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A sauropod tooth, from the Barremian-Aptian ofGalve (Teruel), is described in Spain for the first time. This tooth probably belongs to the sauropod reported by A.F. de Lapparent (1), a Brachiosaurinae different of that reported by J.V. Santafe, M.L. Casanovas & J.L. Sanz (2) and J.L. Sanz, J.V. Santafe & M.L. Casanovas (3) from Morella (Castellon, Spain), Lower Aptian in age. It is probably a lower left piece with a developped worn surface. The subfamily Brachiosaurinae-sensu R. Steel, 1970 (4)-has a certain coherence of tooth morphology in respect of other Camarasauridae-sensu R. Steel, 1970 (4). The piece from Galve belongs to a Brachiosaurinae close to Brachiosaurus, though could differ of this genus in the structure and distribution of enamel ornamentation.

The advantages of incorporating accurate tooth morphology into dental restorations were established. The dimensional rectangle and the fundamental geometric shape are aids in the development of the concept of tooth morphology. This concept forms the basis for the practical application of anatomic features in the construction of restorations. Systematic instrumentation and carving procedures promote the efficient reproduction of detailed anatomy. The use of this procedure results in the saving of carving time, in anatomically accurate work, and satisfies the functional and esthetic needs of the patient. Furthermore, the dentist will become efficient in a facile and refined working method commensurate with the high standard of modern techniques in restorative dentistry.

Using an optical comparator and standardized sections, morphological and caries comparisons were made of the molars of rats which had been subjected to sugar injections during tooth formation. This treatment did not modify tooth morphology. Narrower deeper fissures tended to decay more frequently, the extent of caries was greater in such fissures, and not directly related to enamel thickness. Morphological differences between litters were significant.

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Periodontal health reflects a balance between harmful and protective elements in the gingival marginal area. The total plaque mass, specific periodontopathogens, the tooth morphology, and local environmental factors may challenge this balance. The periodontal ligament attachment loss shifts this balance adversely toward the periodontal disease. Objectives: The aim of this retrospective study was to determine the significance of proximal root grooves as a risk factor in the periodontal attachment loss; the effect of their dimensions and locations has been evaluated. Materials and methods: One hundred (100) extracted formalin stored single rooted permanent anterior teeth were studied by staining with 0.1% toludine blue to visualize attached periodontal ligament remnants. On each tooth, the loss of attachment was measured from the cemento–enamel junction to the most coronal level of the stained periodontal ligament remnants. Results: The prevalence of proximal root grooves was found to be 81% and a statistically significant greater loss of attachment was present on grooved than on non-grooved surfaces (p

The presence of two types of xiphodont crocodiles is reported for the first time from Australia. Crocodiles with this xiphoid type of tooth morphology were previously unknown anywhere in the world since the Miocene except for isolated xiphoid teeth noted by Plane (1967) from a Pliocene deposit in New Guinea.

The incidence of nine minor dental traits, in 540 Queckchi Indians from Guatemala is reported. A combination of frequencies of neither Caucasoid nor Mongoloid groups was observed. The apparently Caucasoid elements of their tooth morphology might well be the result of admixture with Spanish genes during the conquest.

A description of a simple replacement wax carving method for the teaching of dental morphology is presented. It has the potential of diverse usage as a laboratory exercise in other disciplines in dentistry. The simple, clear and fast methodology is extremely time-saving and is very well accepted by the dental student. Following this technique, which concentrates on tooth morphology and the skills of wax manipulation, the student will proceed to his future function-orientated exercises.

It was Cuvier (1805) who complained about the pupils of Linne, who were more interested in sorting superficial characters of organisms for taxonomic purposes than in understanding them physiologically. There is no doubt that classification is an important step in the scientific process of defining an appropriate place within the natural system for any object, but reasoning should not halt at this point. Moreover, classifications have to be considered as preliminary unless based on sound functional and evolutionary reasoning (Bock, 1981).

— Of 8,854 extracted molars in Norwegians, 201 teeth contained a total of 219 macroscopically detectable enamel pearls. The uncertainty in tooth determination had a limited effect upon the prevalence figures. Maxillary molars showed a higher prevalence than mandibular molars. The highest prevalence, 4.6%, was found on maxillary third molars. With few exceptions, the pearls were located in the bifurcation area or in the furrow between incompletely separated roots. The mean pearl diameter was 0.96 mm, and the mean distance to the cemento-enamel junction 2.8 mm. The relationship between enamel pearls and cervical enamel projections is discussed. It is suggested that simple enamel pearls and cervical enamel projections are of a similar nature and origin. The enamel of composite enamel pearls is probably initiated in a different way.

