Orthodontic status and head morphology in young males

Complete anthropometrical data on a sample of 111 Russian males aged 20.0+/-2.3 years were obtained to investigate craniofacial morphology according to individual orthodontic status (OS). Subsample analyses were performed, using a variety of grouping factors. a) 1-spacing on both dental arches; 2-absence of crowding, spacing, rotation, or displacement of teeth on both dental arches; 3-crowding on both dental arches; b) 1-spacing on mandible; 2-absence of crowding, spacing, rotation, or displacement of teeth on mandible; 3-crowding on mandible; c) 1-spacing on maxilla; 2-absence of crowding, spacing, rotation, or displacement of teeth on maxilla; 3-crowding on maxilla. Wilks' Lambdas were found to be 0.29 to 0.59; all were significant. CONCLUSIONS: 1. Significant positive and negative correlations were found between craniofacial measurements and an individual's OS. 2. Measurements exhibited statistically significant differences between the groups with different OS at the p<0.05 level and some at p<0.01. 3. Using forward stepwise discriminant analysis, a high difference in craniofacial architecture between the groups with different OS was found. Canonical discriminant analysis indicates the face pattern connected to crowding: relatively high medial vertical mandible height in combination with a vertically long and narrow face; to spacing: a wide face with wide nose and high upper lip is combined with shortened medial vertical mandible height. 4. Depending upon the grouping factor, 10 to 12 variables were chosen in the canonical discriminant model. Classification functions and means of canonical roots were calculated; morphological interpretations of canonical roots were performed. 5. Definitive OS is a complicated product of interaction during the ontogenesis of jaws between the time of teeth eruption and the growth of two growth fields (alveolar and corpus) under the simultaneous influence of hormonal status and the chronological age of the individual.     

Craniofacial growth in subjects with unilateral complete cleft lip and palate, and unilateral incomplete cleft lip, from 2 to 22 months of age

This paper reports a longitudinal quantitative cephalometric analysis of the craniofacial growth in subjects with unilateral complete cleft lip and palate (UCCLP), and unilateral incomplete cleft lip (UICL), from 2 to 22 months of age. The purpose of the study was to determine the amount and direction of growth in UCCLP compared to UICL (control group) from 2 months of age (just prior to lip repair) to 22 months of age, 20 months later. The sample comprised of 49 subjects with UCCLP (37 males and 11 females) and 45 with UICL (29 males and 16 females). The cephalometric analysis of the craniofacial morphology included lateral, frontal, and axial projections. The data were presented as mean plots of the craniofacial region including the calvaria, cranial base, orbits, nasal bone, maxilla, mandible, cervical column, pharynx, and soft-tissue profile. A valid common coordinate system (registration according to the n-s line in the lateral projection, latero-orbitale line in the frontal projection, and meatus acusticus externus line in the axial projection for the landmark positions at examination 1 and 2) was ascertained. The growth at a specific anatomical location in a patient was defined as the displacement vector from the coordinate of the corresponding landmark in the X-ray at examination 1 to its coordinate at examination 2, corrected for X-ray magnification. The growth of an anatomical region in a patient was assessed by investigating the growth pattern formed by a collection of individual growth vectors in that region. The amount of growth in the UCCLP and UICL group was very similar. The general craniofacial growth pattern, in terms of the direction of growth, was also fairly similar in the UCCLP group and the control group. However, the maxilla and mandible showed a more vertical growth pattern than that observed in the control group. This study confirms that UCCLP is a localized deviation, and not a craniofacial anomaly, due to the fact that a normal growth potential has been observed in all craniofacial regions, except where the growth had been directly influenced by surgical intervention. Furthermore, the vertical growth pattern of the maxilla and mandible supports the hypothesis of a special facial type in cleft lip and palate individuals, and the facial type as a liability factor increasing the probability of cleft lip and palate.     

Growth of the maxillary complex in the rhesus monkey (Macaca mulatta)

The growth of the maxillary complex of 36 rhesus monkeys (Macaca mulatta) was analyzed quantitatively and qualitatively during four defined stages of postnatal development (i.e., infant, juvenile, adolescent, young adult). At each stage, growth was observed during a 24 week period. Since some animals were observed during two successive stages of development, 47 periods of growth were studied. The incremental growth data were collected by superimposing serial cephalograms on cranial base implants and on maxillary implants. The largest increments of growth were observed in the infant animals and were successively less during the other periods studied. The horizontal growth component was more prominent than the vertical component in all age groups. The contribution of sutural growth to the vertical displacement of the maxilla was greater posteriorly, leading to a rotation of the maxillary complex during growth. The occlusal relationship was maintained by selective bone remodeling in conjunction with dentitional migration.     

