Human occlusofacial form commonality: race-related traits, ontogeny, paedomorphism, and functional correlates

Previous cephalometric studies of occlusofacial angular and metric data show small variability within and between population samples of Caucasian children and adults. Comparable results were obtained by use of standardized X-ray cephalometry and direct craniometric measurements of skulls of mature specimens of Alouatta caraya and Cebus capucinus. These data measure facial and occlusofacial form and form relationships. Identical measuring techniques are applied to compare data derived from headplates of 19 young adult American Caucasians and 19 articulated Hindu skulls of mature individuals. The data are expanded to include measurements that relate symphyseal form to occlusal and nasomaxillary structure. The facial plane and an "internal" facial plane (nasion to a point tangential to the superior genial tubercles) straddle the mandibular symphysis. The angles they form at nasion and at their intersections with the maxillary occlusal plane were derived and statistically analyzed. The occlusal plane intersect angles show small absolute variability and are not significantly different (P greater than .05) in the two groups. The nasion plane angles are significantly different (P less than .025), reflecting sample differences in facial height. Linear measurements confirm a considerably larger dentoalveolar prognathism in the Hindu group. Data derived from the geometrically averaged tracings of Bjork, Broadbent, Sassouni, and Solow provide further evidence of occlusofacial form commonality. These shared phyletically conservative traits are evidence of highly integrated morphological adaptations for the attainment, maintenance, and functioning of the species-wide pattern of precisely fitting complementary crowns and crown parts that constitute the dental occlusion.     

基于三维人脸模型及人工测量数据分析现代中国人群面部表型的性别差异

传统体质人类学研究中的样本采集方法是手工测量以及肉眼观察,采集过程中会存在较大的主观性,易产生误差,同时在采集大样本时费时费力。近年来,三维摄像系统被越来越多的应用于人脸分析,其优势是快速高效和准确,并且涵盖了传统测量方法无法精确获取的表型特征信息,可以更加细化地分析人脸表型特征和特征之间的相互关系。本研究探索性地基于三维人脸模型图像,利用曲率和邻域信息的点筛查方法定位了面部的一些关键测量点,建立一套简单、有效、准确率较高的三维人脸模型图像关键点定位方法,能较准确地定位98%以上的眼内角点和鼻尖点,并在此基础上确定了鼻根点、鼻下点、左右鼻翼点和鼻翼外侧最低点等其他面部关键点。并且还提出了在三维人脸模型图像基础上量化部分面部观察类表型特征,如鼻侧深度、鼻根高度、面部扁平度等,尝试性地将这些观察类性状转化为能够测量的性状,建立了一套可以计算的描述方法,具有一定的创新性。本研究还结合三维人脸模型提取数据和人工测量数据,探讨了现代中国人群(以江淮汉族为例)面部表型特征的性别差异,发现大多数面部表型特征在现代中国人群中都存在明显的男女性别差异,鼻侧深度、鼻根高度、面部扁平度的性别差异最为显著,其...     

Genome-wide association study of three-dimensional facial morphology identifies a variant in PAX3 associated with nasion position

Craniofacial morphology is highly heritable, but little is known about which genetic variants influence normal facial variation in the general population. We aimed to identify genetic variants associated with normal facial variation in a population-based cohort of 15-year-olds from the Avon Longitudinal Study of Parents and Children. 3D high-resolution images were obtained with two laser scanners, these were merged and aligned, and 22 landmarks were identified and their x, y, and z coordinates used to generate 54 3D distances reflecting facial features. 14 principal components (PCs) were also generated from the landmark locations. We carried out genome-wide association analyses of these distances and PCs in 2,185 adolescents and attempted to replicate any significant associations in a further 1,622 participants. In the discovery analysis no associations were observed with the PCs, but we identified four associations with the distances, and one of these, the association between rs7559271 in PAX3 and the nasion to midendocanthion distance (n-men), was replicated (p = 4 × 10(-7)). In a combined analysis, each G allele of rs7559271 was associated with an increase in n-men distance of 0.39 mm (p = 4 × 10(-16)), explaining 1.3% of the variance. Independent associations were observed in both the z (nasion prominence) and y (nasion height) dimensions (p = 9 × 10(-9) and p = 9 × 10(-10), respectively), suggesting that the locus primarily influences growth in the yz plane. Rare variants in PAX3 are known to cause Waardenburg syndrome, which involves deafness, pigmentary abnormalities, and facial characteristics including a broad nasal bridge. Our findings show that common variants within this gene also influence normal craniofacial development.     

