Quantitative study of the primary ossification centre of the parietal bone in the human fetus.

BACKGROUND: Detailed morphometric data concentrating on the development of primary ossification centres in human fetuses is critical for the early detection of developmental defects. Thus, an understanding of the growth and development of the parietal bone is crucial in assessing both the normal and pathological development of the calvaria. MATERIALS AND METHODS: The size of the parietal primary ossification centre in 37 spontaneously aborted human fetuses of both sexes (16 males and 21 females) aged 18-30 weeks was studied by means of computed tomography, digital-image analysis and statistics. RESULTS: The numerical data of the parietal primary ossification centre in the human fetus displays neither sex nor laterality differences. With relation to fetal age in weeks, the parietal primary ossification centre grew in sagittal diameter according to the quadratic function: y = 16.322 + 0.0347 × (age)² ± 1.323 (R² = 0.96), in projection surface area according to the cubic function: y = 284.1895 + 0.051 × × (age)³ ± 0.490, while in both coronal diameter and volume according to the quartic functions: y = 21.746 + 0.000025 × (age)4 ± 1.256 and y = 296.984 + + 0.001 × (age)4, respectively. CONCLUSIONS: The obtained morphometric data of the parietal primary ossification centre may be considered age-specific references, and so may contribute to the estimation of gestational ages and be useful in the diagnostics of congenital cranial defects.

Quantitative anatomy of the growing supraspinatus muscle in the human fetus.

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.

Quantitative anatomy of primary ossification centres of the lateral and basilar parts of the occipital bone in the human foetus.

BACKGROUND: Computed tomography (CT)-based quantitative analysis of primary ossification centres in the cranium has not been carried out to date due to the limited availability of the foetal human material. Detailed morphometric data about the development of primary ossification centres in human foetuses may be useful in the early detection of developmental defects. Understanding the growth and development of the occipital bone is crucial in assessing the normal and pathological development of the cranial base, and the cranium as a whole. MATERIALS AND METHODS: The study material comprised 37 human foetuses (16 males and 21 females) aged 18-30 weeks of gestation. Using CT, digital image analysis software, three-dimensional reconstruction and statistical methods, the size of the primary ossification centres of the lateral and basilar parts of the occipital bone was evaluated. RESULTS: The morphometric characteristics of primary ossification centres of the lateral and basilar parts of the occipital bone display neither sex nor laterality differences. These ossification centres grow linearly with respect to their sagittal and transverse diameters, projection surface area and volume. CONCLUSIONS: The obtained morphometric data of primary ossification centres in the lateral and basilar parts of the occipital bone may be considered as normative for their respective prenatal weeks and may contribute to the estimation of gestational ages and the diagnostics of congenital defects.