自体颏部骨移植并种植体修复前牙槽骨缺损的应用研究

目的:评价自体颏部骨移植方法在前牙槽骨缺损植骨及种植的效果。方法:对16例前牙骨缺损的患者进行自体颏部骨移植,分别于植骨12～16周后植入种植体,共植入18枚种植体,术后16～20周完成修复治疗。结果:16例自体骨移植患者中,1例出现术后感染,经局部冲洗换药后后愈合良好,其余患者移植骨均已成活,修复后种植体至今均无脱落,局部外形良好。结论:自体颏部骨移植能有效恢复局部牙槽外形,为前牙美学修复提供良好的基础。     

Age assessment in infant crab-eating monkeys (Macaca fascicularis) based on tooth development

Tooth development was studied in 13 Macaca fascicularis monkeys with known dates of birth. Regular intra-oral examination was carried out and standardized lateral radiographs were collected from 27 until 150 weeks of age under general anaesthesia.
Three stages of tooth development were determined radiographically: onset of crypt formation, onset of mineralization, and crown completion. A fourth stage, the emergence, was determined clinically. Developmental stages were recorded for six mandibular and five maxillary teeth.
The ages of emergence of the permanent teeth and the developmental stages of the third molars showed the largest variation. A significant sex difference with earlier maturation in males was found for the start of crypt formation of the maxillary permanent canines and the maxillary second premolars, and for the start of mineralization of the maxillary permanent canines.
The data provide a tool by which chronological age can be assessed of Macaca fascicularis monkeys between 30 and 80 weeks of age. Owing to an interphase of about one year without significant developmental features in the dentition, age assessment based on tooth development cannot be performed from about 80 to 130 weeks of age. Age assessments are possible for the period between 130 and 150 weeks of age. However, in this period the reliability of the data is lower due to larger time intervals and standard deviations.     

Long-term skeletal stability after maxillary advancement with distraction osteogenesis using a rigid external distraction device in cleft maxillary deformities

Rigid external distraction is a highly effective technique for correction of maxillary hypoplasia in patients with orofacial clefts. The clinical results after correction of sagittal maxillary deformities in both the adult and pediatric age groups have been stable. The purpose of this retrospective longitudinal cephalometric study was to review the long-term stability of the repositioned maxilla in cleft patients who underwent maxillary advancement with rigid external distraction. Between April 1, 1995, and April 1, 1999, 17 consecutive patients with cleft maxillary hypoplasia underwent maxillary advancement using rigid external distraction. There were 13 male patients and four female patients, with ages ranging from 5.2 to 23.6 years (mean, 12.6 years). After a modified complete high Le Fort I osteotomy and a latency period of 3 to 5 days, patients underwent maxillary advancement with rigid external distraction until proper facial convexity and dental overjet and overbite were obtained. After active distraction, a 3- to 4-week period of rigid retention was undertaken; this was followed by removable elastic retention for 6 to 8 weeks using, during sleep time, an orthodontic protraction face mask. Cephalometric radiographs were obtained preoperatively, after distraction, at 1 year after distraction, and 2 or more years after distraction. The mean follow-up was 3.3 years (minimum, 2.1 years; maximum, 5.3 years). The following measurements were obtained in each cephalogram: three linear horizontal and two linear vertical maxillary measurements, two angular craniomaxillary measurements, and one craniomandibular measurement. Differences between the preoperative and postoperative cephalometric values were analyzed by paired t tests (p < 0.05). The cephalometric analysis demonstrated postoperatively significant advancement of the maxilla. In addition, the mandibular plane angle opened 1.2 degrees after surgery. After the 1- to 3-year follow-up period, the maxilla was stable in the sagittal plane. Minimal anteroposterior growth was observed in the maxilla compared with that exhibited in the anterior cranial base. However, there was significant vertical maxillary growth over the 3-year observation period. The mandibular plane angle tended to decrease during the follow-up period. The cephalometric data from this study support the clinical impression of maxillary stability after maxillary advancement with rigid external distraction in cleft patients. This effective and stable technique is now considered for all pediatric patients with severe cleft maxillary hypoplasia and for adolescent and adult patients with moderate to severe deformities.     

