二种萤火虫幼虫捕食行为及头部功能性结构观察比较

对短角窗萤Diaphanes sp.和胸窗萤Pyrocoelia pectoralis Olivier幼虫的捕食行为进行观察。发现短角窗萤捕食蚯蚓而胸窗萤则捕食蜗牛。利用扫描电镜对短角窗萤和胸窗萤幼虫的头部及口器进行观察比较。发现2种幼虫均具有1对侧单眼,1对发达的、左右对称的3节触角。2种幼虫口器非常发达,具1对锋利的、中空的镰刀状上颚,1对下颚须,1对下唇须,1对内颚叶。2种萤火虫口器最具特别的结构在于:短角窗萤上颚的2/3处内侧着生1个球形结构,上面着生1层齿状结构,而胸窗萤则在上颚基部内侧弯曲成齿状突起。     

整体铸造支架式可摘局部义齿添加人工牙的临床修理效果

目的：探讨整体铸造支架式可摘局部义齿添加人工牙的修理体会。方法：对240例佩戴整体铸造支架式可摘局部义齿的患者进行义齿添加人工牙修理,比较修理前后视觉模拟（VAS）评分、咀嚼功能及1年后人工牙的磨耗程度。结果：修复后VAS评分明显低于修复前,两者比较差异有统计学意义（P〈0.05）,但牙槽骨吸收距离未见明显差异（P〉0.05）。经过修复后义齿的固位稳定及咀嚼情况较修复前明显好转,在随访1年后,人工牙大多有轻到中度的磨耗,磨耗后出现23例颌位垂直距离缩短及2例下颌前移及偏移。结论：设计合理的支架连接体,并且尽量作添加人工牙和卡环的修理,可以延长义齿的使用寿命。     

全口义齿修复后造成松软牙槽嵴和／或牙槽嵴粘膜增生的原因初探

目的:研究松软牙槽嵴和/或牙槽嵴粘膜增生形成的原因,探讨预防和治疗措施。方法:对180例戴用全口义齿一年以上的患者进行临床调查研究。研究内容包括缺牙原因,义齿戴用的时间,牙槽嵴粘膜情况,松软牙槽嵴和/或牙槽嵴粘膜增生发生的部位,人工牙的类型等。结果:①180例全口义齿病例中,有松软牙槽嵴者20例,占22％,男:女=6:4,其中下牙槽嵴占60％,上牙槽嵴占,20％,上下牙槽嵴均有者占20％。患牙槽嵴粘膜增生者共8例,占4.4％,最多发生在下舌侧,其次为下唇沟。同时患有松软牙槽嵴和牙槽嵴粘膜增生的有4例,占患牙槽嵴粘膜增生病例的一半。②在患松软牙槽嵴的病例中,人工牙为塑料牙和瓷牙各占50％。缺牙原因为牙周病者共12例,占60％,龋病2例,占10％,龋病-牙周病者8例,占30％。③在患松软牙槽嵴的病例中,下颌牙槽嵴条件均为差,上颌牙槽嵴条件均为中或差。在患增生的粘膜组织的病例中,75％病例义齿固位为中或差,25％义齿固位为较好。结论:发病原因与患者缺牙原因,牙槽嵴部位,牙槽嵴条件,人工牙类型等有关。因此可以认为,牙槽嵴粘膜松软是戴用全口义齿后出现的不可忽视的问题,而牙槽嵴粘膜松软和/或增生的粘膜组织是相辅相成的。所以一副全口义齿不是一劳永逸的,使用一定的时间后需要更换,特别对牙槽嵴条件较差的患者     

Population analysis of dental anomalies of ottersLutra lutra from eastern Germany

