Preserved Teeth Research Articles

A giant mosasaur (Reptilia, Squamata) with an unusually twisted dentition from the Argille Scagliose Complex (late Campanian) of Northern Italy

A snout of a large-sized mosasaur from the Upper Cretaceous pelagic-turbiditic deposits of the Argille Scagliose Complex of Northern Italy is described. Nannofossil assemblages from the immediately overlying strata belong to the late but not latest Campanian calcareous nannofossil standard zone CC22, based on the presence of Uniplanarius trifidus and Eiffellithus eximius. The specimen includes a broken premaxilla, the anterior part of the maxillae and dentaries in articulation: preserved teeth show distinctive characters previously unreported in other mosasaurs. Although the marginal teeth show a posterior migration of the labial carina along the jaw length – diagnostic of derived mosasaurines – they are unusual in the combination of features, including anteriormost teeth with asteroid cross section followed by teeth with crowns twisted labioposteriorly from one-third to one-half of their height toward the apices. A comparison between the new specimen and Mosasaurus hoffmanni skulls suggests an estimated skull length comparable with some of the largest known mosasaurids. Consequently, the new specimen represents the largest mosasaur and the largest fossil reptile found in Italy to date. Several lines of dental evidence also support the interpretation of the Italian mosasaur as a macrophagous generalist predator. Paleogeographic reconstruction for the Argille Scagliose Complex as well as the occurrence of typical low- to mid-latitude nannofossils support a southern Tethyan margin affinity of the taxon.

The Jiyuan tetrapod Fauna of the Upper Permian of China——1. New pareiasaur materials and the reestablishment of Honania complicidentata

Honania complicidentata and Tsiyuania simplicidentata are pareiasaur taxa based on material from the Shangshihezi Formation of Jiyuan, Henan Province, China that were earlier designated as nomina vana. Based on the study of new material, and the reexamination of old specimens, we determine that the pareiasaur material from Jiyuan represents a single species that differs from all known species from other localities. Thus, we resurrect the name H. complicidentata for the material from Jiyuan. H. complicidentata is characterized by maxillary teeth with high crowns, dentary teeth slightly posteriorly inclined compared to the dentary dorsal margin, nearly all preserved marginal teeth have a cusped cingulum on the lingual surface, and humerus without an ectepicondylar foramen. Phylogenetic analysis shows Honania is more basal than Shansisaurus and Shihtienfenia from the Sunjiagou Formation of China.

A new species of the archaic primateZanycterisfrom the late Paleocene of western Colorado and the phylogenetic position of the family Picrodontidae

A new species of an archaic primate (Pleisadapiformes) is described based on a maxilla containing the first and second upper molars from the Fort Union Formation, Atwell Gulch Member in northwestern Colorado. The preserved teeth show the unusual dental characteristics of members of the rare and poorly documented Picrodontidae family, including an elongated centrocrista and wide occlusal surface. The new species is placed within the genus Zanycteris (represented by a single specimen from southern Colorado). This placement is based on similarities in regard to the parastyle, curvilinear centrocrista, and wider anterior stylar shelf on the upper molars. However, the new species differs from the only known species of Zanycteris in exhibiting an upper first molar that is 30% larger in area, while retaining a similarly sized upper second molar. Phylogenetic analysis supports the separation of the Picrodontidae family from the Paromomyidae, while still recognizing picrodontids position within Pleisadapiformes. The unusual dental features of the upper molars likely functioned in life as an enhanced shearing surface between the centrocrista and cristid obliqua crests for a specialized diet of fruit. A similar arrangement is found in the living bat Ariteus (Jamaican fig-eating bat), which feeds on fleshy fruit. The new species showcases the rapid diversification of archaic primates shortly after the extinction of the dinosaurs during the Paleocene, and the unusual dental anatomy of picrodontids to exploit new dietary specializations.

<i>Morotochoerus</i> de Uganda (17.5 Ma) y <i>Kenyapotamus</i> de Kenia (13-11 Ma): implicaciones sobre el origen de los hipopotámidos

El objetivo de este trabajo es describir e interpretar los dientes suiformes de Moroto, Uganda, y Ngorora, Kenia, que contribuyen al debate sobre las relaciones hipo-anthracothere-whale. Las primeras etapas de la evolución de los hipopotámidos son relativamente poco conocidas a causa de la escasez de su registro fósil en edades superiors a los 7 Ma. Nuevos ejemplares de Morotochoerus en Uganda revelan que no están estrechamente relacionados con Hippopotamidae, las semejanzas superficiales de los dientes de la mandíbula con los de los hipopótamos representan convergencias y no homologías. Algunas muestras de Palaeopotamus ternani aparecen en el Medio Mioceno de Kenia {Maboko, ca 16 Ma; Muruyur, ca 14.5 Ma; Fort Ternan, ca 13.7 Ma}, mientras que desde la base del Mioceno tardío, Kenyapotamus coryndonae aparece en Kenia {Ngerngerwa, ca 10.5-10 Ma; Nakali, ca 10.5 Ma; Samburu Hills, ca 9,5 Ma}, {Ch’orora Etiopía, ca 10.5 Ma} {y Túnez Beglia Formación ca 11-10 Ma}. La obtención de especímenes de Kenyapotamus de la Formación Ngorora, Kenya, con edad ca 11 Ma, es de interés porque incluye dientes bien conservados, incluyendo un m/3 en buenas condiciones. Estos ejemplares apoyan la hipótesis de que los hipotámidos descienden de paleoquéridos y no de antracotéridos.