Ameloblastic odontoma in a cynomolgus monkey (Macaca fascicularis)

An ameloblastic odontoma occurred in an adult cynomolgus monkey (Macaca fascicularis). The neoplasm involved the upper left maxilla as a disfiguring, fleshy growth. The tissue and cellular changes were consistent with an ameloblastic odontoma which is rare in man, nonhuman primates (NHP), and other vertebrate animals. The monkey was one of 50 adult, single-caged housed cynomolgus monkeys. No additional clinical signs of disease were present. Hematology and serum chemistries were within normal limits. There have been three reports in the literature of ameloblastic odontomas in NHP; however, this is the first reported case of an ameloblastic odontoma in a cynomolgus monkey.     

记裂齿鱼属(Perleidus)一新种

本文记述了在安徽和县发现的裂齿鱼属一新种——扬子裂齿鱼(Perleidus yangtzensis,sp.nov.)。根据其形态特征,与相近的种作了对比,认为和马达加斯加早三迭世的皮氏裂齿鱼(P.pivetcaui)最为接近。从而认为含鱼化石地层的时代为三迭纪或可能为早三迭世。     

第四纪响蜥(Tinosaurus)化石的首次发现

在陕西洛南张坪洞穴的第四系中采得一些响蜥类(Tinosaurus)化石,有保存相当完好的上下齿骨和齿列,这是响蜥在第四纪的首次报道,使该属化石的地史分布从早第三纪延伸到第四纪。新材料下颌骨较粗壮,但个体很小,有齿间沟,同时兼具亚洲种及北美种的某些特征,因此建立一新种Tinosaurus luonanensis sp．nov．。     

微种植体支抗内收及压低上前牙的有限元研究

目的:探讨在利用微种植体支抗整体内收前牙过程中增加前牙区不同位置压低力对上颌前后牙的生物力学效应的影响。方法:采用螺旋CT扫描获取图像并结合MIMICS等软件进行三维重建,建立拔除上颌第一前磨牙整体内收前牙的三维有限元模型,分析利用第二前磨牙与第一磨牙间微种植体整体内收前牙过程中,增加前牙区不同位置压低力后前后牙的生物力学效应。结果:增加前牙区压低力后,前牙舌向倾斜移动明显减小,不同位置的垂直向力对前牙的影响不同,第一磨牙在整体内收过程中表现为远中倾斜移动。结论:1增加前牙区压低力能够实现对前牙转矩的有效控制;2增加前牙区的压低力使前牙更趋向于整体移动;3在微种植体支抗内收前牙过程实现了较好的垂直向控制。     

陕北槽齿类新发现

本文记述了采自陕北府谷县三迭系和尚沟组上部的一槽齿类化石。根据骨髂形态特征认为属于古鳄亚目的原鳄科,与Chasmatosaurus和Elaphrosuchus相近,但上颌骨参与外鼻孔的构成及前上颌骨不呈喙嘴状等却显著不同。为此另建立一新属(Xilousuchus)。考虑其一些进步的构造、新属种的生存时代应稍晚于上述Chasmatosaurus和Elaphrosuchus。     

Cephalometric analysis of the craniofacial region of the northern Foxe Basin Eskimo

Past investigations of the Eskimo have indicated that there are marked morphological differences in the craniofacial skeleton of this relatively isolated ethnic group compared to other ethnic and racial groups. This study, using cephalometric radiography, attempted to characterize the craniofacial phenotype of the Eskimo living in the northern Foxe Basin, Northwest Territories, Canada. Age changes were examined on a cross-sectional basis with comparisons being made with a Winnipeg Caucasian group. This investigation indicates that the Igloolik Eskimo has a phenotype, established early in life, and is distinct from the Winnipeg group. The overall size of the Eskimo craniofacial complex was significantly larger at three years of age and remained larger through the ages studied. Development of the craniofacial region, however, was fairly similar in rate and direction for both populations. The greatest differences between the Eskimo and Caucasian groups were found in the linear measurements assessing cranial width, facial width, mandibular length, facial height, protrusion of the incisors, chin point development, and nasal morphology. Differences between the two groups in the morphological relationships of the component structures include the angular relationships of the maxilla and nasal bones to the anterior cranial base, the gonial angle of the mandible, and the angle of facial convexity.     