Postnatal growth of the cranial base in Macaca nemestrina.

Postnatal growth of the cranial base was longitudinally studied in 21 male and 11 female Macaca nemestrina. The basicranium of each animal was marked with tantulum implants in order that the tracings of each serial roentgenogram could be superimposed. Between the ages of 3.0 and 5.0 years the degree of sexual demorphism in both angular and linear dimensions increased. The cranial base flattened as a result of the upward and forward migration of nasion and the upward and backward relocation of basion. The movement of basion was primarily due to differential growth recorded at the spheno-occipital synchondrosis. Sexual difference in the relative growth of this synchondrosis resulted in a longer and somewhat flatter male cranial base. Male and female velocity curves showed accelerations that coincide with their estimated age for the onset of puberty.     

Diachronic variation in cranial thickness of Near Eastern populations

Cephalometric radiographs were taken of 111 skulls of skeletal remains of populations living in Israel and Jordan during the last 12,000 years. From these radiographs, skull length and height, and cranial thickness were measured. For each sex and period, high correlations were found between cranial thickness at vertex, bregma, and lambda. Cranial thickness at nasion was correlated with sinus width but not sinus height. All measurements were correlated with skull length but not skull breadth. Using multivariate analysis, no significant differences in cranial thickness were found between the sexes. Significant diachronic trends were found in lambda and sinus width, and they were independent of variation in skull length.     

Origin of the widespread N18 in median nerve SEP

The widespread N18 potential in median nerve SEP was studied in normal subjects and in patients with high cervical, brain-stem and thalamic lesions who had profound disturbances of deep sensation. N18 was well identified in the HSi-CV2 derivation in every normal subject as a broad elevation from the baseline lasting about 20 msec. The cortical N20 was absent in all patients. N18 was absent in a patient with a dorsal column lesion at C1-2 level. The amplitude and configuration of N18 were normal in all other patients with brain-stem and thalamic lesions, including a patient with a lesion at the ponto-medullary junction. The sagittal distribution of N18 was studied in a patient with a thalamic lesion and an oblique distribution with the maximum region between Cz and nasion was demonstrated. The present results indicate that at least the greater part of N18 is generated at the caudalmost brain-stem or through branches from this level. Taking previous animal and intraoperative studies into consideration, we think it most probable that the main part of N18 corresponds to the ventro-rostral negative pole of the dipolar potential generated at the cuneate nucleus by the primary afferent depolarization of presynaptic terminals of dorsal column fibers.     

Nasal region polymorphism frequencies in the FrankfurtPan troglodytes verus collection

The results of a morphometric study on the mid-facial region in a collection of 278Pan troglodytes verus skulls are reported. Upwardly divergent nasal bones were found in 35 of the 124 specimens (28.2%) in which this feature could be analyzed. Appreciable separation (1 cm. or more) between nasion and glabella characterized 13 of the 154 skulls (8.4%) in which both these osteometric points could be observed. These findings document the wide ranges of variation that are normally to be found in modest-sized population samples of hominoid primates, and point to the inherent unreliability of cladistic analyses based on the hypothesis that hominoid primate taxa are monomorphic for these character states in the nasal region.     

Vertical growth of the anterior face and cranium in inner city Negro children

A longitudinal cephalometric study was conducted on the vertical growth of the cranium and anterior face on 60 inner city American Negro children, an equal number of boys and girls from four to nine years. Three vertical measurements were used for the purpose of this study. The head height was measured from sellion to bregma, bony nasal height from nasion to anterior nasal spine, and lower facial height from anterior nasal spine and lower facial height from anterior nasal spine to menton. The data were analyzed at annual ages and observations made relative to the growth trends. The findings of this study were compared with those on Caucasian children. No significant statistical difference was found in the mean head (cranial vault) height between the Negro and Caucasian children. The mean bony nasal height expressed as a percentage of subnasal height was found to be less in the Negro children. The difference decreased with age. The annual increment of growth in head height was greater from four to seven years than from seven to nine years. The findings are considered to imply that severe malnutrition may influence child growth.     