A sample of 1037 skulls of ottersLutra lutra (Linnaeus, 1758) from eastern Germany was analysed for inherent dental abnormalities. Deviations from the normal dental pattern were found in 107 individuals. A total of 150 cases were classified in 5 categories of abnormality. In considering variations from the normal number of teeth, supernumerary (polydonty, 1.7%) was more frequent than missing teeth (oligodonty, 0.9%). In most cases, numerical variations were not connected with phylogenetic background. The most frequent variations were displacement of teeth in the tooth row (6.0%) and deviations of the normal shape of teeth (3.3%). Variations of the local position of teeth occurred in 2.6% of cases. None of these deviations showed significant sex-dependent differences. Furthermore, no regional differences in the frequencies of these anomalies were noticed. Another 459 otters (822 cases) had accessory roots at P2, P3, or P4. These characters were considered as non-metrical traits and used to study epigenetic regional differentiation. The Mean Measure of Divergence segregated the Baltic coast from almost all other regions. Preliminary results of analysis of Fluctuating Asymmetry are presented, using these traits to demonstrate the utility of dental deviations for estimating influences on developmental stability. Generally, it can be stated that the dentition of otters is very stable.     

不同桩核修复上颌前牙残根残冠的疗效比较

目的:对比玻璃纤维桩树脂核与铸造金属桩核修复上颌前牙残根残冠的疗效。方法:选取2011年10月至2013年12月在我院口腔科就诊的120例因前牙牙体缺损或者冠折需行桩核冠修复术的患者,随机分为玻璃纤维桩组及铸造金属桩组,每组各60例。玻璃纤维桩组采取玻璃纤维桩核与烤瓷全冠修复术治疗,铸造金属桩组采取钴铬合金铸造桩核与烤瓷全冠修复术治疗。对比2组患者修复治疗的疗效及失败情况。结果:玻璃纤维桩组有1例(1颗)患者因搬迁失访,铸造金属桩组有2例(2颗)患者因金属致敏性导致治疗中断;余117例(179颗)患者中,玻璃纤维桩组共92颗牙,成功率为89.13%,铸造金属桩组共87颗牙,成功率为79.31%,玻璃纤维桩组的明显高于铸造金属桩组;玻璃纤维桩组牙根折裂、桩核松动或脱落的发生率明显低于铸造金属桩组;而桩核折的发生率则明显高于铸造金属桩组,差异有统计学意义(P0.05)。结论:玻璃纤维桩具有美观、抗疲劳、易于操作、患者复诊次数少等优势,且不存在细胞毒性及过敏反应等问题,其修复效果优于铸造金属桩核。     

牙周炎患者局部应用盐酸米诺环素软膏与碘甘油的临床效果对比研究

目的：对比局部应用盐酸米诺环素软膏与碘甘油在治疗牙周炎的临床疗效区别。方法：选取46例牙周炎患者,共92颗患牙。随机选取患者一侧患牙作为试验组,同一患者对侧患牙作为对照组。两组均进行全口洁治与根面平整术。试验组局部应用盐酸米诺环素软膏。对照纽局部应用碘甘油。分别于基线、治疗第5周及第8周检测菌斑指数（PLI）、牙周袋探诊深度（PD）、龈沟出血指数（SBI）及牙龈指数（GI）。于治疗第8周对比两组患牙疗效。结果：整体比较：两组的4项指标均有显著性差异（P〈0．05）;各组不同时间的4项指标也有显著性差异（P〈0．05）;但以试验组变化更大。精细比较：两组患牙第5周检测指标与基线值相比均具有明显差异（P〈0．01）;试验组患牙第8周检测指标与第5周相比,PLI、PD、SBI与GI差异具有统计学意义（P〈0．01）;试验组在第5周PLI、PD、SBI及GI值均明显优于对照组（P〈0．01）;试验组第8周PD、SBI及GI值均明显优于对照组（P〈0．01）。试验组总有效率（95．65％）明显高于对照组（60．87％）。结论：局部应用盐酸米诺环素软膏辅助治疗牙周炎具有杀菌时间长、杀菌效果强、减轻炎症反应的优点。     

Dental formulae and dental eruption patterns in Parapithecidae (Primates, Anthropoidea)

