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ABSTRACT: This investigation determined the variation, prevalence, tissue-type, and sex bias in the soft-tissue bridge between rectus capitis posterior minor (RCPMi) and the posterior atlanto-occipital membrane (PAO). Seventy-five cadavers (27 females and 48 males) were surveyed. When RCPMi was revealed, its superior attachment was detached and the muscle was reflected inferiorly to determine if it was attached to the underlying PAO. If a soft-tissue bridge was identified, the fibers found within the bridge were classified by visual inspection into three categories: tendon-like, muscle-like, and fascia-like. A fourth category of no attachment was also noted. These results show that RCPMi was present bilaterally in 93% of all cadavers surveyed (89% of the female cadavers and 96% of the male cadavers). On the right side, a soft-tissue bridge was present in 67% of males and 78% of females. On the left side, the soft-tissue bridge was present in 69% of males and 82% of females. The number of male cadavers possessing tendon fibers in a soft-tissue bridge was 56% on the right side and 55% on the left side. In females, the number of cadavers possessing tendon fibers in a soft-tissue bridge was 44% on the right side and 64% on the left side. In males, muscle fibers were present in the soft-tissue bridge, 34% on the right side and 36% on the left. In females, muscle fibers were found in the soft-tissue bridge, 43% on the right side and 36% on the left. There were no significant associations of sex and the presence of the soft-tissue bridge and a fiber-type within a soft-tissue bridge.
Clinical Anatomy 10/2006; 19(6):522-7. · 1.29 Impact Factor
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ABSTRACT: This study investigates whether macaques and humans possess a common pattern of relative growth during the fetal period. The fetal samples consist of 16 male pigtailed macaques (mean age, 20.5 gestational weeks) and 17 humans (9 males and 8 females; mean age, 29.5 gestational weeks). For each individual, three-dimensional coordinates of 18 landmarks on the skull were collected from three-dimensional computed tomographic (CT) reconstructed images and two-dimensional CT axial slices. Early and late groups were created from the human (early mean age, 24 weeks, N = 8; late mean age, 34 weeks, N = 9) and macaque samples (early mean age, 17.7 weeks, N = 7; late mean age, 23 weeks, N = 9). Inter- and intraspecific comparisons were made between the early and late groups. To determine if macaques and humans share a common fetal pattern of relative growth, human change in shape estimated from a comparison of early and late groups was compared to the pattern estimated between early and late macaque groups. Euclidean distance matrix analysis was used in all comparisons. Intraspecific comparisons indicate that the growing fetal skull displays the greatest amount of change along mediolateral dimensions. Changes during human growth are primarily localized to the basicranium and palate, while macaques experience localized change in the midface. Interspecific comparisons indicate that the two primate species do not share a common pattern of relative growth, and the macaque pattern is characterized by increased midfacial growth relative to humans. Our results suggest that morphological differences in the craniofacial skeleton of these species are in part established by differences in fetal growth patterns.
American Journal of Physical Anthropology 05/2003; 120(4):339-51. · 2.82 Impact Factor
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Michael P Zumpano
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ABSTRACT: Form changes within the fetal pigtailed macaque (Macaca nemestrina) craniofacial complex was documented using finite element scaling analysis (FESA) and three-dimensional (3D) coordinate data for 35 craniofacial landmarks. Coordinate data were digitized from 3D reconstructions of computed tomography (CT) images and 2D axial slices. Twenty-two fetal pigtailed macaques ranging in age from 137 to 157 gestational days were included (in this species, birth is estimated at 170 gestational days). The null hypothesis that the craniofacial complex grows with isometry during late fetal growth of the craniofacial complex was tested (P < 0.05), and the prediction that morphological change along an anteroposterior axis dominates late fetal growth was also investigated. The null hypothesis was rejected, indicating that allometric growth is present during late fetal growth. Growth along an anteroposterior axis is localized in the palate and mandible. The neurocranium grows along a superoinferior axis, while the neurofacial junction displays growth along both the anteroposterior and superoinferior axes. Mediolateral changes are localized between asterions, the external auditory meati, and maxillary and mandibular alveolar points. Finally, a 3D model of craniofacial growth for this species was created, localizing size and shape changes that occur during late fetal growth for each of the 35 craniofacial landmarks defined in this study.
The Anatomical Record 09/2002; 267(4):307-20.