Effect of (-)-epigallocatechin-3-gallate on maintaining the periodontal ligament cell viability of avulsed teeth: a preliminary study

PurposeAvulsed tooth can be completely recovered, if sound periodontal ligament (PDL) of tooth is maintained. Although a lot of storage solutions have been explored for the better storage of avulsed tooth, there is a shortcoming that the preservation time is much short. On the other hand, there has been studies that (-)-epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea, which is related to the anti inflammatory, antioxygenic, and antibacterial effects, allows the successful preservations of tissues and cells. This study evaluated the effect of EGCG on avulsed-teeth preservation of Beagle dogs for a period of time.MethodsThe atraumatically extracted teeth of Beagle dogs were washed and preserved with 0/10/100 µM of EGCG at the time of immediate, period 1 (4 days in EGCG-contained media and additional 1 day in EGCG-free media), period 2 (8 days in EGCG-contained media and additional 2 days in EGCG-free media) and period 3 (12 days in EGCG-contained media and additional 2 days in EGCG-free media). Then, the cell viabilities of preserved teeth was calculated by dividing optical density (OD) of 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay with OD of eosin assay to eliminate the measurement errors caused by the different tissue volumes.ResultsFrom the results, the immediately analyzed group presented the highest cell viability, and the rate of living cells on teeth surface decreased dependent on the preservation period. However, the 100 µM of EGCG-treated group showed statistically significant positive cell activity than EGCG-free groups throughout preservation periods.ConclusionsOur findings showed that 100 µM EGCG could maintain PDL cell viability of extracted tooth. These results suggest that although EGCG could not be a perfect additive for tooth preservation, it is able to postpone the period of tooth storage. However, further in-depth studies are required for more plausible use of EGCG.

Tooth socket histology in the Cretaceous snake Dinilysia, with a review of amniote dental attachment tissues

ABSTRACT The dental attachment site histology and gross morphology of Dinilysia patagonica, a Cretaceous terrestrial snake, is examined in a thin section through the tissue-filled mesial-distal region between tooth positions of a left maxilla, and other partial tooth-bearing bones with teeth. We observed compact zonal bone and cancellous bone forming the maxilla, and alveolar bone (a woven-fibered bone) lining the tooth socket and filling the region between tooth positions. The discovery of alveolar bone in D. patagonica is significant because alveolar bone was found previously in only one other group of squamates, mosasaurs (extinct large marine lizards), and other amniotes with a thecodont tooth-attachment anatomy (archosaurs, mammals). The presence of alveolar bone in D. patagonica, associated with the recent finding of alveolar bone and other tissues associated with thecodonty (alveolar bone, cement, periodontal ligament) in mosasaurs, suggest that these tissues might be broadly distributed among squamates. Dinilysia patagonica is inferred to have a hinged tooth-attachment type, based on the tooth socket morphology and relationship between preserved teeth and the tooth-bearing bone.

The Indian Springs #2 Site(41BW512): A Late 18th Century Kadahadacho Settlement in Northeast Texas

The Indian Springs #2 site (41BW512) is on a high alluvial terrace or bluff edge (330 ft. amsl), overlooking the Red River floodplain and Hubbard Slough, an old channel of the river. The current channel of the river is ca. 1.6 km north of the site. The site appears to be a late 18th century Kadohadacho settlement with a small cemetery, although there is evidence in the collections known to have come from it that it was also occupied in Archaic and Early Caddo times (ca. A.D. 900-1200) as well as in the early to mid-19'h century. The site was discovered by the landowner, Mr. Julian Cranfill during earth-moving activities associated with construction of a pond. When European glass beads were noted by Mr. Cranfill on the disturbed ground surface, he began a limited excavation of the area where the beads were found, attempting to ascertain their context and what other kinds of artifacts may be associated with them. He excavated a circular area about 3-4 m in diameter along the eastern side of the bluff, on a small knoll. During this work, he documented three obvious cultural features and a dark charcoal-stained patch of burned soil that may represent remnants of a shallowly-buried burned structure. Feature I and II are burials of Caddo people, and both had European glass beads and pottery vessels placed in the grave as funerary objects. Feature III is a pit that contained butchered hog jaws; it may be associated with the later 19tb century Anglo-American farm occupation also present at the site. The Feature I burial pit was oriented east-west, and was the size of a child or subadult burial. The burial pit extended to ca. 66 em bs, and the bottom 2-5 em of the pit fill was a very dark soil. This soil is probably the product of firing episodes associated with Caddo burial ceremonies. There was a large concentration of glass beads at the eastern end of the burial, probably from necklaces of beads that were worn by the deceased. More than 3000 beads came from this area, along with a few preserved teeth, and three ceramic vessels. Feature II was a larger burial pit, probably that of an adult Caddo, oriented almost north-south. According to Mr. Cranfill, there were four ceramic vessels, more than 430 glass beads, and five triangular Fresno arrow points accompanying this individual.