This paper contains a morphological and comparative study of 68 human fossil teeth recovered from the "Sima de los Huesos" site of the Cueva Mayor-Cueva del Silo karst system (Sierra de Atapuerca, Ibeas de Juarros, Burgos). The morphology of the Ibeas teeth conforms with a pattern of expansion of the anterior dentition characterizing all the Middle Pleistocene human populations, and with a pattern of structural reduction of the posterior teeth characterizing the European population of that period. The Ibeas teeth share several morphological traits with those of other European, North African and Asian Middle Pleistocene fossils. However, the tooth morphology of the European group, in which the Ibeas fossils are included, shows remarkable differences with that of the other groups. This fact permits to reinforce the thesis that a distinctive hominid lineage was established in Europe during the Middle Pleistocene. On the other hand, the Ibeas teeth bring forward new evidence to support the hypothesis of a close filogenetic relationship between the Middle Pleistocene European population and the Nearderthals and, accordingly, of a local evolution during that period and the Early Upper Pleistocene.

The dental models of seventy-seven orthodontically treated patients were evaluated to determine the contribution of lower incisor tooth dimensions to their alignment many years after treatment. Tooth dimensions included the maximum mesiodistal (MD) and faciolingual (FL) dimensions and the shape ratio represented by MD/FL. Incisor alignment was assessed by means of Little's irregularity index, and all measurements were recorded to the nearest 0.1 mm with modified dial calipers. Multiple regression analysis revealed that the total contribution of all these lower incisor dimensions accounted for only 7.4% of the variability in their alignment, which was not statistically significant. A similar lack of association between lower incisor tooth dimensions and their alignment was found in a sample of eighty-six adults with untreated malocclusions. It therefore appears that the size and shape of the lower incisors do not significantly contribute to their alignment many years after orthodontic treatment.

The correct identification of individual teeth is most frequently of forensic importance in the charting of mouths and in comparison of records. Knowledge of tooth morphology may allow identification of isolated teeth and may be of assistance in suggesting the race and sex of an individual or in matching the teeth from the same individual.

Contents, relationships, and origin of geomyoid rodents have been commented on quite differently during the past, in zoology as well as in paleontology. On the part of zoologists this superfamily contains the well defined families Heteromyidae and Geomyidae, both of them restricted more or less to North America. According to jaw musculature they are mostly assigned to the Sciuromorpha. Following Wilson’s (1949) revision of some Oligocene Eomyidae, these also were incorporated into the Geomyoidea by many paleontologists. Moreover, as Wilson (1949) discussed morphological relations to some myomorphs (in which, however, he did not put them), the whole superfamily later became attributed to the Myomorpha in paleontological literature (e.g. Wood, 1955a), a fact, I believe, with which zoologists became scarcely familiar. Some people even considered the whole group to be a separate suborder Geomorpha (Thaler, 1966). Due to the lack of adequate fossils, little is known of the origin of these rodents, except for some necessarily preliminary assumptions dealing with various groups of the Protrogomorpha as possible ancestors.

A sample of 192 male propositi with at least one ULI either missing or reduced has been compared with 197 male controls in terms of the morphology of the other teeth. Every class of propositi exhibits modifications in the following characters: Significant differences between propositi and controls were found for molar cusp number and groove pattern, particularly in the lower first molar and in propositi with reduced ULI. Significant differences between propositi and controls were also found with respect to caniniform pattern of the lower first premolar. The Carabelli's cusp is rarer in propositi. A hypothesis to account for these observations is proposed.

Two dental morphological features, lower incisor shape and Carabelli trait on upper molars, were studied in Down's syndrome (DS) individuals and control groups. Lower incisors were smaller in DS in absolute terms, but showed a relatively greater mesiodistal crown dimension than labiolingual, the opposite relationship to normal. Although the Carabelli trait was present in a high percentage of DS subjects, few showed the cuspal form. These findings are consistent with the concept of a reduction of cellular activity of tooth germs reflecting a general retardation in growth in DS. The altered shape of the lower incisors may influence the pattern of periodontal disease observed in DS subjects.