The eruption sequence for the lower teeth of Apidium phiomense based on 18 juvenile specimens is dP3, dP4, M1, M2, P2, P4, (P3, M3), C. Only five specimens of Parapithecus grangeri show developing lower teeth. P2, M1, and M2 all erupted before P3 and P4; C and M3 were the last cheek teeth to erupt. Late eruption of the lower canines in parapithecids is a possible shared derived resemblance linking these species with Anthropoidea and Adapidae and distinguishing both from Omomyidae, Tarsiidae, and tooth-combed lemurs. Late eruption of M3 in parapithecids is a shared derived resemblance with Anthropoidea alone. The lower dental formula of Apidium phiomense is confirmed as 2 X 1 X 3 X 3 by additional specimens which show the incisors. Based in part on tooth socket counts, the deciduous lower dental formula was 2 X 1 X 3. New specimens of Parapithecus grangeri now demonstrate an adult mandibular dental formula of 0 X 1 X 3 X 3 (not 2 X 1 X 3 X 3 as previously thought) and a juvenile formula of 1 X 1 X 3. The number of incisors possessed by Parapithecus fraasi is again open to debate. Material is insufficient to judge whether this species had a pair of incisors in each lower jaw quadrant, by analogy with Apidium, or had undergone reduction to just one incisor. In any event, the presence of two incisors in another parapithecid Apidium shows anterior tooth reduction of Parapithecus grangeri occurred independent of, and should not be considered a shared derived similarity with, Tarsiidae, as was once thought.     

Dental anomalies in the Japanese mole <Emphasis Type="Italic">Mogera wogura</Emphasis> from northeast China and the Primorsky region of Russia

Dental anomalies in the Japanese mole, Mogera wogura Temminck, 1842, from northeast China and the Primorsky region of Russia were examined based on 241 specimens. The most frequent dental anomaly was oligodonty, i.e., missing P² (18 cases) or P₃ (one case). Supernumerary teeth were observed in three cases, two of which were characterized by abnormal shapes. Morphological abnormalities in teeth (six cases) and an asymmetrically curved rostrum (one case) were also observed. Dental anomalies were found at higher frequencies in populations near the northern range limit of the species. This was not caused by size effects. We suggest that the high incidence of dental anomalies was the result of genetic drift, which increases in marginal populations. Considering the nature of subterranean mammals, our results suggest that the high frequency of dental anomalies in a marginal population could have initiated the evolution of dental formulae if parapatric or peripatric speciation occurs in such populations.     

Dental fluctuating asymmetry in the Gullah: tests of hypotheses regarding developmental stability in deciduous vs. permanent and male vs. female teeth

In this investigation, deciduous teeth (canines, c; first molars, m1; second molars, m2) and their permanent successors (canines, C; first premolars, P1; second premolars, P2) were used to test two related hypotheses about fluctuating asymmetry (FA). First, based on the biology of the developing dentition, it was predicted that deciduous teeth would be more developmentally stable and thus exhibit less dimensional FA than their permanent successors. Second, based on sex differences in tooth development, it was predicted that female canines would have greater developmental stability (less FA) than male canines. Bucco-lingual measurements were made on dental casts from a single Gullah population. Using a repeated-measures study design (n = 3 repeated measures), we tested these hypotheses on sample sizes ranging from 63-82 antimeric pairs. Neither hypothesis was supported by our data. In most cases, Gullah deciduous teeth did not exhibit statistically significantly less FA than their permanent successors; indeed, statistically significant differences were found for only 3 of 12 deciduous vs. permanent contrasts, and in two cases, the deciduous tooth had greater FA. Female mandibular canines exhibited statistically significantly greater FA than those of males, while there was no statistically significant sex difference in FA for the maxillary canine. FA in these Gullah samples is high when compared to Archaic and late prehistoric Ohio Valley Native Americans, consistent with historical and archaeological evidence that environmental stress was relatively higher in the Gullah population. We suggest that when environmental stress in a population is high, the impact of differences in tooth formation time spans and developmental buffering upon FA may be minor relative to the effect of developmental noise.     

