained morphometric data of the fibular shaft ossification center is considered normative for their respective prenatal weeks and may be of relevance in both the estimation of fetal age and the ultrasound diagnostics of congenital defects.

Purposes: Tibial shaft ossification in terms of its size and growth may be criticalin describing both the fetal stage and maturity, and in identifying innate disorders. The present study was executed to quantitatively assess ossification of the tibial shaft, taking its morphometric linear, planar and volumetric parameters into account., Materials and Methods: With the use of methods of CT, digital-image analysis and statistics, the evolutionof tibial shaft ossification in 47 spontaneously aborted human fetuses at the age of 17-30 weeks was studied., Results: Without any male-female and right-left morphometric differences, the best fit growth dynamics fortibial shaft ossification was modelled by the following functions: y = 5.312 + 0.034 × (age) 2  ± 0.001 (R 2  = 0.89) for its length, y = - 2.855 + 0.307 × age ± 0.009 (R 2  = 0.96) for its proximal transverse diameter, y = - 0.758 + 0.153 × age ± 0.005 (R 2  = 0.88) for its middle transverse diameter, y = - 1.844 + 0.272 × age ± 0.09 (R 2  = 0.90) for its distal transverse diameter, y = - 40.263 + 0.258 × (age) 2  ± 0.007 (R 2  = 0.94) for its projection surface area, and y = - 287.996 + 1.186 × (age) 2  ± 0.037 (R 2  = 0.92) for its volume. The femoral-to-tibial ossification length ratio was 1.15 ± 0.1., Conclusions: The size of tibial shaft ossification displays neither sex nor laterality differences. Tibial shaft ossification follows quadratic functions with respect to its length, projection surface area and volume, and linear functions with respect to its proximal, middle and distal transverse diameters. The obtained morphometric data of tibial shaft ossification are considered normative age-specific references of relevance in both the estimation of fetal ages and the ultrasound diagnostics of congenital defects.

Purpose: An understanding of the development of the ilium's primary ossification center may be useful in both determining the fetal stage and maturity, and for detecting congenital disorders. This study was performed to quantitatively examine the ilium's primary ossification center with respect to its linear, planar and volumetric parameters., Materials and Methods: Using methods of CT, digital-image analysis and statistics, the size of the ilium's primary ossification center in 42 spontaneously aborted human fetuses of crown-rump length (CRL) ranged from 130 to 265 mm (aged 18-30 weeks) was studied., Results: With no sex and laterality differences, the best fit growth dynamics for the ilium's primary ossification center was modelled by the following functions: y = - 63.138 + 33.413 × ln(CRL) ± 1.609 for its vertical diameter, y = - 59.220 + 31.353 × ln(CRL) ± 1.736 for its transverse diameter, y = - 105.681 + 1.137 × CRL ± 16.035 for its projection surface area, and y = 478.588 + 4.035 × CRL ± 14.332 for its volume. The shape of the ilium's primary ossification center did not change over the study period, because its transverse -to- vertical diameter ratio was stable at the level of 0.94 ± 0.07. Conclusions The size of the ilium's primary ossification center displays neither sex nor laterality differences. The ilium's primary ossification center grows logarithmically with respect to its vertical and transverse diameters, and linearly with respect to its projection surface area and volume. The shape of the ilium's primary ossification center does not change throughout the examined period. The obtained quantitative data of the ilium's primary ossification center is considered normative for respective prenatal weeks and may contribute to the prenatal ultrasound diagnostics of congenital defects.