Discovery of an archaic Homo sapiens skullcap in Northeast Mongolia

This preliminary study of a human skullcap discovered at Salkhit, Northeast Mongolia, in 2006, shows a mosaic of traits. Plesiomorphies can be seen on the frontal bone: developed brow ridges and a keeled squama. Apomorphies can be observed: high and back-located parietal eminences and absence of a sagittal keel. The skullcap seems to share also some features with Neanderthals that can be observed on the lower part of the frontal bone and in the nasal and orbital region such as a supratoral sulcus, a prominent glabella, prominent rounded lateral supraorbital margins, and a well-defined inward nasion. The comparison of the dimensions of the skullcap with those of skullcaps of a reference sample by multidimensional scaling analysis shows similarities with Neanderthals, Chinese Homo erectus, and West/Far East archaic Homo sapiens. However, the too fragmentary condition of the fossil does not allow any further comparison. Nevertheless, this discovery tackles the modern human origins debate in a region of the world where no human fossil had been discovered before.     

Cranial base and jaw relationship

The lateral skull radiographs of 124 boys aged approximately 10 years divided equally between the four angle classes were digitized in an effort to establish the relationship between cranial base size and shape and jaw relationship. Comparison of the means for occlusal groups showed a trend from class II to class III as cranial base dimensions and angle decreased. The condyle was also more distally positioned with respect to nasion, point A and the Pterygomaxillary vertical in the class II groups. Cranial base length correlated strongly with maxillary length but weakly with mandibular length. Nevertheless, the size of the maxilla did not influence its prognathism. The cranial base angle was strongly correlated (-0.7) with angle sella-nasion-point B. It is concluded that cranial base size and shape influence mandibular prognathism by determining the anteroposterior position of the condyle relative to the facial profile.     

Auditory evoked potential in normal rats and after para-chlorophenylalanine (PCPA) treatment

We have studied the latency behaviour of an early component of the cortical acoustic evoked potentials (EAEP) in albino rats after administration of p-chlorophenylalanine (PCPA), a rather selective tryptophan-hydroxylase inhibitor, at a dose of 100 mg/kg daily for 3 days. The rats were implanted with 3 chronic electrodes: one in the bregma, one in the nasion and 3rd inserted in the periauricular skin. Series of clicks originating from a square pulse of 0.12 msec duration were administrated. Brain responses were amplified by an EEG and averaged by a computer with different post-stimuli analysis times. A first group of 4 rats was tested with clicks of 100 dB (HTL) intensity and brain responses were analysed at 5,10,25,50,100 msec post-stimuli times. Results demonstrate that after PCPA administration there is a latency reduction of EAEP components that have a latency higher than 20 msec. In a second group of 4 rats we have analysed those EAEP components with an intensity of clicks ranging from 60 to 110 dB and results demonstrate that, when PCPA was administered, Latencies of those components were significatively lower than the controls at each stimuli intensity tested. We concluded that 5-HT may influence the acoustic pathways activity and this is according to remarks of other A.A. that found a correlation between acoustic stress and brain 5-HT levels.     

Prospective anthropometric analysis of sagittal orbital-globe relationship following fronto-orbital advancement in childhood

Fronto-orbital advancement is a common procedure for correction of supraorbital retrusion in patients with coronal craniosynostosis. The aim of this study was two-fold: to quantitate change in the sagittal orbital-globe relationship following fronto-orbital advancement in childhood and to determine the ratio of skeletal-to-soft tissue movement. Soft-tissue points on the orbital rim, orbitale superius (os), orbitale laterale (ol), orbitale inferius (oi), and nasion (n), referenced to apex corneae (ac), were measured preoperatively and postoperatively by a custom-made anthropometer. Intraoperative bony advancement was measured with a caliper. Patients were selected with uniform advancement at the fronto-nasal suture and laterally at the mortise and tenon. Fifteen patients with syndromic craniosynostosis were included in the study (six male, nine female): Apert (n = 2), Crouzon (n = 5), Pfeiffer (n = 4), Saethre-Chotzen (n = 3), and Boston type (n = 1). Average age at operation was 8.7 years (range, 4.5 to 10.5 years). Age, sex, method of fixation, postoperative interval, diagnosis, and skeletal movement were analyzed for possible effect on the magnitude of soft-tissue advancement. Average intraoperative skeletal advancement was 12.1 mm, and average postoperative soft-tissue movement was 10.3 mm (p < 0.001), measured at the midpoint of the supraorbital rims (os). The soft tissue: skeletal movement ratio was 0.9:1. Os was the only point at which soft-tissue advancement could be predicted (Spearman's rank correlation coefficient = 0.67); soft-tissue changes at ol, oi, and n were unpredictable. Skeletal movement was the only determinant of soft-tissue advancement of all variables tested, i.e., diagnosis, age, sex, previous fronto-orbital advancement, and wire versus plate fixation. We make recommendations for calculating the magnitude of fronto-orbital advancement, based on preoperative anthropometry and a soft-to-hard tissue advancement factor.     