— A total of 8,854 extracted molars in Norwegians were examined for the occurrence of long cervical enamel projections. The uncertainty in tooth determination was incorporated into the prevalence figures. Mandibular molars showed a higher prevalence than maxillary molars. Within each jaw, second molars showed the highest prevalence, first molars the lowest. The great majority of the projections occurred on the buccal aspect of the tooth. Possible explanations of divergences from previous studies are discussed.

Typical dental changes were present in all cases, although they were of variable degree. However, the tooth morphology would appear to be highly specific for MPS IV A, and is not found in MPS IV B (beta-galactosidase deficiency) or the recently delineated MPS IV C (enzyme defect unknown). Thus the dental changes have a very useful diagnostic potential in mild atypical cases of MPS IV A, although they may only be demonstrable radiologically in some such cases.

Samples from five Jewish and six non-Jewish populations were compared in terms of the frequencies of 19 dental morphological variables. All but one of the samples came from Europe, North Africa, or the Middle East. Nine were from contemporary populations, and two were skeletal. Of the skeletal groups, one was Jewish, excavated on Mount Zion, Jerusalem, and dated at around 3,000 years old; and the other non-Jewish, excavated on the east coast of Australia, and dated at between 1,000 and 200 years old. Assessment of affinity between the different groups was based on smallest space analysis and cluster analysis. The results demonstrated relative proximity of the Jewish groups (with one exception), despite the fact that they came from a wide geographical area. In particular, the sample from Mount Zion showed greater affinity with three of the four living Jewish populations than with most non-Jewish groups. The skeletal Australian sample formed a cluster of its own, distinct from all the other groups. For six of the groups, the relationships based on tooth morphology showed good correspondence with known relationships based on single locus polymorphisms. The similarity of the Jewish groups to each other in terms of both tooth morphology and single locus polymorphisms was of special interest, since differences in other morphological and anthropometric characteristics, thought to be the result of selection, are known to exist between the Jewish populations.

A comprehensive comparative anatomical investigation of the carotid circulation in several mammalian orders, viz., insectivores, primates, rodents, lagomorphs, edentates, pangolins and carnivores (cf. Bugge, 1974b, 1975a, 1978), has shown the cephalic arterial pattern to be an important supplement to other morphological systems, especially tooth morphology and osteology, as a basis for a systematic classification of mammals, reflecting their probable evolutionary history and phylogenetic relationships.

The value of phylogenetic comparisons between populations based on tooth morphology depends on a knowledge of the extent to which the observed morphological variation is genetic in origin. This knowledge can be derived unequivocally only from the analysis of family data. However, in the absence of such knowledge the ability of tooth morphology to distinguish biological differences can be evaluated directly by testing its discriminating power in practice on populations between which the degrees of genetic difference are already known. The results of such an evaluation show that different degrees of subjectivity of scoring are associated with different characters, but that moderately good correspondence between known genetic differences and differences based on tooth morphology can be achieved when characters showing the least subjectivity of scoring are used.

Publisher Summary This chapter reviews tooth morphology and appreciation of primate evolution by a study of tooth morphology. In primates, the processes of fossilized bone destruction are particularly important; skeletons, even skulls, are rare, and in most cases all that is available is teeth and jaws. It is fortunate that the teeth, developing early in life inside the jaws, protected from external environmental influences, reflect the genetic constitution of the individual to a high degree. In practice, it has been found that, if adequately interpreted, teeth provide a reliable basis for the discussion of evolutionary relationships. However, the adequate interpretation of fossil teeth is by no means a simple matter. The number of specimens from any one locality is usually small, and it is difficult to make adequate allowance for variation. Thus, there is a need to know more about what teeth can do in the way of evolutionary change. This necessitates more knowledge acquisition regarding the ontogeny of the bone dentition, particularly the ontogenetic basis of variation and how the ontogeny is modified genetically.