Background: The inferior lumbar triangle of Petit is bounded by the iliac crest, lateral border of the latissimus dorsi and the medial border of the external oblique., Objectives: In the present study, we aimed to quantitatively examine the base, sides, area, and interior angles of the inferior lumbar triangle in the human fetus so as to provide their growth dynamics., Material and Methods: Using anatomical dissection, digital image analysis (NIS-Elements AR 3.0), and statistics (Student's t-test, regression analysis), we measured the base, 2 sides, area and interior angles of Petit's triangle in 35 fetuses of both sexes (16 male, 19 female) aged 14-24 weeks., Results: Neither sex nor laterality differences were found. All the parameters studied increased commensurately with age. The linear functions were computed as follows: y = -0.427 + 0.302 × age for base, y = 1.386 + 0.278 × age for medial side, y = 0.871 + 0.323 × age for lateral side, and y = -13.230 + 1.590 × age for area of the Petit triangle., Conclusions: In terms of geometry, Petit triangle reveals neither male-female nor right-left differences. An increase in both lengths and area of the inferior lumbar triangle follows proportionately. The Petit triangle is an acute one in the human fetus.

Purposes: The purpose of the study was to quantitatively evaluate the size of the quadratus lumborum and to precisely display its growth dynamics in the human foetus., Materials and Methods: Using anatomical dissection, digital-image analysis (NIS Elements AR 3.0) and statistical analysis (Student's t test, regression analysis), the length, width, surface area, and cross-sectional area of the quadratus lumborum were measured, and the width-to-length ratio was calculated in 58 human foetuses of both sexes (26♂, 32♀) aged 16-27 weeks., Results: Neither sex nor right-left significant differences were found in relation with the numerical data of the growing quadratus lumborum. The length, width, and cross-sectional area of the quadratus lumborum muscle increased logarithmically, while its surface area increased proportionately to fetal age. The following growth models were computed for the quadratus lumborum: y = -70.397 + 68.501 × ln(age) ± 1.170 for length, y = -20.435 + 8.815 × ln(age) ± 0.703 for width, y = -196.035 + 14.838 × age ± 13.745 for surface area, and y = -48.958 + 20.909 × ln(age) ± 1.100 for cross-sectional area., Conclusions: The fetal quadratus lumborum reveals neither sex nor bilateral differences. An increase in length and width of the growing quadratus lumborum follows in a commensurate fashion. The quadratus lumborum grows logarithmically with respect to its length, width, and cross-sectional area, and proportionately to age with respect to its surface area.

Purpose: Early clinical distinction of congenital defects in the femur is extremely important, as it determines the prognosis of the development of the lower limb. This study was performed to quantitatively examine the primary center of ossification in the femoral shaft with respect to its linear, planar, and volumetric parameters., Materials and Methods: Using methods of CT, digital-image analysis, and statistics, the size of the primary ossification center of the femoral shaft in 47 spontaneously aborted human fetuses aged 17-30 weeks was studied., Results: With no sex and laterality differences, the best fit growth dynamics for femoral shaft ossification center was modelled by the following functions: y = 5.717 + 0.040 × (age) 2  ± 2.905 (R 2  = 0.86) for its length, y = -3.579 + 0.368 × age ± 0.529 (R 2  = 0.88) for its proximal transverse diameter, y = -1.105 + 0.187 × age ± 0.309 (R 2  = 0.84) for its middle transverse diameter, y = -2.321 + 0.323 × age ± 0.558 (R 2  = 0.83) for its distal transverse diameter, y = -50.306 + 0.308 × (age) 2  ± 18.289 (R 2  = 0.90) for its projection surface area, and y = -91.458 + 0.390 × (age) 3  ± 92.146 (R 2  = 0.88) for its volume., Conclusions: The size of the femoral shaft ossification center displays neither sex nor laterality differences. The ossification center in the femoral shaft follows quadratic functions with respect to its length and projection surface area, linear functions with respect to its proximal, middle, and distal transverse diameters, and a cubic function with respect to its volume. The obtained morphometric data of the femoral shaft ossification center are considered normative for respective prenatal weeks and may be of relevance in both the estimation of fetal ages and the ultrasound diagnostics of congenital defects.