Prenatal ontogeny of subspecific variation in the craniofacial morphology of the Japanese macaque (<Emphasis Type="Italic">Macaca fuscata</Emphasis>)

We cross-sectionally investigated prenatal ontogeny of craniofacial shape in the two subspecies of the Japanese macaque (Macaca fuscata fuscata and Macaca fuscata yakui) using a geometric morphometric technique to explore the process of morphogenetic divergence leading to the adult morphological difference between the subspecies. The sample comprised a total of 32 formalin-fixed fetal specimens of the two subspecies, in approximately the second and third trimesters. Each fetal cranium was scanned using computed tomography to generate a three-dimensional surface model, and 68 landmarks were digitized on the external and internal surface of each cranium to trace the growth-related changes in craniofacial shape of the two subspecies. The results of our study demonstrated that the two subspecies generally shared the same craniofacial growth pattern. Both crania tend to exhibit relative contraction of the neurocranium in the mediolateral and superoinferior directions, a more superiorly positioned cranial base, a more vertically oriented occipital squama, and a more anteriorly positioned viscerocranium as the cranial size increased. However, distinctive subspecific differences, for example relatively narrower orbital breadth, higher orbit, higher position of the nuchal crest, and more protrudent snout found in Macaca fuscata yakui were already present during the prenatal period. This study demonstrated that morphological differentiation in the craniofacial shape may occur at a very early stage of the fetal period even between closely related subspecies of the Japanese macaque.     

Craniofacial growth of fetal Macaca nemestrina: A cephalometric roentgenographic study

The prenatal growth of the macaque craniofacial skeleton is described using lateral radiographs of 82 fetal and 25 neonatal Macaca nemestrina whose known gestational ages range from 50 to 186 days. The ossification sequence of the craniofacial bones resembles that in the human fetus. During gestation, the macaque neurocranium loses its round, globular shape, becoming flattened and elongated in an anteroposterior direction. In contrast, the morphologic pattern of the face is established early in fetal life, and little change takes place during the remaining prenatal period. The macaque craniofacial dimensions develop along the general skeletal growth pattern, unlike the human craniofacial dimensions, which follow an intermediate pattern between the neural and general skeletal patterns. However, despite minor differences, the macaque and human fetal faces follow the same basic patterns of growth.     

食蟹猴微卫星DNA标记遗传监测及多态性分析

目的研究国内食蟹猴种群的遗传背景特性,建立食蟹猴种群遗传质量监测方法。方法采用微卫星DNA遗传标记技术对50只食蟹猴种群个体进行遗传质量监测及DNA多态性分析。结果从100个微卫星DNA位点中筛选出20个多态性高的位点,其食蟹猴种群个体的等位基因数目为5-10条,个体间均呈现高度的多态性;其观察等位基因数（Na）为5.0～10.0,有效等位基因数（Ne）为4.6118～8.3404,基因多样性（H）为0.7832～0.8801和香隆信息指数（I）为1.5651～2.1592。结论本实验有效地分析了食蟹猴种群的遗传多态性,为今后筛选特异性微卫星位点来建立食蟹猴种群遗传质量监测方法提供了理论依据。     

Observations on the polyphyodont dentition of Hemiphractus proboscideus (Anura: Hylidae)

In Hemiphractus fang–like teeth are ankylosed to the premaxilla, maxilla and prevomer, and bony odontoids are found on the dentary, angular and palatine bones. The odontoids are small, but a larger pair at the front of the lower jaw project upwards and backwards into the mouth and fit into a diastema between the anterior premaxillary teeth when the mouth is closed.
The teeth are unipartite and monocuspid, and each consists of a strongly recurved and elongated cone of orthodentine, capped at the tip by a thin layer of enamel. The inner circumpulpal layer of the dentine is tubular, but no tubules are present in the outer pallial layer. During tooth development, dentine is formed before the enamel matrix is produced, and the tooth germs lie horizontally beneath the ventral surface of each dentigerous bone. On eruption, the tooth germs migrate horizontally and become ankylosed to the outer edge of the jaw bone by a layer of cellular cementum.
During tooth replacement, the vast majority of the dentine of each tooth, and the cementum at the tooth base, are resorbed by osteoclasts. It is not clear whether the tips of the teeth are shed or not.     