Factors Influencing Superimposition Error of 3D Cephalometric Landmarks by Plane Orientation Method Using 4 Reference Points: 4 Point Superimposition Error Regression Model

Superimposition has been used as a method to evaluate the changes of orthodontic or orthopedic treatment in the dental field. With the introduction of cone beam CT (CBCT), evaluating 3 dimensional changes after treatment became possible by superimposition. 4 point plane orientation is one of the simplest ways to achieve superimposition of 3 dimensional images. To find factors influencing superimposition error of cephalometric landmarks by 4 point plane orientation method and to evaluate the reproducibility of cephalometric landmarks for analyzing superimposition error, 20 patients were analyzed who had normal skeletal and occlusal relationship and took CBCT for diagnosis of temporomandibular disorder. The nasion, sella turcica, basion and midpoint between the left and the right most posterior point of the lesser wing of sphenoidal bone were used to define a three-dimensional (3D) anatomical reference co-ordinate system. Another 15 reference cephalometric points were also determined three times in the same image. Reorientation error of each landmark could be explained substantially (23%) by linear regression model, which consists of 3 factors describing position of each landmark towards reference axes and locating error. 4 point plane orientation system may produce an amount of reorientation error that may vary according to the perpendicular distance between the landmark and the x-axis; the reorientation error also increases as the locating error and shift of reference axes viewed from each landmark increases. Therefore, in order to reduce the reorientation error, accuracy of all landmarks including the reference points is important. Construction of the regression model using reference points of greater precision is required for the clinical application of this model.     

新疆且末县加瓦艾日克墓地人骨研究

本文通过对新疆且末县托乎拉克勒克乡加瓦艾日克村29座墓地出土的人骨标本进行了观察和分析。共鉴定出150例个体,其中男性73例、女性50例、性别不明者27例。男性、女性平均死亡年龄分别为36.3岁和35.6岁。形态学的分析指出且末人群更多地具有欧洲人种的特点,如鼻根凹陷深、鼻骨明显突起及犬齿窝深等。聚类分析结果显示且末人群与新疆古代人群焉布拉克C组、察吾呼四号组、多岗等人群较为接近。文章还根据线粒体DNA的分析结果讨论了且末古代人群的种族属性,古DNA的分析揭示出且末人群存在欧亚大陆东、西部人群的基因交流,并进一步指出其西部类型的成分来源极有可能来自西伯利亚,其东部成分可能来自西伯利亚或中国甘肃,只是东西方人群的基因融合规模小而且处于初级阶段,所以并未在颅面部形态特征上有大规模明显的改变。此外,本文从考古学文化、体质人类学研究以及古DNA等几个方面探讨了新疆地区古代人群的种族成分来源。本文还对且末人群的身高进行了推算,对一例变形颅骨以及骨骼上的创伤作了简要描述。     

A topography-based model of forest cover at the alpine tree line in the tropical Andes

Aim  To present a method that assesses the influence of environmental variables, including climate, substrate, topography, and anthropogenic disturbances, on the distribution of Andean forest at the tree line, and to compare this forest distribution between areas.
Location  Sangay National Park, on the eastern slopes of the Andes in central Ecuador.
Methods  A logistic regression model was built using topographical variables and environmental indices, derived from a digital elevation model, to explain forest cover, derived from a Landsat ETM image, in a zone around the average tree line altitude.
Results  The model shows that after altitude, which can explain about 80% of forest cover, wetness has the next strongest effect (areas accumulating water, but also cold air, were devoid of forest, resulting in inverted tree lines), followed by eastness (western slopes had forest to higher altitudes). Application of the model in two nearby areas showed that the real tree line was lower than the predicted tree line in both areas, probably owing mainly to macroclimatic differences in one area, and partly also to human land use in the other. The locations with the largest deviations could be the focus of further research concerning human impacts on tree line vegetation.
Main conclusions  The tree line is located at lower altitudes on east-facing slopes, which may be because high levels of radiation are received by east-facing slopes in the clear mornings, resulting in the photoinhibition of tree seedlings in the páramo. In spite of the limitations of the quality and resolution of the remote sensing data, the presented method provides indications for important ecological factors at the tree line. The method also allows the detection of differences in tree line position between areas, which may reflect climatic differences or the location of anthropogenic disturbances.     