Purpose: The knowledge of the development of the humeral shaft ossification center may be useful both in determining the fetal stage and maturity and for detecting congenital disorders, as well. This study was performed to quantitatively examine the humeral shaft ossification center with respect to its linear, planar, and volumetric parameters., Materials and Method: Using methods of CT, digital image analysis, and statistics, the size of the humeral shaft ossification center in 48 spontaneously aborted human fetuses aged 17-30 weeks was studied., Results: With no sex differences, the best-fit growth dynamics for the humeral shaft ossification center was modeled by the following functions: y = -78.568 + 34.114 × ln (age) ± 2.160 for its length, y = -12.733 + 5.654 × ln(age) ± 0.515 for its proximal transverse diameter, y = -4.750 + 2.609 × ln (age) ± 0.294 for its middle transverse diameter, y = -10.037 + 4.648 × ln (age) ± 0.560 for its distal transverse diameter, y = -146.601 + 11.237 × age ± 19.907 for its projection surface area, and y = 121.159 + 0.001 × (age) 4 ± 102.944 for its volume., Conclusions: With no sex differences, the ossification center of the humeral shaft grows logarithmically with respect to its length and transverse diameters, linearly with respect to its projection surface area, and fourth-degree polynomially with respect to its volume. The obtained morphometric data of the humeral shaft ossification center are considered normative for respective prenatal weeks and may be of relevance in both the estimation of fetal ages and the ultrasonic diagnostics of congenital defects.

Purposes: Knowledge of dimensions of fetal long bones is useful in both the assessment of fetal growth and early detection of inherited defects. Measurements of the fetal clavicle may facilitate detection of numerous defects, e.g., cleidocranial dysplasia, Holt-Oram syndrome, Goltz syndrome, and Melnick-Needles syndrome., Methods: Using the methods of CT, digital image analysis, and statistics, the size of the growing clavicle in 42 spontaneously aborted human fetuses (21 males and 21 females) at ages of 18-30 weeks was studied., Results: Without any male-female and right-left significant differences, the best fit growth models for the growing clavicle with relation to age in weeks were as follows: y = -54.439 + 24.673 × ln(age) ± 0.237 (R 2  = 0.86) for length, y = -12.042 + 4.906 × ln(age) ± 0.362 (R 2  = 0.82) for width of acromial end, y = -4.210 + 2.028 × ln(age) ± 0.177 (R 2  = 0.77) for width of central part, y = -4.687 + 2.364 × ln(age) ± 0.242 (R 2  = 0.70) for width of sternal end, y = -51.078 + 4.174 × ln(age) ± 6.943 (R 2  = 0.82) for cross-sectional area, and y = -766.948 + 281.774 × ln(age) ± 19.610 (R 2  = 0.84) for volume., Conclusions: With no sex and laterality differences, the clavicle grows logarithmically with respect to its length, width, and volume, and linearly with respect to its projection surface area. The obtained morphometric data of the growing clavicle are considered normative for their respective weeks of gestation and may be of relevance in the diagnosis of congenital defects.

Purposes: The knowledge of the developing cervical spine and its individual vertebrae, including their neural processes may be useful in the diagnostics of congenital vertebral malformations. This study was performed to quantitatively examine the neural ossification centers of the atlas and axis with respect to their linear, planar and volumetric parameters., Methods: Using the methods of CT, digital-image analysis and statistics, the size of neural ossification centers in the atlas and axis in 55 spontaneously aborted human fetuses aged 17-30 weeks was studied., Results: Without any male-female and right-left significant differences, the best fit growth dynamics for the neural ossification centers of the atlas and axis were, respectively, modelled by the following functions: for length: y = -13.461 + 6.140 × ln(age) ± 0.570 and y = -15.683 + 6.882 × ln(age) ± 0.503, for width: y = -4.006 + 1.930 × ln(age) ± 0.178 and y = -3.054 + 1.648 × ln(age) ± 0.178, for cross-sectional area: y = -7.362 + 0.780 × age ± 1.700 and y = -9.930 + 0.869 × age ± 1.911, and for volume: y = -6.417 + 0.836 × age ± 1.924 and y = -11.592 + 1.087 × age ± 2.509., Conclusions: The size of neural ossification centers of the atlas and axis shows neither sexual nor bilateral differences. The neural ossification centers of the atlas and axis grow logarithmically in both length and width and linearly in both cross-sectional area and volume. The numerical data relating to the size of neural ossification centers of the atlas and axis derived from the CT and digital-image analysis are considered specific-age reference values of potential relevance in both the ultrasound monitoring and the early detection of spinal abnormalities relating to the neural processes of the first two cervical vertebrae in the fetus., Competing Interests: The authors declare that they have no conflict of interest.