Taphonomy of the Miocene bone accumulations at Paşalar, Turkey

The bone assemblage from the Miocene deposits at Paşalar, Turkey is described. The fossil bones are concentrated in a single horizon of poorly sorted sands and gravels which were accumulated rapidly. The source of the sedimentary particles was the lower slopes of the hills bordering the site, and the distribution of bones relative to sediment shows that they were transported to the burial site as part of the sedimentary load. Bone size and distribution are correlated with particle size, and orientations and dips of the bones are indicative of turbulent flow during deposition. It is concluded, therefore, that the bones came from the same source area as the mineral constituents of the sediments, namely from the lower hill slopes close to the site. The fossil bones are extremely fragmentary, with isolated teeth being the most common parts preserved, and some of this breakage may be attributed to the effects of transport. The majority of bones are edgerounded, and in most cases the abrasion is superimposed on weathered and broken surfaces, indicating that the bones accumulated and were broken before abrasion. The bone degradation caused by these processes has resulted in the destruction of all but the strongest elements, but it does not appear to have selectively destroyed particular faunal elements. Predator activity is demonstrated for small mammals by the presence on some of their preserved teeth of surface corrosion caused by digestion, and it is inferred for large mammals by age structure anomalies in the samples of certain of the larger sized species. The biases introduced by these processes are considered to be loss of the smallest size groups of small mammals and over-respresentation of rhinocerotids and giraffids, but apart from this the fossil assemblage approximates to a life assemblage accumulated over a short period of time and from a limited geographical area.

Prehistoric Seasonality Studies in Coastal Southern New England

The results of seasonality studies undertaken with prehistoric faunal materials from the Greenwich Cove site in coastal Rhode Island are presented. Growth patterns in shells of the hard clam or quahog (Mercenaria mercenaria) are used to reconstruct the time(s) of year this species was collected. A controlled study of seasonal growth provides a comparative baseline for this analysis. Seasonality of white‐tailed deer (Odocoileus virginianus) hunting is interpreted through the examination of growth structures in preserved teeth. The seasonal availability of migratory species is also considered. Relatively year‐round coastal settlement is proposed for the final centuries of the prehistoric period.

Forecasts of preserved teeth and denture wearers among Danish adults early in the next century.

To assist in the planning of oral health services, forecasts were made and goals specified with regard to the numbers of preserved teeth and subjects wearing full or partial dentures among Danish adults in 1992 and 2002. Forecasting was based on existing data, viz. a survey in 1982, including clinical examination, of a representative sample of 20-80-yr-olds (n = 2548), on register data from the National Health Insurance, and survival rates. By combining information from these sources, an increase was estimated in number of preserved teeth among 20-99-yr-olds from 68 million in 1982 to 82 and 92 million in 1992 and 2002, respectively. Correspondingly, a 28% increase in the mean number of remaining teeth was proposed as a goal for the year 2002. A decrease was estimated in the number of denture wearers, from 1.4 million in 1982 to 1.07 and 0.74 million in 1992 and 2002, respectively. The corresponding goal was specified as a 50% reduction in the proportion of denture wearers in 2002. In the middle aged and older part of the population the increasing number of remaining teeth may be expected to imply considerable needs for professional care even in the beginning of the next century.

Implications of preparation processes on the interpretation of reptilian enamel structure

It is generally agreed that reptilian enamel is devoid of prisms. However an etching of teeth shows that reptilian enamel consists of an outer homogeneous layer which overlaps an inner prismatic layer. The examination of the unetched outer surface of living taxa or well preserved fossil teeth does not reveal the presence of inner prisms.

Orthodontics: A survey

Knowledge of the anatomical course of the anterior maxillary wall and alveolar process arteries is essential for sinus lift procedures. The aim of this study was to analyse the localization of anastomoses between the infraorbital and posterior superior alveolar artery on 101 computed tomography (CT) scans of maxillary sinuses (patients aged 18–70 years). The distance from the anastomosis to the bone point was measured on CT scans for each tooth location; for edentulous patients measurements were made to the lower edge of the alveolar process, and for dentate patients to the neck of the tooth. Measurements were done independently by two observers. The anastomosis analysed was identified on 50% of CT scans. The distance to the anastomosis was longest above the premolar (20.4 mm from tooth cervical line) and shortest above the first molar (15.9 mm to the edge of the alveolar process). The anastomosis can be localized on a CT scan for exact positioning of the antrotomy in 50% of patients. For the remaining patients, the anatomical information provided in this study can be used to reduce the risk of damage to the anastomosis. This study provides information on the distance from the anastomosis to the neck of preserved teeth in partially edentulous patients, which can be used as a reference point during sinus lift procedures.