GENETIC inheritance is probably the most important determinant of dentition. Severe local or metabolic disturbances during tooth formation can upset predetermined development patterns, and cause pathological changes such as hypoplasia of enamel, or alteration in eruption pattern. Until lately, little had been done to determine whether more subtle alterations in tooth development could be produced by less traumatic alterations in the environment, and if so, whether such changes were related to dental disease. In this paper the relation of genetics to dentition, the recent attempts to vary developmental environment through nutrition, and the effect of these variations on developing teeth in terms of tooth morphology and caries susceptibility will be reviewed. The relation of this experimental work to human disease also will be discussed. Relation of Genetics to Dentition Genetic inheritance determines many of our dental characteristics, including such broad aspects as general arrangement of teeth in the arch

Background The purpose was to determine whether or not a novel device used in conjunction with orthodontic treatment produced root resorption shown on 3D images generated from a new cone beam computerized tomography. Methods Subjects were actively recruited and those who received braces for the first time were invited to participate. Patients were assigned to receive a functioning device and used the devices for 20 min daily for a six month study period. CBCT images were taken of the dentition at the start of treatment and at the end of the study period. Results 14 subjects out of a possible 17 subjects completed using the device during the study period. The mean age of the subjects was 20.3 years. Measurements of all teeth present were made from the mesial buccal roots of the first molar on one side of the dental arch to the mesial buccal roots of the first molar on the opposing side of the same arch. These measurements were recorded as linear lengths in mm. A paired t-test was used to determine if significant differences occurred for root lengths at the end of treatment compared to the start of treatment for each of the individual tooth groups. No statistical differences were noted for root length changes above 0.5 mm and 1 mm. Conclusions No statistically significant findings were noted for root length change at the end of treatment compared to the start of treatment when using this novel robotic device. No significant differences were noted between roots of anterior and posterior teeth. No clinically significant changes between root lengths were noted above 0.5 mm.

(2005). Detailed tooth morphology in a durophagous ichthyosaur captured by 3D laser scanner. Journal of Vertebrate Paleontology: Vol. 25, No. 2, pp. 462-465.

Ichthyosaurus communis De la Beche & Conybeare, 1821 and I. intermedius Conybeare, 1822 have been considered synonymous by some researchers, but distinct species by others. The distinction between the two species was originally based on tooth morphology, which has been shown to vary ontogenetically as well as within an individual. Subsequent literature of the nineteenth century did not propose adequate diagnostic features to distinguish the two species. In addition, illustrations suggest that both species were confused with I. breviceps, which was defined over 50 years later. The type specimens of both species are missing, making the problem unresolvable. However, a neotype was designated for I. communis to retain the widely used species name and to stabilize the taxonomy. The species can be recognized by a symmetric, triangular maxilla with long processes and a large, broad, triradiate lacrimal, as well as a unique combination of other characters. The neotype shares numerous features with the I. intermed...

Summary A case report is given to increase the practitioner's awareness of aberrations in tooth morphology of maxillary lateral incisors.

A morphological study comparing Desmognathus welteri with D. monticola and D. fuscus was conducted. The structure of two characters, toe friction pads and jaw teeth, were assessed. Darkened toe friction pads were found in D. welteri and D. monticola, but were absent in D. fuscus. In contrast, D. welteri and D. fuscus share similar jaw dentitions (blunt-crowned teeth) as opposed to the dentition of D. monticola (piercing, pointed teeth). age-specific relationships and dimorphic variations of the three species in question and also presented information on dimorphism in size and number of teeth. Characters previously used to separate the three species are helpful, but are not totally reliable because of the extreme amount of variability in Desmognathus salamanders. Desmognathus fuscus is smaller than the other two species. The dorsal pattern varies from a straight mid-dorsal line to subdued spotting. Ventrally, D. fuscus varies from very light to dark. Barbour (1971) stated that D. welteri can be separated from D. monticola by the presence of a mottled venter in the former versus an immaculate venter in the latter. However, his description of the dorsal pattern differences is somewhat confusing. He stated that D. welteri has dark blotches on a light background, but that D. monticola has light dorsal blotches on a dark background. It is difficult to differentiate between these two states. The dorsal blotches of D. welteri are generally more subdued than in D. monticola, the latter having darker marking. Caldwell (in press) presented a lens character, not used before, which facilitates separation of D. welteri and D. monticola from D. fuscus. To determine the taxonomic status of D. welteri, a study was initiated in 1975 to obtain comparative taxonomic information of D. welteri, D. monticola, and D. fuscus. This paper presents new information supporting the validity of D. welteri, and gives additional morphological features which can be used to differentiate the three species in their area of sympatry.