Purposes: The detailed understanding of the anatomy and timing of ossification centers is indispensable in both determining the fetal stage and maturity and for detecting congenital disorders. This study was performed to quantitatively examine the odontoid and body ossification centers in the axis with respect to their linear, planar and volumetric parameters., Methods: Using the methods of CT, digital image analysis and statistics, the size of the odontoid and body ossification centers in the axis in 55 spontaneously aborted human fetuses aged 17-30 weeks was studied., Results: With no sex difference, the best fit growth dynamics for odontoid and body ossification centers of the axis were, respectively, as follows: for transverse diameter y = -10.752 + 4.276 × ln(age) ± 0.335 and y = -10.578 + 4.265 × ln(age) ± 0.338, for sagittal diameter y = -4.329 + 2.010 × ln(age) ± 0.182 and y = -3.934 + 1.930 × ln(age) ± 0.182, for cross-sectional area y = -7.102 + 0.520 × age ± 0.724 and y = -7.002 + 0.521 × age ± 0.726, and for volume y = -37.021 + 14.014 × ln(age) ± 1.091 and y = -37.425 + 14.197 × ln(age) ± 1.109., Conclusions: With no sex differences, the odontoid and body ossification centers of the axis grow logarithmically in transverse and sagittal diameters, and in volume, while proportionately in cross-sectional area. Our specific-age reference data for the odontoid and body ossification centers of the axis may be relevant for determining the fetal stage and maturity and for in utero three-dimensional sonographic detecting segmentation anomalies of the axis., Competing Interests: The authors declare that they have no conflict of interest.

Purposes: A satisfactory understanding of the clavicle development may be contributing to both the diagnosis of its congenital defects and prevention of perinatal damage to the shoulder girdle. This study was carried out to examine the transverse and sagittal diameters, cross-sectional area and volume of the two fused primary ossification centers of the clavicle., Methods: Using the methods of CT, digital-image analysis and statistics, the size for two fused primary ossification centers of the clavicle in 42 spontaneously aborted human fetuses at ages of 18-30 weeks was studied., Results: Without any male-female and right-left significant differences, the best fit growth models for two fused primary ossification centers of the clavicle were as follows: y = -31.373 + 15.243 × ln(age) ± 1.424 (R (2) = 0.74) for transverse diameter, y = -7.945 + 3.225 × ln(age) ± 0.262 (R (2) = 0.78), y = -4.503 + 2.007 × ln(age) ± 0.218 (R (2) = 0.68), and y = -4.860 + 2.117 × ln(age) ± 0.200 (R (2) = 0.73) for sagittal diameters of the lateral, middle and medial ends respectively, y = -31.390 + 2.432 × age ± 4.599 (R (2) = 0.78) for cross-sectional area, and y = 28.161 + 0.00017 × (age)(4) ± 15.357 (R (2) = 0.83) for volume., Conclusions: With no sex and laterality differences, the fused primary ossification centers of the clavicle grow logarithmically in both transverse and sagittal diameters, linearly in cross-sectional area, and fourth-degree polynomially in volume. Our normative quantitative findings may be conducive in monitoring normal fetal growth and screening for inherited faults and anomalies of the clavicle in European human fetuses., Competing Interests: The authors declare that they have no conflict of interest.