The basicranial axis in certain fossil hominoids

The publication of accurate sagittal diagrams of the skulls of certain australopithecine fossils has permitted biometrical comparison of their basicranial axis, together with its anterior extension to the nasion, its posterior extension to the opisthion and the two associated angles, to be made with the corresponding regions in monkeys, apes and Man.
Univariate study has shown that after appropriate correction for differences in overall size, each of these quantities effects discrimination between certain extant primate groups. All can be separated if the measurements are taken seriatim. Australopithecus transvaalensis and Australopithecus boisei are thus distinguished both from extant groups and from each other.
Multivariate study (generalized distances and canonical coordinates) shows that both these fossils are distinct from all living groups which, in turn, are separate from one another.
Such unique characterization of the basicranial axis in the Australopithecinae parallels taxonomic distinctiveness already established in respect of their teeth, their occipital condyles and several regions of their postcranial skeleton.     

Technical note: calculation of age at formation of radiopaque transverse lines

A simple method for determining the age of an individual at the time of radiopaque transverse (Harris) line formation is presented. To use this method, only two measurements are required: total bone length and distance of line to nearest bone end; these are put into formulae that calculate the percent of total bone growth when the line appeared. The result of this calculation is compared with tables of percent bone growth per year (one to 16 years in females and one to 18 years in males) to arrive at estimations of age at line formation. Since these tables are presented for the femur, tibia, humerus, and radius, this technique can be used on any one of the major long bones exhibiting lines.     

A statistical method for determining the breakpoint of two lines

A method is presented for determining the breakpoint of a line which suddenly changes slope at some unknown point. A statistical test is given for testing whether the broken line is a significantly better fit to the data than a single straight line. An approximate confidence interval can be obtained for the position of the breakpoint.     

Development of at‐line assay to monitor charge variants of MAbs during production

One major challenge currently facing the biopharmaceutical industry is to understand how MAb microheterogeneity affects therapeutic efficacy, potency, immunogenicity, and clearance. MAb micro‐heterogeneity can result from post‐translational modifications such as sialylation, galactosylation, C‐terminal lysine cleavage, glycine amidation, and tryptophan oxidation, each of which can generate MAb charge variants; such heterogeneity can affect pharmacokinetics (PK) considerably. Implementation of appropriate on‐line quality control strategies may help to regulate bioprocesses, thus enabling more homogenous material with desired post‐translational modifications and PK behavior. However, one major restriction to implementation of quality control strategies is the availability of techniques for obtaining on‐line or at‐line measurements of these attributes. In this work, we describe the development of an at‐line assay to separate MAb charge variants in near real‐time, which could ultimately be used to implement on‐line quality control strategies for MAb production. The assay consists of a 2D‐HPLC method with sequential in‐line Protein A and WCX‐10 HPLC column steps. To perform the 2D‐HPLC assay at‐line, the two columns steps were integrated into a single method using a novel system configuration that allowed parallel flow over column 1 or column 2 or sequential flow from column 1 to column 2. A bioreactor system was also developed such that media samples could be removed automatically from bioreactor vessels during production and delivered to the 2D‐HPLC for analysis. With this at‐line HPLC assay, we have demonstrated that MAb microheterogeneity occurs throughout the cell cycle whether the host cell line is grown under different or the same nominal culture conditions. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 30:249–255, 2014     

肉桂油成分分析及肉桂醛体外抗肿瘤活性研究

目的探讨肉桂醛对不同肿瘤细胞株的生长抑制作用。方法通过水蒸气蒸馏法提取肉桂油,用气相色谱—质谱联用仪进行肉桂油成分分析;采用噻唑蓝（MTT）比色法检测肉桂醛对体外培养的人宫颈癌细胞系HeLa细胞株、人肺癌细胞系A-549细胞株和人肝癌细胞系HepG2细胞株的生长抑制作用,计算半数抑制浓度（IC50）。结果肉桂油的收率为1.96%,分析了肉桂油中的10种成分,主要为肉桂醛,占总馏出峰面积的93.94%;肉桂醛能抑制人宫颈癌细胞系HeLa细胞、人肺癌细胞系A-549细胞和人肝癌细胞系HepG2细胞增殖,且呈剂量依赖性,IC50值分为0.20、0.36和0.73 mg/mL。结论肉桂醛具有体外抗肿瘤活性。