Tooth replacement in the teleost fish Prionurus microlepidotus Lacépède

Previous studies on tooth replacement in lower vertebrates have been plagued by a lack of common integrative approaches and methods, making it impossible to furnish a phylogenetic synthesis. This study is based on serial sections of the jaw of Prionurus microlepidotus. Each Toothgerm was characterized by its developmental stage and its position in the jaw. The relationship between the developmental stage of toothgerm and position in the jaw has been studied and expressed in several graphical illustrations. The following conclusions have been made: (1) The initiation of toothgerms in P. microlepidotus is governed by two Zahnreihen, which respectively initiate toothgerms on the lingual and labial side of the functioning teeth in an alternating pattern. (2) Therefore, functioning teeth in one locus are supplied by the alternate eruption of lingual and labial toothgerms. (3) Advancing of tooth replacement in each locus is independent of functioning teeth and their successors in adjacent loci. (4) The disorders of replacement patterns are caused by an alternated rate of eruption of successive toothgerms as a response to unusual shedding of the functioning teeth.     

不同修复方式对儿童乳牙牙体缺损的疗效和安全性比较

目的:探讨不同修复方式对儿童乳牙牙体缺损修复的治疗效果和安全性。方法:选择2011年1月至2015年1月在我院因牙体缺损严重无法填充修复的乳牙牙体缺损患儿67例。将所有患者随机分为三组,记为A组(22例)、B组(22例)和C组(23例)。A组患儿进行金属预成冠修复,B组患儿进行铸瓷嵌体修复,C组患儿进行银汞合金充填修复。随访18个月,比较3组患儿的治疗效果和不良反应的发生情况。结果:C组患儿随访期间发生牙痛6例,食物嵌塞、修复体和牙体之间出现裂缝的患儿各5例,牙龈充血3例,继发龋2例;B组患儿发生牙痛3例,食物嵌塞、牙龈充血、修复体和牙体之间出现裂缝以及继发龋等各1例;A组患儿发生疼痛和食物嵌塞各2例,牙龈充血1例。A组和B组患儿以上不良事件的发生率明显低于C组(P0.05),A组发生不良事件的发生率低于B组,但是差异无统计学意义(P0.05)。结论:应用金属预成冠修复和铸瓷嵌体修复儿童乳牙牙体缺损较银汞合金充填修复具有更好的临床效果,且安全性更高。     

Foraging behaviour and functional morphology of two scale-eating cichlids from Lake Tanganyika

The foraging behaviours of two Tanganyikan scale-eating cichlids, Perissodus straeleni and Perissodus microlepis , were observed in laboratory. Video analyses of their feeding behaviours showed the distinct differences in scale-eating action between the two species. Perissodus straeleni presses and shifts its mouth laterally along the body of the prey as the prey attempts to break free. In contrast, P. microlepis quickly rotates its body, with both jaws pressed tightly against the flank of the prey. Scanning electron microscopy of tooth shapes confirmed that dental morphology clearly differs between the two species: the teeth of P. straeleni are laminar and leaf-shaped with sharp edges along the lateral sides, whereas P. microlepis has thick, broad-based teeth with spine-like points in the upper corners. In addition, inspection of tooth condition in wild-caught fishes showed that the ratio of wearing teeth was significantly higher in P. straeleni than in P. microlepis . These results indicate that the functional morphology of the teeth plays an important role in their scale-eating actions; in P. straeleni , the sharp edges of the teeth appear to function as blades for scraping while shifting the mouth laterally along the body of the prey, whereas the spine-like projections on the teeth of P. microlepis appear to effectively catch scales while pressing and rotating the mouth, simultaneously wrenching off scales. These results clearly demonstrate that the different scale-eating behaviours of the two species are closely associated with the functional diversification of their jaw teeth.     