In the present work, we have proposed a statistical model predicting the toxicity of ionic liquids (ILs) to Vibrio fischeri bacteria using the Quantitative Structure-Activity Relationships (QSAR) method. The model was developed with Multiple Linear Regression (MLR) technique, using the Gutman molecular topological index (GMTI), the lopping centric information index (LOC) and the number of oxygen atoms. Presented model is characterized by the good fit to the experimental data (R(2) = 0.78), high robustness (Q(2)CV = 0.72) and good predictive ability (Q(2)EXT = 0.75). This approach, with using very simple descriptors, helps to initially evaluate the toxicity of newly designed ionic liquids. The studied toxicity of ionic liquids depends mainly on their cations' structure: larger, more branched cations with long alkyl chains are more toxic than the smaller, linear ones. The presence of polar functional groups in the cation's structure reduces the toxic properties of ionic liquids. The structure of the anion has little effect on the toxicity of the studied ionic liquids. Obtained results will provide insight into the toxicity mechanisms and useful information for assessing the potential ecological risk of ionic liquids., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Ionic liquids (ILs) found a variety of applications in today's chemistry. Since their properties depend on the ions constituting particular ionic liquid, it is possible to synthetize IL with desired specification, dependently on its further function. However, this task is not trivial, since knowledge regarding the influence of particular ion on the property of concern is crucial. Therefore, there is a strong need for new, fast and inexpensive methods supporting the process of ionic liquids' design, making it possible to predefine IL's properties even before the synthesis., Results: We have developed a simple tool (called Ionic Liquid PhysicoChemical predictor: ILPC) that allows for the simultaneous qualitative prediction of four physicochemical properties of ionic liquids: viscosity, n-octanol-water partition coefficient, solubility and enthalpy of fusion. By the means of Principal Component Analysis, we studied 172 ILs and defined distribution trends of those four properties, dependently on the ILs structures. We proved that the qualitative prediction of mentioned properties could be performed on the basis of most simple information we can deliver about ILs, which are their molecular formulas., Conclusions: Created tool presented in this paper allows fast, pre-synthesis screening of ILs, with the omission of any experimental steps. It can be helpful in the process of designing ILs with preferred properties. We proved that the information encrypted in molecular formula of ionic liquid could be a valuable source of knowledge regarding the IL's viscosity, n-octanol-water partition coefficient, solubility and enthalpy of fusion. Moreover, we proved that the influence of both ions, constituting the IL, on each of those four properties indicates same, additive trend.Graphical AbstractSchematic representation of ILPC performance - the exact position of the ionic liquid on the linear map is determined by its chemical structure.

Background: The trapezius muscle consists of three parts that are capable of functioning independently. Its superior part together with the levator scapulae and rhomboids elevate the shoulder, the middle part retracts the scapula, while the inferior part lowers the shoulder., Objectives: The present study aimed to supplement numerical data and to provide growth dynamics of the trapezius in the human fetus., Material and Methods: Using methods of anatomical dissection, digital image analysis (NIS Elements AR 3.0), and statistics (Student's t-test, regression analysis), we measured the length, the width and the surface area of the trapezius in 30 fetuses of both sexes (13™ k,17™ … ) aged 13-19 weeks., Results: Neither sex nor laterality differences were found. All the studied parameters of the trapezius increased proportionately with age. The linear functions were computed as follows: y = -103.288 + 10.514 × age (r = 0.957) for total length of the trapezius muscle, y = -67.439 + 6.689 × age (r = 0.856) for length of its descending part, y = -8.493 + 1.033 × age (r = 0.53) for length of its transverse part, y = -27.545 + 2.802 × age (r = 0.791) for length of its ascending part, y = -19.970 + 2.505 × age (r = 0.875) for width of the trapezius muscle, and y = -2670.458 + 212.029 × age (r = 0.915) for its surface area., Conclusions: Neither sex nor laterality differences exist in the numerical data of the trapezius muscle in the human fetus. The descending part of trapezius is the longest, while its transverse part is the shortest. The growth dynamics of the fetal trapezius muscle follows proportionately.