笼养食蟹猴行为时间分配对抑郁模型行为评价的启示

为了从笼养食蟹猴行为时间分配的研究中分析影响行为时间分配的因素并为抑郁模型行为评价选择最佳的时间窗,2011年1月～6月,采用动物焦点观察法对江苏省苏州中科实验动物有限公司的40只笼养食蟹猴的昼间活动规律进行昼间7个时段行为观察.研究发现,笼养食蟹猴昼间7个时段行为时间分配表现为休息最多(68.58％),其次是进食(10.14％)、社会交流(9.92％)、运动(5.57％);争斗和交配较少;社会交流行为持续时间在上午时段( 10:30～11:30)明显高于下午时段(14:30 ～ 16:30)(Z=-4.72,P＜0.01);幼崽对母亲猴的行为影响明显,有幼崽组较无幼崽组具有更高的社会行为(Z=-2.86,P＜0.01)和运动行为(Z=-6.57,P＜0.01);运动行为与年龄呈负相关(rs=-0.357).研究表明幼崽和年龄因素影响食蟹猴7个时段行为时间分配,抑郁模型行为评价宜选择上午时段(10:30 ～11:30).     

Differential correlates of diet and phylogeny on the shape of the premaxilla and anterior tooth in sparid fishes (Perciformes: Sparidae)

We explore the correlational patterns of diet and phylogeny on the shape of the premaxilla and anterior tooth in sparid fishes (Perciformes: Sparidae) from the western Mediterranean Sea. The premaxilla is less variable, and in spite of the presence of species-specific features, a common structural pattern is easily recognizable in all species (i.e. the ascending and the articular processes are fused in a single branch, as in many percoid fishes). In contrast, tooth shape is more variable, and different structural types can be recognized (e.g. canine-like or incisive). Coupling geometric morphometric and comparative methods we found that the relationship between shape, diet and phylogeny also differs between premaxilla and tooth. Thus, the shape of the premaxilla is significantly correlated with food type, whereas the shape of the teeth is not correlated with diet, and probably reflects the species phylogenetic relationships. Two biological roles, resistance against compressive forces generated in the buccal cavity and the size of the oral gape, would explain the ecomorphological patterns of the premaxilla. The premaxilla and anterior tooth appear to evolve at different rates (mosaic evolution) and represent an example of morphological traits belonging to the same functional unit but following uncoupled evolutionary pathways.     

Lip-nasal aesthetics following Le Fort I osteotomy

Forty-one patients undergoing Le Fort I osteotomy for superior and/or anterior repositioning of the maxilla were prospectively studied for changes in soft-tissue morphology of the nasomaxillary region. Nasal parameters studied were changes in interalar rim width and nasal tip projection. It was observed that alar rim width increases with anterior and/or superior repositioning of the maxilla, but increases in nasal tip projection occur only when there is an anterior vector of maxillary movement. These nasal changes could not be quantitatively correlated to magnitude of maxillary movement. Lip changes studied were the horizontal displacement at the vermilion border and subnasale versus that of the incisal edge and point A, respectively, when the maxilla is sagittally advanced and the vertical shortening of the lip versus that of the incisal edge when the maxilla is shortened. Using linear regression analysis, horizontal displacement of the upper lip at the vermilion border was 0.82 +/- 0.13 mm for every 1 mm of maxillary advancement at the incisal edge (p less than 0.001) and 0.51 +/- 0.13 at the subnasale for every 1 mm of maxillary advancement at point A (p less than 0.001). Eighty percent of patients undergoing maxillary intrusive procedures had lip shortening ranging from 20 to 50 percent of the vertical maxillary reduction. Surprisingly, no statistically significant correlation could be demonstrated for lip shortening versus extent of vertical maxillary reduction. Previous literature in disagreement with these findings is discussed. Guidelines for treatment planning utilizing these data are suggested.     

Comparative analysis of the fragments of highly repeated DNA of Homo, Pan, Macaca and Cercopithecus

In the present paper the restriction patterns of Homo, Pan troglodytes, Macaca fascicularis and Cercopithecus aethiops, obtained by digestion with Eco RI endonuclease, were compared. All these species showed two common bands at 0.3 and 0.6 Kb. In this region another band at 0.5 Kb was present in Macaca fascicularis and Cercopithecus aethiops. Furthermore Macaca fascicularis, Cercopithecus aethiops and Pan troglodytes showed a series of bands not present in humans. The distance matrix shows a strong similarity between Homo and Pan and a decreasing similarity with Macaca fascicularis and Cercopithecus aethiops. No intraspecific variability was observed.