河南栾川发现直立人化石及其演化意义

洛阳考古研究院2012年5月至10月在栾川孙家洞作抢救性发掘,于原生层位发现古人类化石,同时伴有大量哺乳动物化石,以及少量人工石制品。根据伴生动物群的初步鉴定,栾川古人类的生存时代为中更新世。6件古人类化石代表3个个体:1个成年人和2个未成年人,未成年人的牙齿生长发育阶段分别与6～7岁和11～12岁的现代青少年相当。栾川孙家洞古人类牙齿具有一定的原始性,明显区别于现代人,其形态大小位于周口店直立人牙齿的变异范围内,可归入直立人的形态范畴;同时具有东亚古人类及现代蒙古人群的地区性特征。基于幼年个体上下颌骨的牙齿发育,推测栾川古人类第一臼齿萌出年龄可能接近6岁,提示具有接近于现代人的牙齿生长模式和生活史特点。栾川中更新世古人类化石的发现为中国古人类连续演化假说提供了新证据。     

Maxillary canine-first premolar transposition in two Native American skeletal samples from New Mexico

Tooth transposition is a rare anomaly in which the position of two adjacent teeth in the dental arcade is reversed. Maxillary canine and first premolar transposition (Mx.C.P1 transposition) is most commonly observed. Data from Native Americans samples are lacking. The purpose of this study was: 1) to document the occurrence of Mx.C.P1 transposition, and 2) to generate information on the prevalence of this transposition type among world populations. Eleven cases (M = 5, F = 4, ? = 2) of Mx.C.P1 transposition were identified in skeletal samples from Pecos Pueblo (n = 500) and Sambrito Village (n = 10), both in northern New Mexico. Nine cases were unilateral, 6 affecting the right side and 3 affecting the left side. The remaining 2 cases were bilateral. The prevalence rate of Mx.C.P1 transposition in African and Native American samples, including Pecos Pueblo (1.8%), is higher than in samples from Scotland, Sweden, Saudi Arabia, and India. Mx.C.P1 transposition frequencies vary between geographically distinct populations, although sample composition may be a factor contributing to sample variation. Am J Phys Anthropol 116:45–50, 2001. © 2001 Wiley‐Liss, Inc.     

Model for the examination of evolutionary trends in tooth development

Through the use of serial computerized tomography (C-t) scans, two distinct developmental stages can be identified in mature teeth. C-t scans thus provide a non-destructive method for assessing growth within individual teeth, as well as for comparison of the development of modern and fossil teeth. The second deciduous molar (DM2) and first permanent molar (M1) resemble one another morphologically, despite differences in size and developmental rates. Thus, they provide an excellent model for studying variation in growth within an individual. To test the C-t method, we first examined a recent archaeological sample and then examined teeth from Skhul I. Serial C-t scans were used to compare two distinct developmental stages represented by the dentine-enamel junction (DEJ) and outer enamel surface (OES), respectively, in mandibular DM2 and M1 of 31 archaeological specimens. The difference in form and size between these two surfaces in and between teeth was calculated from intercusp distances measured at the DEJ and OES using the form distance matrix. Intercusp distances at the DEJ and OES of these teeth were then compared to their counterparts in the DM2 and M1 of Skhul I, taken here as representative of early anatomically modern Homo sapiens sapiens. Form differences between paired DM2 and M1 at the DEJ were smaller than those at the OES, supporting the hypothesis that differences between the two teeth increase throughout development. The increase in intercusp distances from the DEJ to OES was found to reflect the angulation of cusps relative to one another, rather than enamel thickness. Form differences between the Skhul DM2 and M1 were smaller than those observed in the recent series, and the recent M1 differed more than the DM2 from its fossil counterpart. The similarities found between the Skhul permanent and deciduous teeth and the recent DM2, may reflect a similar growth pattern. This would contribute to earlier crown completion in the fossil M1. Am. J. Phys. Anthropol. 102:283–294, 1997 © 1997 Wiley-Liss, Inc.     