Ionic liquids (ILs) form a wide group of compounds characterized by specific properties that allow using ILs in different fields of science and industry. Regarding that the growing production and use of ionic liquids increase probability of their emission to the environment, it is important to estimate the ability of these compounds to spread in the environment. One of the most important parameters that allow evaluating environmental mobility of compound is n-octanol/water partition coefficient (KOW). Experimental measuring of the KOW values for a large number of compounds could be time consuming and costly. Instead, computational predictions are nowadays being used more often. The paper presents new Quantitative Structure-Property Relationship (QSPR) model that allows predicting the logarithmic values of KOW for 335 ILs, for which the experimentally measured values had been unavailable. We also estimated bioaccumulation potential and point out which group of ILs could have negative impact on environment., (Copyright © 2015 Elsevier B.V. All rights reserved.)

In this contribution, the advantages and limitations of two computational techniques that can be used for the investigation of nanoparticles activity and toxicity: classic nano-QSAR (Quantitative Structure-Activity Relationships employed for nanomaterials) and 3D nano-QSAR (three-dimensional Quantitative Structure-Activity Relationships, such us Comparative Molecular Field Analysis, CoMFA/Comparative Molecular Similarity Indices Analysis, CoMSIA analysis employed for nanomaterials) have been briefly summarized. Both approaches were compared according to the selected criteria, including: efficiency, type of experimental data, class of nanomaterials, time required for calculations and computational cost, difficulties in the interpretation. Taking into account the advantages and limitations of each method, we provide the recommendations for nano-QSAR modellers and QSAR model users to be able to determine a proper and efficient methodology to investigate biological activity of nanoparticles in order to describe the underlying interactions in the most reliable and useful manner.

Background: The triceps brachii muscle, the strongest extensor of the elbow joint, is characterized by the three heads: long, lateral and medial., Objectives: In the present study we aimed to examine the linear parameters (length, width) of the fetal triceps brachii muscle and to provide their growth dynamics., Material and Methods: Using anatomical dissection, digital image analysis (Multiscan v.14.02), and statistics (Student's t-test, regression analysis) we measured in mm the length and width of the triceps brachii in 30 fetuses of both sexes (12♂,18♀) aged 12-29 weeks., Results: Neither sex nor laterality differences were found. All the parameters studied increased proportionately with age. The linear functions were computed as follows: y = 6.797 + 2.079 x Age (r = 0.886) for length of the long head's belly, y = - 0.041 + 0.215 × Age (r = 0.786) for width of the long head's belly, y = 1.889 + 0.174 × Age (r = 0.796) for length of the long head's proximal tendon, y = 0.158 + 0.052 × Age (r = 0.864) for width of the long head's proximal tendon, y = 5.270 + 1.809 × Age (r = 0.855) for length of the lateral head's belly, y = 0.348 + 0.284 × A ge (r = 0.829) for width of the lateral head's belly, y = 0.942 + 1.837 × Age (r = 0.839) for length of the medial head's belly, y = 0.314 + 0.234 × Age (r = 0.852) for width of the medial head's belly, y = - 3.191 + 0.984 × Age (r = 0.929) for lenght of the common tendon, and y = - 0.478 + 0.133 × Age (r = 0.933) for width of the common tendon., Conclusions: Neither male-female nor right-left differences are observed in morphometric parameters of the triceps brachii muscle. The long head's belly is the thinnest, while the lateral head's belly is the widest one. The long head is the longest and the medial head is the shortest one. The developmental dynamics of the triceps brachii muscle follow proportionately.