河北秦皇岛柳江盆地中更新世野兔一新种

在河北秦皇岛柳江盆地山羊寨附近中更新世洞穴堆积中发现一种小型野兔化石:秦皇岛兔Lepus qinhuangdaoensis sp.nov.,该种以其个体小、p3后外褶沟深达内侧齿缘或贯穿整个齿冠面、部分标本p3具有釉岛及前内褶沟等特征区别于其他已知种。它是迄今为止所知的体形最小的野兔。     

Mechanical wear of the gastropod radula: a scanning electron microscope study

The wear sustained by the teeth of the highly mineralized radula of Patella vulgata and the unmineralized radula of Agriolomax reticulatus has been studied with the scanning electron microscope. The unworn teeth of P. vulgata have tall pointed cusps and wear is first seen as a chipping of the tips then as abrasion. There is a well defined abraded surface giving the worn teeth a chisel shape. In cleaved teeth fibres ˜ 800 Å in diameter are observed parallel to the axis of the tooth. Evidence is presented for chemical etching and for the existence of a surface coat on the tooth. A. reticulatus teeth show wear over their whole surface. With the aid of the grooves in the jaw caused by the teeth the role of the jaw in flattening the radula and protracting and retracting the odontophore is confirmed. From the arrangement of the abraded surfaces on the teeth of P. vulgata it was deduced that the teeth rows are abraded one at a time while on a convex surface at or near the bending plane.     

MANDIBULAR DENTAL ONTOGENY OF RINGED SEALS (PHOCA HISPIDA)

X-rays of mandibles from ringed seal fetuses ( n = 15), newborns ( n = 12), and young-of-the-year ( n = 11), collected up to early June, were examined for the presence, location, and eruption patterns of deciduous and permanent teeth. The presence of a neonatal line and cementum in permanent canines was determined microscopically. Fetuses sampled in October-November had only unerupted, deciduous tooth germs, but by late January there were robust, deciduous teeth at il-2 pc2-4 and small permanent teeth at 11-2 Cl PCl-5. In newborns collected in early April, 109 of 143 (76%) deciduous teeth were resorbed completely. The remaining 34 deciduous teeth were partially resorbed; six (18%) had erupted and likely would be shed. By late April young-of-the-year had no deciduous teeth remaining. In newborns 54% of the permanent teeth (102/188) were erupted < 2 mm, and by late May the permanent dentition was erupted fully. The neonatal line first appeared in the canine teeth of young-of-the-year collected in mid-April and was 100% present after early May. There was no cementum apparent on any canine collected up to early June. Two seals were missing one and two permanent incisors, respectively. No supernumerary teeth or morphological variants were observed.     

Sequences and timing of dental eruption in Bolivian captive-born squirrel monkeys (Saimiri sciureus)

Squirrel monkeys, colony-born from Bolivian parents, were studied to establish the sequences and timing of eruption for deciduous and permanent teeth. Infants were born with a naked gingiva, and in only one monkey was di₁ present at birth. The eruption of the lower deciduous teeth preceded their upper counterparts with the exception of di2, dc, and dpm2. No significant differences were found between the right and left quadrants of the mandible and maxilla. No significant sexual differences were found in the age of eruption. By the age of 14 weeks, all deciduous teeth had erupted. The sequence of eruption of the replacement teeth was different from that of milk teeth. The differences lie in the delayed eruption of canine teeth and in the inverted sequence, from the back to the front, of the premolar series. Significant sexual differences were found in total eruption (TE) for PM₃ and I² (P < 0.05) and highly significant differences (P < 0.01) in TE and initial eruption (IE) for C¹, females being more precocious than males. The age at which monkeys completed dental eruption was highly variable, 103–119 weeks for males and 89–112 weeks for females. Differences were found when our results were compared with those of Long and Cooper [1968] for Colombian squirrel monkeys.